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adding pods method of package managing

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talksik
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Pods/abseil/absl/container/fixed_array.h
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// Copyright 2018 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// -----------------------------------------------------------------------------
// File: fixed_array.h
// -----------------------------------------------------------------------------
//
// A `FixedArray<T>` represents a non-resizable array of `T` where the length of
// the array can be determined at run-time. It is a good replacement for
// non-standard and deprecated uses of `alloca()` and variable length arrays
// within the GCC extension. (See
// https://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html).
//
// `FixedArray` allocates small arrays inline, keeping performance fast by
// avoiding heap operations. It also helps reduce the chances of
// accidentally overflowing your stack if large input is passed to
// your function.
#ifndef ABSL_CONTAINER_FIXED_ARRAY_H_
#define ABSL_CONTAINER_FIXED_ARRAY_H_
#include <algorithm>
#include <cassert>
#include <cstddef>
#include <initializer_list>
#include <iterator>
#include <limits>
#include <memory>
#include <new>
#include <type_traits>
#include "absl/algorithm/algorithm.h"
#include "absl/base/dynamic_annotations.h"
#include "absl/base/internal/throw_delegate.h"
#include "absl/base/macros.h"
#include "absl/base/optimization.h"
#include "absl/base/port.h"
#include "absl/container/internal/compressed_tuple.h"
#include "absl/memory/memory.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
constexpr static auto kFixedArrayUseDefault = static_cast<size_t>(-1);
// -----------------------------------------------------------------------------
// FixedArray
// -----------------------------------------------------------------------------
//
// A `FixedArray` provides a run-time fixed-size array, allocating a small array
// inline for efficiency.
//
// Most users should not specify an `inline_elements` argument and let
// `FixedArray` automatically determine the number of elements
// to store inline based on `sizeof(T)`. If `inline_elements` is specified, the
// `FixedArray` implementation will use inline storage for arrays with a
// length <= `inline_elements`.
//
// Note that a `FixedArray` constructed with a `size_type` argument will
// default-initialize its values by leaving trivially constructible types
// uninitialized (e.g. int, int[4], double), and others default-constructed.
// This matches the behavior of c-style arrays and `std::array`, but not
// `std::vector`.
//
// Note that `FixedArray` does not provide a public allocator; if it requires a
// heap allocation, it will do so with global `::operator new[]()` and
// `::operator delete[]()`, even if T provides class-scope overrides for these
// operators.
template <typename T, size_t N = kFixedArrayUseDefault,
typename A = std::allocator<T>>
class FixedArray {
static_assert(!std::is_array<T>::value || std::extent<T>::value > 0,
"Arrays with unknown bounds cannot be used with FixedArray.");
static constexpr size_t kInlineBytesDefault = 256;
using AllocatorTraits = std::allocator_traits<A>;
// std::iterator_traits isn't guaranteed to be SFINAE-friendly until C++17,
// but this seems to be mostly pedantic.
template <typename Iterator>
using EnableIfForwardIterator = absl::enable_if_t<std::is_convertible<
typename std::iterator_traits<Iterator>::iterator_category,
std::forward_iterator_tag>::value>;
static constexpr bool NoexceptCopyable() {
return std::is_nothrow_copy_constructible<StorageElement>::value &&
absl::allocator_is_nothrow<allocator_type>::value;
}
static constexpr bool NoexceptMovable() {
return std::is_nothrow_move_constructible<StorageElement>::value &&
absl::allocator_is_nothrow<allocator_type>::value;
}
static constexpr bool DefaultConstructorIsNonTrivial() {
return !absl::is_trivially_default_constructible<StorageElement>::value;
}
public:
using allocator_type = typename AllocatorTraits::allocator_type;
using value_type = typename allocator_type::value_type;
using pointer = typename allocator_type::pointer;
using const_pointer = typename allocator_type::const_pointer;
using reference = typename allocator_type::reference;
using const_reference = typename allocator_type::const_reference;
using size_type = typename allocator_type::size_type;
using difference_type = typename allocator_type::difference_type;
using iterator = pointer;
using const_iterator = const_pointer;
using reverse_iterator = std::reverse_iterator<iterator>;
using const_reverse_iterator = std::reverse_iterator<const_iterator>;
static constexpr size_type inline_elements =
(N == kFixedArrayUseDefault ? kInlineBytesDefault / sizeof(value_type)
: static_cast<size_type>(N));
FixedArray(
const FixedArray& other,
const allocator_type& a = allocator_type()) noexcept(NoexceptCopyable())
: FixedArray(other.begin(), other.end(), a) {}
FixedArray(
FixedArray&& other,
const allocator_type& a = allocator_type()) noexcept(NoexceptMovable())
: FixedArray(std::make_move_iterator(other.begin()),
std::make_move_iterator(other.end()), a) {}
// Creates an array object that can store `n` elements.
// Note that trivially constructible elements will be uninitialized.
explicit FixedArray(size_type n, const allocator_type& a = allocator_type())
: storage_(n, a) {
if (DefaultConstructorIsNonTrivial()) {
memory_internal::ConstructRange(storage_.alloc(), storage_.begin(),
storage_.end());
}
}
// Creates an array initialized with `n` copies of `val`.
FixedArray(size_type n, const value_type& val,
const allocator_type& a = allocator_type())
: storage_(n, a) {
memory_internal::ConstructRange(storage_.alloc(), storage_.begin(),
storage_.end(), val);
}
// Creates an array initialized with the size and contents of `init_list`.
FixedArray(std::initializer_list<value_type> init_list,
const allocator_type& a = allocator_type())
: FixedArray(init_list.begin(), init_list.end(), a) {}
// Creates an array initialized with the elements from the input
// range. The array's size will always be `std::distance(first, last)`.
// REQUIRES: Iterator must be a forward_iterator or better.
template <typename Iterator, EnableIfForwardIterator<Iterator>* = nullptr>
FixedArray(Iterator first, Iterator last,
const allocator_type& a = allocator_type())
: storage_(std::distance(first, last), a) {
memory_internal::CopyRange(storage_.alloc(), storage_.begin(), first, last);
}
~FixedArray() noexcept {
for (auto* cur = storage_.begin(); cur != storage_.end(); ++cur) {
AllocatorTraits::destroy(storage_.alloc(), cur);
}
}
// Assignments are deleted because they break the invariant that the size of a
// `FixedArray` never changes.
void operator=(FixedArray&&) = delete;
void operator=(const FixedArray&) = delete;
// FixedArray::size()
//
// Returns the length of the fixed array.
size_type size() const { return storage_.size(); }
// FixedArray::max_size()
//
// Returns the largest possible value of `std::distance(begin(), end())` for a
// `FixedArray<T>`. This is equivalent to the most possible addressable bytes
// over the number of bytes taken by T.
constexpr size_type max_size() const {
return (std::numeric_limits<difference_type>::max)() / sizeof(value_type);
}
// FixedArray::empty()
//
// Returns whether or not the fixed array is empty.
bool empty() const { return size() == 0; }
// FixedArray::memsize()
//
// Returns the memory size of the fixed array in bytes.
size_t memsize() const { return size() * sizeof(value_type); }
// FixedArray::data()
//
// Returns a const T* pointer to elements of the `FixedArray`. This pointer
// can be used to access (but not modify) the contained elements.
const_pointer data() const { return AsValueType(storage_.begin()); }
// Overload of FixedArray::data() to return a T* pointer to elements of the
// fixed array. This pointer can be used to access and modify the contained
// elements.
pointer data() { return AsValueType(storage_.begin()); }
// FixedArray::operator[]
//
// Returns a reference the ith element of the fixed array.
// REQUIRES: 0 <= i < size()
reference operator[](size_type i) {
assert(i < size());
return data()[i];
}
// Overload of FixedArray::operator()[] to return a const reference to the
// ith element of the fixed array.
// REQUIRES: 0 <= i < size()
const_reference operator[](size_type i) const {
assert(i < size());
return data()[i];
}
// FixedArray::at
//
// Bounds-checked access. Returns a reference to the ith element of the
// fiexed array, or throws std::out_of_range
reference at(size_type i) {
if (ABSL_PREDICT_FALSE(i >= size())) {
base_internal::ThrowStdOutOfRange("FixedArray::at failed bounds check");
}
return data()[i];
}
// Overload of FixedArray::at() to return a const reference to the ith element
// of the fixed array.
const_reference at(size_type i) const {
if (ABSL_PREDICT_FALSE(i >= size())) {
base_internal::ThrowStdOutOfRange("FixedArray::at failed bounds check");
}
return data()[i];
}
// FixedArray::front()
//
// Returns a reference to the first element of the fixed array.
reference front() { return *begin(); }
// Overload of FixedArray::front() to return a reference to the first element
// of a fixed array of const values.
const_reference front() const { return *begin(); }
// FixedArray::back()
//
// Returns a reference to the last element of the fixed array.
reference back() { return *(end() - 1); }
// Overload of FixedArray::back() to return a reference to the last element
// of a fixed array of const values.
const_reference back() const { return *(end() - 1); }
// FixedArray::begin()
//
// Returns an iterator to the beginning of the fixed array.
iterator begin() { return data(); }
// Overload of FixedArray::begin() to return a const iterator to the
// beginning of the fixed array.
const_iterator begin() const { return data(); }
// FixedArray::cbegin()
//
// Returns a const iterator to the beginning of the fixed array.
const_iterator cbegin() const { return begin(); }
// FixedArray::end()
//
// Returns an iterator to the end of the fixed array.
iterator end() { return data() + size(); }
// Overload of FixedArray::end() to return a const iterator to the end of the
// fixed array.
const_iterator end() const { return data() + size(); }
// FixedArray::cend()
//
// Returns a const iterator to the end of the fixed array.
const_iterator cend() const { return end(); }
// FixedArray::rbegin()
//
// Returns a reverse iterator from the end of the fixed array.
reverse_iterator rbegin() { return reverse_iterator(end()); }
// Overload of FixedArray::rbegin() to return a const reverse iterator from
// the end of the fixed array.
const_reverse_iterator rbegin() const {
return const_reverse_iterator(end());
}
// FixedArray::crbegin()
//
// Returns a const reverse iterator from the end of the fixed array.
const_reverse_iterator crbegin() const { return rbegin(); }
// FixedArray::rend()
//
// Returns a reverse iterator from the beginning of the fixed array.
reverse_iterator rend() { return reverse_iterator(begin()); }
// Overload of FixedArray::rend() for returning a const reverse iterator
// from the beginning of the fixed array.
const_reverse_iterator rend() const {
return const_reverse_iterator(begin());
}
// FixedArray::crend()
//
// Returns a reverse iterator from the beginning of the fixed array.
const_reverse_iterator crend() const { return rend(); }
// FixedArray::fill()
//
// Assigns the given `value` to all elements in the fixed array.
void fill(const value_type& val) { std::fill(begin(), end(), val); }
// Relational operators. Equality operators are elementwise using
// `operator==`, while order operators order FixedArrays lexicographically.
friend bool operator==(const FixedArray& lhs, const FixedArray& rhs) {
return absl::equal(lhs.begin(), lhs.end(), rhs.begin(), rhs.end());
}
friend bool operator!=(const FixedArray& lhs, const FixedArray& rhs) {
return !(lhs == rhs);
}
friend bool operator<(const FixedArray& lhs, const FixedArray& rhs) {
return std::lexicographical_compare(lhs.begin(), lhs.end(), rhs.begin(),
rhs.end());
}
friend bool operator>(const FixedArray& lhs, const FixedArray& rhs) {
return rhs < lhs;
}
friend bool operator<=(const FixedArray& lhs, const FixedArray& rhs) {
return !(rhs < lhs);
}
friend bool operator>=(const FixedArray& lhs, const FixedArray& rhs) {
return !(lhs < rhs);
}
template <typename H>
friend H AbslHashValue(H h, const FixedArray& v) {
return H::combine(H::combine_contiguous(std::move(h), v.data(), v.size()),
v.size());
}
private:
// StorageElement
//
// For FixedArrays with a C-style-array value_type, StorageElement is a POD
// wrapper struct called StorageElementWrapper that holds the value_type
// instance inside. This is needed for construction and destruction of the
// entire array regardless of how many dimensions it has. For all other cases,
// StorageElement is just an alias of value_type.
//
// Maintainer's Note: The simpler solution would be to simply wrap value_type
// in a struct whether it's an array or not. That causes some paranoid
// diagnostics to misfire, believing that 'data()' returns a pointer to a
// single element, rather than the packed array that it really is.
// e.g.:
//
// FixedArray<char> buf(1);
// sprintf(buf.data(), "foo");
//
// error: call to int __builtin___sprintf_chk(etc...)
// will always overflow destination buffer [-Werror]
//
template <typename OuterT, typename InnerT = absl::remove_extent_t<OuterT>,
size_t InnerN = std::extent<OuterT>::value>
struct StorageElementWrapper {
InnerT array[InnerN];
};
using StorageElement =
absl::conditional_t<std::is_array<value_type>::value,
StorageElementWrapper<value_type>, value_type>;
static pointer AsValueType(pointer ptr) { return ptr; }
static pointer AsValueType(StorageElementWrapper<value_type>* ptr) {
return std::addressof(ptr->array);
}
static_assert(sizeof(StorageElement) == sizeof(value_type), "");
static_assert(alignof(StorageElement) == alignof(value_type), "");
class NonEmptyInlinedStorage {
public:
StorageElement* data() { return reinterpret_cast<StorageElement*>(buff_); }
void AnnotateConstruct(size_type n);
void AnnotateDestruct(size_type n);
#ifdef ADDRESS_SANITIZER
void* RedzoneBegin() { return &redzone_begin_; }
void* RedzoneEnd() { return &redzone_end_ + 1; }
#endif // ADDRESS_SANITIZER
private:
ADDRESS_SANITIZER_REDZONE(redzone_begin_);
alignas(StorageElement) char buff_[sizeof(StorageElement[inline_elements])];
ADDRESS_SANITIZER_REDZONE(redzone_end_);
};
class EmptyInlinedStorage {
public:
StorageElement* data() { return nullptr; }
void AnnotateConstruct(size_type) {}
void AnnotateDestruct(size_type) {}
};
using InlinedStorage =
absl::conditional_t<inline_elements == 0, EmptyInlinedStorage,
NonEmptyInlinedStorage>;
// Storage
//
// An instance of Storage manages the inline and out-of-line memory for
// instances of FixedArray. This guarantees that even when construction of
// individual elements fails in the FixedArray constructor body, the
// destructor for Storage will still be called and out-of-line memory will be
// properly deallocated.
//
class Storage : public InlinedStorage {
public:
Storage(size_type n, const allocator_type& a)
: size_alloc_(n, a), data_(InitializeData()) {}
~Storage() noexcept {
if (UsingInlinedStorage(size())) {
InlinedStorage::AnnotateDestruct(size());
} else {
AllocatorTraits::deallocate(alloc(), AsValueType(begin()), size());
}
}
size_type size() const { return size_alloc_.template get<0>(); }
StorageElement* begin() const { return data_; }
StorageElement* end() const { return begin() + size(); }
allocator_type& alloc() { return size_alloc_.template get<1>(); }
private:
static bool UsingInlinedStorage(size_type n) {
return n <= inline_elements;
}
StorageElement* InitializeData() {
if (UsingInlinedStorage(size())) {
InlinedStorage::AnnotateConstruct(size());
return InlinedStorage::data();
} else {
return reinterpret_cast<StorageElement*>(
AllocatorTraits::allocate(alloc(), size()));
}
}
// `CompressedTuple` takes advantage of EBCO for stateless `allocator_type`s
container_internal::CompressedTuple<size_type, allocator_type> size_alloc_;
StorageElement* data_;
};
Storage storage_;
};
template <typename T, size_t N, typename A>
constexpr size_t FixedArray<T, N, A>::kInlineBytesDefault;
template <typename T, size_t N, typename A>
constexpr typename FixedArray<T, N, A>::size_type
FixedArray<T, N, A>::inline_elements;
template <typename T, size_t N, typename A>
void FixedArray<T, N, A>::NonEmptyInlinedStorage::AnnotateConstruct(
typename FixedArray<T, N, A>::size_type n) {
#ifdef ADDRESS_SANITIZER
if (!n) return;
ANNOTATE_CONTIGUOUS_CONTAINER(data(), RedzoneEnd(), RedzoneEnd(), data() + n);
ANNOTATE_CONTIGUOUS_CONTAINER(RedzoneBegin(), data(), data(), RedzoneBegin());
#endif // ADDRESS_SANITIZER
static_cast<void>(n); // Mark used when not in asan mode
}
template <typename T, size_t N, typename A>
void FixedArray<T, N, A>::NonEmptyInlinedStorage::AnnotateDestruct(
typename FixedArray<T, N, A>::size_type n) {
#ifdef ADDRESS_SANITIZER
if (!n) return;
ANNOTATE_CONTIGUOUS_CONTAINER(data(), RedzoneEnd(), data() + n, RedzoneEnd());
ANNOTATE_CONTIGUOUS_CONTAINER(RedzoneBegin(), data(), RedzoneBegin(), data());
#endif // ADDRESS_SANITIZER
static_cast<void>(n); // Mark used when not in asan mode
}
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_CONTAINER_FIXED_ARRAY_H_
Pods/abseil/absl/container/flat_hash_map.h
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// Copyright 2018 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// -----------------------------------------------------------------------------
// File: flat_hash_map.h
// -----------------------------------------------------------------------------
//
// An `absl::flat_hash_map<K, V>` is an unordered associative container of
// unique keys and associated values designed to be a more efficient replacement
// for `std::unordered_map`. Like `unordered_map`, search, insertion, and
// deletion of map elements can be done as an `O(1)` operation. However,
// `flat_hash_map` (and other unordered associative containers known as the
// collection of Abseil "Swiss tables") contain other optimizations that result
// in both memory and computation advantages.
//
// In most cases, your default choice for a hash map should be a map of type
// `flat_hash_map`.
#ifndef ABSL_CONTAINER_FLAT_HASH_MAP_H_
#define ABSL_CONTAINER_FLAT_HASH_MAP_H_
#include <cstddef>
#include <new>
#include <type_traits>
#include <utility>
#include "absl/algorithm/container.h"
#include "absl/container/internal/container_memory.h"
#include "absl/container/internal/hash_function_defaults.h" // IWYU pragma: export
#include "absl/container/internal/raw_hash_map.h" // IWYU pragma: export
#include "absl/memory/memory.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace container_internal {
template <class K, class V>
struct FlatHashMapPolicy;
} // namespace container_internal
// -----------------------------------------------------------------------------
// absl::flat_hash_map
// -----------------------------------------------------------------------------
//
// An `absl::flat_hash_map<K, V>` is an unordered associative container which
// has been optimized for both speed and memory footprint in most common use
// cases. Its interface is similar to that of `std::unordered_map<K, V>` with
// the following notable differences:
//
// * Requires keys that are CopyConstructible
// * Requires values that are MoveConstructible
// * Supports heterogeneous lookup, through `find()`, `operator[]()` and
// `insert()`, provided that the map is provided a compatible heterogeneous
// hashing function and equality operator.
// * Invalidates any references and pointers to elements within the table after
// `rehash()`.
// * Contains a `capacity()` member function indicating the number of element
// slots (open, deleted, and empty) within the hash map.
// * Returns `void` from the `erase(iterator)` overload.
//
// By default, `flat_hash_map` uses the `absl::Hash` hashing framework.
// All fundamental and Abseil types that support the `absl::Hash` framework have
// a compatible equality operator for comparing insertions into `flat_hash_map`.
// If your type is not yet supported by the `absl::Hash` framework, see
// absl/hash/hash.h for information on extending Abseil hashing to user-defined
// types.
//
// NOTE: A `flat_hash_map` stores its value types directly inside its
// implementation array to avoid memory indirection. Because a `flat_hash_map`
// is designed to move data when rehashed, map values will not retain pointer
// stability. If you require pointer stability, or if your values are large,
// consider using `absl::flat_hash_map<Key, std::unique_ptr<Value>>` instead.
// If your types are not moveable or you require pointer stability for keys,
// consider `absl::node_hash_map`.
//
// Example:
//
// // Create a flat hash map of three strings (that map to strings)
// absl::flat_hash_map<std::string, std::string> ducks =
// {{"a", "huey"}, {"b", "dewey"}, {"c", "louie"}};
//
// // Insert a new element into the flat hash map
// ducks.insert({"d", "donald"});
//
// // Force a rehash of the flat hash map
// ducks.rehash(0);
//
// // Find the element with the key "b"
// std::string search_key = "b";
// auto result = ducks.find(search_key);
// if (result != ducks.end()) {
// std::cout << "Result: " << result->second << std::endl;
// }
template <class K, class V,
class Hash = absl::container_internal::hash_default_hash<K>,
class Eq = absl::container_internal::hash_default_eq<K>,
class Allocator = std::allocator<std::pair<const K, V>>>
class flat_hash_map : public absl::container_internal::raw_hash_map<
absl::container_internal::FlatHashMapPolicy<K, V>,
Hash, Eq, Allocator> {
using Base = typename flat_hash_map::raw_hash_map;
public:
// Constructors and Assignment Operators
//
// A flat_hash_map supports the same overload set as `std::unordered_map`
// for construction and assignment:
//
// * Default constructor
//
// // No allocation for the table's elements is made.
// absl::flat_hash_map<int, std::string> map1;
//
// * Initializer List constructor
//
// absl::flat_hash_map<int, std::string> map2 =
// {{1, "huey"}, {2, "dewey"}, {3, "louie"},};
//
// * Copy constructor
//
// absl::flat_hash_map<int, std::string> map3(map2);
//
// * Copy assignment operator
//
// // Hash functor and Comparator are copied as well
// absl::flat_hash_map<int, std::string> map4;
// map4 = map3;
//
// * Move constructor
//
// // Move is guaranteed efficient
// absl::flat_hash_map<int, std::string> map5(std::move(map4));
//
// * Move assignment operator
//
// // May be efficient if allocators are compatible
// absl::flat_hash_map<int, std::string> map6;
// map6 = std::move(map5);
//
// * Range constructor
//
// std::vector<std::pair<int, std::string>> v = {{1, "a"}, {2, "b"}};
// absl::flat_hash_map<int, std::string> map7(v.begin(), v.end());
flat_hash_map() {}
using Base::Base;
// flat_hash_map::begin()
//
// Returns an iterator to the beginning of the `flat_hash_map`.
using Base::begin;
// flat_hash_map::cbegin()
//
// Returns a const iterator to the beginning of the `flat_hash_map`.
using Base::cbegin;
// flat_hash_map::cend()
//
// Returns a const iterator to the end of the `flat_hash_map`.
using Base::cend;
// flat_hash_map::end()
//
// Returns an iterator to the end of the `flat_hash_map`.
using Base::end;
// flat_hash_map::capacity()
//
// Returns the number of element slots (assigned, deleted, and empty)
// available within the `flat_hash_map`.
//
// NOTE: this member function is particular to `absl::flat_hash_map` and is
// not provided in the `std::unordered_map` API.
using Base::capacity;
// flat_hash_map::empty()
//
// Returns whether or not the `flat_hash_map` is empty.
using Base::empty;
// flat_hash_map::max_size()
//
// Returns the largest theoretical possible number of elements within a
// `flat_hash_map` under current memory constraints. This value can be thought
// of the largest value of `std::distance(begin(), end())` for a
// `flat_hash_map<K, V>`.
using Base::max_size;
// flat_hash_map::size()
//
// Returns the number of elements currently within the `flat_hash_map`.
using Base::size;
// flat_hash_map::clear()
//
// Removes all elements from the `flat_hash_map`. Invalidates any references,
// pointers, or iterators referring to contained elements.
//
// NOTE: this operation may shrink the underlying buffer. To avoid shrinking
// the underlying buffer call `erase(begin(), end())`.
using Base::clear;
// flat_hash_map::erase()
//
// Erases elements within the `flat_hash_map`. Erasing does not trigger a
// rehash. Overloads are listed below.
//
// void erase(const_iterator pos):
//
// Erases the element at `position` of the `flat_hash_map`, returning
// `void`.
//
// NOTE: returning `void` in this case is different than that of STL
// containers in general and `std::unordered_map` in particular (which
// return an iterator to the element following the erased element). If that
// iterator is needed, simply post increment the iterator:
//
// map.erase(it++);
//
// iterator erase(const_iterator first, const_iterator last):
//
// Erases the elements in the open interval [`first`, `last`), returning an
// iterator pointing to `last`.
//
// size_type erase(const key_type& key):
//
// Erases the element with the matching key, if it exists.
using Base::erase;
// flat_hash_map::insert()
//
// Inserts an element of the specified value into the `flat_hash_map`,
// returning an iterator pointing to the newly inserted element, provided that
// an element with the given key does not already exist. If rehashing occurs
// due to the insertion, all iterators are invalidated. Overloads are listed
// below.
//
// std::pair<iterator,bool> insert(const init_type& value):
//
// Inserts a value into the `flat_hash_map`. Returns a pair consisting of an
// iterator to the inserted element (or to the element that prevented the
// insertion) and a bool denoting whether the insertion took place.
//
// std::pair<iterator,bool> insert(T&& value):
// std::pair<iterator,bool> insert(init_type&& value):
//
// Inserts a moveable value into the `flat_hash_map`. Returns a pair
// consisting of an iterator to the inserted element (or to the element that
// prevented the insertion) and a bool denoting whether the insertion took
// place.
//
// iterator insert(const_iterator hint, const init_type& value):
// iterator insert(const_iterator hint, T&& value):
// iterator insert(const_iterator hint, init_type&& value);
//
// Inserts a value, using the position of `hint` as a non-binding suggestion
// for where to begin the insertion search. Returns an iterator to the
// inserted element, or to the existing element that prevented the
// insertion.
//
// void insert(InputIterator first, InputIterator last):
//
// Inserts a range of values [`first`, `last`).
//
// NOTE: Although the STL does not specify which element may be inserted if
// multiple keys compare equivalently, for `flat_hash_map` we guarantee the
// first match is inserted.
//
// void insert(std::initializer_list<init_type> ilist):
//
// Inserts the elements within the initializer list `ilist`.
//
// NOTE: Although the STL does not specify which element may be inserted if
// multiple keys compare equivalently within the initializer list, for
// `flat_hash_map` we guarantee the first match is inserted.
using Base::insert;
// flat_hash_map::insert_or_assign()
//
// Inserts an element of the specified value into the `flat_hash_map` provided
// that a value with the given key does not already exist, or replaces it with
// the element value if a key for that value already exists, returning an
// iterator pointing to the newly inserted element. If rehashing occurs due
// to the insertion, all existing iterators are invalidated. Overloads are
// listed below.
//
// pair<iterator, bool> insert_or_assign(const init_type& k, T&& obj):
// pair<iterator, bool> insert_or_assign(init_type&& k, T&& obj):
//
// Inserts/Assigns (or moves) the element of the specified key into the
// `flat_hash_map`.
//
// iterator insert_or_assign(const_iterator hint,
// const init_type& k, T&& obj):
// iterator insert_or_assign(const_iterator hint, init_type&& k, T&& obj):
//
// Inserts/Assigns (or moves) the element of the specified key into the
// `flat_hash_map` using the position of `hint` as a non-binding suggestion
// for where to begin the insertion search.
using Base::insert_or_assign;
// flat_hash_map::emplace()
//
// Inserts an element of the specified value by constructing it in-place
// within the `flat_hash_map`, provided that no element with the given key
// already exists.
//
// The element may be constructed even if there already is an element with the
// key in the container, in which case the newly constructed element will be
// destroyed immediately. Prefer `try_emplace()` unless your key is not
// copyable or moveable.
//
// If rehashing occurs due to the insertion, all iterators are invalidated.
using Base::emplace;
// flat_hash_map::emplace_hint()
//
// Inserts an element of the specified value by constructing it in-place
// within the `flat_hash_map`, using the position of `hint` as a non-binding
// suggestion for where to begin the insertion search, and only inserts
// provided that no element with the given key already exists.
//
// The element may be constructed even if there already is an element with the
// key in the container, in which case the newly constructed element will be
// destroyed immediately. Prefer `try_emplace()` unless your key is not
// copyable or moveable.
//
// If rehashing occurs due to the insertion, all iterators are invalidated.
using Base::emplace_hint;
// flat_hash_map::try_emplace()
//
// Inserts an element of the specified value by constructing it in-place
// within the `flat_hash_map`, provided that no element with the given key
// already exists. Unlike `emplace()`, if an element with the given key
// already exists, we guarantee that no element is constructed.
//
// If rehashing occurs due to the insertion, all iterators are invalidated.
// Overloads are listed below.
//
// pair<iterator, bool> try_emplace(const key_type& k, Args&&... args):
// pair<iterator, bool> try_emplace(key_type&& k, Args&&... args):
//
// Inserts (via copy or move) the element of the specified key into the
// `flat_hash_map`.
//
// iterator try_emplace(const_iterator hint,
// const init_type& k, Args&&... args):
// iterator try_emplace(const_iterator hint, init_type&& k, Args&&... args):
//
// Inserts (via copy or move) the element of the specified key into the
// `flat_hash_map` using the position of `hint` as a non-binding suggestion
// for where to begin the insertion search.
//
// All `try_emplace()` overloads make the same guarantees regarding rvalue
// arguments as `std::unordered_map::try_emplace()`, namely that these
// functions will not move from rvalue arguments if insertions do not happen.
using Base::try_emplace;
// flat_hash_map::extract()
//
// Extracts the indicated element, erasing it in the process, and returns it
// as a C++17-compatible node handle. Overloads are listed below.
//
// node_type extract(const_iterator position):
//
// Extracts the key,value pair of the element at the indicated position and
// returns a node handle owning that extracted data.
//
// node_type extract(const key_type& x):
//
// Extracts the key,value pair of the element with a key matching the passed
// key value and returns a node handle owning that extracted data. If the
// `flat_hash_map` does not contain an element with a matching key, this
// function returns an empty node handle.
using Base::extract;
// flat_hash_map::merge()
//
// Extracts elements from a given `source` flat hash map into this
// `flat_hash_map`. If the destination `flat_hash_map` already contains an
// element with an equivalent key, that element is not extracted.
using Base::merge;
// flat_hash_map::swap(flat_hash_map& other)
//
// Exchanges the contents of this `flat_hash_map` with those of the `other`
// flat hash map, avoiding invocation of any move, copy, or swap operations on
// individual elements.
//
// All iterators and references on the `flat_hash_map` remain valid, excepting
// for the past-the-end iterator, which is invalidated.
//
// `swap()` requires that the flat hash map's hashing and key equivalence
// functions be Swappable, and are exchanged using unqualified calls to
// non-member `swap()`. If the map's allocator has
// `std::allocator_traits<allocator_type>::propagate_on_container_swap::value`
// set to `true`, the allocators are also exchanged using an unqualified call
// to non-member `swap()`; otherwise, the allocators are not swapped.
using Base::swap;
// flat_hash_map::rehash(count)
//
// Rehashes the `flat_hash_map`, setting the number of slots to be at least
// the passed value. If the new number of slots increases the load factor more
// than the current maximum load factor
// (`count` < `size()` / `max_load_factor()`), then the new number of slots
// will be at least `size()` / `max_load_factor()`.
//
// To force a rehash, pass rehash(0).
//
// NOTE: unlike behavior in `std::unordered_map`, references are also
// invalidated upon a `rehash()`.
using Base::rehash;
// flat_hash_map::reserve(count)
//
// Sets the number of slots in the `flat_hash_map` to the number needed to
// accommodate at least `count` total elements without exceeding the current
// maximum load factor, and may rehash the container if needed.
using Base::reserve;
// flat_hash_map::at()
//
// Returns a reference to the mapped value of the element with key equivalent
// to the passed key.
using Base::at;
// flat_hash_map::contains()
//
// Determines whether an element with a key comparing equal to the given `key`
// exists within the `flat_hash_map`, returning `true` if so or `false`
// otherwise.
using Base::contains;
// flat_hash_map::count(const Key& key) const
//
// Returns the number of elements with a key comparing equal to the given
// `key` within the `flat_hash_map`. note that this function will return
// either `1` or `0` since duplicate keys are not allowed within a
// `flat_hash_map`.
using Base::count;
// flat_hash_map::equal_range()
//
// Returns a closed range [first, last], defined by a `std::pair` of two
// iterators, containing all elements with the passed key in the
// `flat_hash_map`.
using Base::equal_range;
// flat_hash_map::find()
//
// Finds an element with the passed `key` within the `flat_hash_map`.
using Base::find;
// flat_hash_map::operator[]()
//
// Returns a reference to the value mapped to the passed key within the
// `flat_hash_map`, performing an `insert()` if the key does not already
// exist.
//
// If an insertion occurs and results in a rehashing of the container, all
// iterators are invalidated. Otherwise iterators are not affected and
// references are not invalidated. Overloads are listed below.
//
// T& operator[](const Key& key):
//
// Inserts an init_type object constructed in-place if the element with the
// given key does not exist.
//
// T& operator[](Key&& key):
//
// Inserts an init_type object constructed in-place provided that an element
// with the given key does not exist.
using Base::operator[];
// flat_hash_map::bucket_count()
//
// Returns the number of "buckets" within the `flat_hash_map`. Note that
// because a flat hash map contains all elements within its internal storage,
// this value simply equals the current capacity of the `flat_hash_map`.
using Base::bucket_count;
// flat_hash_map::load_factor()
//
// Returns the current load factor of the `flat_hash_map` (the average number
// of slots occupied with a value within the hash map).
using Base::load_factor;
// flat_hash_map::max_load_factor()
//
// Manages the maximum load factor of the `flat_hash_map`. Overloads are
// listed below.
//
// float flat_hash_map::max_load_factor()
//
// Returns the current maximum load factor of the `flat_hash_map`.
//
// void flat_hash_map::max_load_factor(float ml)
//
// Sets the maximum load factor of the `flat_hash_map` to the passed value.
//
// NOTE: This overload is provided only for API compatibility with the STL;
// `flat_hash_map` will ignore any set load factor and manage its rehashing
// internally as an implementation detail.
using Base::max_load_factor;
// flat_hash_map::get_allocator()
//
// Returns the allocator function associated with this `flat_hash_map`.
using Base::get_allocator;
// flat_hash_map::hash_function()
//
// Returns the hashing function used to hash the keys within this
// `flat_hash_map`.
using Base::hash_function;
// flat_hash_map::key_eq()
//
// Returns the function used for comparing keys equality.
using Base::key_eq;
};
// erase_if(flat_hash_map<>, Pred)
//
// Erases all elements that satisfy the predicate `pred` from the container `c`.
template <typename K, typename V, typename H, typename E, typename A,
typename Predicate>
void erase_if(flat_hash_map<K, V, H, E, A>& c, Predicate pred) {
container_internal::EraseIf(pred, &c);
}
namespace container_internal {
template <class K, class V>
struct FlatHashMapPolicy {
using slot_policy = container_internal::map_slot_policy<K, V>;
using slot_type = typename slot_policy::slot_type;
using key_type = K;
using mapped_type = V;
using init_type = std::pair</*non const*/ key_type, mapped_type>;
template <class Allocator, class... Args>
static void construct(Allocator* alloc, slot_type* slot, Args&&... args) {
slot_policy::construct(alloc, slot, std::forward<Args>(args)...);
}
template <class Allocator>
static void destroy(Allocator* alloc, slot_type* slot) {
slot_policy::destroy(alloc, slot);
}
template <class Allocator>
static void transfer(Allocator* alloc, slot_type* new_slot,
slot_type* old_slot) {
slot_policy::transfer(alloc, new_slot, old_slot);
}
template <class F, class... Args>
static decltype(absl::container_internal::DecomposePair(
std::declval<F>(), std::declval<Args>()...))
apply(F&& f, Args&&... args) {
return absl::container_internal::DecomposePair(std::forward<F>(f),
std::forward<Args>(args)...);
}
static size_t space_used(const slot_type*) { return 0; }
static std::pair<const K, V>& element(slot_type* slot) { return slot->value; }
static V& value(std::pair<const K, V>* kv) { return kv->second; }
static const V& value(const std::pair<const K, V>* kv) { return kv->second; }
};
} // namespace container_internal
namespace container_algorithm_internal {
// Specialization of trait in absl/algorithm/container.h
template <class Key, class T, class Hash, class KeyEqual, class Allocator>
struct IsUnorderedContainer<
absl::flat_hash_map<Key, T, Hash, KeyEqual, Allocator>> : std::true_type {};
} // namespace container_algorithm_internal
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_CONTAINER_FLAT_HASH_MAP_H_
Pods/abseil/absl/container/inlined_vector.h
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// Copyright 2019 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// -----------------------------------------------------------------------------
// File: inlined_vector.h
// -----------------------------------------------------------------------------
//
// This header file contains the declaration and definition of an "inlined
// vector" which behaves in an equivalent fashion to a `std::vector`, except
// that storage for small sequences of the vector are provided inline without
// requiring any heap allocation.
//
// An `absl::InlinedVector<T, N>` specifies the default capacity `N` as one of
// its template parameters. Instances where `size() <= N` hold contained
// elements in inline space. Typically `N` is very small so that sequences that
// are expected to be short do not require allocations.
//
// An `absl::InlinedVector` does not usually require a specific allocator. If
// the inlined vector grows beyond its initial constraints, it will need to
// allocate (as any normal `std::vector` would). This is usually performed with
// the default allocator (defined as `std::allocator<T>`). Optionally, a custom
// allocator type may be specified as `A` in `absl::InlinedVector<T, N, A>`.
#ifndef ABSL_CONTAINER_INLINED_VECTOR_H_
#define ABSL_CONTAINER_INLINED_VECTOR_H_
#include <algorithm>
#include <cassert>
#include <cstddef>
#include <cstdlib>
#include <cstring>
#include <initializer_list>
#include <iterator>
#include <memory>
#include <type_traits>
#include <utility>
#include "absl/algorithm/algorithm.h"
#include "absl/base/internal/throw_delegate.h"
#include "absl/base/optimization.h"
#include "absl/base/port.h"
#include "absl/container/internal/inlined_vector.h"
#include "absl/memory/memory.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
// -----------------------------------------------------------------------------
// InlinedVector
// -----------------------------------------------------------------------------
//
// An `absl::InlinedVector` is designed to be a drop-in replacement for
// `std::vector` for use cases where the vector's size is sufficiently small
// that it can be inlined. If the inlined vector does grow beyond its estimated
// capacity, it will trigger an initial allocation on the heap, and will behave
// as a `std:vector`. The API of the `absl::InlinedVector` within this file is
// designed to cover the same API footprint as covered by `std::vector`.
template <typename T, size_t N, typename A = std::allocator<T>>
class InlinedVector {
static_assert(N > 0, "`absl::InlinedVector` requires an inlined capacity.");
using Storage = inlined_vector_internal::Storage<T, N, A>;
using AllocatorTraits = typename Storage::AllocatorTraits;
using RValueReference = typename Storage::RValueReference;
using MoveIterator = typename Storage::MoveIterator;
using IsMemcpyOk = typename Storage::IsMemcpyOk;
template <typename Iterator>
using IteratorValueAdapter =
typename Storage::template IteratorValueAdapter<Iterator>;
using CopyValueAdapter = typename Storage::CopyValueAdapter;
using DefaultValueAdapter = typename Storage::DefaultValueAdapter;
template <typename Iterator>
using EnableIfAtLeastForwardIterator = absl::enable_if_t<
inlined_vector_internal::IsAtLeastForwardIterator<Iterator>::value>;
template <typename Iterator>
using DisableIfAtLeastForwardIterator = absl::enable_if_t<
!inlined_vector_internal::IsAtLeastForwardIterator<Iterator>::value>;
public:
using allocator_type = typename Storage::allocator_type;
using value_type = typename Storage::value_type;
using pointer = typename Storage::pointer;
using const_pointer = typename Storage::const_pointer;
using size_type = typename Storage::size_type;
using difference_type = typename Storage::difference_type;
using reference = typename Storage::reference;
using const_reference = typename Storage::const_reference;
using iterator = typename Storage::iterator;
using const_iterator = typename Storage::const_iterator;
using reverse_iterator = typename Storage::reverse_iterator;
using const_reverse_iterator = typename Storage::const_reverse_iterator;
// ---------------------------------------------------------------------------
// InlinedVector Constructors and Destructor
// ---------------------------------------------------------------------------
// Creates an empty inlined vector with a value-initialized allocator.
InlinedVector() noexcept(noexcept(allocator_type())) : storage_() {}
// Creates an empty inlined vector with a copy of `alloc`.
explicit InlinedVector(const allocator_type& alloc) noexcept
: storage_(alloc) {}
// Creates an inlined vector with `n` copies of `value_type()`.
explicit InlinedVector(size_type n,
const allocator_type& alloc = allocator_type())
: storage_(alloc) {
storage_.Initialize(DefaultValueAdapter(), n);
}
// Creates an inlined vector with `n` copies of `v`.
InlinedVector(size_type n, const_reference v,
const allocator_type& alloc = allocator_type())
: storage_(alloc) {
storage_.Initialize(CopyValueAdapter(v), n);
}
// Creates an inlined vector with copies of the elements of `list`.
InlinedVector(std::initializer_list<value_type> list,
const allocator_type& alloc = allocator_type())
: InlinedVector(list.begin(), list.end(), alloc) {}
// Creates an inlined vector with elements constructed from the provided
// forward iterator range [`first`, `last`).
//
// NOTE: the `enable_if` prevents ambiguous interpretation between a call to
// this constructor with two integral arguments and a call to the above
// `InlinedVector(size_type, const_reference)` constructor.
template <typename ForwardIterator,
EnableIfAtLeastForwardIterator<ForwardIterator>* = nullptr>
InlinedVector(ForwardIterator first, ForwardIterator last,
const allocator_type& alloc = allocator_type())
: storage_(alloc) {
storage_.Initialize(IteratorValueAdapter<ForwardIterator>(first),
std::distance(first, last));
}
// Creates an inlined vector with elements constructed from the provided input
// iterator range [`first`, `last`).
template <typename InputIterator,
DisableIfAtLeastForwardIterator<InputIterator>* = nullptr>
InlinedVector(InputIterator first, InputIterator last,
const allocator_type& alloc = allocator_type())
: storage_(alloc) {
std::copy(first, last, std::back_inserter(*this));
}
// Creates an inlined vector by copying the contents of `other` using
// `other`'s allocator.
InlinedVector(const InlinedVector& other)
: InlinedVector(other, *other.storage_.GetAllocPtr()) {}
// Creates an inlined vector by copying the contents of `other` using `alloc`.
InlinedVector(const InlinedVector& other, const allocator_type& alloc)
: storage_(alloc) {
if (IsMemcpyOk::value && !other.storage_.GetIsAllocated()) {
storage_.MemcpyFrom(other.storage_);
} else {
storage_.Initialize(IteratorValueAdapter<const_pointer>(other.data()),
other.size());
}
}
// Creates an inlined vector by moving in the contents of `other` without
// allocating. If `other` contains allocated memory, the newly-created inlined
// vector will take ownership of that memory. However, if `other` does not
// contain allocated memory, the newly-created inlined vector will perform
// element-wise move construction of the contents of `other`.
//
// NOTE: since no allocation is performed for the inlined vector in either
// case, the `noexcept(...)` specification depends on whether moving the
// underlying objects can throw. It is assumed assumed that...
// a) move constructors should only throw due to allocation failure.
// b) if `value_type`'s move constructor allocates, it uses the same
// allocation function as the inlined vector's allocator.
// Thus, the move constructor is non-throwing if the allocator is non-throwing
// or `value_type`'s move constructor is specified as `noexcept`.
InlinedVector(InlinedVector&& other) noexcept(
absl::allocator_is_nothrow<allocator_type>::value ||
std::is_nothrow_move_constructible<value_type>::value)
: storage_(*other.storage_.GetAllocPtr()) {
if (IsMemcpyOk::value) {
storage_.MemcpyFrom(other.storage_);
other.storage_.SetInlinedSize(0);
} else if (other.storage_.GetIsAllocated()) {
storage_.SetAllocatedData(other.storage_.GetAllocatedData(),
other.storage_.GetAllocatedCapacity());
storage_.SetAllocatedSize(other.storage_.GetSize());
other.storage_.SetInlinedSize(0);
} else {
IteratorValueAdapter<MoveIterator> other_values(
MoveIterator(other.storage_.GetInlinedData()));
inlined_vector_internal::ConstructElements(
storage_.GetAllocPtr(), storage_.GetInlinedData(), &other_values,
other.storage_.GetSize());
storage_.SetInlinedSize(other.storage_.GetSize());
}
}
// Creates an inlined vector by moving in the contents of `other` with a copy
// of `alloc`.
//
// NOTE: if `other`'s allocator is not equal to `alloc`, even if `other`
// contains allocated memory, this move constructor will still allocate. Since
// allocation is performed, this constructor can only be `noexcept` if the
// specified allocator is also `noexcept`.
InlinedVector(InlinedVector&& other, const allocator_type& alloc) noexcept(
absl::allocator_is_nothrow<allocator_type>::value)
: storage_(alloc) {
if (IsMemcpyOk::value) {
storage_.MemcpyFrom(other.storage_);
other.storage_.SetInlinedSize(0);
} else if ((*storage_.GetAllocPtr() == *other.storage_.GetAllocPtr()) &&
other.storage_.GetIsAllocated()) {
storage_.SetAllocatedData(other.storage_.GetAllocatedData(),
other.storage_.GetAllocatedCapacity());
storage_.SetAllocatedSize(other.storage_.GetSize());
other.storage_.SetInlinedSize(0);
} else {
storage_.Initialize(
IteratorValueAdapter<MoveIterator>(MoveIterator(other.data())),
other.size());
}
}
~InlinedVector() {}
// ---------------------------------------------------------------------------
// InlinedVector Member Accessors
// ---------------------------------------------------------------------------
// `InlinedVector::empty()`
//
// Returns whether the inlined vector contains no elements.
bool empty() const noexcept { return !size(); }
// `InlinedVector::size()`
//
// Returns the number of elements in the inlined vector.
size_type size() const noexcept { return storage_.GetSize(); }
// `InlinedVector::max_size()`
//
// Returns the maximum number of elements the inlined vector can hold.
size_type max_size() const noexcept {
// One bit of the size storage is used to indicate whether the inlined
// vector contains allocated memory. As a result, the maximum size that the
// inlined vector can express is half of the max for `size_type`.
return (std::numeric_limits<size_type>::max)() / 2;
}
// `InlinedVector::capacity()`
//
// Returns the number of elements that could be stored in the inlined vector
// without requiring a reallocation.
//
// NOTE: for most inlined vectors, `capacity()` should be equal to the
// template parameter `N`. For inlined vectors which exceed this capacity,
// they will no longer be inlined and `capacity()` will equal the capactity of
// the allocated memory.
size_type capacity() const noexcept {
return storage_.GetIsAllocated() ? storage_.GetAllocatedCapacity()
: storage_.GetInlinedCapacity();
}
// `InlinedVector::data()`
//
// Returns a `pointer` to the elements of the inlined vector. This pointer
// can be used to access and modify the contained elements.
//
// NOTE: only elements within [`data()`, `data() + size()`) are valid.
pointer data() noexcept {
return storage_.GetIsAllocated() ? storage_.GetAllocatedData()
: storage_.GetInlinedData();
}
// Overload of `InlinedVector::data()` that returns a `const_pointer` to the
// elements of the inlined vector. This pointer can be used to access but not
// modify the contained elements.
//
// NOTE: only elements within [`data()`, `data() + size()`) are valid.
const_pointer data() const noexcept {
return storage_.GetIsAllocated() ? storage_.GetAllocatedData()
: storage_.GetInlinedData();
}
// `InlinedVector::operator[](...)`
//
// Returns a `reference` to the `i`th element of the inlined vector.
reference operator[](size_type i) {
assert(i < size());
return data()[i];
}
// Overload of `InlinedVector::operator[](...)` that returns a
// `const_reference` to the `i`th element of the inlined vector.
const_reference operator[](size_type i) const {
assert(i < size());
return data()[i];
}
// `InlinedVector::at(...)`
//
// Returns a `reference` to the `i`th element of the inlined vector.
//
// NOTE: if `i` is not within the required range of `InlinedVector::at(...)`,
// in both debug and non-debug builds, `std::out_of_range` will be thrown.
reference at(size_type i) {
if (ABSL_PREDICT_FALSE(i >= size())) {
base_internal::ThrowStdOutOfRange(
"`InlinedVector::at(size_type)` failed bounds check");
}
return data()[i];
}
// Overload of `InlinedVector::at(...)` that returns a `const_reference` to
// the `i`th element of the inlined vector.
//
// NOTE: if `i` is not within the required range of `InlinedVector::at(...)`,
// in both debug and non-debug builds, `std::out_of_range` will be thrown.
const_reference at(size_type i) const {
if (ABSL_PREDICT_FALSE(i >= size())) {
base_internal::ThrowStdOutOfRange(
"`InlinedVector::at(size_type) const` failed bounds check");
}
return data()[i];
}
// `InlinedVector::front()`
//
// Returns a `reference` to the first element of the inlined vector.
reference front() {
assert(!empty());
return at(0);
}
// Overload of `InlinedVector::front()` that returns a `const_reference` to
// the first element of the inlined vector.
const_reference front() const {
assert(!empty());
return at(0);
}
// `InlinedVector::back()`
//
// Returns a `reference` to the last element of the inlined vector.
reference back() {
assert(!empty());
return at(size() - 1);
}
// Overload of `InlinedVector::back()` that returns a `const_reference` to the
// last element of the inlined vector.
const_reference back() const {
assert(!empty());
return at(size() - 1);
}
// `InlinedVector::begin()`
//
// Returns an `iterator` to the beginning of the inlined vector.
iterator begin() noexcept { return data(); }
// Overload of `InlinedVector::begin()` that returns a `const_iterator` to
// the beginning of the inlined vector.
const_iterator begin() const noexcept { return data(); }
// `InlinedVector::end()`
//
// Returns an `iterator` to the end of the inlined vector.
iterator end() noexcept { return data() + size(); }
// Overload of `InlinedVector::end()` that returns a `const_iterator` to the
// end of the inlined vector.
const_iterator end() const noexcept { return data() + size(); }
// `InlinedVector::cbegin()`
//
// Returns a `const_iterator` to the beginning of the inlined vector.
const_iterator cbegin() const noexcept { return begin(); }
// `InlinedVector::cend()`
//
// Returns a `const_iterator` to the end of the inlined vector.
const_iterator cend() const noexcept { return end(); }
// `InlinedVector::rbegin()`
//
// Returns a `reverse_iterator` from the end of the inlined vector.
reverse_iterator rbegin() noexcept { return reverse_iterator(end()); }
// Overload of `InlinedVector::rbegin()` that returns a
// `const_reverse_iterator` from the end of the inlined vector.
const_reverse_iterator rbegin() const noexcept {
return const_reverse_iterator(end());
}
// `InlinedVector::rend()`
//
// Returns a `reverse_iterator` from the beginning of the inlined vector.
reverse_iterator rend() noexcept { return reverse_iterator(begin()); }
// Overload of `InlinedVector::rend()` that returns a `const_reverse_iterator`
// from the beginning of the inlined vector.
const_reverse_iterator rend() const noexcept {
return const_reverse_iterator(begin());
}
// `InlinedVector::crbegin()`
//
// Returns a `const_reverse_iterator` from the end of the inlined vector.
const_reverse_iterator crbegin() const noexcept { return rbegin(); }
// `InlinedVector::crend()`
//
// Returns a `const_reverse_iterator` from the beginning of the inlined
// vector.
const_reverse_iterator crend() const noexcept { return rend(); }
// `InlinedVector::get_allocator()`
//
// Returns a copy of the inlined vector's allocator.
allocator_type get_allocator() const { return *storage_.GetAllocPtr(); }
// ---------------------------------------------------------------------------
// InlinedVector Member Mutators
// ---------------------------------------------------------------------------
// `InlinedVector::operator=(...)`
//
// Replaces the elements of the inlined vector with copies of the elements of
// `list`.
InlinedVector& operator=(std::initializer_list<value_type> list) {
assign(list.begin(), list.end());
return *this;
}
// Overload of `InlinedVector::operator=(...)` that replaces the elements of
// the inlined vector with copies of the elements of `other`.
InlinedVector& operator=(const InlinedVector& other) {
if (ABSL_PREDICT_TRUE(this != std::addressof(other))) {
const_pointer other_data = other.data();
assign(other_data, other_data + other.size());
}
return *this;
}
// Overload of `InlinedVector::operator=(...)` that moves the elements of
// `other` into the inlined vector.
//
// NOTE: as a result of calling this overload, `other` is left in a valid but
// unspecified state.
InlinedVector& operator=(InlinedVector&& other) {
if (ABSL_PREDICT_TRUE(this != std::addressof(other))) {
if (IsMemcpyOk::value || other.storage_.GetIsAllocated()) {
inlined_vector_internal::DestroyElements(storage_.GetAllocPtr(), data(),
size());
storage_.DeallocateIfAllocated();
storage_.MemcpyFrom(other.storage_);
other.storage_.SetInlinedSize(0);
} else {
storage_.Assign(IteratorValueAdapter<MoveIterator>(
MoveIterator(other.storage_.GetInlinedData())),
other.size());
}
}
return *this;
}
// `InlinedVector::assign(...)`
//
// Replaces the contents of the inlined vector with `n` copies of `v`.
void assign(size_type n, const_reference v) {
storage_.Assign(CopyValueAdapter(v), n);
}
// Overload of `InlinedVector::assign(...)` that replaces the contents of the
// inlined vector with copies of the elements of `list`.
void assign(std::initializer_list<value_type> list) {
assign(list.begin(), list.end());
}
// Overload of `InlinedVector::assign(...)` to replace the contents of the
// inlined vector with the range [`first`, `last`).
//
// NOTE: this overload is for iterators that are "forward" category or better.
template <typename ForwardIterator,
EnableIfAtLeastForwardIterator<ForwardIterator>* = nullptr>
void assign(ForwardIterator first, ForwardIterator last) {
storage_.Assign(IteratorValueAdapter<ForwardIterator>(first),
std::distance(first, last));
}
// Overload of `InlinedVector::assign(...)` to replace the contents of the
// inlined vector with the range [`first`, `last`).
//
// NOTE: this overload is for iterators that are "input" category.
template <typename InputIterator,
DisableIfAtLeastForwardIterator<InputIterator>* = nullptr>
void assign(InputIterator first, InputIterator last) {
size_type i = 0;
for (; i < size() && first != last; ++i, static_cast<void>(++first)) {
at(i) = *first;
}
erase(data() + i, data() + size());
std::copy(first, last, std::back_inserter(*this));
}
// `InlinedVector::resize(...)`
//
// Resizes the inlined vector to contain `n` elements.
//
// NOTE: if `n` is smaller than `size()`, extra elements are destroyed. If `n`
// is larger than `size()`, new elements are value-initialized.
void resize(size_type n) { storage_.Resize(DefaultValueAdapter(), n); }
// Overload of `InlinedVector::resize(...)` that resizes the inlined vector to
// contain `n` elements.
//
// NOTE: if `n` is smaller than `size()`, extra elements are destroyed. If `n`
// is larger than `size()`, new elements are copied-constructed from `v`.
void resize(size_type n, const_reference v) {
storage_.Resize(CopyValueAdapter(v), n);
}
// `InlinedVector::insert(...)`
//
// Inserts a copy of `v` at `pos`, returning an `iterator` to the newly
// inserted element.
iterator insert(const_iterator pos, const_reference v) {
return emplace(pos, v);
}
// Overload of `InlinedVector::insert(...)` that inserts `v` at `pos` using
// move semantics, returning an `iterator` to the newly inserted element.
iterator insert(const_iterator pos, RValueReference v) {
return emplace(pos, std::move(v));
}
// Overload of `InlinedVector::insert(...)` that inserts `n` contiguous copies
// of `v` starting at `pos`, returning an `iterator` pointing to the first of
// the newly inserted elements.
iterator insert(const_iterator pos, size_type n, const_reference v) {
assert(pos >= begin());
assert(pos <= end());
if (ABSL_PREDICT_TRUE(n != 0)) {
value_type dealias = v;
return storage_.Insert(pos, CopyValueAdapter(dealias), n);
} else {
return const_cast<iterator>(pos);
}
}
// Overload of `InlinedVector::insert(...)` that inserts copies of the
// elements of `list` starting at `pos`, returning an `iterator` pointing to
// the first of the newly inserted elements.
iterator insert(const_iterator pos, std::initializer_list<value_type> list) {
return insert(pos, list.begin(), list.end());
}
// Overload of `InlinedVector::insert(...)` that inserts the range [`first`,
// `last`) starting at `pos`, returning an `iterator` pointing to the first
// of the newly inserted elements.
//
// NOTE: this overload is for iterators that are "forward" category or better.
template <typename ForwardIterator,
EnableIfAtLeastForwardIterator<ForwardIterator>* = nullptr>
iterator insert(const_iterator pos, ForwardIterator first,
ForwardIterator last) {
assert(pos >= begin());
assert(pos <= end());
if (ABSL_PREDICT_TRUE(first != last)) {
return storage_.Insert(pos, IteratorValueAdapter<ForwardIterator>(first),
std::distance(first, last));
} else {
return const_cast<iterator>(pos);
}
}
// Overload of `InlinedVector::insert(...)` that inserts the range [`first`,
// `last`) starting at `pos`, returning an `iterator` pointing to the first
// of the newly inserted elements.
//
// NOTE: this overload is for iterators that are "input" category.
template <typename InputIterator,
DisableIfAtLeastForwardIterator<InputIterator>* = nullptr>
iterator insert(const_iterator pos, InputIterator first, InputIterator last) {
assert(pos >= begin());
assert(pos <= end());
size_type index = std::distance(cbegin(), pos);
for (size_type i = index; first != last; ++i, static_cast<void>(++first)) {
insert(data() + i, *first);
}
return iterator(data() + index);
}
// `InlinedVector::emplace(...)`
//
// Constructs and inserts an element using `args...` in the inlined vector at
// `pos`, returning an `iterator` pointing to the newly emplaced element.
template <typename... Args>
iterator emplace(const_iterator pos, Args&&... args) {
assert(pos >= begin());
assert(pos <= end());
value_type dealias(std::forward<Args>(args)...);
return storage_.Insert(pos,
IteratorValueAdapter<MoveIterator>(
MoveIterator(std::addressof(dealias))),
1);
}
// `InlinedVector::emplace_back(...)`
//
// Constructs and inserts an element using `args...` in the inlined vector at
// `end()`, returning a `reference` to the newly emplaced element.
template <typename... Args>
reference emplace_back(Args&&... args) {
return storage_.EmplaceBack(std::forward<Args>(args)...);
}
// `InlinedVector::push_back(...)`
//
// Inserts a copy of `v` in the inlined vector at `end()`.
void push_back(const_reference v) { static_cast<void>(emplace_back(v)); }
// Overload of `InlinedVector::push_back(...)` for inserting `v` at `end()`
// using move semantics.
void push_back(RValueReference v) {
static_cast<void>(emplace_back(std::move(v)));
}
// `InlinedVector::pop_back()`
//
// Destroys the element at `back()`, reducing the size by `1`.
void pop_back() noexcept {
assert(!empty());
AllocatorTraits::destroy(*storage_.GetAllocPtr(), data() + (size() - 1));
storage_.SubtractSize(1);
}
// `InlinedVector::erase(...)`
//
// Erases the element at `pos`, returning an `iterator` pointing to where the
// erased element was located.
//
// NOTE: may return `end()`, which is not dereferencable.
iterator erase(const_iterator pos) {
assert(pos >= begin());
assert(pos < end());
return storage_.Erase(pos, pos + 1);
}
// Overload of `InlinedVector::erase(...)` that erases every element in the
// range [`from`, `to`), returning an `iterator` pointing to where the first
// erased element was located.
//
// NOTE: may return `end()`, which is not dereferencable.
iterator erase(const_iterator from, const_iterator to) {
assert(from >= begin());
assert(from <= to);
assert(to <= end());
if (ABSL_PREDICT_TRUE(from != to)) {
return storage_.Erase(from, to);
} else {
return const_cast<iterator>(from);
}
}
// `InlinedVector::clear()`
//
// Destroys all elements in the inlined vector, setting the size to `0` and
// deallocating any held memory.
void clear() noexcept {
inlined_vector_internal::DestroyElements(storage_.GetAllocPtr(), data(),
size());
storage_.DeallocateIfAllocated();
storage_.SetInlinedSize(0);
}
// `InlinedVector::reserve(...)`
//
// Ensures that there is enough room for at least `n` elements.
void reserve(size_type n) { storage_.Reserve(n); }
// `InlinedVector::shrink_to_fit()`
//
// Reduces memory usage by freeing unused memory. After being called, calls to
// `capacity()` will be equal to `max(N, size())`.
//
// If `size() <= N` and the inlined vector contains allocated memory, the
// elements will all be moved to the inlined space and the allocated memory
// will be deallocated.
//
// If `size() > N` and `size() < capacity()`, the elements will be moved to a
// smaller allocation.
void shrink_to_fit() {
if (storage_.GetIsAllocated()) {
storage_.ShrinkToFit();
}
}
// `InlinedVector::swap(...)`
//
// Swaps the contents of the inlined vector with `other`.
void swap(InlinedVector& other) {
if (ABSL_PREDICT_TRUE(this != std::addressof(other))) {
storage_.Swap(std::addressof(other.storage_));
}
}
private:
template <typename H, typename TheT, size_t TheN, typename TheA>
friend H AbslHashValue(H h, const absl::InlinedVector<TheT, TheN, TheA>& a);
Storage storage_;
};
// -----------------------------------------------------------------------------
// InlinedVector Non-Member Functions
// -----------------------------------------------------------------------------
// `swap(...)`
//
// Swaps the contents of two inlined vectors.
template <typename T, size_t N, typename A>
void swap(absl::InlinedVector<T, N, A>& a,
absl::InlinedVector<T, N, A>& b) noexcept(noexcept(a.swap(b))) {
a.swap(b);
}
// `operator==(...)`
//
// Tests for value-equality of two inlined vectors.
template <typename T, size_t N, typename A>
bool operator==(const absl::InlinedVector<T, N, A>& a,
const absl::InlinedVector<T, N, A>& b) {
auto a_data = a.data();
auto b_data = b.data();
return absl::equal(a_data, a_data + a.size(), b_data, b_data + b.size());
}
// `operator!=(...)`
//
// Tests for value-inequality of two inlined vectors.
template <typename T, size_t N, typename A>
bool operator!=(const absl::InlinedVector<T, N, A>& a,
const absl::InlinedVector<T, N, A>& b) {
return !(a == b);
}
// `operator<(...)`
//
// Tests whether the value of an inlined vector is less than the value of
// another inlined vector using a lexicographical comparison algorithm.
template <typename T, size_t N, typename A>
bool operator<(const absl::InlinedVector<T, N, A>& a,
const absl::InlinedVector<T, N, A>& b) {
auto a_data = a.data();
auto b_data = b.data();
return std::lexicographical_compare(a_data, a_data + a.size(), b_data,
b_data + b.size());
}
// `operator>(...)`
//
// Tests whether the value of an inlined vector is greater than the value of
// another inlined vector using a lexicographical comparison algorithm.
template <typename T, size_t N, typename A>
bool operator>(const absl::InlinedVector<T, N, A>& a,
const absl::InlinedVector<T, N, A>& b) {
return b < a;
}
// `operator<=(...)`
//
// Tests whether the value of an inlined vector is less than or equal to the
// value of another inlined vector using a lexicographical comparison algorithm.
template <typename T, size_t N, typename A>
bool operator<=(const absl::InlinedVector<T, N, A>& a,
const absl::InlinedVector<T, N, A>& b) {
return !(b < a);
}
// `operator>=(...)`
//
// Tests whether the value of an inlined vector is greater than or equal to the
// value of another inlined vector using a lexicographical comparison algorithm.
template <typename T, size_t N, typename A>
bool operator>=(const absl::InlinedVector<T, N, A>& a,
const absl::InlinedVector<T, N, A>& b) {
return !(a < b);
}
// `AbslHashValue(...)`
//
// Provides `absl::Hash` support for `absl::InlinedVector`. It is uncommon to
// call this directly.
template <typename H, typename T, size_t N, typename A>
H AbslHashValue(H h, const absl::InlinedVector<T, N, A>& a) {
auto size = a.size();
return H::combine(H::combine_contiguous(std::move(h), a.data(), size), size);
}
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_CONTAINER_INLINED_VECTOR_H_
Pods/abseil/absl/container/internal/common.h
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// Copyright 2018 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef ABSL_CONTAINER_INTERNAL_CONTAINER_H_
#define ABSL_CONTAINER_INTERNAL_CONTAINER_H_
#include <cassert>
#include <type_traits>
#include "absl/meta/type_traits.h"
#include "absl/types/optional.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace container_internal {
template <class, class = void>
struct IsTransparent : std::false_type {};
template <class T>
struct IsTransparent<T, absl::void_t<typename T::is_transparent>>
: std::true_type {};
template <bool is_transparent>
struct KeyArg {
// Transparent. Forward `K`.
template <typename K, typename key_type>
using type = K;
};
template <>
struct KeyArg<false> {
// Not transparent. Always use `key_type`.
template <typename K, typename key_type>
using type = key_type;
};
// The node_handle concept from C++17.
// We specialize node_handle for sets and maps. node_handle_base holds the
// common API of both.
template <typename PolicyTraits, typename Alloc>
class node_handle_base {
protected:
using slot_type = typename PolicyTraits::slot_type;
public:
using allocator_type = Alloc;
constexpr node_handle_base() = default;
node_handle_base(node_handle_base&& other) noexcept {
*this = std::move(other);
}
~node_handle_base() { destroy(); }
node_handle_base& operator=(node_handle_base&& other) noexcept {
destroy();
if (!other.empty()) {
alloc_ = other.alloc_;
PolicyTraits::transfer(alloc(), slot(), other.slot());
other.reset();
}
return *this;
}
bool empty() const noexcept { return !alloc_; }
explicit operator bool() const noexcept { return !empty(); }
allocator_type get_allocator() const { return *alloc_; }
protected:
friend struct CommonAccess;
struct transfer_tag_t {};
node_handle_base(transfer_tag_t, const allocator_type& a, slot_type* s)
: alloc_(a) {
PolicyTraits::transfer(alloc(), slot(), s);
}
struct move_tag_t {};
node_handle_base(move_tag_t, const allocator_type& a, slot_type* s)
: alloc_(a) {
PolicyTraits::construct(alloc(), slot(), s);
}
void destroy() {
if (!empty()) {
PolicyTraits::destroy(alloc(), slot());
reset();
}
}
void reset() {
assert(alloc_.has_value());
alloc_ = absl::nullopt;
}
slot_type* slot() const {
assert(!empty());
return reinterpret_cast<slot_type*>(std::addressof(slot_space_));
}
allocator_type* alloc() { return std::addressof(*alloc_); }
private:
absl::optional<allocator_type> alloc_ = {};
alignas(slot_type) mutable unsigned char slot_space_[sizeof(slot_type)] = {};
};
// For sets.
template <typename Policy, typename PolicyTraits, typename Alloc,
typename = void>
class node_handle : public node_handle_base<PolicyTraits, Alloc> {
using Base = node_handle_base<PolicyTraits, Alloc>;
public:
using value_type = typename PolicyTraits::value_type;
constexpr node_handle() {}
value_type& value() const { return PolicyTraits::element(this->slot()); }
private:
friend struct CommonAccess;
using Base::Base;
};
// For maps.
template <typename Policy, typename PolicyTraits, typename Alloc>
class node_handle<Policy, PolicyTraits, Alloc,
absl::void_t<typename Policy::mapped_type>>
: public node_handle_base<PolicyTraits, Alloc> {
using Base = node_handle_base<PolicyTraits, Alloc>;
public:
using key_type = typename Policy::key_type;
using mapped_type = typename Policy::mapped_type;
constexpr node_handle() {}
auto key() const -> decltype(PolicyTraits::key(this->slot())) {
return PolicyTraits::key(this->slot());
}
mapped_type& mapped() const {
return PolicyTraits::value(&PolicyTraits::element(this->slot()));
}
private:
friend struct CommonAccess;
using Base::Base;
};
// Provide access to non-public node-handle functions.
struct CommonAccess {
template <typename Node>
static auto GetSlot(const Node& node) -> decltype(node.slot()) {
return node.slot();
}
template <typename Node>
static void Destroy(Node* node) {
node->destroy();
}
template <typename Node>
static void Reset(Node* node) {
node->reset();
}
template <typename T, typename... Args>
static T Transfer(Args&&... args) {
return T(typename T::transfer_tag_t{}, std::forward<Args>(args)...);
}
template <typename T, typename... Args>
static T Move(Args&&... args) {
return T(typename T::move_tag_t{}, std::forward<Args>(args)...);
}
};
// Implement the insert_return_type<> concept of C++17.
template <class Iterator, class NodeType>
struct InsertReturnType {
Iterator position;
bool inserted;
NodeType node;
};
} // namespace container_internal
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_CONTAINER_INTERNAL_CONTAINER_H_
Pods/abseil/absl/container/internal/compressed_tuple.h
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// Copyright 2018 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Helper class to perform the Empty Base Optimization.
// Ts can contain classes and non-classes, empty or not. For the ones that
// are empty classes, we perform the optimization. If all types in Ts are empty
// classes, then CompressedTuple<Ts...> is itself an empty class.
//
// To access the members, use member get<N>() function.
//
// Eg:
// absl::container_internal::CompressedTuple<int, T1, T2, T3> value(7, t1, t2,
// t3);
// assert(value.get<0>() == 7);
// T1& t1 = value.get<1>();
// const T2& t2 = value.get<2>();
// ...
//
// https://en.cppreference.com/w/cpp/language/ebo
#ifndef ABSL_CONTAINER_INTERNAL_COMPRESSED_TUPLE_H_
#define ABSL_CONTAINER_INTERNAL_COMPRESSED_TUPLE_H_
#include <initializer_list>
#include <tuple>
#include <type_traits>
#include <utility>
#include "absl/utility/utility.h"
#if defined(_MSC_VER) && !defined(__NVCC__)
// We need to mark these classes with this declspec to ensure that
// CompressedTuple happens.
#define ABSL_INTERNAL_COMPRESSED_TUPLE_DECLSPEC __declspec(empty_bases)
#else
#define ABSL_INTERNAL_COMPRESSED_TUPLE_DECLSPEC
#endif
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace container_internal {
template <typename... Ts>
class CompressedTuple;
namespace internal_compressed_tuple {
template <typename D, size_t I>
struct Elem;
template <typename... B, size_t I>
struct Elem<CompressedTuple<B...>, I>
: std::tuple_element<I, std::tuple<B...>> {};
template <typename D, size_t I>
using ElemT = typename Elem<D, I>::type;
// Use the __is_final intrinsic if available. Where it's not available, classes
// declared with the 'final' specifier cannot be used as CompressedTuple
// elements.
// TODO(sbenza): Replace this with std::is_final in C++14.
template <typename T>
constexpr bool IsFinal() {
#if defined(__clang__) || defined(__GNUC__)
return __is_final(T);
#else
return false;
#endif
}
// We can't use EBCO on other CompressedTuples because that would mean that we
// derive from multiple Storage<> instantiations with the same I parameter,
// and potentially from multiple identical Storage<> instantiations. So anytime
// we use type inheritance rather than encapsulation, we mark
// CompressedTupleImpl, to make this easy to detect.
struct uses_inheritance {};
template <typename T>
constexpr bool ShouldUseBase() {
return std::is_class<T>::value && std::is_empty<T>::value && !IsFinal<T>() &&
!std::is_base_of<uses_inheritance, T>::value;
}
// The storage class provides two specializations:
// - For empty classes, it stores T as a base class.
// - For everything else, it stores T as a member.
template <typename T, size_t I,
#if defined(_MSC_VER)
bool UseBase =
ShouldUseBase<typename std::enable_if<true, T>::type>()>
#else
bool UseBase = ShouldUseBase<T>()>
#endif
struct Storage {
T value;
constexpr Storage() = default;
template <typename V>
explicit constexpr Storage(absl::in_place_t, V&& v)
: value(absl::forward<V>(v)) {}
constexpr const T& get() const& { return value; }
T& get() & { return value; }
constexpr const T&& get() const&& { return absl::move(*this).value; }
T&& get() && { return std::move(*this).value; }
};
template <typename T, size_t I>
struct ABSL_INTERNAL_COMPRESSED_TUPLE_DECLSPEC Storage<T, I, true> : T {
constexpr Storage() = default;
template <typename V>
explicit constexpr Storage(absl::in_place_t, V&& v)
: T(absl::forward<V>(v)) {}
constexpr const T& get() const& { return *this; }
T& get() & { return *this; }
constexpr const T&& get() const&& { return absl::move(*this); }
T&& get() && { return std::move(*this); }
};
template <typename D, typename I, bool ShouldAnyUseBase>
struct ABSL_INTERNAL_COMPRESSED_TUPLE_DECLSPEC CompressedTupleImpl;
template <typename... Ts, size_t... I, bool ShouldAnyUseBase>
struct ABSL_INTERNAL_COMPRESSED_TUPLE_DECLSPEC CompressedTupleImpl<
CompressedTuple<Ts...>, absl::index_sequence<I...>, ShouldAnyUseBase>
// We use the dummy identity function through std::integral_constant to
// convince MSVC of accepting and expanding I in that context. Without it
// you would get:
// error C3548: 'I': parameter pack cannot be used in this context
: uses_inheritance,
Storage<Ts, std::integral_constant<size_t, I>::value>... {
constexpr CompressedTupleImpl() = default;
template <typename... Vs>
explicit constexpr CompressedTupleImpl(absl::in_place_t, Vs&&... args)
: Storage<Ts, I>(absl::in_place, absl::forward<Vs>(args))... {}
friend CompressedTuple<Ts...>;
};
template <typename... Ts, size_t... I>
struct ABSL_INTERNAL_COMPRESSED_TUPLE_DECLSPEC CompressedTupleImpl<
CompressedTuple<Ts...>, absl::index_sequence<I...>, false>
// We use the dummy identity function as above...
: Storage<Ts, std::integral_constant<size_t, I>::value, false>... {
constexpr CompressedTupleImpl() = default;
template <typename... Vs>
explicit constexpr CompressedTupleImpl(absl::in_place_t, Vs&&... args)
: Storage<Ts, I, false>(absl::in_place, absl::forward<Vs>(args))... {}
friend CompressedTuple<Ts...>;
};
std::false_type Or(std::initializer_list<std::false_type>);
std::true_type Or(std::initializer_list<bool>);
// MSVC requires this to be done separately rather than within the declaration
// of CompressedTuple below.
template <typename... Ts>
constexpr bool ShouldAnyUseBase() {
return decltype(
Or({std::integral_constant<bool, ShouldUseBase<Ts>()>()...})){};
}
template <typename T, typename V>
using TupleMoveConstructible = typename std::conditional<
std::is_reference<T>::value, std::is_convertible<V, T>,
std::is_constructible<T, V&&>>::type;
} // namespace internal_compressed_tuple
// Helper class to perform the Empty Base Class Optimization.
// Ts can contain classes and non-classes, empty or not. For the ones that
// are empty classes, we perform the CompressedTuple. If all types in Ts are
// empty classes, then CompressedTuple<Ts...> is itself an empty class. (This
// does not apply when one or more of those empty classes is itself an empty
// CompressedTuple.)
//
// To access the members, use member .get<N>() function.
//
// Eg:
// absl::container_internal::CompressedTuple<int, T1, T2, T3> value(7, t1, t2,
// t3);
// assert(value.get<0>() == 7);
// T1& t1 = value.get<1>();
// const T2& t2 = value.get<2>();
// ...
//
// https://en.cppreference.com/w/cpp/language/ebo
template <typename... Ts>
class ABSL_INTERNAL_COMPRESSED_TUPLE_DECLSPEC CompressedTuple
: private internal_compressed_tuple::CompressedTupleImpl<
CompressedTuple<Ts...>, absl::index_sequence_for<Ts...>,
internal_compressed_tuple::ShouldAnyUseBase<Ts...>()> {
private:
template <int I>
using ElemT = internal_compressed_tuple::ElemT<CompressedTuple, I>;
template <int I>
using StorageT = internal_compressed_tuple::Storage<ElemT<I>, I>;
public:
// There seems to be a bug in MSVC dealing in which using '=default' here will
// cause the compiler to ignore the body of other constructors. The work-
// around is to explicitly implement the default constructor.
#if defined(_MSC_VER)
constexpr CompressedTuple() : CompressedTuple::CompressedTupleImpl() {}
#else
constexpr CompressedTuple() = default;
#endif
explicit constexpr CompressedTuple(const Ts&... base)
: CompressedTuple::CompressedTupleImpl(absl::in_place, base...) {}
template <typename... Vs,
absl::enable_if_t<
absl::conjunction<
// Ensure we are not hiding default copy/move constructors.
absl::negation<std::is_same<void(CompressedTuple),
void(absl::decay_t<Vs>...)>>,
internal_compressed_tuple::TupleMoveConstructible<
Ts, Vs&&>...>::value,
bool> = true>
explicit constexpr CompressedTuple(Vs&&... base)
: CompressedTuple::CompressedTupleImpl(absl::in_place,
absl::forward<Vs>(base)...) {}
template <int I>
ElemT<I>& get() & {
return internal_compressed_tuple::Storage<ElemT<I>, I>::get();
}
template <int I>
constexpr const ElemT<I>& get() const& {
return StorageT<I>::get();
}
template <int I>
ElemT<I>&& get() && {
return std::move(*this).StorageT<I>::get();
}
template <int I>
constexpr const ElemT<I>&& get() const&& {
return absl::move(*this).StorageT<I>::get();
}
};
// Explicit specialization for a zero-element tuple
// (needed to avoid ambiguous overloads for the default constructor).
template <>
class ABSL_INTERNAL_COMPRESSED_TUPLE_DECLSPEC CompressedTuple<> {};
} // namespace container_internal
ABSL_NAMESPACE_END
} // namespace absl
#undef ABSL_INTERNAL_COMPRESSED_TUPLE_DECLSPEC
#endif // ABSL_CONTAINER_INTERNAL_COMPRESSED_TUPLE_H_
Pods/abseil/absl/container/internal/container_memory.h
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// Copyright 2018 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef ABSL_CONTAINER_INTERNAL_CONTAINER_MEMORY_H_
#define ABSL_CONTAINER_INTERNAL_CONTAINER_MEMORY_H_
#ifdef ADDRESS_SANITIZER
#include <sanitizer/asan_interface.h>
#endif
#ifdef MEMORY_SANITIZER
#include <sanitizer/msan_interface.h>
#endif
#include <cassert>
#include <cstddef>
#include <memory>
#include <tuple>
#include <type_traits>
#include <utility>
#include "absl/memory/memory.h"
#include "absl/utility/utility.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace container_internal {
// Allocates at least n bytes aligned to the specified alignment.
// Alignment must be a power of 2. It must be positive.
//
// Note that many allocators don't honor alignment requirements above certain
// threshold (usually either alignof(std::max_align_t) or alignof(void*)).
// Allocate() doesn't apply alignment corrections. If the underlying allocator
// returns insufficiently alignment pointer, that's what you are going to get.
template <size_t Alignment, class Alloc>
void* Allocate(Alloc* alloc, size_t n) {
static_assert(Alignment > 0, "");
assert(n && "n must be positive");
struct alignas(Alignment) M {};
using A = typename absl::allocator_traits<Alloc>::template rebind_alloc<M>;
using AT = typename absl::allocator_traits<Alloc>::template rebind_traits<M>;
A mem_alloc(*alloc);
void* p = AT::allocate(mem_alloc, (n + sizeof(M) - 1) / sizeof(M));
assert(reinterpret_cast<uintptr_t>(p) % Alignment == 0 &&
"allocator does not respect alignment");
return p;
}
// The pointer must have been previously obtained by calling
// Allocate<Alignment>(alloc, n).
template <size_t Alignment, class Alloc>
void Deallocate(Alloc* alloc, void* p, size_t n) {
static_assert(Alignment > 0, "");
assert(n && "n must be positive");
struct alignas(Alignment) M {};
using A = typename absl::allocator_traits<Alloc>::template rebind_alloc<M>;
using AT = typename absl::allocator_traits<Alloc>::template rebind_traits<M>;
A mem_alloc(*alloc);
AT::deallocate(mem_alloc, static_cast<M*>(p),
(n + sizeof(M) - 1) / sizeof(M));
}
namespace memory_internal {
// Constructs T into uninitialized storage pointed by `ptr` using the args
// specified in the tuple.
template <class Alloc, class T, class Tuple, size_t... I>
void ConstructFromTupleImpl(Alloc* alloc, T* ptr, Tuple&& t,
absl::index_sequence<I...>) {
absl::allocator_traits<Alloc>::construct(
*alloc, ptr, std::get<I>(std::forward<Tuple>(t))...);
}
template <class T, class F>
struct WithConstructedImplF {
template <class... Args>
decltype(std::declval<F>()(std::declval<T>())) operator()(
Args&&... args) const {
return std::forward<F>(f)(T(std::forward<Args>(args)...));
}
F&& f;
};
template <class T, class Tuple, size_t... Is, class F>
decltype(std::declval<F>()(std::declval<T>())) WithConstructedImpl(
Tuple&& t, absl::index_sequence<Is...>, F&& f) {
return WithConstructedImplF<T, F>{std::forward<F>(f)}(
std::get<Is>(std::forward<Tuple>(t))...);
}
template <class T, size_t... Is>
auto TupleRefImpl(T&& t, absl::index_sequence<Is...>)
-> decltype(std::forward_as_tuple(std::get<Is>(std::forward<T>(t))...)) {
return std::forward_as_tuple(std::get<Is>(std::forward<T>(t))...);
}
// Returns a tuple of references to the elements of the input tuple. T must be a
// tuple.
template <class T>
auto TupleRef(T&& t) -> decltype(
TupleRefImpl(std::forward<T>(t),
absl::make_index_sequence<
std::tuple_size<typename std::decay<T>::type>::value>())) {
return TupleRefImpl(
std::forward<T>(t),
absl::make_index_sequence<
std::tuple_size<typename std::decay<T>::type>::value>());
}
template <class F, class K, class V>
decltype(std::declval<F>()(std::declval<const K&>(), std::piecewise_construct,
std::declval<std::tuple<K>>(), std::declval<V>()))
DecomposePairImpl(F&& f, std::pair<std::tuple<K>, V> p) {
const auto& key = std::get<0>(p.first);
return std::forward<F>(f)(key, std::piecewise_construct, std::move(p.first),
std::move(p.second));
}
} // namespace memory_internal
// Constructs T into uninitialized storage pointed by `ptr` using the args
// specified in the tuple.
template <class Alloc, class T, class Tuple>
void ConstructFromTuple(Alloc* alloc, T* ptr, Tuple&& t) {
memory_internal::ConstructFromTupleImpl(
alloc, ptr, std::forward<Tuple>(t),
absl::make_index_sequence<
std::tuple_size<typename std::decay<Tuple>::type>::value>());
}
// Constructs T using the args specified in the tuple and calls F with the
// constructed value.
template <class T, class Tuple, class F>
decltype(std::declval<F>()(std::declval<T>())) WithConstructed(
Tuple&& t, F&& f) {
return memory_internal::WithConstructedImpl<T>(
std::forward<Tuple>(t),
absl::make_index_sequence<
std::tuple_size<typename std::decay<Tuple>::type>::value>(),
std::forward<F>(f));
}
// Given arguments of an std::pair's consructor, PairArgs() returns a pair of
// tuples with references to the passed arguments. The tuples contain
// constructor arguments for the first and the second elements of the pair.
//
// The following two snippets are equivalent.
//
// 1. std::pair<F, S> p(args...);
//
// 2. auto a = PairArgs(args...);
// std::pair<F, S> p(std::piecewise_construct,
// std::move(p.first), std::move(p.second));
inline std::pair<std::tuple<>, std::tuple<>> PairArgs() { return {}; }
template <class F, class S>
std::pair<std::tuple<F&&>, std::tuple<S&&>> PairArgs(F&& f, S&& s) {
return {std::piecewise_construct, std::forward_as_tuple(std::forward<F>(f)),
std::forward_as_tuple(std::forward<S>(s))};
}
template <class F, class S>
std::pair<std::tuple<const F&>, std::tuple<const S&>> PairArgs(
const std::pair<F, S>& p) {
return PairArgs(p.first, p.second);
}
template <class F, class S>
std::pair<std::tuple<F&&>, std::tuple<S&&>> PairArgs(std::pair<F, S>&& p) {
return PairArgs(std::forward<F>(p.first), std::forward<S>(p.second));
}
template <class F, class S>
auto PairArgs(std::piecewise_construct_t, F&& f, S&& s)
-> decltype(std::make_pair(memory_internal::TupleRef(std::forward<F>(f)),
memory_internal::TupleRef(std::forward<S>(s)))) {
return std::make_pair(memory_internal::TupleRef(std::forward<F>(f)),
memory_internal::TupleRef(std::forward<S>(s)));
}
// A helper function for implementing apply() in map policies.
template <class F, class... Args>
auto DecomposePair(F&& f, Args&&... args)
-> decltype(memory_internal::DecomposePairImpl(
std::forward<F>(f), PairArgs(std::forward<Args>(args)...))) {
return memory_internal::DecomposePairImpl(
std::forward<F>(f), PairArgs(std::forward<Args>(args)...));
}
// A helper function for implementing apply() in set policies.
template <class F, class Arg>
decltype(std::declval<F>()(std::declval<const Arg&>(), std::declval<Arg>()))
DecomposeValue(F&& f, Arg&& arg) {
const auto& key = arg;
return std::forward<F>(f)(key, std::forward<Arg>(arg));
}
// Helper functions for asan and msan.
inline void SanitizerPoisonMemoryRegion(const void* m, size_t s) {
#ifdef ADDRESS_SANITIZER
ASAN_POISON_MEMORY_REGION(m, s);
#endif
#ifdef MEMORY_SANITIZER
__msan_poison(m, s);
#endif
(void)m;
(void)s;
}
inline void SanitizerUnpoisonMemoryRegion(const void* m, size_t s) {
#ifdef ADDRESS_SANITIZER
ASAN_UNPOISON_MEMORY_REGION(m, s);
#endif
#ifdef MEMORY_SANITIZER
__msan_unpoison(m, s);
#endif
(void)m;
(void)s;
}
template <typename T>
inline void SanitizerPoisonObject(const T* object) {
SanitizerPoisonMemoryRegion(object, sizeof(T));
}
template <typename T>
inline void SanitizerUnpoisonObject(const T* object) {
SanitizerUnpoisonMemoryRegion(object, sizeof(T));
}
namespace memory_internal {
// If Pair is a standard-layout type, OffsetOf<Pair>::kFirst and
// OffsetOf<Pair>::kSecond are equivalent to offsetof(Pair, first) and
// offsetof(Pair, second) respectively. Otherwise they are -1.
//
// The purpose of OffsetOf is to avoid calling offsetof() on non-standard-layout
// type, which is non-portable.
template <class Pair, class = std::true_type>
struct OffsetOf {
static constexpr size_t kFirst = -1;
static constexpr size_t kSecond = -1;
};
template <class Pair>
struct OffsetOf<Pair, typename std::is_standard_layout<Pair>::type> {
static constexpr size_t kFirst = offsetof(Pair, first);
static constexpr size_t kSecond = offsetof(Pair, second);
};
template <class K, class V>
struct IsLayoutCompatible {
private:
struct Pair {
K first;
V second;
};
// Is P layout-compatible with Pair?
template <class P>
static constexpr bool LayoutCompatible() {
return std::is_standard_layout<P>() && sizeof(P) == sizeof(Pair) &&
alignof(P) == alignof(Pair) &&
memory_internal::OffsetOf<P>::kFirst ==
memory_internal::OffsetOf<Pair>::kFirst &&
memory_internal::OffsetOf<P>::kSecond ==
memory_internal::OffsetOf<Pair>::kSecond;
}
public:
// Whether pair<const K, V> and pair<K, V> are layout-compatible. If they are,
// then it is safe to store them in a union and read from either.
static constexpr bool value = std::is_standard_layout<K>() &&
std::is_standard_layout<Pair>() &&
memory_internal::OffsetOf<Pair>::kFirst == 0 &&
LayoutCompatible<std::pair<K, V>>() &&
LayoutCompatible<std::pair<const K, V>>();
};
} // namespace memory_internal
// The internal storage type for key-value containers like flat_hash_map.
//
// It is convenient for the value_type of a flat_hash_map<K, V> to be
// pair<const K, V>; the "const K" prevents accidental modification of the key
// when dealing with the reference returned from find() and similar methods.
// However, this creates other problems; we want to be able to emplace(K, V)
// efficiently with move operations, and similarly be able to move a
// pair<K, V> in insert().
//
// The solution is this union, which aliases the const and non-const versions
// of the pair. This also allows flat_hash_map<const K, V> to work, even though
// that has the same efficiency issues with move in emplace() and insert() -
// but people do it anyway.
//
// If kMutableKeys is false, only the value member can be accessed.
//
// If kMutableKeys is true, key can be accessed through all slots while value
// and mutable_value must be accessed only via INITIALIZED slots. Slots are
// created and destroyed via mutable_value so that the key can be moved later.
//
// Accessing one of the union fields while the other is active is safe as
// long as they are layout-compatible, which is guaranteed by the definition of
// kMutableKeys. For C++11, the relevant section of the standard is
// https://timsong-cpp.github.io/cppwp/n3337/class.mem#19 (9.2.19)
template <class K, class V>
union map_slot_type {
map_slot_type() {}
~map_slot_type() = delete;
using value_type = std::pair<const K, V>;
using mutable_value_type = std::pair<K, V>;
value_type value;
mutable_value_type mutable_value;
K key;
};
template <class K, class V>
struct map_slot_policy {
using slot_type = map_slot_type<K, V>;
using value_type = std::pair<const K, V>;
using mutable_value_type = std::pair<K, V>;
private:
static void emplace(slot_type* slot) {
// The construction of union doesn't do anything at runtime but it allows us
// to access its members without violating aliasing rules.
new (slot) slot_type;
}
// If pair<const K, V> and pair<K, V> are layout-compatible, we can accept one
// or the other via slot_type. We are also free to access the key via
// slot_type::key in this case.
using kMutableKeys = memory_internal::IsLayoutCompatible<K, V>;
public:
static value_type& element(slot_type* slot) { return slot->value; }
static const value_type& element(const slot_type* slot) {
return slot->value;
}
static const K& key(const slot_type* slot) {
return kMutableKeys::value ? slot->key : slot->value.first;
}
template <class Allocator, class... Args>
static void construct(Allocator* alloc, slot_type* slot, Args&&... args) {
emplace(slot);
if (kMutableKeys::value) {
absl::allocator_traits<Allocator>::construct(*alloc, &slot->mutable_value,
std::forward<Args>(args)...);
} else {
absl::allocator_traits<Allocator>::construct(*alloc, &slot->value,
std::forward<Args>(args)...);
}
}
// Construct this slot by moving from another slot.
template <class Allocator>
static void construct(Allocator* alloc, slot_type* slot, slot_type* other) {
emplace(slot);
if (kMutableKeys::value) {
absl::allocator_traits<Allocator>::construct(
*alloc, &slot->mutable_value, std::move(other->mutable_value));
} else {
absl::allocator_traits<Allocator>::construct(*alloc, &slot->value,
std::move(other->value));
}
}
template <class Allocator>
static void destroy(Allocator* alloc, slot_type* slot) {
if (kMutableKeys::value) {
absl::allocator_traits<Allocator>::destroy(*alloc, &slot->mutable_value);
} else {
absl::allocator_traits<Allocator>::destroy(*alloc, &slot->value);
}
}
template <class Allocator>
static void transfer(Allocator* alloc, slot_type* new_slot,
slot_type* old_slot) {
emplace(new_slot);
if (kMutableKeys::value) {
absl::allocator_traits<Allocator>::construct(
*alloc, &new_slot->mutable_value, std::move(old_slot->mutable_value));
} else {
absl::allocator_traits<Allocator>::construct(*alloc, &new_slot->value,
std::move(old_slot->value));
}
destroy(alloc, old_slot);
}
template <class Allocator>
static void swap(Allocator* alloc, slot_type* a, slot_type* b) {
if (kMutableKeys::value) {
using std::swap;
swap(a->mutable_value, b->mutable_value);
} else {
value_type tmp = std::move(a->value);
absl::allocator_traits<Allocator>::destroy(*alloc, &a->value);
absl::allocator_traits<Allocator>::construct(*alloc, &a->value,
std::move(b->value));
absl::allocator_traits<Allocator>::destroy(*alloc, &b->value);
absl::allocator_traits<Allocator>::construct(*alloc, &b->value,
std::move(tmp));
}
}
template <class Allocator>
static void move(Allocator* alloc, slot_type* src, slot_type* dest) {
if (kMutableKeys::value) {
dest->mutable_value = std::move(src->mutable_value);
} else {
absl::allocator_traits<Allocator>::destroy(*alloc, &dest->value);
absl::allocator_traits<Allocator>::construct(*alloc, &dest->value,
std::move(src->value));
}
}
template <class Allocator>
static void move(Allocator* alloc, slot_type* first, slot_type* last,
slot_type* result) {
for (slot_type *src = first, *dest = result; src != last; ++src, ++dest)
move(alloc, src, dest);
}
};
} // namespace container_internal
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_CONTAINER_INTERNAL_CONTAINER_MEMORY_H_
Pods/abseil/absl/container/internal/hash_function_defaults.h
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// Copyright 2018 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Define the default Hash and Eq functions for SwissTable containers.
//
// std::hash<T> and std::equal_to<T> are not appropriate hash and equal
// functions for SwissTable containers. There are two reasons for this.
//
// SwissTable containers are power of 2 sized containers:
//
// This means they use the lower bits of the hash value to find the slot for
// each entry. The typical hash function for integral types is the identity.
// This is a very weak hash function for SwissTable and any power of 2 sized
// hashtable implementation which will lead to excessive collisions. For
// SwissTable we use murmur3 style mixing to reduce collisions to a minimum.
//
// SwissTable containers support heterogeneous lookup:
//
// In order to make heterogeneous lookup work, hash and equal functions must be
// polymorphic. At the same time they have to satisfy the same requirements the
// C++ standard imposes on hash functions and equality operators. That is:
//
// if hash_default_eq<T>(a, b) returns true for any a and b of type T, then
// hash_default_hash<T>(a) must equal hash_default_hash<T>(b)
//
// For SwissTable containers this requirement is relaxed to allow a and b of
// any and possibly different types. Note that like the standard the hash and
// equal functions are still bound to T. This is important because some type U
// can be hashed by/tested for equality differently depending on T. A notable
// example is `const char*`. `const char*` is treated as a c-style string when
// the hash function is hash<std::string> but as a pointer when the hash
// function is hash<void*>.
//
#ifndef ABSL_CONTAINER_INTERNAL_HASH_FUNCTION_DEFAULTS_H_
#define ABSL_CONTAINER_INTERNAL_HASH_FUNCTION_DEFAULTS_H_
#include <stdint.h>
#include <cstddef>
#include <memory>
#include <string>
#include <type_traits>
#include "absl/base/config.h"
#include "absl/hash/hash.h"
#include "absl/strings/string_view.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace container_internal {
// The hash of an object of type T is computed by using absl::Hash.
template <class T, class E = void>
struct HashEq {
using Hash = absl::Hash<T>;
using Eq = std::equal_to<T>;
};
struct StringHash {
using is_transparent = void;
size_t operator()(absl::string_view v) const {
return absl::Hash<absl::string_view>{}(v);
}
};
// Supports heterogeneous lookup for string-like elements.
struct StringHashEq {
using Hash = StringHash;
struct Eq {
using is_transparent = void;
bool operator()(absl::string_view lhs, absl::string_view rhs) const {
return lhs == rhs;
}
};
};
template <>
struct HashEq<std::string> : StringHashEq {};
template <>
struct HashEq<absl::string_view> : StringHashEq {};
// Supports heterogeneous lookup for pointers and smart pointers.
template <class T>
struct HashEq<T*> {
struct Hash {
using is_transparent = void;
template <class U>
size_t operator()(const U& ptr) const {
return absl::Hash<const T*>{}(HashEq::ToPtr(ptr));
}
};
struct Eq {
using is_transparent = void;
template <class A, class B>
bool operator()(const A& a, const B& b) const {
return HashEq::ToPtr(a) == HashEq::ToPtr(b);
}
};
private:
static const T* ToPtr(const T* ptr) { return ptr; }
template <class U, class D>
static const T* ToPtr(const std::unique_ptr<U, D>& ptr) {
return ptr.get();
}
template <class U>
static const T* ToPtr(const std::shared_ptr<U>& ptr) {
return ptr.get();
}
};
template <class T, class D>
struct HashEq<std::unique_ptr<T, D>> : HashEq<T*> {};
template <class T>
struct HashEq<std::shared_ptr<T>> : HashEq<T*> {};
// This header's visibility is restricted. If you need to access the default
// hasher please use the container's ::hasher alias instead.
//
// Example: typename Hash = typename absl::flat_hash_map<K, V>::hasher
template <class T>
using hash_default_hash = typename container_internal::HashEq<T>::Hash;
// This header's visibility is restricted. If you need to access the default
// key equal please use the container's ::key_equal alias instead.
//
// Example: typename Eq = typename absl::flat_hash_map<K, V, Hash>::key_equal
template <class T>
using hash_default_eq = typename container_internal::HashEq<T>::Eq;
} // namespace container_internal
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_CONTAINER_INTERNAL_HASH_FUNCTION_DEFAULTS_H_
Pods/abseil/absl/container/internal/hash_policy_traits.h
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// Copyright 2018 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef ABSL_CONTAINER_INTERNAL_HASH_POLICY_TRAITS_H_
#define ABSL_CONTAINER_INTERNAL_HASH_POLICY_TRAITS_H_
#include <cstddef>
#include <memory>
#include <type_traits>
#include <utility>
#include "absl/meta/type_traits.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace container_internal {
// Defines how slots are initialized/destroyed/moved.
template <class Policy, class = void>
struct hash_policy_traits {
private:
struct ReturnKey {
// We return `Key` here.
// When Key=T&, we forward the lvalue reference.
// When Key=T, we return by value to avoid a dangling reference.
// eg, for string_hash_map.
template <class Key, class... Args>
Key operator()(Key&& k, const Args&...) const {
return std::forward<Key>(k);
}
};
template <class P = Policy, class = void>
struct ConstantIteratorsImpl : std::false_type {};
template <class P>
struct ConstantIteratorsImpl<P, absl::void_t<typename P::constant_iterators>>
: P::constant_iterators {};
public:
// The actual object stored in the hash table.
using slot_type = typename Policy::slot_type;
// The type of the keys stored in the hashtable.
using key_type = typename Policy::key_type;
// The argument type for insertions into the hashtable. This is different
// from value_type for increased performance. See initializer_list constructor
// and insert() member functions for more details.
using init_type = typename Policy::init_type;
using reference = decltype(Policy::element(std::declval<slot_type*>()));
using pointer = typename std::remove_reference<reference>::type*;
using value_type = typename std::remove_reference<reference>::type;
// Policies can set this variable to tell raw_hash_set that all iterators
// should be constant, even `iterator`. This is useful for set-like
// containers.
// Defaults to false if not provided by the policy.
using constant_iterators = ConstantIteratorsImpl<>;
// PRECONDITION: `slot` is UNINITIALIZED
// POSTCONDITION: `slot` is INITIALIZED
template <class Alloc, class... Args>
static void construct(Alloc* alloc, slot_type* slot, Args&&... args) {
Policy::construct(alloc, slot, std::forward<Args>(args)...);
}
// PRECONDITION: `slot` is INITIALIZED
// POSTCONDITION: `slot` is UNINITIALIZED
template <class Alloc>
static void destroy(Alloc* alloc, slot_type* slot) {
Policy::destroy(alloc, slot);
}
// Transfers the `old_slot` to `new_slot`. Any memory allocated by the
// allocator inside `old_slot` to `new_slot` can be transferred.
//
// OPTIONAL: defaults to:
//
// clone(new_slot, std::move(*old_slot));
// destroy(old_slot);
//
// PRECONDITION: `new_slot` is UNINITIALIZED and `old_slot` is INITIALIZED
// POSTCONDITION: `new_slot` is INITIALIZED and `old_slot` is
// UNINITIALIZED
template <class Alloc>
static void transfer(Alloc* alloc, slot_type* new_slot, slot_type* old_slot) {
transfer_impl(alloc, new_slot, old_slot, 0);
}
// PRECONDITION: `slot` is INITIALIZED
// POSTCONDITION: `slot` is INITIALIZED
template <class P = Policy>
static auto element(slot_type* slot) -> decltype(P::element(slot)) {
return P::element(slot);
}
// Returns the amount of memory owned by `slot`, exclusive of `sizeof(*slot)`.
//
// If `slot` is nullptr, returns the constant amount of memory owned by any
// full slot or -1 if slots own variable amounts of memory.
//
// PRECONDITION: `slot` is INITIALIZED or nullptr
template <class P = Policy>
static size_t space_used(const slot_type* slot) {
return P::space_used(slot);
}
// Provides generalized access to the key for elements, both for elements in
// the table and for elements that have not yet been inserted (or even
// constructed). We would like an API that allows us to say: `key(args...)`
// but we cannot do that for all cases, so we use this more general API that
// can be used for many things, including the following:
//
// - Given an element in a table, get its key.
// - Given an element initializer, get its key.
// - Given `emplace()` arguments, get the element key.
//
// Implementations of this must adhere to a very strict technical
// specification around aliasing and consuming arguments:
//
// Let `value_type` be the result type of `element()` without ref- and
// cv-qualifiers. The first argument is a functor, the rest are constructor
// arguments for `value_type`. Returns `std::forward<F>(f)(k, xs...)`, where
// `k` is the element key, and `xs...` are the new constructor arguments for
// `value_type`. It's allowed for `k` to alias `xs...`, and for both to alias
// `ts...`. The key won't be touched once `xs...` are used to construct an
// element; `ts...` won't be touched at all, which allows `apply()` to consume
// any rvalues among them.
//
// If `value_type` is constructible from `Ts&&...`, `Policy::apply()` must not
// trigger a hard compile error unless it originates from `f`. In other words,
// `Policy::apply()` must be SFINAE-friendly. If `value_type` is not
// constructible from `Ts&&...`, either SFINAE or a hard compile error is OK.
//
// If `Ts...` is `[cv] value_type[&]` or `[cv] init_type[&]`,
// `Policy::apply()` must work. A compile error is not allowed, SFINAE or not.
template <class F, class... Ts, class P = Policy>
static auto apply(F&& f, Ts&&... ts)
-> decltype(P::apply(std::forward<F>(f), std::forward<Ts>(ts)...)) {
return P::apply(std::forward<F>(f), std::forward<Ts>(ts)...);
}
// Returns the "key" portion of the slot.
// Used for node handle manipulation.
template <class P = Policy>
static auto key(slot_type* slot)
-> decltype(P::apply(ReturnKey(), element(slot))) {
return P::apply(ReturnKey(), element(slot));
}
// Returns the "value" (as opposed to the "key") portion of the element. Used
// by maps to implement `operator[]`, `at()` and `insert_or_assign()`.
template <class T, class P = Policy>
static auto value(T* elem) -> decltype(P::value(elem)) {
return P::value(elem);
}
private:
// Use auto -> decltype as an enabler.
template <class Alloc, class P = Policy>
static auto transfer_impl(Alloc* alloc, slot_type* new_slot,
slot_type* old_slot, int)
-> decltype((void)P::transfer(alloc, new_slot, old_slot)) {
P::transfer(alloc, new_slot, old_slot);
}
template <class Alloc>
static void transfer_impl(Alloc* alloc, slot_type* new_slot,
slot_type* old_slot, char) {
construct(alloc, new_slot, std::move(element(old_slot)));
destroy(alloc, old_slot);
}
};
} // namespace container_internal
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_CONTAINER_INTERNAL_HASH_POLICY_TRAITS_H_
Pods/abseil/absl/container/internal/hashtable_debug_hooks.h
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// Copyright 2018 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Provides the internal API for hashtable_debug.h.
#ifndef ABSL_CONTAINER_INTERNAL_HASHTABLE_DEBUG_HOOKS_H_
#define ABSL_CONTAINER_INTERNAL_HASHTABLE_DEBUG_HOOKS_H_
#include <cstddef>
#include <algorithm>
#include <type_traits>
#include <vector>
#include "absl/base/config.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace container_internal {
namespace hashtable_debug_internal {
// If it is a map, call get<0>().
using std::get;
template <typename T, typename = typename T::mapped_type>
auto GetKey(const typename T::value_type& pair, int) -> decltype(get<0>(pair)) {
return get<0>(pair);
}
// If it is not a map, return the value directly.
template <typename T>
const typename T::key_type& GetKey(const typename T::key_type& key, char) {
return key;
}
// Containers should specialize this to provide debug information for that
// container.
template <class Container, typename Enabler = void>
struct HashtableDebugAccess {
// Returns the number of probes required to find `key` in `c`. The "number of
// probes" is a concept that can vary by container. Implementations should
// return 0 when `key` was found in the minimum number of operations and
// should increment the result for each non-trivial operation required to find
// `key`.
//
// The default implementation uses the bucket api from the standard and thus
// works for `std::unordered_*` containers.
static size_t GetNumProbes(const Container& c,
const typename Container::key_type& key) {
if (!c.bucket_count()) return {};
size_t num_probes = 0;
size_t bucket = c.bucket(key);
for (auto it = c.begin(bucket), e = c.end(bucket);; ++it, ++num_probes) {
if (it == e) return num_probes;
if (c.key_eq()(key, GetKey<Container>(*it, 0))) return num_probes;
}
}
// Returns the number of bytes requested from the allocator by the container
// and not freed.
//
// static size_t AllocatedByteSize(const Container& c);
// Returns a tight lower bound for AllocatedByteSize(c) where `c` is of type
// `Container` and `c.size()` is equal to `num_elements`.
//
// static size_t LowerBoundAllocatedByteSize(size_t num_elements);
};
} // namespace hashtable_debug_internal
} // namespace container_internal
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_CONTAINER_INTERNAL_HASHTABLE_DEBUG_HOOKS_H_
Pods/abseil/absl/container/internal/hashtablez_sampler.cc
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// Copyright 2018 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "absl/container/internal/hashtablez_sampler.h"
#include <atomic>
#include <cassert>
#include <cmath>
#include <functional>
#include <limits>
#include "absl/base/attributes.h"
#include "absl/base/internal/exponential_biased.h"
#include "absl/container/internal/have_sse.h"
#include "absl/debugging/stacktrace.h"
#include "absl/memory/memory.h"
#include "absl/synchronization/mutex.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace container_internal {
constexpr int HashtablezInfo::kMaxStackDepth;
namespace {
ABSL_CONST_INIT std::atomic<bool> g_hashtablez_enabled{
false
};
ABSL_CONST_INIT std::atomic<int32_t> g_hashtablez_sample_parameter{1 << 10};
ABSL_CONST_INIT std::atomic<int32_t> g_hashtablez_max_samples{1 << 20};
#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
ABSL_PER_THREAD_TLS_KEYWORD absl::base_internal::ExponentialBiased
g_exponential_biased_generator;
#endif
} // namespace
#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
ABSL_PER_THREAD_TLS_KEYWORD int64_t global_next_sample = 0;
#endif // defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
HashtablezSampler& HashtablezSampler::Global() {
static auto* sampler = new HashtablezSampler();
return *sampler;
}
HashtablezSampler::DisposeCallback HashtablezSampler::SetDisposeCallback(
DisposeCallback f) {
return dispose_.exchange(f, std::memory_order_relaxed);
}
HashtablezInfo::HashtablezInfo() { PrepareForSampling(); }
HashtablezInfo::~HashtablezInfo() = default;
void HashtablezInfo::PrepareForSampling() {
capacity.store(0, std::memory_order_relaxed);
size.store(0, std::memory_order_relaxed);
num_erases.store(0, std::memory_order_relaxed);
max_probe_length.store(0, std::memory_order_relaxed);
total_probe_length.store(0, std::memory_order_relaxed);
hashes_bitwise_or.store(0, std::memory_order_relaxed);
hashes_bitwise_and.store(~size_t{}, std::memory_order_relaxed);
create_time = absl::Now();
// The inliner makes hardcoded skip_count difficult (especially when combined
// with LTO). We use the ability to exclude stacks by regex when encoding
// instead.
depth = absl::GetStackTrace(stack, HashtablezInfo::kMaxStackDepth,
/* skip_count= */ 0);
dead = nullptr;
}
HashtablezSampler::HashtablezSampler()
: dropped_samples_(0), size_estimate_(0), all_(nullptr), dispose_(nullptr) {
absl::MutexLock l(&graveyard_.init_mu);
graveyard_.dead = &graveyard_;
}
HashtablezSampler::~HashtablezSampler() {
HashtablezInfo* s = all_.load(std::memory_order_acquire);
while (s != nullptr) {
HashtablezInfo* next = s->next;
delete s;
s = next;
}
}
void HashtablezSampler::PushNew(HashtablezInfo* sample) {
sample->next = all_.load(std::memory_order_relaxed);
while (!all_.compare_exchange_weak(sample->next, sample,
std::memory_order_release,
std::memory_order_relaxed)) {
}
}
void HashtablezSampler::PushDead(HashtablezInfo* sample) {
if (auto* dispose = dispose_.load(std::memory_order_relaxed)) {
dispose(*sample);
}
absl::MutexLock graveyard_lock(&graveyard_.init_mu);
absl::MutexLock sample_lock(&sample->init_mu);
sample->dead = graveyard_.dead;
graveyard_.dead = sample;
}
HashtablezInfo* HashtablezSampler::PopDead() {
absl::MutexLock graveyard_lock(&graveyard_.init_mu);
// The list is circular, so eventually it collapses down to
// graveyard_.dead == &graveyard_
// when it is empty.
HashtablezInfo* sample = graveyard_.dead;
if (sample == &graveyard_) return nullptr;
absl::MutexLock sample_lock(&sample->init_mu);
graveyard_.dead = sample->dead;
sample->PrepareForSampling();
return sample;
}
HashtablezInfo* HashtablezSampler::Register() {
int64_t size = size_estimate_.fetch_add(1, std::memory_order_relaxed);
if (size > g_hashtablez_max_samples.load(std::memory_order_relaxed)) {
size_estimate_.fetch_sub(1, std::memory_order_relaxed);
dropped_samples_.fetch_add(1, std::memory_order_relaxed);
return nullptr;
}
HashtablezInfo* sample = PopDead();
if (sample == nullptr) {
// Resurrection failed. Hire a new warlock.
sample = new HashtablezInfo();
PushNew(sample);
}
return sample;
}
void HashtablezSampler::Unregister(HashtablezInfo* sample) {
PushDead(sample);
size_estimate_.fetch_sub(1, std::memory_order_relaxed);
}
int64_t HashtablezSampler::Iterate(
const std::function<void(const HashtablezInfo& stack)>& f) {
HashtablezInfo* s = all_.load(std::memory_order_acquire);
while (s != nullptr) {
absl::MutexLock l(&s->init_mu);
if (s->dead == nullptr) {
f(*s);
}
s = s->next;
}
return dropped_samples_.load(std::memory_order_relaxed);
}
static bool ShouldForceSampling() {
enum ForceState {
kDontForce,
kForce,
kUninitialized
};
ABSL_CONST_INIT static std::atomic<ForceState> global_state{
kUninitialized};
ForceState state = global_state.load(std::memory_order_relaxed);
if (ABSL_PREDICT_TRUE(state == kDontForce)) return false;
if (state == kUninitialized) {
state = AbslContainerInternalSampleEverything() ? kForce : kDontForce;
global_state.store(state, std::memory_order_relaxed);
}
return state == kForce;
}
HashtablezInfo* SampleSlow(int64_t* next_sample) {
if (ABSL_PREDICT_FALSE(ShouldForceSampling())) {
*next_sample = 1;
return HashtablezSampler::Global().Register();
}
#if !defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
*next_sample = std::numeric_limits<int64_t>::max();
return nullptr;
#else
bool first = *next_sample < 0;
*next_sample = g_exponential_biased_generator.GetStride(
g_hashtablez_sample_parameter.load(std::memory_order_relaxed));
// Small values of interval are equivalent to just sampling next time.
ABSL_ASSERT(*next_sample >= 1);
// g_hashtablez_enabled can be dynamically flipped, we need to set a threshold
// low enough that we will start sampling in a reasonable time, so we just use
// the default sampling rate.
if (!g_hashtablez_enabled.load(std::memory_order_relaxed)) return nullptr;
// We will only be negative on our first count, so we should just retry in
// that case.
if (first) {
if (ABSL_PREDICT_TRUE(--*next_sample > 0)) return nullptr;
return SampleSlow(next_sample);
}
return HashtablezSampler::Global().Register();
#endif
}
void UnsampleSlow(HashtablezInfo* info) {
HashtablezSampler::Global().Unregister(info);
}
void RecordInsertSlow(HashtablezInfo* info, size_t hash,
size_t distance_from_desired) {
// SwissTables probe in groups of 16, so scale this to count items probes and
// not offset from desired.
size_t probe_length = distance_from_desired;
#if SWISSTABLE_HAVE_SSE2
probe_length /= 16;
#else
probe_length /= 8;
#endif
info->hashes_bitwise_and.fetch_and(hash, std::memory_order_relaxed);
info->hashes_bitwise_or.fetch_or(hash, std::memory_order_relaxed);
info->max_probe_length.store(
std::max(info->max_probe_length.load(std::memory_order_relaxed),
probe_length),
std::memory_order_relaxed);
info->total_probe_length.fetch_add(probe_length, std::memory_order_relaxed);
info->size.fetch_add(1, std::memory_order_relaxed);
}
void SetHashtablezEnabled(bool enabled) {
g_hashtablez_enabled.store(enabled, std::memory_order_release);
}
void SetHashtablezSampleParameter(int32_t rate) {
if (rate > 0) {
g_hashtablez_sample_parameter.store(rate, std::memory_order_release);
} else {
ABSL_RAW_LOG(ERROR, "Invalid hashtablez sample rate: %lld",
static_cast<long long>(rate)); // NOLINT(runtime/int)
}
}
void SetHashtablezMaxSamples(int32_t max) {
if (max > 0) {
g_hashtablez_max_samples.store(max, std::memory_order_release);
} else {
ABSL_RAW_LOG(ERROR, "Invalid hashtablez max samples: %lld",
static_cast<long long>(max)); // NOLINT(runtime/int)
}
}
} // namespace container_internal
ABSL_NAMESPACE_END
} // namespace absl
Pods/abseil/absl/container/internal/hashtablez_sampler.h
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// Copyright 2018 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// -----------------------------------------------------------------------------
// File: hashtablez_sampler.h
// -----------------------------------------------------------------------------
//
// This header file defines the API for a low level library to sample hashtables
// and collect runtime statistics about them.
//
// `HashtablezSampler` controls the lifecycle of `HashtablezInfo` objects which
// store information about a single sample.
//
// `Record*` methods store information into samples.
// `Sample()` and `Unsample()` make use of a single global sampler with
// properties controlled by the flags hashtablez_enabled,
// hashtablez_sample_rate, and hashtablez_max_samples.
//
// WARNING
//
// Using this sampling API may cause sampled Swiss tables to use the global
// allocator (operator `new`) in addition to any custom allocator. If you
// are using a table in an unusual circumstance where allocation or calling a
// linux syscall is unacceptable, this could interfere.
//
// This utility is internal-only. Use at your own risk.
#ifndef ABSL_CONTAINER_INTERNAL_HASHTABLEZ_SAMPLER_H_
#define ABSL_CONTAINER_INTERNAL_HASHTABLEZ_SAMPLER_H_
#include <atomic>
#include <functional>
#include <memory>
#include <vector>
#include "absl/base/internal/per_thread_tls.h"
#include "absl/base/optimization.h"
#include "absl/container/internal/have_sse.h"
#include "absl/synchronization/mutex.h"
#include "absl/utility/utility.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace container_internal {
// Stores information about a sampled hashtable. All mutations to this *must*
// be made through `Record*` functions below. All reads from this *must* only
// occur in the callback to `HashtablezSampler::Iterate`.
struct HashtablezInfo {
// Constructs the object but does not fill in any fields.
HashtablezInfo();
~HashtablezInfo();
HashtablezInfo(const HashtablezInfo&) = delete;
HashtablezInfo& operator=(const HashtablezInfo&) = delete;
// Puts the object into a clean state, fills in the logically `const` members,
// blocking for any readers that are currently sampling the object.
void PrepareForSampling() ABSL_EXCLUSIVE_LOCKS_REQUIRED(init_mu);
// These fields are mutated by the various Record* APIs and need to be
// thread-safe.
std::atomic<size_t> capacity;
std::atomic<size_t> size;
std::atomic<size_t> num_erases;
std::atomic<size_t> max_probe_length;
std::atomic<size_t> total_probe_length;
std::atomic<size_t> hashes_bitwise_or;
std::atomic<size_t> hashes_bitwise_and;
// `HashtablezSampler` maintains intrusive linked lists for all samples. See
// comments on `HashtablezSampler::all_` for details on these. `init_mu`
// guards the ability to restore the sample to a pristine state. This
// prevents races with sampling and resurrecting an object.
absl::Mutex init_mu;
HashtablezInfo* next;
HashtablezInfo* dead ABSL_GUARDED_BY(init_mu);
// All of the fields below are set by `PrepareForSampling`, they must not be
// mutated in `Record*` functions. They are logically `const` in that sense.
// These are guarded by init_mu, but that is not externalized to clients, who
// can only read them during `HashtablezSampler::Iterate` which will hold the
// lock.
static constexpr int kMaxStackDepth = 64;
absl::Time create_time;
int32_t depth;
void* stack[kMaxStackDepth];
};
inline void RecordRehashSlow(HashtablezInfo* info, size_t total_probe_length) {
#if SWISSTABLE_HAVE_SSE2
total_probe_length /= 16;
#else
total_probe_length /= 8;
#endif
info->total_probe_length.store(total_probe_length, std::memory_order_relaxed);
info->num_erases.store(0, std::memory_order_relaxed);
}
inline void RecordStorageChangedSlow(HashtablezInfo* info, size_t size,
size_t capacity) {
info->size.store(size, std::memory_order_relaxed);
info->capacity.store(capacity, std::memory_order_relaxed);
if (size == 0) {
// This is a clear, reset the total/num_erases too.
RecordRehashSlow(info, 0);
}
}
void RecordInsertSlow(HashtablezInfo* info, size_t hash,
size_t distance_from_desired);
inline void RecordEraseSlow(HashtablezInfo* info) {
info->size.fetch_sub(1, std::memory_order_relaxed);
info->num_erases.fetch_add(1, std::memory_order_relaxed);
}
HashtablezInfo* SampleSlow(int64_t* next_sample);
void UnsampleSlow(HashtablezInfo* info);
class HashtablezInfoHandle {
public:
explicit HashtablezInfoHandle() : info_(nullptr) {}
explicit HashtablezInfoHandle(HashtablezInfo* info) : info_(info) {}
~HashtablezInfoHandle() {
if (ABSL_PREDICT_TRUE(info_ == nullptr)) return;
UnsampleSlow(info_);
}
HashtablezInfoHandle(const HashtablezInfoHandle&) = delete;
HashtablezInfoHandle& operator=(const HashtablezInfoHandle&) = delete;
HashtablezInfoHandle(HashtablezInfoHandle&& o) noexcept
: info_(absl::exchange(o.info_, nullptr)) {}
HashtablezInfoHandle& operator=(HashtablezInfoHandle&& o) noexcept {
if (ABSL_PREDICT_FALSE(info_ != nullptr)) {
UnsampleSlow(info_);
}
info_ = absl::exchange(o.info_, nullptr);
return *this;
}
inline void RecordStorageChanged(size_t size, size_t capacity) {
if (ABSL_PREDICT_TRUE(info_ == nullptr)) return;
RecordStorageChangedSlow(info_, size, capacity);
}
inline void RecordRehash(size_t total_probe_length) {
if (ABSL_PREDICT_TRUE(info_ == nullptr)) return;
RecordRehashSlow(info_, total_probe_length);
}
inline void RecordInsert(size_t hash, size_t distance_from_desired) {
if (ABSL_PREDICT_TRUE(info_ == nullptr)) return;
RecordInsertSlow(info_, hash, distance_from_desired);
}
inline void RecordErase() {
if (ABSL_PREDICT_TRUE(info_ == nullptr)) return;
RecordEraseSlow(info_);
}
friend inline void swap(HashtablezInfoHandle& lhs,
HashtablezInfoHandle& rhs) {
std::swap(lhs.info_, rhs.info_);
}
private:
friend class HashtablezInfoHandlePeer;
HashtablezInfo* info_;
};
#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
#error ABSL_INTERNAL_HASHTABLEZ_SAMPLE cannot be directly set
#endif // defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
#if (ABSL_PER_THREAD_TLS == 1) && !defined(ABSL_BUILD_DLL) && \
!defined(ABSL_CONSUME_DLL)
#define ABSL_INTERNAL_HASHTABLEZ_SAMPLE
#endif
#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
extern ABSL_PER_THREAD_TLS_KEYWORD int64_t global_next_sample;
#endif // ABSL_PER_THREAD_TLS
// Returns an RAII sampling handle that manages registration and unregistation
// with the global sampler.
inline HashtablezInfoHandle Sample() {
#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
if (ABSL_PREDICT_TRUE(--global_next_sample > 0)) {
return HashtablezInfoHandle(nullptr);
}
return HashtablezInfoHandle(SampleSlow(&global_next_sample));
#else
return HashtablezInfoHandle(nullptr);
#endif // !ABSL_PER_THREAD_TLS
}
// Holds samples and their associated stack traces with a soft limit of
// `SetHashtablezMaxSamples()`.
//
// Thread safe.
class HashtablezSampler {
public:
// Returns a global Sampler.
static HashtablezSampler& Global();
HashtablezSampler();
~HashtablezSampler();
// Registers for sampling. Returns an opaque registration info.
HashtablezInfo* Register();
// Unregisters the sample.
void Unregister(HashtablezInfo* sample);
// The dispose callback will be called on all samples the moment they are
// being unregistered. Only affects samples that are unregistered after the
// callback has been set.
// Returns the previous callback.
using DisposeCallback = void (*)(const HashtablezInfo&);
DisposeCallback SetDisposeCallback(DisposeCallback f);
// Iterates over all the registered `StackInfo`s. Returning the number of
// samples that have been dropped.
int64_t Iterate(const std::function<void(const HashtablezInfo& stack)>& f);
private:
void PushNew(HashtablezInfo* sample);
void PushDead(HashtablezInfo* sample);
HashtablezInfo* PopDead();
std::atomic<size_t> dropped_samples_;
std::atomic<size_t> size_estimate_;
// Intrusive lock free linked lists for tracking samples.
//
// `all_` records all samples (they are never removed from this list) and is
// terminated with a `nullptr`.
//
// `graveyard_.dead` is a circular linked list. When it is empty,
// `graveyard_.dead == &graveyard`. The list is circular so that
// every item on it (even the last) has a non-null dead pointer. This allows
// `Iterate` to determine if a given sample is live or dead using only
// information on the sample itself.
//
// For example, nodes [A, B, C, D, E] with [A, C, E] alive and [B, D] dead
// looks like this (G is the Graveyard):
//
// +---+ +---+ +---+ +---+ +---+
// all -->| A |--->| B |--->| C |--->| D |--->| E |
// | | | | | | | | | |
// +---+ | | +->| |-+ | | +->| |-+ | |
// | G | +---+ | +---+ | +---+ | +---+ | +---+
// | | | | | |
// | | --------+ +--------+ |
// +---+ |
// ^ |
// +--------------------------------------+
//
std::atomic<HashtablezInfo*> all_;
HashtablezInfo graveyard_;
std::atomic<DisposeCallback> dispose_;
};
// Enables or disables sampling for Swiss tables.
void SetHashtablezEnabled(bool enabled);
// Sets the rate at which Swiss tables will be sampled.
void SetHashtablezSampleParameter(int32_t rate);
// Sets a soft max for the number of samples that will be kept.
void SetHashtablezMaxSamples(int32_t max);
// Configuration override.
// This allows process-wide sampling without depending on order of
// initialization of static storage duration objects.
// The definition of this constant is weak, which allows us to inject a
// different value for it at link time.
extern "C" bool AbslContainerInternalSampleEverything();
} // namespace container_internal
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_CONTAINER_INTERNAL_HASHTABLEZ_SAMPLER_H_
Pods/abseil/absl/container/internal/hashtablez_sampler_force_weak_definition.cc
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// Copyright 2018 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "absl/container/internal/hashtablez_sampler.h"
#include "absl/base/attributes.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace container_internal {
// See hashtablez_sampler.h for details.
extern "C" ABSL_ATTRIBUTE_WEAK bool AbslContainerInternalSampleEverything() {
return false;
}
} // namespace container_internal
ABSL_NAMESPACE_END
} // namespace absl
Pods/abseil/absl/container/internal/have_sse.h
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// Copyright 2018 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Shared config probing for SSE instructions used in Swiss tables.
#ifndef ABSL_CONTAINER_INTERNAL_HAVE_SSE_H_
#define ABSL_CONTAINER_INTERNAL_HAVE_SSE_H_
#ifndef SWISSTABLE_HAVE_SSE2
#if defined(__SSE2__) || \
(defined(_MSC_VER) && \
(defined(_M_X64) || (defined(_M_IX86) && _M_IX86_FP >= 2)))
#define SWISSTABLE_HAVE_SSE2 1
#else
#define SWISSTABLE_HAVE_SSE2 0
#endif
#endif
#ifndef SWISSTABLE_HAVE_SSSE3
#ifdef __SSSE3__
#define SWISSTABLE_HAVE_SSSE3 1
#else
#define SWISSTABLE_HAVE_SSSE3 0
#endif
#endif
#if SWISSTABLE_HAVE_SSSE3 && !SWISSTABLE_HAVE_SSE2
#error "Bad configuration!"
#endif
#if SWISSTABLE_HAVE_SSE2
#include <emmintrin.h>
#endif
#if SWISSTABLE_HAVE_SSSE3
#include <tmmintrin.h>
#endif
#endif // ABSL_CONTAINER_INTERNAL_HAVE_SSE_H_
Pods/abseil/absl/container/internal/inlined_vector.h
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// Copyright 2019 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef ABSL_CONTAINER_INTERNAL_INLINED_VECTOR_INTERNAL_H_
#define ABSL_CONTAINER_INTERNAL_INLINED_VECTOR_INTERNAL_H_
#include <algorithm>
#include <cstddef>
#include <cstring>
#include <iterator>
#include <limits>
#include <memory>
#include <utility>
#include "absl/base/macros.h"
#include "absl/container/internal/compressed_tuple.h"
#include "absl/memory/memory.h"
#include "absl/meta/type_traits.h"
#include "absl/types/span.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace inlined_vector_internal {
template <typename Iterator>
using IsAtLeastForwardIterator = std::is_convertible<
typename std::iterator_traits<Iterator>::iterator_category,
std::forward_iterator_tag>;
template <typename AllocatorType,
typename ValueType =
typename absl::allocator_traits<AllocatorType>::value_type>
using IsMemcpyOk =
absl::conjunction<std::is_same<AllocatorType, std::allocator<ValueType>>,
absl::is_trivially_copy_constructible<ValueType>,
absl::is_trivially_copy_assignable<ValueType>,
absl::is_trivially_destructible<ValueType>>;
template <typename AllocatorType, typename Pointer, typename SizeType>
void DestroyElements(AllocatorType* alloc_ptr, Pointer destroy_first,
SizeType destroy_size) {
using AllocatorTraits = absl::allocator_traits<AllocatorType>;
if (destroy_first != nullptr) {
for (auto i = destroy_size; i != 0;) {
--i;
AllocatorTraits::destroy(*alloc_ptr, destroy_first + i);
}
#if !defined(NDEBUG)
{
using ValueType = typename AllocatorTraits::value_type;
// Overwrite unused memory with `0xab` so we can catch uninitialized
// usage.
//
// Cast to `void*` to tell the compiler that we don't care that we might
// be scribbling on a vtable pointer.
void* memory_ptr = destroy_first;
auto memory_size = destroy_size * sizeof(ValueType);
std::memset(memory_ptr, 0xab, memory_size);
}
#endif // !defined(NDEBUG)
}
}
template <typename AllocatorType, typename Pointer, typename ValueAdapter,
typename SizeType>
void ConstructElements(AllocatorType* alloc_ptr, Pointer construct_first,
ValueAdapter* values_ptr, SizeType construct_size) {
for (SizeType i = 0; i < construct_size; ++i) {
ABSL_INTERNAL_TRY {
values_ptr->ConstructNext(alloc_ptr, construct_first + i);
}
ABSL_INTERNAL_CATCH_ANY {
inlined_vector_internal::DestroyElements(alloc_ptr, construct_first, i);
ABSL_INTERNAL_RETHROW;
}
}
}
template <typename Pointer, typename ValueAdapter, typename SizeType>
void AssignElements(Pointer assign_first, ValueAdapter* values_ptr,
SizeType assign_size) {
for (SizeType i = 0; i < assign_size; ++i) {
values_ptr->AssignNext(assign_first + i);
}
}
template <typename AllocatorType>
struct StorageView {
using AllocatorTraits = absl::allocator_traits<AllocatorType>;
using Pointer = typename AllocatorTraits::pointer;
using SizeType = typename AllocatorTraits::size_type;
Pointer data;
SizeType size;
SizeType capacity;
};
template <typename AllocatorType, typename Iterator>
class IteratorValueAdapter {
using AllocatorTraits = absl::allocator_traits<AllocatorType>;
using Pointer = typename AllocatorTraits::pointer;
public:
explicit IteratorValueAdapter(const Iterator& it) : it_(it) {}
void ConstructNext(AllocatorType* alloc_ptr, Pointer construct_at) {
AllocatorTraits::construct(*alloc_ptr, construct_at, *it_);
++it_;
}
void AssignNext(Pointer assign_at) {
*assign_at = *it_;
++it_;
}
private:
Iterator it_;
};
template <typename AllocatorType>
class CopyValueAdapter {
using AllocatorTraits = absl::allocator_traits<AllocatorType>;
using ValueType = typename AllocatorTraits::value_type;
using Pointer = typename AllocatorTraits::pointer;
using ConstPointer = typename AllocatorTraits::const_pointer;
public:
explicit CopyValueAdapter(const ValueType& v) : ptr_(std::addressof(v)) {}
void ConstructNext(AllocatorType* alloc_ptr, Pointer construct_at) {
AllocatorTraits::construct(*alloc_ptr, construct_at, *ptr_);
}
void AssignNext(Pointer assign_at) { *assign_at = *ptr_; }
private:
ConstPointer ptr_;
};
template <typename AllocatorType>
class DefaultValueAdapter {
using AllocatorTraits = absl::allocator_traits<AllocatorType>;
using ValueType = typename AllocatorTraits::value_type;
using Pointer = typename AllocatorTraits::pointer;
public:
explicit DefaultValueAdapter() {}
void ConstructNext(AllocatorType* alloc_ptr, Pointer construct_at) {
AllocatorTraits::construct(*alloc_ptr, construct_at);
}
void AssignNext(Pointer assign_at) { *assign_at = ValueType(); }
};
template <typename AllocatorType>
class AllocationTransaction {
using AllocatorTraits = absl::allocator_traits<AllocatorType>;
using Pointer = typename AllocatorTraits::pointer;
using SizeType = typename AllocatorTraits::size_type;
public:
explicit AllocationTransaction(AllocatorType* alloc_ptr)
: alloc_data_(*alloc_ptr, nullptr) {}
~AllocationTransaction() {
if (DidAllocate()) {
AllocatorTraits::deallocate(GetAllocator(), GetData(), GetCapacity());
}
}
AllocationTransaction(const AllocationTransaction&) = delete;
void operator=(const AllocationTransaction&) = delete;
AllocatorType& GetAllocator() { return alloc_data_.template get<0>(); }
Pointer& GetData() { return alloc_data_.template get<1>(); }
SizeType& GetCapacity() { return capacity_; }
bool DidAllocate() { return GetData() != nullptr; }
Pointer Allocate(SizeType capacity) {
GetData() = AllocatorTraits::allocate(GetAllocator(), capacity);
GetCapacity() = capacity;
return GetData();
}
void Reset() {
GetData() = nullptr;
GetCapacity() = 0;
}
private:
container_internal::CompressedTuple<AllocatorType, Pointer> alloc_data_;
SizeType capacity_ = 0;
};
template <typename AllocatorType>
class ConstructionTransaction {
using AllocatorTraits = absl::allocator_traits<AllocatorType>;
using Pointer = typename AllocatorTraits::pointer;
using SizeType = typename AllocatorTraits::size_type;
public:
explicit ConstructionTransaction(AllocatorType* alloc_ptr)
: alloc_data_(*alloc_ptr, nullptr) {}
~ConstructionTransaction() {
if (DidConstruct()) {
inlined_vector_internal::DestroyElements(std::addressof(GetAllocator()),
GetData(), GetSize());
}
}
ConstructionTransaction(const ConstructionTransaction&) = delete;
void operator=(const ConstructionTransaction&) = delete;
AllocatorType& GetAllocator() { return alloc_data_.template get<0>(); }
Pointer& GetData() { return alloc_data_.template get<1>(); }
SizeType& GetSize() { return size_; }
bool DidConstruct() { return GetData() != nullptr; }
template <typename ValueAdapter>
void Construct(Pointer data, ValueAdapter* values_ptr, SizeType size) {
inlined_vector_internal::ConstructElements(std::addressof(GetAllocator()),
data, values_ptr, size);
GetData() = data;
GetSize() = size;
}
void Commit() {
GetData() = nullptr;
GetSize() = 0;
}
private:
container_internal::CompressedTuple<AllocatorType, Pointer> alloc_data_;
SizeType size_ = 0;
};
template <typename T, size_t N, typename A>
class Storage {
public:
using AllocatorTraits = absl::allocator_traits<A>;
using allocator_type = typename AllocatorTraits::allocator_type;
using value_type = typename AllocatorTraits::value_type;
using pointer = typename AllocatorTraits::pointer;
using const_pointer = typename AllocatorTraits::const_pointer;
using size_type = typename AllocatorTraits::size_type;
using difference_type = typename AllocatorTraits::difference_type;
using reference = value_type&;
using const_reference = const value_type&;
using RValueReference = value_type&&;
using iterator = pointer;
using const_iterator = const_pointer;
using reverse_iterator = std::reverse_iterator<iterator>;
using const_reverse_iterator = std::reverse_iterator<const_iterator>;
using MoveIterator = std::move_iterator<iterator>;
using IsMemcpyOk = inlined_vector_internal::IsMemcpyOk<allocator_type>;
using StorageView = inlined_vector_internal::StorageView<allocator_type>;
template <typename Iterator>
using IteratorValueAdapter =
inlined_vector_internal::IteratorValueAdapter<allocator_type, Iterator>;
using CopyValueAdapter =
inlined_vector_internal::CopyValueAdapter<allocator_type>;
using DefaultValueAdapter =
inlined_vector_internal::DefaultValueAdapter<allocator_type>;
using AllocationTransaction =
inlined_vector_internal::AllocationTransaction<allocator_type>;
using ConstructionTransaction =
inlined_vector_internal::ConstructionTransaction<allocator_type>;
static size_type NextCapacity(size_type current_capacity) {
return current_capacity * 2;
}
static size_type ComputeCapacity(size_type current_capacity,
size_type requested_capacity) {
return (std::max)(NextCapacity(current_capacity), requested_capacity);
}
// ---------------------------------------------------------------------------
// Storage Constructors and Destructor
// ---------------------------------------------------------------------------
Storage() : metadata_() {}
explicit Storage(const allocator_type& alloc) : metadata_(alloc, {}) {}
~Storage() {
pointer data = GetIsAllocated() ? GetAllocatedData() : GetInlinedData();
inlined_vector_internal::DestroyElements(GetAllocPtr(), data, GetSize());
DeallocateIfAllocated();
}
// ---------------------------------------------------------------------------
// Storage Member Accessors
// ---------------------------------------------------------------------------
size_type& GetSizeAndIsAllocated() { return metadata_.template get<1>(); }
const size_type& GetSizeAndIsAllocated() const {
return metadata_.template get<1>();
}
size_type GetSize() const { return GetSizeAndIsAllocated() >> 1; }
bool GetIsAllocated() const { return GetSizeAndIsAllocated() & 1; }
pointer GetAllocatedData() { return data_.allocated.allocated_data; }
const_pointer GetAllocatedData() const {
return data_.allocated.allocated_data;
}
pointer GetInlinedData() {
return reinterpret_cast<pointer>(
std::addressof(data_.inlined.inlined_data[0]));
}
const_pointer GetInlinedData() const {
return reinterpret_cast<const_pointer>(
std::addressof(data_.inlined.inlined_data[0]));
}
size_type GetAllocatedCapacity() const {
return data_.allocated.allocated_capacity;
}
size_type GetInlinedCapacity() const { return static_cast<size_type>(N); }
StorageView MakeStorageView() {
return GetIsAllocated()
? StorageView{GetAllocatedData(), GetSize(),
GetAllocatedCapacity()}
: StorageView{GetInlinedData(), GetSize(), GetInlinedCapacity()};
}
allocator_type* GetAllocPtr() {
return std::addressof(metadata_.template get<0>());
}
const allocator_type* GetAllocPtr() const {
return std::addressof(metadata_.template get<0>());
}
// ---------------------------------------------------------------------------
// Storage Member Mutators
// ---------------------------------------------------------------------------
template <typename ValueAdapter>
void Initialize(ValueAdapter values, size_type new_size);
template <typename ValueAdapter>
void Assign(ValueAdapter values, size_type new_size);
template <typename ValueAdapter>
void Resize(ValueAdapter values, size_type new_size);
template <typename ValueAdapter>
iterator Insert(const_iterator pos, ValueAdapter values,
size_type insert_count);
template <typename... Args>
reference EmplaceBack(Args&&... args);
iterator Erase(const_iterator from, const_iterator to);
void Reserve(size_type requested_capacity);
void ShrinkToFit();
void Swap(Storage* other_storage_ptr);
void SetIsAllocated() {
GetSizeAndIsAllocated() |= static_cast<size_type>(1);
}
void UnsetIsAllocated() {
GetSizeAndIsAllocated() &= ((std::numeric_limits<size_type>::max)() - 1);
}
void SetSize(size_type size) {
GetSizeAndIsAllocated() =
(size << 1) | static_cast<size_type>(GetIsAllocated());
}
void SetAllocatedSize(size_type size) {
GetSizeAndIsAllocated() = (size << 1) | static_cast<size_type>(1);
}
void SetInlinedSize(size_type size) {
GetSizeAndIsAllocated() = size << static_cast<size_type>(1);
}
void AddSize(size_type count) {
GetSizeAndIsAllocated() += count << static_cast<size_type>(1);
}
void SubtractSize(size_type count) {
assert(count <= GetSize());
GetSizeAndIsAllocated() -= count << static_cast<size_type>(1);
}
void SetAllocatedData(pointer data, size_type capacity) {
data_.allocated.allocated_data = data;
data_.allocated.allocated_capacity = capacity;
}
void AcquireAllocatedData(AllocationTransaction* allocation_tx_ptr) {
SetAllocatedData(allocation_tx_ptr->GetData(),
allocation_tx_ptr->GetCapacity());
allocation_tx_ptr->Reset();
}
void MemcpyFrom(const Storage& other_storage) {
assert(IsMemcpyOk::value || other_storage.GetIsAllocated());
GetSizeAndIsAllocated() = other_storage.GetSizeAndIsAllocated();
data_ = other_storage.data_;
}
void DeallocateIfAllocated() {
if (GetIsAllocated()) {
AllocatorTraits::deallocate(*GetAllocPtr(), GetAllocatedData(),
GetAllocatedCapacity());
}
}
private:
using Metadata =
container_internal::CompressedTuple<allocator_type, size_type>;
struct Allocated {
pointer allocated_data;
size_type allocated_capacity;
};
struct Inlined {
alignas(value_type) char inlined_data[sizeof(value_type[N])];
};
union Data {
Allocated allocated;
Inlined inlined;
};
Metadata metadata_;
Data data_;
};
template <typename T, size_t N, typename A>
template <typename ValueAdapter>
auto Storage<T, N, A>::Initialize(ValueAdapter values, size_type new_size)
-> void {
// Only callable from constructors!
assert(!GetIsAllocated());
assert(GetSize() == 0);
pointer construct_data;
if (new_size > GetInlinedCapacity()) {
// Because this is only called from the `InlinedVector` constructors, it's
// safe to take on the allocation with size `0`. If `ConstructElements(...)`
// throws, deallocation will be automatically handled by `~Storage()`.
size_type new_capacity = ComputeCapacity(GetInlinedCapacity(), new_size);
construct_data = AllocatorTraits::allocate(*GetAllocPtr(), new_capacity);
SetAllocatedData(construct_data, new_capacity);
SetIsAllocated();
} else {
construct_data = GetInlinedData();
}
inlined_vector_internal::ConstructElements(GetAllocPtr(), construct_data,
&values, new_size);
// Since the initial size was guaranteed to be `0` and the allocated bit is
// already correct for either case, *adding* `new_size` gives us the correct
// result faster than setting it directly.
AddSize(new_size);
}
template <typename T, size_t N, typename A>
template <typename ValueAdapter>
auto Storage<T, N, A>::Assign(ValueAdapter values, size_type new_size) -> void {
StorageView storage_view = MakeStorageView();
AllocationTransaction allocation_tx(GetAllocPtr());
absl::Span<value_type> assign_loop;
absl::Span<value_type> construct_loop;
absl::Span<value_type> destroy_loop;
if (new_size > storage_view.capacity) {
size_type new_capacity = ComputeCapacity(storage_view.capacity, new_size);
construct_loop = {allocation_tx.Allocate(new_capacity), new_size};
destroy_loop = {storage_view.data, storage_view.size};
} else if (new_size > storage_view.size) {
assign_loop = {storage_view.data, storage_view.size};
construct_loop = {storage_view.data + storage_view.size,
new_size - storage_view.size};
} else {
assign_loop = {storage_view.data, new_size};
destroy_loop = {storage_view.data + new_size, storage_view.size - new_size};
}
inlined_vector_internal::AssignElements(assign_loop.data(), &values,
assign_loop.size());
inlined_vector_internal::ConstructElements(
GetAllocPtr(), construct_loop.data(), &values, construct_loop.size());
inlined_vector_internal::DestroyElements(GetAllocPtr(), destroy_loop.data(),
destroy_loop.size());
if (allocation_tx.DidAllocate()) {
DeallocateIfAllocated();
AcquireAllocatedData(&allocation_tx);
SetIsAllocated();
}
SetSize(new_size);
}
template <typename T, size_t N, typename A>
template <typename ValueAdapter>
auto Storage<T, N, A>::Resize(ValueAdapter values, size_type new_size) -> void {
StorageView storage_view = MakeStorageView();
IteratorValueAdapter<MoveIterator> move_values(
MoveIterator(storage_view.data));
AllocationTransaction allocation_tx(GetAllocPtr());
ConstructionTransaction construction_tx(GetAllocPtr());
absl::Span<value_type> construct_loop;
absl::Span<value_type> move_construct_loop;
absl::Span<value_type> destroy_loop;
if (new_size > storage_view.capacity) {
size_type new_capacity = ComputeCapacity(storage_view.capacity, new_size);
pointer new_data = allocation_tx.Allocate(new_capacity);
construct_loop = {new_data + storage_view.size,
new_size - storage_view.size};
move_construct_loop = {new_data, storage_view.size};
destroy_loop = {storage_view.data, storage_view.size};
} else if (new_size > storage_view.size) {
construct_loop = {storage_view.data + storage_view.size,
new_size - storage_view.size};
} else {
destroy_loop = {storage_view.data + new_size, storage_view.size - new_size};
}
construction_tx.Construct(construct_loop.data(), &values,
construct_loop.size());
inlined_vector_internal::ConstructElements(
GetAllocPtr(), move_construct_loop.data(), &move_values,
move_construct_loop.size());
inlined_vector_internal::DestroyElements(GetAllocPtr(), destroy_loop.data(),
destroy_loop.size());
construction_tx.Commit();
if (allocation_tx.DidAllocate()) {
DeallocateIfAllocated();
AcquireAllocatedData(&allocation_tx);
SetIsAllocated();
}
SetSize(new_size);
}
template <typename T, size_t N, typename A>
template <typename ValueAdapter>
auto Storage<T, N, A>::Insert(const_iterator pos, ValueAdapter values,
size_type insert_count) -> iterator {
StorageView storage_view = MakeStorageView();
size_type insert_index =
std::distance(const_iterator(storage_view.data), pos);
size_type insert_end_index = insert_index + insert_count;
size_type new_size = storage_view.size + insert_count;
if (new_size > storage_view.capacity) {
AllocationTransaction allocation_tx(GetAllocPtr());
ConstructionTransaction construction_tx(GetAllocPtr());
ConstructionTransaction move_construciton_tx(GetAllocPtr());
IteratorValueAdapter<MoveIterator> move_values(
MoveIterator(storage_view.data));
size_type new_capacity = ComputeCapacity(storage_view.capacity, new_size);
pointer new_data = allocation_tx.Allocate(new_capacity);
construction_tx.Construct(new_data + insert_index, &values, insert_count);
move_construciton_tx.Construct(new_data, &move_values, insert_index);
inlined_vector_internal::ConstructElements(
GetAllocPtr(), new_data + insert_end_index, &move_values,
storage_view.size - insert_index);
inlined_vector_internal::DestroyElements(GetAllocPtr(), storage_view.data,
storage_view.size);
construction_tx.Commit();
move_construciton_tx.Commit();
DeallocateIfAllocated();
AcquireAllocatedData(&allocation_tx);
SetAllocatedSize(new_size);
return iterator(new_data + insert_index);
} else {
size_type move_construction_destination_index =
(std::max)(insert_end_index, storage_view.size);
ConstructionTransaction move_construction_tx(GetAllocPtr());
IteratorValueAdapter<MoveIterator> move_construction_values(
MoveIterator(storage_view.data +
(move_construction_destination_index - insert_count)));
absl::Span<value_type> move_construction = {
storage_view.data + move_construction_destination_index,
new_size - move_construction_destination_index};
pointer move_assignment_values = storage_view.data + insert_index;
absl::Span<value_type> move_assignment = {
storage_view.data + insert_end_index,
move_construction_destination_index - insert_end_index};
absl::Span<value_type> insert_assignment = {move_assignment_values,
move_construction.size()};
absl::Span<value_type> insert_construction = {
insert_assignment.data() + insert_assignment.size(),
insert_count - insert_assignment.size()};
move_construction_tx.Construct(move_construction.data(),
&move_construction_values,
move_construction.size());
for (pointer destination = move_assignment.data() + move_assignment.size(),
last_destination = move_assignment.data(),
source = move_assignment_values + move_assignment.size();
;) {
--destination;
--source;
if (destination < last_destination) break;
*destination = std::move(*source);
}
inlined_vector_internal::AssignElements(insert_assignment.data(), &values,
insert_assignment.size());
inlined_vector_internal::ConstructElements(
GetAllocPtr(), insert_construction.data(), &values,
insert_construction.size());
move_construction_tx.Commit();
AddSize(insert_count);
return iterator(storage_view.data + insert_index);
}
}
template <typename T, size_t N, typename A>
template <typename... Args>
auto Storage<T, N, A>::EmplaceBack(Args&&... args) -> reference {
StorageView storage_view = MakeStorageView();
AllocationTransaction allocation_tx(GetAllocPtr());
IteratorValueAdapter<MoveIterator> move_values(
MoveIterator(storage_view.data));
pointer construct_data;
if (storage_view.size == storage_view.capacity) {
size_type new_capacity = NextCapacity(storage_view.capacity);
construct_data = allocation_tx.Allocate(new_capacity);
} else {
construct_data = storage_view.data;
}
pointer last_ptr = construct_data + storage_view.size;
AllocatorTraits::construct(*GetAllocPtr(), last_ptr,
std::forward<Args>(args)...);
if (allocation_tx.DidAllocate()) {
ABSL_INTERNAL_TRY {
inlined_vector_internal::ConstructElements(
GetAllocPtr(), allocation_tx.GetData(), &move_values,
storage_view.size);
}
ABSL_INTERNAL_CATCH_ANY {
AllocatorTraits::destroy(*GetAllocPtr(), last_ptr);
ABSL_INTERNAL_RETHROW;
}
inlined_vector_internal::DestroyElements(GetAllocPtr(), storage_view.data,
storage_view.size);
DeallocateIfAllocated();
AcquireAllocatedData(&allocation_tx);
SetIsAllocated();
}
AddSize(1);
return *last_ptr;
}
template <typename T, size_t N, typename A>
auto Storage<T, N, A>::Erase(const_iterator from, const_iterator to)
-> iterator {
StorageView storage_view = MakeStorageView();
size_type erase_size = std::distance(from, to);
size_type erase_index =
std::distance(const_iterator(storage_view.data), from);
size_type erase_end_index = erase_index + erase_size;
IteratorValueAdapter<MoveIterator> move_values(
MoveIterator(storage_view.data + erase_end_index));
inlined_vector_internal::AssignElements(storage_view.data + erase_index,
&move_values,
storage_view.size - erase_end_index);
inlined_vector_internal::DestroyElements(
GetAllocPtr(), storage_view.data + (storage_view.size - erase_size),
erase_size);
SubtractSize(erase_size);
return iterator(storage_view.data + erase_index);
}
template <typename T, size_t N, typename A>
auto Storage<T, N, A>::Reserve(size_type requested_capacity) -> void {
StorageView storage_view = MakeStorageView();
if (ABSL_PREDICT_FALSE(requested_capacity <= storage_view.capacity)) return;
AllocationTransaction allocation_tx(GetAllocPtr());
IteratorValueAdapter<MoveIterator> move_values(
MoveIterator(storage_view.data));
size_type new_capacity =
ComputeCapacity(storage_view.capacity, requested_capacity);
pointer new_data = allocation_tx.Allocate(new_capacity);
inlined_vector_internal::ConstructElements(GetAllocPtr(), new_data,
&move_values, storage_view.size);
inlined_vector_internal::DestroyElements(GetAllocPtr(), storage_view.data,
storage_view.size);
DeallocateIfAllocated();
AcquireAllocatedData(&allocation_tx);
SetIsAllocated();
}
template <typename T, size_t N, typename A>
auto Storage<T, N, A>::ShrinkToFit() -> void {
// May only be called on allocated instances!
assert(GetIsAllocated());
StorageView storage_view{GetAllocatedData(), GetSize(),
GetAllocatedCapacity()};
if (ABSL_PREDICT_FALSE(storage_view.size == storage_view.capacity)) return;
AllocationTransaction allocation_tx(GetAllocPtr());
IteratorValueAdapter<MoveIterator> move_values(
MoveIterator(storage_view.data));
pointer construct_data;
if (storage_view.size > GetInlinedCapacity()) {
size_type new_capacity = storage_view.size;
construct_data = allocation_tx.Allocate(new_capacity);
} else {
construct_data = GetInlinedData();
}
ABSL_INTERNAL_TRY {
inlined_vector_internal::ConstructElements(GetAllocPtr(), construct_data,
&move_values, storage_view.size);
}
ABSL_INTERNAL_CATCH_ANY {
SetAllocatedData(storage_view.data, storage_view.capacity);
ABSL_INTERNAL_RETHROW;
}
inlined_vector_internal::DestroyElements(GetAllocPtr(), storage_view.data,
storage_view.size);
AllocatorTraits::deallocate(*GetAllocPtr(), storage_view.data,
storage_view.capacity);
if (allocation_tx.DidAllocate()) {
AcquireAllocatedData(&allocation_tx);
} else {
UnsetIsAllocated();
}
}
template <typename T, size_t N, typename A>
auto Storage<T, N, A>::Swap(Storage* other_storage_ptr) -> void {
using std::swap;
assert(this != other_storage_ptr);
if (GetIsAllocated() && other_storage_ptr->GetIsAllocated()) {
swap(data_.allocated, other_storage_ptr->data_.allocated);
} else if (!GetIsAllocated() && !other_storage_ptr->GetIsAllocated()) {
Storage* small_ptr = this;
Storage* large_ptr = other_storage_ptr;
if (small_ptr->GetSize() > large_ptr->GetSize()) swap(small_ptr, large_ptr);
for (size_type i = 0; i < small_ptr->GetSize(); ++i) {
swap(small_ptr->GetInlinedData()[i], large_ptr->GetInlinedData()[i]);
}
IteratorValueAdapter<MoveIterator> move_values(
MoveIterator(large_ptr->GetInlinedData() + small_ptr->GetSize()));
inlined_vector_internal::ConstructElements(
large_ptr->GetAllocPtr(),
small_ptr->GetInlinedData() + small_ptr->GetSize(), &move_values,
large_ptr->GetSize() - small_ptr->GetSize());
inlined_vector_internal::DestroyElements(
large_ptr->GetAllocPtr(),
large_ptr->GetInlinedData() + small_ptr->GetSize(),
large_ptr->GetSize() - small_ptr->GetSize());
} else {
Storage* allocated_ptr = this;
Storage* inlined_ptr = other_storage_ptr;
if (!allocated_ptr->GetIsAllocated()) swap(allocated_ptr, inlined_ptr);
StorageView allocated_storage_view{allocated_ptr->GetAllocatedData(),
allocated_ptr->GetSize(),
allocated_ptr->GetAllocatedCapacity()};
IteratorValueAdapter<MoveIterator> move_values(
MoveIterator(inlined_ptr->GetInlinedData()));
ABSL_INTERNAL_TRY {
inlined_vector_internal::ConstructElements(
inlined_ptr->GetAllocPtr(), allocated_ptr->GetInlinedData(),
&move_values, inlined_ptr->GetSize());
}
ABSL_INTERNAL_CATCH_ANY {
allocated_ptr->SetAllocatedData(allocated_storage_view.data,
allocated_storage_view.capacity);
ABSL_INTERNAL_RETHROW;
}
inlined_vector_internal::DestroyElements(inlined_ptr->GetAllocPtr(),
inlined_ptr->GetInlinedData(),
inlined_ptr->GetSize());
inlined_ptr->SetAllocatedData(allocated_storage_view.data,
allocated_storage_view.capacity);
}
swap(GetSizeAndIsAllocated(), other_storage_ptr->GetSizeAndIsAllocated());
swap(*GetAllocPtr(), *other_storage_ptr->GetAllocPtr());
}
} // namespace inlined_vector_internal
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_CONTAINER_INTERNAL_INLINED_VECTOR_INTERNAL_H_
Pods/abseil/absl/container/internal/layout.h
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// Copyright 2018 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// MOTIVATION AND TUTORIAL
//
// If you want to put in a single heap allocation N doubles followed by M ints,
// it's easy if N and M are known at compile time.
//
// struct S {
// double a[N];
// int b[M];
// };
//
// S* p = new S;
//
// But what if N and M are known only in run time? Class template Layout to the
// rescue! It's a portable generalization of the technique known as struct hack.
//
// // This object will tell us everything we need to know about the memory
// // layout of double[N] followed by int[M]. It's structurally identical to
// // size_t[2] that stores N and M. It's very cheap to create.
// const Layout<double, int> layout(N, M);
//
// // Allocate enough memory for both arrays. `AllocSize()` tells us how much
// // memory is needed. We are free to use any allocation function we want as
// // long as it returns aligned memory.
// std::unique_ptr<unsigned char[]> p(new unsigned char[layout.AllocSize()]);
//
// // Obtain the pointer to the array of doubles.
// // Equivalent to `reinterpret_cast<double*>(p.get())`.
// //
// // We could have written layout.Pointer<0>(p) instead. If all the types are
// // unique you can use either form, but if some types are repeated you must
// // use the index form.
// double* a = layout.Pointer<double>(p.get());
//
// // Obtain the pointer to the array of ints.
// // Equivalent to `reinterpret_cast<int*>(p.get() + N * 8)`.
// int* b = layout.Pointer<int>(p);
//
// If we are unable to specify sizes of all fields, we can pass as many sizes as
// we can to `Partial()`. In return, it'll allow us to access the fields whose
// locations and sizes can be computed from the provided information.
// `Partial()` comes in handy when the array sizes are embedded into the
// allocation.
//
// // size_t[1] containing N, size_t[1] containing M, double[N], int[M].
// using L = Layout<size_t, size_t, double, int>;
//
// unsigned char* Allocate(size_t n, size_t m) {
// const L layout(1, 1, n, m);
// unsigned char* p = new unsigned char[layout.AllocSize()];
// *layout.Pointer<0>(p) = n;
// *layout.Pointer<1>(p) = m;
// return p;
// }
//
// void Use(unsigned char* p) {
// // First, extract N and M.
// // Specify that the first array has only one element. Using `prefix` we
// // can access the first two arrays but not more.
// constexpr auto prefix = L::Partial(1);
// size_t n = *prefix.Pointer<0>(p);
// size_t m = *prefix.Pointer<1>(p);
//
// // Now we can get pointers to the payload.
// const L layout(1, 1, n, m);
// double* a = layout.Pointer<double>(p);
// int* b = layout.Pointer<int>(p);
// }
//
// The layout we used above combines fixed-size with dynamically-sized fields.
// This is quite common. Layout is optimized for this use case and generates
// optimal code. All computations that can be performed at compile time are
// indeed performed at compile time.
//
// Efficiency tip: The order of fields matters. In `Layout<T1, ..., TN>` try to
// ensure that `alignof(T1) >= ... >= alignof(TN)`. This way you'll have no
// padding in between arrays.
//
// You can manually override the alignment of an array by wrapping the type in
// `Aligned<T, N>`. `Layout<..., Aligned<T, N>, ...>` has exactly the same API
// and behavior as `Layout<..., T, ...>` except that the first element of the
// array of `T` is aligned to `N` (the rest of the elements follow without
// padding). `N` cannot be less than `alignof(T)`.
//
// `AllocSize()` and `Pointer()` are the most basic methods for dealing with
// memory layouts. Check out the reference or code below to discover more.
//
// EXAMPLE
//
// // Immutable move-only string with sizeof equal to sizeof(void*). The
// // string size and the characters are kept in the same heap allocation.
// class CompactString {
// public:
// CompactString(const char* s = "") {
// const size_t size = strlen(s);
// // size_t[1] followed by char[size + 1].
// const L layout(1, size + 1);
// p_.reset(new unsigned char[layout.AllocSize()]);
// // If running under ASAN, mark the padding bytes, if any, to catch
// // memory errors.
// layout.PoisonPadding(p_.get());
// // Store the size in the allocation.
// *layout.Pointer<size_t>(p_.get()) = size;
// // Store the characters in the allocation.
// memcpy(layout.Pointer<char>(p_.get()), s, size + 1);
// }
//
// size_t size() const {
// // Equivalent to reinterpret_cast<size_t&>(*p).
// return *L::Partial().Pointer<size_t>(p_.get());
// }
//
// const char* c_str() const {
// // Equivalent to reinterpret_cast<char*>(p.get() + sizeof(size_t)).
// // The argument in Partial(1) specifies that we have size_t[1] in front
// // of the characters.
// return L::Partial(1).Pointer<char>(p_.get());
// }
//
// private:
// // Our heap allocation contains a size_t followed by an array of chars.
// using L = Layout<size_t, char>;
// std::unique_ptr<unsigned char[]> p_;
// };
//
// int main() {
// CompactString s = "hello";
// assert(s.size() == 5);
// assert(strcmp(s.c_str(), "hello") == 0);
// }
//
// DOCUMENTATION
//
// The interface exported by this file consists of:
// - class `Layout<>` and its public members.
// - The public members of class `internal_layout::LayoutImpl<>`. That class
// isn't intended to be used directly, and its name and template parameter
// list are internal implementation details, but the class itself provides
// most of the functionality in this file. See comments on its members for
// detailed documentation.
//
// `Layout<T1,... Tn>::Partial(count1,..., countm)` (where `m` <= `n`) returns a
// `LayoutImpl<>` object. `Layout<T1,..., Tn> layout(count1,..., countn)`
// creates a `Layout` object, which exposes the same functionality by inheriting
// from `LayoutImpl<>`.
#ifndef ABSL_CONTAINER_INTERNAL_LAYOUT_H_
#define ABSL_CONTAINER_INTERNAL_LAYOUT_H_
#include <assert.h>
#include <stddef.h>
#include <stdint.h>
#include <ostream>
#include <string>
#include <tuple>
#include <type_traits>
#include <typeinfo>
#include <utility>
#ifdef ADDRESS_SANITIZER
#include <sanitizer/asan_interface.h>
#endif
#include "absl/meta/type_traits.h"
#include "absl/strings/str_cat.h"
#include "absl/types/span.h"
#include "absl/utility/utility.h"
#if defined(__GXX_RTTI)
#define ABSL_INTERNAL_HAS_CXA_DEMANGLE
#endif
#ifdef ABSL_INTERNAL_HAS_CXA_DEMANGLE
#include <cxxabi.h>
#endif
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace container_internal {
// A type wrapper that instructs `Layout` to use the specific alignment for the
// array. `Layout<..., Aligned<T, N>, ...>` has exactly the same API
// and behavior as `Layout<..., T, ...>` except that the first element of the
// array of `T` is aligned to `N` (the rest of the elements follow without
// padding).
//
// Requires: `N >= alignof(T)` and `N` is a power of 2.
template <class T, size_t N>
struct Aligned;
namespace internal_layout {
template <class T>
struct NotAligned {};
template <class T, size_t N>
struct NotAligned<const Aligned<T, N>> {
static_assert(sizeof(T) == 0, "Aligned<T, N> cannot be const-qualified");
};
template <size_t>
using IntToSize = size_t;
template <class>
using TypeToSize = size_t;
template <class T>
struct Type : NotAligned<T> {
using type = T;
};
template <class T, size_t N>
struct Type<Aligned<T, N>> {
using type = T;
};
template <class T>
struct SizeOf : NotAligned<T>, std::integral_constant<size_t, sizeof(T)> {};
template <class T, size_t N>
struct SizeOf<Aligned<T, N>> : std::integral_constant<size_t, sizeof(T)> {};
// Note: workaround for https://gcc.gnu.org/PR88115
template <class T>
struct AlignOf : NotAligned<T> {
static constexpr size_t value = alignof(T);
};
template <class T, size_t N>
struct AlignOf<Aligned<T, N>> {
static_assert(N % alignof(T) == 0,
"Custom alignment can't be lower than the type's alignment");
static constexpr size_t value = N;
};
// Does `Ts...` contain `T`?
template <class T, class... Ts>
using Contains = absl::disjunction<std::is_same<T, Ts>...>;
template <class From, class To>
using CopyConst =
typename std::conditional<std::is_const<From>::value, const To, To>::type;
// Note: We're not qualifying this with absl:: because it doesn't compile under
// MSVC.
template <class T>
using SliceType = Span<T>;
// This namespace contains no types. It prevents functions defined in it from
// being found by ADL.
namespace adl_barrier {
template <class Needle, class... Ts>
constexpr size_t Find(Needle, Needle, Ts...) {
static_assert(!Contains<Needle, Ts...>(), "Duplicate element type");
return 0;
}
template <class Needle, class T, class... Ts>
constexpr size_t Find(Needle, T, Ts...) {
return adl_barrier::Find(Needle(), Ts()...) + 1;
}
constexpr bool IsPow2(size_t n) { return !(n & (n - 1)); }
// Returns `q * m` for the smallest `q` such that `q * m >= n`.
// Requires: `m` is a power of two. It's enforced by IsLegalElementType below.
constexpr size_t Align(size_t n, size_t m) { return (n + m - 1) & ~(m - 1); }
constexpr size_t Min(size_t a, size_t b) { return b < a ? b : a; }
constexpr size_t Max(size_t a) { return a; }
template <class... Ts>
constexpr size_t Max(size_t a, size_t b, Ts... rest) {
return adl_barrier::Max(b < a ? a : b, rest...);
}
template <class T>
std::string TypeName() {
std::string out;
int status = 0;
char* demangled = nullptr;
#ifdef ABSL_INTERNAL_HAS_CXA_DEMANGLE
demangled = abi::__cxa_demangle(typeid(T).name(), nullptr, nullptr, &status);
#endif
if (status == 0 && demangled != nullptr) { // Demangling succeeded.
absl::StrAppend(&out, "<", demangled, ">");
free(demangled);
} else {
#if defined(__GXX_RTTI) || defined(_CPPRTTI)
absl::StrAppend(&out, "<", typeid(T).name(), ">");
#endif
}
return out;
}
} // namespace adl_barrier
template <bool C>
using EnableIf = typename std::enable_if<C, int>::type;
// Can `T` be a template argument of `Layout`?
template <class T>
using IsLegalElementType = std::integral_constant<
bool, !std::is_reference<T>::value && !std::is_volatile<T>::value &&
!std::is_reference<typename Type<T>::type>::value &&
!std::is_volatile<typename Type<T>::type>::value &&
adl_barrier::IsPow2(AlignOf<T>::value)>;
template <class Elements, class SizeSeq, class OffsetSeq>
class LayoutImpl;
// Public base class of `Layout` and the result type of `Layout::Partial()`.
//
// `Elements...` contains all template arguments of `Layout` that created this
// instance.
//
// `SizeSeq...` is `[0, NumSizes)` where `NumSizes` is the number of arguments
// passed to `Layout::Partial()` or `Layout::Layout()`.
//
// `OffsetSeq...` is `[0, NumOffsets)` where `NumOffsets` is
// `Min(sizeof...(Elements), NumSizes + 1)` (the number of arrays for which we
// can compute offsets).
template <class... Elements, size_t... SizeSeq, size_t... OffsetSeq>
class LayoutImpl<std::tuple<Elements...>, absl::index_sequence<SizeSeq...>,
absl::index_sequence<OffsetSeq...>> {
private:
static_assert(sizeof...(Elements) > 0, "At least one field is required");
static_assert(absl::conjunction<IsLegalElementType<Elements>...>::value,
"Invalid element type (see IsLegalElementType)");
enum {
NumTypes = sizeof...(Elements),
NumSizes = sizeof...(SizeSeq),
NumOffsets = sizeof...(OffsetSeq),
};
// These are guaranteed by `Layout`.
static_assert(NumOffsets == adl_barrier::Min(NumTypes, NumSizes + 1),
"Internal error");
static_assert(NumTypes > 0, "Internal error");
// Returns the index of `T` in `Elements...`. Results in a compilation error
// if `Elements...` doesn't contain exactly one instance of `T`.
template <class T>
static constexpr size_t ElementIndex() {
static_assert(Contains<Type<T>, Type<typename Type<Elements>::type>...>(),
"Type not found");
return adl_barrier::Find(Type<T>(),
Type<typename Type<Elements>::type>()...);
}
template <size_t N>
using ElementAlignment =
AlignOf<typename std::tuple_element<N, std::tuple<Elements...>>::type>;
public:
// Element types of all arrays packed in a tuple.
using ElementTypes = std::tuple<typename Type<Elements>::type...>;
// Element type of the Nth array.
template <size_t N>
using ElementType = typename std::tuple_element<N, ElementTypes>::type;
constexpr explicit LayoutImpl(IntToSize<SizeSeq>... sizes)
: size_{sizes...} {}
// Alignment of the layout, equal to the strictest alignment of all elements.
// All pointers passed to the methods of layout must be aligned to this value.
static constexpr size_t Alignment() {
return adl_barrier::Max(AlignOf<Elements>::value...);
}
// Offset in bytes of the Nth array.
//
// // int[3], 4 bytes of padding, double[4].
// Layout<int, double> x(3, 4);
// assert(x.Offset<0>() == 0); // The ints starts from 0.
// assert(x.Offset<1>() == 16); // The doubles starts from 16.
//
// Requires: `N <= NumSizes && N < sizeof...(Ts)`.
template <size_t N, EnableIf<N == 0> = 0>
constexpr size_t Offset() const {
return 0;
}
template <size_t N, EnableIf<N != 0> = 0>
constexpr size_t Offset() const {
static_assert(N < NumOffsets, "Index out of bounds");
return adl_barrier::Align(
Offset<N - 1>() + SizeOf<ElementType<N - 1>>() * size_[N - 1],
ElementAlignment<N>::value);
}
// Offset in bytes of the array with the specified element type. There must
// be exactly one such array and its zero-based index must be at most
// `NumSizes`.
//
// // int[3], 4 bytes of padding, double[4].
// Layout<int, double> x(3, 4);
// assert(x.Offset<int>() == 0); // The ints starts from 0.
// assert(x.Offset<double>() == 16); // The doubles starts from 16.
template <class T>
constexpr size_t Offset() const {
return Offset<ElementIndex<T>()>();
}
// Offsets in bytes of all arrays for which the offsets are known.
constexpr std::array<size_t, NumOffsets> Offsets() const {
return {{Offset<OffsetSeq>()...}};
}
// The number of elements in the Nth array. This is the Nth argument of
// `Layout::Partial()` or `Layout::Layout()` (zero-based).
//
// // int[3], 4 bytes of padding, double[4].
// Layout<int, double> x(3, 4);
// assert(x.Size<0>() == 3);
// assert(x.Size<1>() == 4);
//
// Requires: `N < NumSizes`.
template <size_t N>
constexpr size_t Size() const {
static_assert(N < NumSizes, "Index out of bounds");
return size_[N];
}
// The number of elements in the array with the specified element type.
// There must be exactly one such array and its zero-based index must be
// at most `NumSizes`.
//
// // int[3], 4 bytes of padding, double[4].
// Layout<int, double> x(3, 4);
// assert(x.Size<int>() == 3);
// assert(x.Size<double>() == 4);
template <class T>
constexpr size_t Size() const {
return Size<ElementIndex<T>()>();
}
// The number of elements of all arrays for which they are known.
constexpr std::array<size_t, NumSizes> Sizes() const {
return {{Size<SizeSeq>()...}};
}
// Pointer to the beginning of the Nth array.
//
// `Char` must be `[const] [signed|unsigned] char`.
//
// // int[3], 4 bytes of padding, double[4].
// Layout<int, double> x(3, 4);
// unsigned char* p = new unsigned char[x.AllocSize()];
// int* ints = x.Pointer<0>(p);
// double* doubles = x.Pointer<1>(p);
//
// Requires: `N <= NumSizes && N < sizeof...(Ts)`.
// Requires: `p` is aligned to `Alignment()`.
template <size_t N, class Char>
CopyConst<Char, ElementType<N>>* Pointer(Char* p) const {
using C = typename std::remove_const<Char>::type;
static_assert(
std::is_same<C, char>() || std::is_same<C, unsigned char>() ||
std::is_same<C, signed char>(),
"The argument must be a pointer to [const] [signed|unsigned] char");
constexpr size_t alignment = Alignment();
(void)alignment;
assert(reinterpret_cast<uintptr_t>(p) % alignment == 0);
return reinterpret_cast<CopyConst<Char, ElementType<N>>*>(p + Offset<N>());
}
// Pointer to the beginning of the array with the specified element type.
// There must be exactly one such array and its zero-based index must be at
// most `NumSizes`.
//
// `Char` must be `[const] [signed|unsigned] char`.
//
// // int[3], 4 bytes of padding, double[4].
// Layout<int, double> x(3, 4);
// unsigned char* p = new unsigned char[x.AllocSize()];
// int* ints = x.Pointer<int>(p);
// double* doubles = x.Pointer<double>(p);
//
// Requires: `p` is aligned to `Alignment()`.
template <class T, class Char>
CopyConst<Char, T>* Pointer(Char* p) const {
return Pointer<ElementIndex<T>()>(p);
}
// Pointers to all arrays for which pointers are known.
//
// `Char` must be `[const] [signed|unsigned] char`.
//
// // int[3], 4 bytes of padding, double[4].
// Layout<int, double> x(3, 4);
// unsigned char* p = new unsigned char[x.AllocSize()];
//
// int* ints;
// double* doubles;
// std::tie(ints, doubles) = x.Pointers(p);
//
// Requires: `p` is aligned to `Alignment()`.
//
// Note: We're not using ElementType alias here because it does not compile
// under MSVC.
template <class Char>
std::tuple<CopyConst<
Char, typename std::tuple_element<OffsetSeq, ElementTypes>::type>*...>
Pointers(Char* p) const {
return std::tuple<CopyConst<Char, ElementType<OffsetSeq>>*...>(
Pointer<OffsetSeq>(p)...);
}
// The Nth array.
//
// `Char` must be `[const] [signed|unsigned] char`.
//
// // int[3], 4 bytes of padding, double[4].
// Layout<int, double> x(3, 4);
// unsigned char* p = new unsigned char[x.AllocSize()];
// Span<int> ints = x.Slice<0>(p);
// Span<double> doubles = x.Slice<1>(p);
//
// Requires: `N < NumSizes`.
// Requires: `p` is aligned to `Alignment()`.
template <size_t N, class Char>
SliceType<CopyConst<Char, ElementType<N>>> Slice(Char* p) const {
return SliceType<CopyConst<Char, ElementType<N>>>(Pointer<N>(p), Size<N>());
}
// The array with the specified element type. There must be exactly one
// such array and its zero-based index must be less than `NumSizes`.
//
// `Char` must be `[const] [signed|unsigned] char`.
//
// // int[3], 4 bytes of padding, double[4].
// Layout<int, double> x(3, 4);
// unsigned char* p = new unsigned char[x.AllocSize()];
// Span<int> ints = x.Slice<int>(p);
// Span<double> doubles = x.Slice<double>(p);
//
// Requires: `p` is aligned to `Alignment()`.
template <class T, class Char>
SliceType<CopyConst<Char, T>> Slice(Char* p) const {
return Slice<ElementIndex<T>()>(p);
}
// All arrays with known sizes.
//
// `Char` must be `[const] [signed|unsigned] char`.
//
// // int[3], 4 bytes of padding, double[4].
// Layout<int, double> x(3, 4);
// unsigned char* p = new unsigned char[x.AllocSize()];
//
// Span<int> ints;
// Span<double> doubles;
// std::tie(ints, doubles) = x.Slices(p);
//
// Requires: `p` is aligned to `Alignment()`.
//
// Note: We're not using ElementType alias here because it does not compile
// under MSVC.
template <class Char>
std::tuple<SliceType<CopyConst<
Char, typename std::tuple_element<SizeSeq, ElementTypes>::type>>...>
Slices(Char* p) const {
// Workaround for https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63875 (fixed
// in 6.1).
(void)p;
return std::tuple<SliceType<CopyConst<Char, ElementType<SizeSeq>>>...>(
Slice<SizeSeq>(p)...);
}
// The size of the allocation that fits all arrays.
//
// // int[3], 4 bytes of padding, double[4].
// Layout<int, double> x(3, 4);
// unsigned char* p = new unsigned char[x.AllocSize()]; // 48 bytes
//
// Requires: `NumSizes == sizeof...(Ts)`.
constexpr size_t AllocSize() const {
static_assert(NumTypes == NumSizes, "You must specify sizes of all fields");
return Offset<NumTypes - 1>() +
SizeOf<ElementType<NumTypes - 1>>() * size_[NumTypes - 1];
}
// If built with --config=asan, poisons padding bytes (if any) in the
// allocation. The pointer must point to a memory block at least
// `AllocSize()` bytes in length.
//
// `Char` must be `[const] [signed|unsigned] char`.
//
// Requires: `p` is aligned to `Alignment()`.
template <class Char, size_t N = NumOffsets - 1, EnableIf<N == 0> = 0>
void PoisonPadding(const Char* p) const {
Pointer<0>(p); // verify the requirements on `Char` and `p`
}
template <class Char, size_t N = NumOffsets - 1, EnableIf<N != 0> = 0>
void PoisonPadding(const Char* p) const {
static_assert(N < NumOffsets, "Index out of bounds");
(void)p;
#ifdef ADDRESS_SANITIZER
PoisonPadding<Char, N - 1>(p);
// The `if` is an optimization. It doesn't affect the observable behaviour.
if (ElementAlignment<N - 1>::value % ElementAlignment<N>::value) {
size_t start =
Offset<N - 1>() + SizeOf<ElementType<N - 1>>() * size_[N - 1];
ASAN_POISON_MEMORY_REGION(p + start, Offset<N>() - start);
}
#endif
}
// Human-readable description of the memory layout. Useful for debugging.
// Slow.
//
// // char[5], 3 bytes of padding, int[3], 4 bytes of padding, followed
// // by an unknown number of doubles.
// auto x = Layout<char, int, double>::Partial(5, 3);
// assert(x.DebugString() ==
// "@0<char>(1)[5]; @8<int>(4)[3]; @24<double>(8)");
//
// Each field is in the following format: @offset<type>(sizeof)[size] (<type>
// may be missing depending on the target platform). For example,
// @8<int>(4)[3] means that at offset 8 we have an array of ints, where each
// int is 4 bytes, and we have 3 of those ints. The size of the last field may
// be missing (as in the example above). Only fields with known offsets are
// described. Type names may differ across platforms: one compiler might
// produce "unsigned*" where another produces "unsigned int *".
std::string DebugString() const {
const auto offsets = Offsets();
const size_t sizes[] = {SizeOf<ElementType<OffsetSeq>>()...};
const std::string types[] = {
adl_barrier::TypeName<ElementType<OffsetSeq>>()...};
std::string res = absl::StrCat("@0", types[0], "(", sizes[0], ")");
for (size_t i = 0; i != NumOffsets - 1; ++i) {
absl::StrAppend(&res, "[", size_[i], "]; @", offsets[i + 1], types[i + 1],
"(", sizes[i + 1], ")");
}
// NumSizes is a constant that may be zero. Some compilers cannot see that
// inside the if statement "size_[NumSizes - 1]" must be valid.
int last = static_cast<int>(NumSizes) - 1;
if (NumTypes == NumSizes && last >= 0) {
absl::StrAppend(&res, "[", size_[last], "]");
}
return res;
}
private:
// Arguments of `Layout::Partial()` or `Layout::Layout()`.
size_t size_[NumSizes > 0 ? NumSizes : 1];
};
template <size_t NumSizes, class... Ts>
using LayoutType = LayoutImpl<
std::tuple<Ts...>, absl::make_index_sequence<NumSizes>,
absl::make_index_sequence<adl_barrier::Min(sizeof...(Ts), NumSizes + 1)>>;
} // namespace internal_layout
// Descriptor of arrays of various types and sizes laid out in memory one after
// another. See the top of the file for documentation.
//
// Check out the public API of internal_layout::LayoutImpl above. The type is
// internal to the library but its methods are public, and they are inherited
// by `Layout`.
template <class... Ts>
class Layout : public internal_layout::LayoutType<sizeof...(Ts), Ts...> {
public:
static_assert(sizeof...(Ts) > 0, "At least one field is required");
static_assert(
absl::conjunction<internal_layout::IsLegalElementType<Ts>...>::value,
"Invalid element type (see IsLegalElementType)");
// The result type of `Partial()` with `NumSizes` arguments.
template <size_t NumSizes>
using PartialType = internal_layout::LayoutType<NumSizes, Ts...>;
// `Layout` knows the element types of the arrays we want to lay out in
// memory but not the number of elements in each array.
// `Partial(size1, ..., sizeN)` allows us to specify the latter. The
// resulting immutable object can be used to obtain pointers to the
// individual arrays.
//
// It's allowed to pass fewer array sizes than the number of arrays. E.g.,
// if all you need is to the offset of the second array, you only need to
// pass one argument -- the number of elements in the first array.
//
// // int[3] followed by 4 bytes of padding and an unknown number of
// // doubles.
// auto x = Layout<int, double>::Partial(3);
// // doubles start at byte 16.
// assert(x.Offset<1>() == 16);
//
// If you know the number of elements in all arrays, you can still call
// `Partial()` but it's more convenient to use the constructor of `Layout`.
//
// Layout<int, double> x(3, 5);
//
// Note: The sizes of the arrays must be specified in number of elements,
// not in bytes.
//
// Requires: `sizeof...(Sizes) <= sizeof...(Ts)`.
// Requires: all arguments are convertible to `size_t`.
template <class... Sizes>
static constexpr PartialType<sizeof...(Sizes)> Partial(Sizes&&... sizes) {
static_assert(sizeof...(Sizes) <= sizeof...(Ts), "");
return PartialType<sizeof...(Sizes)>(absl::forward<Sizes>(sizes)...);
}
// Creates a layout with the sizes of all arrays specified. If you know
// only the sizes of the first N arrays (where N can be zero), you can use
// `Partial()` defined above. The constructor is essentially equivalent to
// calling `Partial()` and passing in all array sizes; the constructor is
// provided as a convenient abbreviation.
//
// Note: The sizes of the arrays must be specified in number of elements,
// not in bytes.
constexpr explicit Layout(internal_layout::TypeToSize<Ts>... sizes)
: internal_layout::LayoutType<sizeof...(Ts), Ts...>(sizes...) {}
};
} // namespace container_internal
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_CONTAINER_INTERNAL_LAYOUT_H_
Pods/abseil/absl/container/internal/raw_hash_map.h
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// Copyright 2018 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef ABSL_CONTAINER_INTERNAL_RAW_HASH_MAP_H_
#define ABSL_CONTAINER_INTERNAL_RAW_HASH_MAP_H_
#include <tuple>
#include <type_traits>
#include <utility>
#include "absl/base/internal/throw_delegate.h"
#include "absl/container/internal/container_memory.h"
#include "absl/container/internal/raw_hash_set.h" // IWYU pragma: export
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace container_internal {
template <class Policy, class Hash, class Eq, class Alloc>
class raw_hash_map : public raw_hash_set<Policy, Hash, Eq, Alloc> {
// P is Policy. It's passed as a template argument to support maps that have
// incomplete types as values, as in unordered_map<K, IncompleteType>.
// MappedReference<> may be a non-reference type.
template <class P>
using MappedReference = decltype(P::value(
std::addressof(std::declval<typename raw_hash_map::reference>())));
// MappedConstReference<> may be a non-reference type.
template <class P>
using MappedConstReference = decltype(P::value(
std::addressof(std::declval<typename raw_hash_map::const_reference>())));
using KeyArgImpl =
KeyArg<IsTransparent<Eq>::value && IsTransparent<Hash>::value>;
public:
using key_type = typename Policy::key_type;
using mapped_type = typename Policy::mapped_type;
template <class K>
using key_arg = typename KeyArgImpl::template type<K, key_type>;
static_assert(!std::is_reference<key_type>::value, "");
// TODO(alkis): remove this assertion and verify that reference mapped_type is
// supported.
static_assert(!std::is_reference<mapped_type>::value, "");
using iterator = typename raw_hash_map::raw_hash_set::iterator;
using const_iterator = typename raw_hash_map::raw_hash_set::const_iterator;
raw_hash_map() {}
using raw_hash_map::raw_hash_set::raw_hash_set;
// The last two template parameters ensure that both arguments are rvalues
// (lvalue arguments are handled by the overloads below). This is necessary
// for supporting bitfield arguments.
//
// union { int n : 1; };
// flat_hash_map<int, int> m;
// m.insert_or_assign(n, n);
template <class K = key_type, class V = mapped_type, K* = nullptr,
V* = nullptr>
std::pair<iterator, bool> insert_or_assign(key_arg<K>&& k, V&& v) {
return insert_or_assign_impl(std::forward<K>(k), std::forward<V>(v));
}
template <class K = key_type, class V = mapped_type, K* = nullptr>
std::pair<iterator, bool> insert_or_assign(key_arg<K>&& k, const V& v) {
return insert_or_assign_impl(std::forward<K>(k), v);
}
template <class K = key_type, class V = mapped_type, V* = nullptr>
std::pair<iterator, bool> insert_or_assign(const key_arg<K>& k, V&& v) {
return insert_or_assign_impl(k, std::forward<V>(v));
}
template <class K = key_type, class V = mapped_type>
std::pair<iterator, bool> insert_or_assign(const key_arg<K>& k, const V& v) {
return insert_or_assign_impl(k, v);
}
template <class K = key_type, class V = mapped_type, K* = nullptr,
V* = nullptr>
iterator insert_or_assign(const_iterator, key_arg<K>&& k, V&& v) {
return insert_or_assign(std::forward<K>(k), std::forward<V>(v)).first;
}
template <class K = key_type, class V = mapped_type, K* = nullptr>
iterator insert_or_assign(const_iterator, key_arg<K>&& k, const V& v) {
return insert_or_assign(std::forward<K>(k), v).first;
}
template <class K = key_type, class V = mapped_type, V* = nullptr>
iterator insert_or_assign(const_iterator, const key_arg<K>& k, V&& v) {
return insert_or_assign(k, std::forward<V>(v)).first;
}
template <class K = key_type, class V = mapped_type>
iterator insert_or_assign(const_iterator, const key_arg<K>& k, const V& v) {
return insert_or_assign(k, v).first;
}
// All `try_emplace()` overloads make the same guarantees regarding rvalue
// arguments as `std::unordered_map::try_emplace()`, namely that these
// functions will not move from rvalue arguments if insertions do not happen.
template <class K = key_type, class... Args,
typename std::enable_if<
!std::is_convertible<K, const_iterator>::value, int>::type = 0,
K* = nullptr>
std::pair<iterator, bool> try_emplace(key_arg<K>&& k, Args&&... args) {
return try_emplace_impl(std::forward<K>(k), std::forward<Args>(args)...);
}
template <class K = key_type, class... Args,
typename std::enable_if<
!std::is_convertible<K, const_iterator>::value, int>::type = 0>
std::pair<iterator, bool> try_emplace(const key_arg<K>& k, Args&&... args) {
return try_emplace_impl(k, std::forward<Args>(args)...);
}
template <class K = key_type, class... Args, K* = nullptr>
iterator try_emplace(const_iterator, key_arg<K>&& k, Args&&... args) {
return try_emplace(std::forward<K>(k), std::forward<Args>(args)...).first;
}
template <class K = key_type, class... Args>
iterator try_emplace(const_iterator, const key_arg<K>& k, Args&&... args) {
return try_emplace(k, std::forward<Args>(args)...).first;
}
template <class K = key_type, class P = Policy>
MappedReference<P> at(const key_arg<K>& key) {
auto it = this->find(key);
if (it == this->end()) {
base_internal::ThrowStdOutOfRange(
"absl::container_internal::raw_hash_map<>::at");
}
return Policy::value(&*it);
}
template <class K = key_type, class P = Policy>
MappedConstReference<P> at(const key_arg<K>& key) const {
auto it = this->find(key);
if (it == this->end()) {
base_internal::ThrowStdOutOfRange(
"absl::container_internal::raw_hash_map<>::at");
}
return Policy::value(&*it);
}
template <class K = key_type, class P = Policy, K* = nullptr>
MappedReference<P> operator[](key_arg<K>&& key) {
return Policy::value(&*try_emplace(std::forward<K>(key)).first);
}
template <class K = key_type, class P = Policy>
MappedReference<P> operator[](const key_arg<K>& key) {
return Policy::value(&*try_emplace(key).first);
}
private:
template <class K, class V>
std::pair<iterator, bool> insert_or_assign_impl(K&& k, V&& v) {
auto res = this->find_or_prepare_insert(k);
if (res.second)
this->emplace_at(res.first, std::forward<K>(k), std::forward<V>(v));
else
Policy::value(&*this->iterator_at(res.first)) = std::forward<V>(v);
return {this->iterator_at(res.first), res.second};
}
template <class K = key_type, class... Args>
std::pair<iterator, bool> try_emplace_impl(K&& k, Args&&... args) {
auto res = this->find_or_prepare_insert(k);
if (res.second)
this->emplace_at(res.first, std::piecewise_construct,
std::forward_as_tuple(std::forward<K>(k)),
std::forward_as_tuple(std::forward<Args>(args)...));
return {this->iterator_at(res.first), res.second};
}
};
} // namespace container_internal
ABSL_NAMESPACE_END
} // namespace absl
#endif // ABSL_CONTAINER_INTERNAL_RAW_HASH_MAP_H_
Pods/abseil/absl/container/internal/raw_hash_set.cc
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// Copyright 2018 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "absl/container/internal/raw_hash_set.h"
#include <atomic>
#include <cstddef>
#include "absl/base/config.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace container_internal {
constexpr size_t Group::kWidth;
// Returns "random" seed.
inline size_t RandomSeed() {
#if ABSL_HAVE_THREAD_LOCAL
static thread_local size_t counter = 0;
size_t value = ++counter;
#else // ABSL_HAVE_THREAD_LOCAL
static std::atomic<size_t> counter(0);
size_t value = counter.fetch_add(1, std::memory_order_relaxed);
#endif // ABSL_HAVE_THREAD_LOCAL
return value ^ static_cast<size_t>(reinterpret_cast<uintptr_t>(&counter));
}
bool ShouldInsertBackwards(size_t hash, ctrl_t* ctrl) {
// To avoid problems with weak hashes and single bit tests, we use % 13.
// TODO(kfm,sbenza): revisit after we do unconditional mixing
return (H1(hash, ctrl) ^ RandomSeed()) % 13 > 6;
}
} // namespace container_internal
ABSL_NAMESPACE_END
} // namespace absl
Pods/abseil/absl/container/internal/raw_hash_set.h
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