talksik/uWebSockets
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Update TopicTreeDraft.h

Browse Source
This commit is contained in:
Alex Hultman
2019-10-07 10:21:46 +02:00
committed by GitHub
parent 4a8bfe6c3b
commit a35d7f2ff3
1 changed files with 111 additions and 64 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/TopicTreeDraft.h
+111 -64
View File
@@ -3,15 +3,13 @@
#include <map>
#include <string_view>
#include <functional>
#include <set>
#include <chrono>
/* A Subscriber is an extension of a socket */
struct Subscriber {
/* List of all our subscriptions (subscribersNextSubscription) */
struct Subscription *subscriptions;
/* Reserved */
bool triggered = false;
Subscriber *nextTriggeredSubscriber = nullptr;
};
struct Topic {
@@ -23,7 +21,6 @@ struct Topic {
Topic *parent = nullptr;
/* Next triggered Topic */
Topic *nextTriggered = nullptr;
bool triggered = false;
/* Exact string matches */
@@ -35,11 +32,10 @@ struct Topic {
/* Terminating wildcard child */
Topic *terminatingWildcardChild = nullptr;
/* Subscriptions to this very topic */
Subscription *subscriptions;
/* What we published */
std::map<int, std::string> messages;
/* Collective backpressure */
std::string backpressure;
std::set<Subscriber *> subs;
};
/* A Subscription is a link between Topic and Subscriber */
@@ -62,12 +58,21 @@ struct Subscription {
struct TopicTree {
private:
Topic *root = new Topic;
Topic *triggered = nullptr;
std::function<int(Subscriber *, std::string_view)> cb;
Topic *root = new Topic;
/* Global messageId for deduplication of overlapping topics and ordering between topics */
int messageId = 0;
/* The triggered topics */
Topic *triggeredTopics[64];
int numTriggeredTopics = 0;
Subscriber *min = (Subscriber *) UINTPTR_MAX;
/* Cull or trim unused Topic nodes from leaf to root */
void trimTree(Topic *topic) {
if (!topic->subscriptions && !topic->children.size() && !topic->terminatingWildcardChild && !topic->wildcardChild) {
if (!topic->subs.size() && !topic->children.size() && !topic->terminatingWildcardChild && !topic->wildcardChild) {
Topic *parent = topic->parent;
if (topic->length == 1) {
@@ -84,7 +89,7 @@ private:
}
}
/* Should be getData and commit */
/* Should be getData and commit? */
void publish(Topic *iterator, size_t start, size_t stop, std::string_view topic, std::string_view message) {
for (; stop != std::string::npos; start = stop + 1) {
stop = topic.find('/', start);
@@ -92,16 +97,17 @@ private:
/* Do we have a terminating wildcard child? */
if (iterator->terminatingWildcardChild) {
iterator->terminatingWildcardChild->backpressure.append(message);
iterator->terminatingWildcardChild->messages[messageId] = message;
/* Add this topic to triggered */
if (!iterator->terminatingWildcardChild->triggered) {
if (triggered == nullptr) {
triggered = iterator->terminatingWildcardChild;
} else {
iterator->terminatingWildcardChild->nextTriggered = triggered;
triggered = iterator->terminatingWildcardChild;
triggeredTopics[numTriggeredTopics++] = iterator->terminatingWildcardChild;
/* Keep track of lowest subscriber */
if (*iterator->terminatingWildcardChild->subs.begin() < min) {
min = *iterator->terminatingWildcardChild->subs.begin();
}
iterator->terminatingWildcardChild->triggered = true;
}
}
@@ -121,21 +127,27 @@ private:
}
/* If we went all the way we matched exactly */
iterator->backpressure.append(message);
iterator->messages[messageId] = message;
/* Add this topic to triggered */
if (!iterator->triggered) {
if (triggered == nullptr) {
triggered = iterator;
}
else {
iterator->nextTriggered = triggered;
triggered = iterator;
triggeredTopics[numTriggeredTopics++] = iterator;
/* Keep track of lowest subscriber */
if (*iterator->subs.begin() < min) {
min = *iterator->subs.begin();
}
iterator->triggered = true;
}
}
public:
TopicTree(std::function<int(Subscriber *, std::string_view)> cb) {
this->cb = cb;
}
void subscribe(std::string_view topic, Subscriber *subscriber) {
/* Start iterating from the root */
Topic *iterator = root;
@@ -155,7 +167,6 @@ public:
newTopic->parent = iterator;
newTopic->name = new char[segment.length()];
newTopic->length = segment.length();
newTopic->subscriptions = nullptr;
newTopic->terminatingWildcardChild = nullptr;
newTopic->wildcardChild = nullptr;
memcpy(newTopic->name, segment.data(), segment.length());
@@ -179,65 +190,101 @@ public:
}
}
/* Allocate new Subscription */
Subscription *subscription = new Subscription;
subscription->subscriber = subscriber;
subscription->topic = iterator;
/* Link Subscription to Subscriber*/
subscription->subscribersNextSubscription = subscriber->subscriptions;
subscriber->subscriptions = subscription;
/* Link Subscription to Topic */
subscription->topicNextSubscription = iterator->subscriptions;
iterator->subscriptions = subscription;
/* Add socket to Topic's Set */
iterator->subs.insert(subscriber);
}
void publish(std::string_view topic, std::string_view message) {
publish(root, 0, 0, topic, message);
messageId++;
}
/* Rarely used, probably */
void unsubscribe(std::string_view topic, Subscriber *subscriber) {
/* Subscribers are likely to have very few subscriptions (20 or fewer) */
/*Subscription *iterator = subscriber->subscriptions;
while (iterator) {
// avlänka OM DET ÄR RÄTT TOPIC!
iterator->topic->subscriptions = nullptr;
trimTree(iterator->topic);
iterator = iterator->subscribersNextSubscription;
}*/
}
void unsubscribeAll(Subscriber *subscriber) {
Subscription *iterator = subscriber->subscriptions;
while (iterator) {
// avlänka
iterator->topic->subscriptions = nullptr;
for (Subscription *iterator = subscriber->subscriptions; iterator; iterator = iterator->subscribersNextSubscription) {
iterator->topic->subs.erase(subscriber);
trimTree(iterator->topic);
iterator = iterator->subscribersNextSubscription;
}
}
/* Drain the tree by emitting what to send with every Subscriber */
void drain(std::function<int(Subscriber *, std::string_view)> cb) {
void drain(/*std::function<int(Subscriber *, std::string_view)> cb*/) {
// for all triggered topics
Topic *iterator = triggered;
while (iterator) {
cb(nullptr, iterator->backpressure);
/* Up to 64 triggered Topics per batch */
std::map<uint64_t, std::string> intersectionCache;
iterator = iterator->nextTriggered;
/* Loop over these here */
std::set<Subscriber *>::iterator it[64];
std::set<Subscriber *>::iterator end[64];
for (int i = 0; i < numTriggeredTopics; i++) {
it[i] = triggeredTopics[i]->subs.begin();
end[i] = triggeredTopics[i]->subs.end();
}
}
/* Empty all sets from unique subscribers */
for (int nonEmpty = numTriggeredTopics; nonEmpty; ) {
/* Drain one particular Subscriber, as called from its writable callback */
void drain(Subscriber *subscriber, std::function<int(std::string_view)> cb) {
// know what backpressure to send
Subscriber *nextMin = (Subscriber *)UINTPTR_MAX;
/* The message sets relevant for this intersection */
std::map<int, std::string> *perSubscriberIntersectingTopicMessages[64];
int numPerSubscriberIntersectingTopicMessages = 0;
uint64_t intersection = 0;
for (int i = 0; i < numTriggeredTopics; i++) {
if ((it[i] != end[i]) && (*it[i] == min)) {
/* Mark this intersection */
intersection |= (1 << i);
perSubscriberIntersectingTopicMessages[numPerSubscriberIntersectingTopicMessages++] = &triggeredTopics[i]->messages;
it[i]++;
if (it[i] == end[i]) {
nonEmpty--;
}
else {
if (nextMin > *it[i]) {
nextMin = *it[i];
}
}
}
else {
/* We need to lower nextMin to us, in the case of min being the last in a set */
if ((it[i] != end[i]) && (nextMin > *it[i])) {
nextMin = *it[i];
}
}
}
/* Generate cache for intersection */
if (intersectionCache[intersection].length() == 0) {
/* Build the union in order without duplicates */
std::map<int, std::string> complete;
for (int i = 0; i < numPerSubscriberIntersectingTopicMessages; i++) {
complete.insert(perSubscriberIntersectingTopicMessages[i]->begin(), perSubscriberIntersectingTopicMessages[i]->end());
}
/* Create the linear cache */
std::string res;
for (auto &p : complete) {
res.append(p.second);
}
cb(min, intersectionCache[intersection] = std::move(res));
}
else {
cb(min, intersectionCache[intersection]);
}
min = nextMin;
}
}
void print(Topic *root = nullptr, int indentation = 1) {
@@ -250,7 +297,7 @@ public:
for (int i = 0; i < indentation; i++) {
std::cout << " ";
}
std::cout << std::string_view(p.second->name, p.second->length) << " = " << p.second->backpressure.c_str() << std::endl;
std::cout << std::string_view(p.second->name, p.second->length) << " = " << p.second->messages.size() << " publishes, " << p.second->subs.size() << " subscribers" << std::endl;
print(p.second, indentation + 1);
}
}