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PiperOrigin-RevId: 253489161

mediapipe/gpu/gl_texture_buffer_pool.cc

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+// Copyright 2019 The MediaPipe 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
+//
+//      http://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 "mediapipe/gpu/gl_texture_buffer_pool.h"
+
+#include "absl/synchronization/mutex.h"
+
+namespace mediapipe {
+
+GlTextureBufferPool::GlTextureBufferPool(int width, int height,
+                                         GpuBufferFormat format, int keep_count)
+    : width_(width),
+      height_(height),
+      format_(format),
+      keep_count_(keep_count) {}
+
+GlTextureBufferSharedPtr GlTextureBufferPool::GetBuffer() {
+  absl::MutexLock lock(&mutex_);
+
+  std::unique_ptr<GlTextureBuffer> buffer;
+  if (available_.empty()) {
+    buffer = GlTextureBuffer::Create(width_, height_, format_);
+    if (!buffer) return nullptr;
+  } else {
+    buffer = std::move(available_.back());
+    available_.pop_back();
+    buffer->Reuse();
+  }
+
+  ++in_use_count_;
+
+  // Return a shared_ptr with a custom deleter that adds the buffer back
+  // to our available list.
+  std::weak_ptr<GlTextureBufferPool> weak_pool(shared_from_this());
+  return std::shared_ptr<GlTextureBuffer>(buffer.release(),
+                                          [weak_pool](GlTextureBuffer* buf) {
+                                            auto pool = weak_pool.lock();
+                                            if (pool) {
+                                              pool->Return(buf);
+                                            } else {
+                                              delete buf;
+                                            }
+                                          });
+}
+
+std::pair<int, int> GlTextureBufferPool::GetInUseAndAvailableCounts() {
+  absl::MutexLock lock(&mutex_);
+  return {in_use_count_, available_.size()};
+}
+
+void GlTextureBufferPool::Return(GlTextureBuffer* buf) {
+  absl::MutexLock lock(&mutex_);
+  --in_use_count_;
+  available_.emplace_back(buf);
+  TrimAvailable();
+}
+
+void GlTextureBufferPool::TrimAvailable() {
+  int keep = std::max(keep_count_ - in_use_count_, 0);
+  if (available_.size() > keep) {
+    available_.resize(keep);
+  }
+}
+
+}  // namespace mediapipe