| /* |
| * Copyright (c) 2019 The WebRTC project authors. All Rights Reserved. |
| * |
| * Use of this source code is governed by a BSD-style license |
| * that can be found in the LICENSE file in the root of the source |
| * tree. An additional intellectual property rights grant can be found |
| * in the file PATENTS. All contributing project authors may |
| * be found in the AUTHORS file in the root of the source tree. |
| */ |
| |
| #ifndef TEST_PC_E2E_ANALYZER_VIDEO_MULTI_HEAD_QUEUE_H_ |
| #define TEST_PC_E2E_ANALYZER_VIDEO_MULTI_HEAD_QUEUE_H_ |
| |
| #include <deque> |
| #include <memory> |
| #include <vector> |
| |
| #include "absl/types/optional.h" |
| #include "rtc_base/checks.h" |
| |
| namespace webrtc { |
| |
| // A queue that allows more than one reader. Readers are independent, and all |
| // readers will see all elements; an inserted element stays in the queue until |
| // all readers have extracted it. Elements are copied and copying is assumed to |
| // be cheap. |
| template <typename T> |
| class MultiHeadQueue { |
| public: |
| // Creates queue with exactly `readers_count` readers. |
| explicit MultiHeadQueue(size_t readers_count) { |
| for (size_t i = 0; i < readers_count; ++i) { |
| queues_.push_back(std::deque<T>()); |
| } |
| } |
| |
| // Creates a copy of an existing head. Complexity O(MultiHeadQueue::size()). |
| // `copy_index` - index of the queue that will be used as a source for |
| // copying. |
| void AddHead(size_t copy_index) { queues_.push_back(queues_[copy_index]); } |
| |
| // Add value to the end of the queue. Complexity O(readers_count). |
| void PushBack(T value) { |
| for (auto& queue : queues_) { |
| queue.push_back(value); |
| } |
| } |
| |
| // Extract element from specified head. Complexity O(1). |
| absl::optional<T> PopFront(size_t index) { |
| RTC_CHECK_LT(index, queues_.size()); |
| if (queues_[index].empty()) { |
| return absl::nullopt; |
| } |
| T out = queues_[index].front(); |
| queues_[index].pop_front(); |
| return out; |
| } |
| |
| // Returns element at specified head. Complexity O(1). |
| absl::optional<T> Front(size_t index) const { |
| RTC_CHECK_LT(index, queues_.size()); |
| if (queues_[index].empty()) { |
| return absl::nullopt; |
| } |
| return queues_[index].front(); |
| } |
| |
| // Returns true if for specified head there are no more elements in the queue |
| // or false otherwise. Complexity O(1). |
| bool IsEmpty(size_t index) const { |
| RTC_CHECK_LT(index, queues_.size()); |
| return queues_[index].empty(); |
| } |
| |
| // Returns size of the longest queue between all readers. |
| // Complexity O(readers_count). |
| size_t size() const { |
| size_t size = 0; |
| for (auto& queue : queues_) { |
| if (queue.size() > size) { |
| size = queue.size(); |
| } |
| } |
| return size; |
| } |
| |
| // Returns size of the specified queue. Complexity O(1). |
| size_t size(size_t index) const { |
| RTC_CHECK_LT(index, queues_.size()); |
| return queues_[index].size(); |
| } |
| |
| size_t readers_count() const { return queues_.size(); } |
| |
| private: |
| std::vector<std::deque<T>> queues_; |
| }; |
| |
| } // namespace webrtc |
| |
| #endif // TEST_PC_E2E_ANALYZER_VIDEO_MULTI_HEAD_QUEUE_H_ |