| /* |
| * Copyright 2020 The Android Open Source Project |
| * |
| * 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. |
| */ |
| |
| #pragma once |
| |
| #include <cstddef> |
| #include <iterator> |
| #include <memory> |
| #include <mutex> |
| #include <queue> |
| |
| namespace bluetooth { |
| namespace common { |
| |
| template <typename T> |
| class CircularBuffer { |
| public: |
| explicit CircularBuffer(size_t size); |
| |
| // Push one item to the circular buffer |
| void Push(T item); |
| // Take a snapshot of the circular buffer and return it as a vector |
| std::vector<T> Pull() const; |
| // Drain everything from the circular buffer and return them as a vector |
| std::vector<T> Drain(); |
| |
| private: |
| const size_t size_; |
| std::deque<T> queue_; |
| mutable std::mutex mutex_; |
| }; |
| |
| class Timestamper { |
| public: |
| virtual long long GetTimestamp() const = 0; |
| virtual ~Timestamper() {} |
| }; |
| |
| class TimestamperInMilliseconds : public Timestamper { |
| public: |
| long long GetTimestamp() const override { |
| return std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now().time_since_epoch()) |
| .count(); |
| } |
| virtual ~TimestamperInMilliseconds() {} |
| }; |
| |
| template <typename T> |
| struct TimestampedEntry { |
| long long timestamp; |
| T entry; |
| }; |
| |
| template <typename T> |
| class TimestampedCircularBuffer : public CircularBuffer<TimestampedEntry<T>> { |
| public: |
| explicit TimestampedCircularBuffer( |
| size_t size, std::unique_ptr<Timestamper> timestamper = std::make_unique<TimestamperInMilliseconds>()); |
| |
| void Push(T item); |
| std::vector<TimestampedEntry<T>> Pull() const; |
| std::vector<TimestampedEntry<T>> Drain(); |
| |
| private: |
| std::unique_ptr<Timestamper> timestamper_{std::make_unique<TimestamperInMilliseconds>()}; |
| }; |
| |
| } // namespace common |
| } // namespace bluetooth |
| |
| template <typename T> |
| bluetooth::common::CircularBuffer<T>::CircularBuffer(size_t size) : size_(size) {} |
| |
| template <typename T> |
| void bluetooth::common::CircularBuffer<T>::Push(const T item) { |
| std::unique_lock<std::mutex> lock(mutex_); |
| queue_.push_back(item); |
| while (queue_.size() > size_) { |
| queue_.pop_front(); |
| } |
| } |
| |
| template <typename T> |
| std::vector<T> bluetooth::common::CircularBuffer<T>::Pull() const { |
| std::unique_lock<std::mutex> lock(mutex_); |
| return std::vector<T>(queue_.cbegin(), queue_.cend()); |
| } |
| |
| template <typename T> |
| std::vector<T> bluetooth::common::CircularBuffer<T>::Drain() { |
| std::unique_lock<std::mutex> lock(mutex_); |
| std::vector<T> items(std::make_move_iterator(queue_.begin()), std::make_move_iterator(queue_.end())); |
| queue_.clear(); |
| return items; |
| } |
| |
| template <typename T> |
| bluetooth::common::TimestampedCircularBuffer<T>::TimestampedCircularBuffer( |
| size_t size, std::unique_ptr<Timestamper> timestamper) |
| : CircularBuffer<TimestampedEntry<T>>(size), timestamper_(std::move(timestamper)) {} |
| |
| template <typename T> |
| void bluetooth::common::TimestampedCircularBuffer<T>::Push(const T item) { |
| TimestampedEntry<T> timestamped_entry{timestamper_->GetTimestamp(), item}; |
| bluetooth::common::CircularBuffer<TimestampedEntry<T>>::Push(timestamped_entry); |
| } |
| |
| template <typename T> |
| std::vector<struct bluetooth::common::TimestampedEntry<T>> bluetooth::common::TimestampedCircularBuffer<T>::Pull() |
| const { |
| return bluetooth::common::CircularBuffer<TimestampedEntry<T>>::Pull(); |
| } |
| |
| template <typename T> |
| std::vector<struct bluetooth::common::TimestampedEntry<T>> bluetooth::common::TimestampedCircularBuffer<T>::Drain() { |
| return bluetooth::common::CircularBuffer<TimestampedEntry<T>>::Drain(); |
| } |