BufferQueue.h

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/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */
 
#ifndef FACEBOOK_NETWORK_BUFFER_QUEUE_H
#define FACEBOOK_NETWORK_BUFFER_QUEUE_H
 
#include "ocean/network/Network.h"
 
#include "ocean/base/Lock.h"
 
#include <deque>
#include <vector>
 
namespace Ocean
{
 
namespace Network
{
 
/**
 * This class implements a thread-safe buffer queue.
 * @ingroup network
 */
class BufferQueue
{
    protected:
 
        /**
         * Definition of a vector holding bytes.
         */
        typedef std::vector<uint8_t> Buffer;
 
        /**
         * Definition of a double-ended queue holding buffers.
         */
        typedef std::deque<Buffer> Queue;
 
    public:
 
        /**
         * Pushes a new buffer to the queue.
         * @param data The data to push, will be copied, can be nullptr if 'size == 0'
         * @param size The number of bytes to copy, with range [0, infinity)
         */
        inline void push(const void* data, const size_t size);
 
        /**
         * Pushes a new buffer to the queue.
         * @param data The data to push, will be moved
         */
        inline void push(Buffer&& data);
 
        /**
         * Pops a buffer from the queue.
         * @return The buffer, if any
         */
        inline Buffer pop();
 
        /**
         * Clears the buffer queue.
         */
        inline void clear();
 
        /**
         * Returns the number of buffers in this queue.
         * @return The number of buffers
         */
        inline size_t size() const;
 
        /**
         * Returns whether this queue holds no buffers.
         * @return True, if so
         */
        inline bool isEmpty() const;
 
    protected:
 
        /// The internal buffer queue.
        Queue queue_;
 
        /// The buffer lock.
        mutable Lock lock_;
};
 
inline void BufferQueue::push(const void* data, const size_t size)
{
    if (size == 0)
    {
        return;
    }
 
    ocean_assert(data != nullptr);
 
    const ScopedLock scopedLock(lock_);
 
    Buffer buffer(size);
    memcpy(buffer.data(), data, size);
 
    queue_.emplace_back(std::move(buffer));
}
 
inline void BufferQueue::push(Buffer&& data)
{
    ocean_assert(!data.empty());
    if (data.empty())
    {
        return;
    }
 
    const ScopedLock scopedLock(lock_);
 
    queue_.emplace_back(std::move(data));
}
 
inline BufferQueue::Buffer BufferQueue::pop()
{
    const ScopedLock scopedLock(lock_);
 
    if (queue_.empty())
    {
        return Buffer();
    }
 
    Buffer buffer(std::move(queue_.front()));
    queue_.pop_front();
 
    return buffer;
}
 
inline void BufferQueue::clear()
{
    const ScopedLock scopedLock(lock_);
    queue_.clear();
}
 
inline size_t BufferQueue::size() const
{
    const ScopedLock scopedLock(lock_);
    return queue_.size();
}
 
inline bool BufferQueue::isEmpty() const
{
    const ScopedLock scopedLock(lock_);
    return queue_.empty();
}
 
}
 
}
 
#endif // FACEBOOK_NETWORK_BUFFER_QUEUE_H