blob: bc5bd6015f387e7453f17f4f715f63bd0f15251b [file] [log] [blame]
// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <stdint.h>
#include <list>
#include <queue>
#include <utility>
#include "base/macros.h"
#include "blimp/net/blimp_message_checkpoint_observer.h"
#include "blimp/net/blimp_message_processor.h"
#include "blimp/net/blimp_net_export.h"
#include "net/base/completion_callback.h"
namespace blimp {
class BlimpConnection;
// Provides a FIFO buffer for reliable, ordered message delivery.
// Messages are retained for redelivery until they are acknowledged by the
// receiving end (via BlimpMessageCheckpointObserver).
// Messages can be paired with callbacks that are invoked on successful
// message acknowledgment.
// (Redelivery will be used in a future CL to implement Fast Recovery
// of dropped connections.)
// BlimpMessageOutputBuffer is created on the UI thread, and then used and
// destroyed on the IO thread.
class BLIMP_NET_EXPORT BlimpMessageOutputBuffer
: public BlimpMessageProcessor,
public BlimpMessageCheckpointObserver {
explicit BlimpMessageOutputBuffer(int max_buffer_size_bytes);
~BlimpMessageOutputBuffer() override;
// Sets the processor that will be used for writing buffered messages.
void SetOutputProcessor(BlimpMessageProcessor* processor);
// Marks all messages in buffer for retransmission.
void RetransmitBufferedMessages();
// BlimpMessageProcessor implementation.
// |callback|, if set, will be called once the remote end has acknowledged the
// receipt of |message|.
void ProcessMessage(std::unique_ptr<BlimpMessage> message,
const net::CompletionCallback& callback) override;
// MessageCheckpointObserver implementation.
void OnMessageCheckpoint(int64_t message_id) override;
int GetBufferByteSizeForTest() const;
int GetUnacknowledgedMessageCountForTest() const;
struct BufferEntry {
BufferEntry(std::unique_ptr<BlimpMessage> message,
net::CompletionCallback callback);
const std::unique_ptr<BlimpMessage> message;
const net::CompletionCallback callback;
typedef std::list<std::unique_ptr<BufferEntry>> MessageBuffer;
// Writes the next message in the buffer if an output processor is attached
// and the buffer contains a message.
void WriteNextMessageIfReady();
// Receives the completion status of a write operation.
void OnWriteComplete(int result);
BlimpMessageProcessor* output_processor_ = nullptr;
net::CancelableCompletionCallback write_complete_cb_;
// Maximum serialized footprint of buffered messages.
int max_buffer_size_bytes_;
// Serialized footprint of the messages contained in the write and ack
// buffers.
int current_buffer_size_bytes_ = 0;
// The ID used by the last outgoing message.
int64_t prev_message_id_ = 0;
// List of unsent messages.
MessageBuffer write_buffer_;
// List of messages that are sent and awaiting acknowledgment.
// The messages in |ack_buffer_| are contiguous with the messages in
// |write_buffer_|.
MessageBuffer ack_buffer_;
} // namespace blimp