| // Copyright 2018 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. |
| |
| #ifndef CHROMECAST_NET_SMALL_MESSAGE_SOCKET_H_ |
| #define CHROMECAST_NET_SMALL_MESSAGE_SOCKET_H_ |
| |
| #include <memory> |
| |
| #include "base/macros.h" |
| #include "base/memory/ref_counted.h" |
| #include "base/memory/weak_ptr.h" |
| |
| namespace base { |
| class SequencedTaskRunner; |
| } // namespace base |
| |
| namespace net { |
| class GrowableIOBuffer; |
| class IOBuffer; |
| class Socket; |
| } // namespace net |
| |
| namespace chromecast { |
| class IOBufferPool; |
| |
| // Sends small messages (< 64 KB) over a Socket. All methods must be called on |
| // the same sequence. Any of the virtual methods can destroy this object if |
| // desired. |
| class SmallMessageSocket { |
| public: |
| class Delegate { |
| public: |
| // Called when sending becomes possible again, if a previous attempt to send |
| // was rejected. |
| virtual void OnSendUnblocked() {} |
| |
| // Called when an unrecoverable error occurs while sending or receiving. Is |
| // only called asynchronously. |
| virtual void OnError(int error) {} |
| |
| // Called when the end of stream has been read. No more data will be |
| // received. |
| virtual void OnEndOfStream() {} |
| |
| // Called when a message has been received and there is no buffer pool. The |
| // |data| buffer contains |size| bytes of data. Return |true| to continue |
| // reading messages after OnMessage() returns. |
| virtual bool OnMessage(char* data, int size) = 0; |
| |
| // Called when a message has been received. The |buffer| contains |size| |
| // bytes of data, which includes the first 2 bytes which are the size in |
| // network byte order. Note that these 2 bytes are not included in |
| // OnMessage()! Return |true| to continue receiving messages. |
| virtual bool OnMessageBuffer(scoped_refptr<net::IOBuffer> buffer, int size); |
| |
| protected: |
| virtual ~Delegate() = default; |
| }; |
| |
| SmallMessageSocket(Delegate* delegate, std::unique_ptr<net::Socket> socket); |
| virtual ~SmallMessageSocket(); |
| |
| net::Socket* socket() const { return socket_.get(); } |
| base::SequencedTaskRunner* task_runner() const { return task_runner_.get(); } |
| IOBufferPool* buffer_pool() const { return buffer_pool_.get(); } |
| |
| // Adds a |buffer_pool| used to allocate buffers to receive messages into; |
| // received messages are passed to OnMessageBuffer(). If a message would be |
| // too big to fit in a pool-provided buffer, a dynamically allocated IOBuffer |
| // will be used instead for that message. |
| void UseBufferPool(scoped_refptr<IOBufferPool> buffer_pool); |
| |
| // Removes the buffer pool; subsequent received messages will be passed to |
| // OnMessage(). |
| void RemoveBufferPool(); |
| |
| // Prepares a buffer to send a message of the given |message_size|. Returns |
| // nullptr if sending is not allowed right now (ie, another send is currently |
| // in progress). Otherwise, returns a buffer at least large enough to contain |
| // |message_size| bytes. The caller should fill in the buffer as desired and |
| // then call Send() to send the finished message. |
| // If nullptr is returned, then OnSendUnblocked() will be called once sending |
| // is possible again. |
| void* PrepareSend(int message_size); |
| void Send(); |
| |
| // Sends an already-prepared buffer of data, if possible. The first 2 bytes of |
| // the buffer must contain the size of the rest of the data, encoded as a |
| // 16-bit integer in big-endian byte order. Returns true if the buffer will be |
| // sent; returns false if sending is not allowed right now (ie, another send |
| // is currently in progress). If false is returned, then OnSendUnblocked() |
| // will be called once sending is possible again. |
| bool SendBuffer(scoped_refptr<net::IOBuffer> data, int size); |
| |
| // Enables receiving messages from the stream. Messages will be received and |
| // passed to OnMessage() until either an error occurs, the end of stream is |
| // reached, or OnMessage() returns false. If OnMessage() returns false, you |
| // may call ReceiveMessages() to start receiving again. OnMessage() will not |
| // be called synchronously from within this method (it always posts a task). |
| void ReceiveMessages(); |
| |
| // Same as ReceiveMessages(), but OnMessage() may be called synchronously. |
| // This is more efficient because it doesn't post a task to ensure |
| // asynchronous reads. |
| void ReceiveMessagesSynchronously(); |
| |
| private: |
| class BufferWrapper; |
| |
| void OnWriteComplete(int result); |
| bool HandleWriteResult(int result); |
| void OnError(int error); |
| |
| void Read(); |
| void OnReadComplete(int result); |
| bool HandleReadResult(int result); |
| bool HandleCompletedMessages(); |
| bool HandleCompletedMessageBuffers(); |
| void ActivateBufferPool(char* current_data, size_t current_size); |
| |
| Delegate* const delegate_; |
| const std::unique_ptr<net::Socket> socket_; |
| const scoped_refptr<base::SequencedTaskRunner> task_runner_; |
| |
| const scoped_refptr<net::GrowableIOBuffer> write_storage_; |
| const scoped_refptr<BufferWrapper> write_buffer_; |
| bool send_blocked_ = false; |
| |
| const scoped_refptr<net::GrowableIOBuffer> read_storage_; |
| |
| scoped_refptr<IOBufferPool> buffer_pool_; |
| const scoped_refptr<BufferWrapper> read_buffer_; |
| |
| bool in_message_ = false; |
| |
| base::WeakPtrFactory<SmallMessageSocket> weak_factory_; |
| |
| DISALLOW_COPY_AND_ASSIGN(SmallMessageSocket); |
| }; |
| |
| } // namespace chromecast |
| |
| #endif // CHROMECAST_NET_SMALL_MESSAGE_SOCKET_H_ |