Revert of [cast_channel] Move cast_channel related files from //extensions to //components

components/cast_channel/cast_transport.h

-// Copyright 2014 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 COMPONENTS_CAST_CHANNEL_CAST_TRANSPORT_H_
-#define COMPONENTS_CAST_CHANNEL_CAST_TRANSPORT_H_
-
-#include <queue>
-#include <string>
-
-#include "base/macros.h"
-#include "base/memory/ref_counted.h"
-#include "base/sequence_checker.h"
-#include "base/threading/thread_checker.h"
-#include "components/cast_channel/cast_channel_enum.h"
-#include "components/cast_channel/logger.h"
-#include "components/cast_channel/proto/logging.pb.h"
-#include "net/base/completion_callback.h"
-#include "net/base/ip_endpoint.h"
-
-namespace net {
-class DrainableIOBuffer;
-class DrainableIOBuffer;
-class GrowableIOBuffer;
-class Socket;
-}  // namespace net
-
-namespace cast_channel {
-class CastMessage;
-class MessageFramer;
-
-class CastTransport {
- public:
-  virtual ~CastTransport() {}
-
-  // Object to be informed of incoming messages and read errors.
-  class Delegate {
-   public:
-    using ChannelError = ::cast_channel::ChannelError;
-
-    virtual ~Delegate() {}
-
-    // Called once Transport is successfully initialized and started.
-    // Owned read delegates are Start()ed automatically.
-    virtual void Start() = 0;
-
-    // An error occurred on the channel.
-    // The caller is responsible for closing |socket| if an error occurred.
-    virtual void OnError(ChannelError error_state) = 0;
-
-    // A message was received on the channel.
-    virtual void OnMessage(const CastMessage& message) = 0;
-  };
-
-  // Sends a CastMessage to |socket_|.
-  // |message|: The message to send.
-  // |callback|: Callback to be invoked when the write operation has finished.
-  // Virtual for testing.
-  virtual void SendMessage(const CastMessage& message,
-                           const net::CompletionCallback& callback) = 0;
-
-  // Initializes the reading state machine and starts reading from the
-  // underlying socket.
-  // Virtual for testing.
-  virtual void Start() = 0;
-
-  // Changes the delegate for processing read events. Pending reads remain
-  // in-flight.
-  // Ownership of the pointee of |delegate| is assumed by the transport.
-  // Prior delegates are deleted automatically.
-  virtual void SetReadDelegate(std::unique_ptr<Delegate> delegate) = 0;
-};
-
-// Manager class for reading and writing messages to/from a socket.
-class CastTransportImpl : public CastTransport {
- public:
-  using ChannelAuthType = ::cast_channel::ChannelAuthType;
-  using ChannelError = ::cast_channel::ChannelError;
-
-  // Adds a CastMessage read/write layer to a socket.
-  // Message read events are propagated to the owner via |read_delegate|.
-  // |vlog_prefix| sets the prefix used for all VLOGged output.
-  // |socket| and |logger| must all out-live the
-  // CastTransportImpl instance.
-  // |read_delegate| is owned by this CastTransportImpl object.
-  CastTransportImpl(net::Socket* socket,
-                    int channel_id,
-                    const net::IPEndPoint& ip_endpoint_,
-                    ChannelAuthType channel_auth_,
-                    scoped_refptr<Logger> logger);
-
-  ~CastTransportImpl() override;
-
-  // CastTransport interface.
-  void SendMessage(const CastMessage& message,
-                   const net::CompletionCallback& callback) override;
-  void Start() override;
-  void SetReadDelegate(std::unique_ptr<Delegate> delegate) override;
-
- private:
-  // Internal write states.
-  enum WriteState {
-    WRITE_STATE_UNKNOWN,
-    WRITE_STATE_WRITE,
-    WRITE_STATE_WRITE_COMPLETE,
-    WRITE_STATE_DO_CALLBACK,
-    WRITE_STATE_HANDLE_ERROR,
-    WRITE_STATE_ERROR,
-    WRITE_STATE_IDLE,
-  };
-
-  // Internal read states.
-  enum ReadState {
-    READ_STATE_UNKNOWN,
-    READ_STATE_READ,
-    READ_STATE_READ_COMPLETE,
-    READ_STATE_DO_CALLBACK,
-    READ_STATE_HANDLE_ERROR,
-    READ_STATE_ERROR,
-  };
-
-  // Holds a message to be written to the socket. |callback| is invoked when the
-  // message is fully written or an error occurrs.
-  struct WriteRequest {
-    explicit WriteRequest(const std::string& namespace_,
-                          const std::string& payload,
-                          const net::CompletionCallback& callback);
-    WriteRequest(const WriteRequest& other);
-    ~WriteRequest();
-
-    // Namespace of the serialized message.
-    std::string message_namespace;
-    // Write completion callback, invoked when the operation has completed or
-    // failed.
-    net::CompletionCallback callback;
-    // Buffer with outgoing data.
-    scoped_refptr<net::DrainableIOBuffer> io_buffer;
-  };
-
-  static proto::ReadState ReadStateToProto(CastTransportImpl::ReadState state);
-  static proto::WriteState WriteStateToProto(
-      CastTransportImpl::WriteState state);
-  static proto::ErrorState ErrorStateToProto(ChannelError state);
-  static bool IsTerminalReadState(ReadState read_state);
-  static bool IsTerminalWriteState(WriteState write_state);
-
-  void SetReadState(ReadState read_state);
-  void SetWriteState(WriteState write_state);
-  void SetErrorState(ChannelError error_state);
-
-  // Terminates all in-flight write callbacks with error code ERR_FAILED.
-  void FlushWriteQueue();
-
-  // Main method that performs write flow state transitions.
-  void OnWriteResult(int result);
-
-  // Each of the below Do* method is executed in the corresponding
-  // write state. For example when write state is WRITE_STATE_WRITE_COMPLETE
-  // DowriteComplete is called, and so on.
-  int DoWrite();
-  int DoWriteComplete(int result);
-  int DoWriteCallback();
-  int DoWriteHandleError(int result);
-
-  // Main method that performs write flow state transitions.
-  void OnReadResult(int result);
-
-  // Each of the below Do* method is executed in the corresponding
-  // write state. For example when read state is READ_STATE_READ_COMPLETE
-  // DoReadComplete is called, and so on.
-  int DoRead();
-  int DoReadComplete(int result);
-  int DoReadCallback();
-  int DoReadHandleError(int result);
-
-  // Indicates that the transport object is started and may receive and send
-  // messages.
-  bool started_;
-
-  // Queue of pending writes. The message at the front of the queue is the one
-  // being written.
-  std::queue<WriteRequest> write_queue_;
-
-  // Buffer used for read operations. Reused for every read.
-  scoped_refptr<net::GrowableIOBuffer> read_buffer_;
-
-  // Constructs and parses the wire representation of message frames.
-  std::unique_ptr<MessageFramer> framer_;
-
-  // Last message received on the socket.
-  std::unique_ptr<CastMessage> current_message_;
-
-  // Socket used for I/O operations.
-  net::Socket* const socket_;
-
-  // Methods for communicating message receipt and error status to client code.
-  std::unique_ptr<Delegate> delegate_;
-
-  // Write flow state machine state.
-  WriteState write_state_;
-
-  // Read flow state machine state.
-  ReadState read_state_;
-
-  // The last error encountered by the channel.
-  ChannelError error_state_;
-
-  // Connection metadata for logging purposes.
-  // Socket ID assigned by ApiResourceManager.
-  int channel_id_;
-
-  // IP address of the remote end.
-  const net::IPEndPoint ip_endpoint_;
-
-  // Authentication level for the connection.
-  ChannelAuthType channel_auth_;
-
-  // Accumulates details of events and errors, for debugging purposes.
-  scoped_refptr<Logger> logger_;
-
-  SEQUENCE_CHECKER(sequence_checker_);
-
-  DISALLOW_COPY_AND_ASSIGN(CastTransportImpl);
-};
-}  // namespace cast_channel
-
-#endif  // COMPONENTS_CAST_CHANNEL_CAST_TRANSPORT_H_