Revert of Revert "Revert of Moving gRPC support interfaces out of cronet and into a new component. (patchset …

components/grpc_support/bidirectional_stream.h

-// Copyright 2016 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_GRPC_SUPPORT_BIDIRECTIONAL_STREAM_H_
-#define COMPONENTS_GRPC_SUPPORT_BIDIRECTIONAL_STREAM_H_
-
-#include <memory>
-#include <vector>
-
-#include "base/macros.h"
-#include "base/memory/ref_counted.h"
-#include "base/memory/weak_ptr.h"
-#include "base/synchronization/lock.h"
-#include "net/http/bidirectional_stream.h"
-#include "net/url_request/url_request_context_getter.h"
-
-namespace net {
-class HttpRequestHeaders;
-class WrappedIOBuffer;
-}  // namespace net
-
-namespace grpc_support {
-
-// An adapter to net::BidirectionalStream.
-// Created and configured from any thread. Start, ReadData, WriteData and
-// Destroy can be called on any thread (including network thread), and post
-// calls to corresponding {Start|ReadData|WriteData|Destroy}OnNetworkThread to
-// the network thread. The object is always deleted on network thread. All
-// callbacks into the Delegate are done on the network thread.
-// The app is expected to initiate the next step like ReadData or Destroy.
-// Public methods can be called on any thread.
-class BidirectionalStream : public net::BidirectionalStream::Delegate {
- public:
-  class Delegate {
-   public:
-    virtual void OnStreamReady() = 0;
-
-    virtual void OnHeadersReceived(const net::SpdyHeaderBlock& response_headers,
-                                   const char* negotiated_protocol) = 0;
-
-    virtual void OnDataRead(char* data, int size) = 0;
-
-    virtual void OnDataSent(const char* data) = 0;
-
-    virtual void OnTrailersReceived(const net::SpdyHeaderBlock& trailers) = 0;
-
-    virtual void OnSucceeded() = 0;
-
-    virtual void OnFailed(int error) = 0;
-
-    virtual void OnCanceled() = 0;
-  };
-
-  BidirectionalStream(net::URLRequestContextGetter* request_context_getter,
-                      Delegate* delegate);
-  ~BidirectionalStream() override;
-
-  // Disables automatic flushing of each buffer passed to WriteData().
-  void disable_auto_flush(bool disable_auto_flush) {
-    disable_auto_flush_ = disable_auto_flush;
-  }
-
-  // Delays sending request headers until first call to Flush().
-  void delay_headers_until_flush(bool delay_headers_until_flush) {
-    delay_headers_until_flush_ = delay_headers_until_flush;
-  }
-
-  // Validates method and headers, initializes and starts the request. If
-  // |end_of_stream| is true, then stream is half-closed after sending header
-  // frame and no data is expected to be written.
-  // Returns 0 if request is valid and started successfully,
-  // Returns -1 if |method| is not valid HTTP method name.
-  // Returns position of invalid header value in |headers| if header name is
-  // not valid.
-  int Start(const char* url,
-            int priority,
-            const char* method,
-            const net::HttpRequestHeaders& headers,
-            bool end_of_stream);
-
-  // Reads more data into |buffer| up to |capacity| bytes.
-  bool ReadData(char* buffer, int capacity);
-
-  // Writes |count| bytes of data from |buffer|. The |end_of_stream| is
-  // passed to remote to indicate end of stream.
-  bool WriteData(const char* buffer, int count, bool end_of_stream);
-
-  // Sends buffers passed to WriteData().
-  void Flush();
-
-  // Cancels the request. The OnCanceled callback is invoked when request is
-  // caneceled, and not other callbacks are invoked afterwards..
-  void Cancel();
-
-  // Releases all resources for the request and deletes the object itself.
-  void Destroy();
-
- private:
-  // States of BidirectionalStream are tracked in |read_state_| and
-  // |write_state_|.
-  // The write state is separated as it changes independently of the read state.
-  // There is one initial state: NOT_STARTED. There is one normal final state:
-  // SUCCESS, reached after READING_DONE and WRITING_DONE. There are two
-  // exceptional final states: CANCELED and ERROR, which can be reached from
-  // any other non-final state.
-  enum State {
-    // Initial state, stream not started.
-    NOT_STARTED,
-    // Stream started, request headers are being sent.
-    STARTED,
-    // Waiting for ReadData() to be called.
-    WAITING_FOR_READ,
-    // Reading from the remote, OnDataRead callback will be invoked when done.
-    READING,
-    // There is no more data to read and stream is half-closed by the remote
-    // side.
-    READING_DONE,
-    // Stream is canceled.
-    CANCELED,
-    // Error has occured, stream is closed.
-    ERR,
-    // Reading and writing are done, and the stream is closed successfully.
-    SUCCESS,
-    // Waiting for Flush() to be called.
-    WAITING_FOR_FLUSH,
-    // Writing to the remote, callback will be invoked when done.
-    WRITING,
-    // There is no more data to write and stream is half-closed by the local
-    // side.
-    WRITING_DONE,
-  };
-
-  // Container to hold buffers and sizes of the pending data to be written.
-  class WriteBuffers {
-   public:
-    WriteBuffers();
-    ~WriteBuffers();
-
-    // Clears Write Buffers list.
-    void Clear();
-
-    // Appends |buffer| of |buffer_size| length to the end of buffer list.
-    void AppendBuffer(const scoped_refptr<net::IOBuffer>& buffer,
-                      int buffer_size);
-
-    void MoveTo(WriteBuffers* target);
-
-    // Returns true of Write Buffers list is empty.
-    bool Empty() const;
-
-    const std::vector<scoped_refptr<net::IOBuffer>>& buffers() const {
-      return write_buffer_list;
-    }
-
-    const std::vector<int>& lengths() const { return write_buffer_len_list; }
-
-   private:
-    // Every IOBuffer in |write_buffer_list| points to the memory owned by the
-    // application.
-    std::vector<scoped_refptr<net::IOBuffer>> write_buffer_list;
-    // A list of the length of each IOBuffer in |write_buffer_list|.
-    std::vector<int> write_buffer_len_list;
-
-    DISALLOW_COPY_AND_ASSIGN(WriteBuffers);
-  };
-
-  // net::BidirectionalStream::Delegate implementations:
-  void OnStreamReady(bool request_headers_sent) override;
-  void OnHeadersReceived(const net::SpdyHeaderBlock& response_headers) override;
-  void OnDataRead(int bytes_read) override;
-  void OnDataSent() override;
-  void OnTrailersReceived(const net::SpdyHeaderBlock& trailers) override;
-  void OnFailed(int error) override;
-  // Helper method to derive OnSucceeded.
-  void MaybeOnSucceded();
-
-  void StartOnNetworkThread(
-      std::unique_ptr<net::BidirectionalStreamRequestInfo> request_info);
-  void ReadDataOnNetworkThread(scoped_refptr<net::WrappedIOBuffer> read_buffer,
-                               int buffer_size);
-  void WriteDataOnNetworkThread(scoped_refptr<net::WrappedIOBuffer> read_buffer,
-                                int buffer_size,
-                                bool end_of_stream);
-  void FlushOnNetworkThread();
-  void SendFlushingWriteData();
-  void CancelOnNetworkThread();
-  void DestroyOnNetworkThread();
-
-  bool IsOnNetworkThread();
-  void PostToNetworkThread(const tracked_objects::Location& from_here,
-                           const base::Closure& task);
-
-  // Read state is tracking reading flow. Only accessed on network thread.
-  //                         | <--- READING <--- |
-  //                         |                   |
-  //                         |                   |
-  // NOT_STARTED -> STARTED --> WAITING_FOR_READ -> READING_DONE -> SUCCESS
-  State read_state_;
-
-  // Write state is tracking writing flow.  Only accessed on network thread.
-  //                         | <--- WRITING <---  |
-  //                         |                    |
-  //                         |                    |
-  // NOT_STARTED -> STARTED --> WAITING_FOR_FLUSH -> WRITING_DONE -> SUCCESS
-  State write_state_;
-
-  bool write_end_of_stream_;
-  bool request_headers_sent_;
-
-  bool disable_auto_flush_;
-  bool delay_headers_until_flush_;
-
-  net::URLRequestContextGetter* const request_context_getter_;
-
-  scoped_refptr<net::WrappedIOBuffer> read_buffer_;
-
-  // Write data that is pending the flush.
-  std::unique_ptr<WriteBuffers> pending_write_data_;
-  // Write data that is flushed, but not sending yet.
-  std::unique_ptr<WriteBuffers> flushing_write_data_;
-  // Write data that is sending.
-  std::unique_ptr<WriteBuffers> sending_write_data_;
-
-  std::unique_ptr<net::BidirectionalStream> bidi_stream_;
-  Delegate* delegate_;
-
-  base::WeakPtr<BidirectionalStream> weak_this_;
-  base::WeakPtrFactory<BidirectionalStream> weak_factory_;
-
-  DISALLOW_COPY_AND_ASSIGN(BidirectionalStream);
-};
-
-}  // namespace grpc_support
-
-#endif  // COMPONENTS_GRPC_SUPPORT_BIDIRECTIONAL_STREAM_H_