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

components/cronet/ios/cronet_bidirectional_stream.h

Index: components/cronet/ios/cronet_bidirectional_stream.h
diff --git a/components/cronet/ios/cronet_bidirectional_stream.h b/components/cronet/ios/cronet_bidirectional_stream.h
new file mode 100644
index 0000000000000000000000000000000000000000..9df7de1766f55db7bca49b8e06a6a9b31c442d80
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+++ b/components/cronet/ios/cronet_bidirectional_stream.h
@@ -0,0 +1,232 @@
+// 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_CRONET_IOS_CRONET_BIDIRECTIONAL_STREAM_H_
+#define COMPONENTS_CRONET_IOS_CRONET_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"
+
+namespace net {
+class HttpRequestHeaders;
+class WrappedIOBuffer;
+}  // namespace net
+
+namespace cronet {
+
+class CronetEnvironment;
+
+// 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 CronetBidirectionalStream : 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;
+  };
+
+  CronetBidirectionalStream(CronetEnvironment* environment, Delegate* delegate);
+  ~CronetBidirectionalStream() 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.
+    ERROR,
+    // 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();
+
+  // 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_;
+
+  CronetEnvironment* const environment_;
+
+  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<CronetBidirectionalStream> weak_this_;
+  base::WeakPtrFactory<CronetBidirectionalStream> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(CronetBidirectionalStream);
+};
+
+}  // namespace cronet
+
+#endif  // COMPONENTS_CRONET_IOS_CRONET_BIDIRECTIONAL_STREAM_H_