Change BlimpTransport to vend BlimpConnections.

This removes the dependency StreamSocket from BlimpTransport.
Make PacketReader and PacketWriter stream/datagram agnostic,
moving framing logic to the new classes StreamPacketReader and
StreamPacketWriter.
Add channel reader/writer objects and fields to BlimpConnection,
and create a specialization of BlimpConnection for receiving
ownership of StreamSocket.

R=wez@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1430963002

Cr-Commit-Position: refs/heads/master@{#358142}

1 files changed, 81 insertions, 0 deletions

diff --git a/blimp/net/stream_packet_reader.h b/blimp/net/stream_packet_reader.h
new file mode 100644
index 0000000..4468638
--- /dev/null
+++ b/blimp/net/stream_packet_reader.h
@@ -0,0 +1,81 @@
+// 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.
+
+#ifndef BLIMP_NET_STREAM_PACKET_READER_H_
+#define BLIMP_NET_STREAM_PACKET_READER_H_
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+#include "blimp/net/blimp_net_export.h"
+#include "blimp/net/packet_reader.h"
+#include "net/base/completion_callback.h"
+#include "net/base/net_errors.h"
+
+namespace net {
+class GrowableIOBuffer;
+class StreamSocket;
+}  // namespace net
+
+namespace blimp {
+
+// Reads opaque length-prefixed packets of bytes from a StreamSocket.
+// The header segment is 32-bit, encoded in network byte order.
+// The body segment length is specified in the header (capped at
+//     kMaxPacketPayloadSizeBytes).
+class BLIMP_NET_EXPORT StreamPacketReader : public PacketReader {
+ public:
+  // |socket|: The socket to read packets from. The caller must ensure |socket|
+  // is valid while the reader is in-use (see ReadPacket below).
+  explicit StreamPacketReader(net::StreamSocket* socket);
+
+  ~StreamPacketReader() override;
+
+  // PacketReader implementation.
+  int ReadPacket(const scoped_refptr<net::GrowableIOBuffer>& buf,
+                 const net::CompletionCallback& cb) override;
+
+ private:
+  enum class ReadState {
+    IDLE,
+    HEADER,
+    PAYLOAD,
+  };
+
+  friend std::ostream& operator<<(std::ostream& out, const ReadState state);
+
+  // State machine implementation.
+  // |result| - the result value of the most recent network operation.
+  // See comments for ReadPacket() for documentation on return values.
+  int DoReadLoop(int result);
+
+  // Reads the header and parses it when, done, to get the payload size.
+  int DoReadHeader(int result);
+
+  // Reads payload bytes until the payload is complete.
+  int DoReadPayload(int result);
+
+  // Processes an asynchronous header or payload read, and invokes |callback_|
+  // on packet read completion.
+  void OnReadComplete(int result);
+
+  ReadState read_state_;
+
+  net::StreamSocket* socket_;
+
+  // The size of the payload, in bytes.
+  size_t payload_size_;
+
+  scoped_refptr<net::GrowableIOBuffer> header_buffer_;
+  scoped_refptr<net::GrowableIOBuffer> payload_buffer_;
+  net::CompletionCallback callback_;
+
+  base::WeakPtrFactory<StreamPacketReader> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(StreamPacketReader);
+};
+
+}  // namespace blimp
+
+#endif  // BLIMP_NET_STREAM_PACKET_READER_H_