Added a net::BidirectionalStream to expose a bidirectional streaming interface

net/http/bidirectional_stream.h

+// 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 NET_HTTP_BIDIRECTIONAL_STREAM_H_
+#define NET_HTTP_BIDIRECTIONAL_STREAM_H_
+
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "net/base/request_priority.h"
+#include "net/http/bidirectional_stream_job.h"
+#include "net/http/http_stream_factory.h"
+#include "net/ssl/ssl_config.h"
+
+namespace net {
+
+class BoundNetLog;
+class HttpAuthController;
+class HttpNetworkSession;
+class HttpStream;
+class HttpStreamRequest;
+class IOBuffer;
+class ProxyInfo;
+struct HttpRequestInfo;
+
+// A class to do HTTP/2 bidirectional streaming. Note that only one
+// ReadData or SendData should be in flight until the operation completes
+// synchronously or asynchronously. The BidirectionalStream must be torn down
+// before the HttpNetworkSession.
+class NET_EXPORT BidirectionalStream : public BidirectionalStreamJob::Delegate,
+                                       public HttpStreamRequest::Delegate {
+ public:
+  // Delegate interface to get notified of success of failure. Callbacks will be
+  // invoked asynchronously.
+  // TODO(xunjieli): Surface the protocol negotiated.
+  class NET_EXPORT Delegate {
+   public:
+    Delegate() {}
+
+    // Called when an error occurs. E.g. when a connection to the server cannot
+    // be established.
+    virtual void OnFailed(Error error) = 0;
+
+    // Called when the request headers have been sent.
+    virtual void OnRequestHeadersSent() = 0;
+
+    // Called when response headers are received.
+    virtual void OnHeaders(const SpdyHeaderBlock& response_headers) = 0;
+
+    // Called when read is completed asynchronously. |bytes_read| specifies how
+    // much data is available.
+    virtual void OnReadCompleted(int bytes_read) = 0;
+
+    // Called when the entire buffer passed through SendData is sent.
+    virtual void OnDataSent() = 0;
+
+    // Called when trailers are received.
+    virtual void OnTrailers(const SpdyHeaderBlock& trailers) = 0;
+
+    // Called when the stream is closed. No other delegate functions will be
+    // called after this. |status| is an error code or OK.

[mef, 2015/11/10 23:00:27]

Is |status| indeed a net Error Code?

[xunjieli, 2015/11/13 23:41:44]

Done. Yes. I modified the comment to make this clear.

+    virtual void OnClose(int status) = 0;
+
+   protected:
+    virtual ~Delegate() {}
+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(Delegate);
+  };
+
+  // Parts of |request_info| are ignored (e.g. |upload_data_stream| and most
+  // load flags).

[mef, 2015/11/10 23:00:27]

That's a good point, should we specify which load_flags are not ignored?

[xunjieli, 2015/11/13 23:41:44]

I'd like to say all for now. But I don't really know.. We currently have a check
to make sure there aren't any load flags set. (DCHECK_EQ(LOAD_NORMAL,
request_info.load_flags) in bidirectional_stream.cc)

+  BidirectionalStream(const HttpRequestInfo& request_info,
+                      RequestPriority priority,
+                      HttpNetworkSession* session,
+                      Delegate* delegate);
+
+  // Destroys the helper and cancels any pending request.
+  ~BidirectionalStream() override;
+
+  // Reads at most |buf_len| bytes into |buf|. Returns the number of bytes read,
+  // or ERR_IO_PENDING if the read is to be completed asynchronously.

[mef, 2015/11/10 23:00:27]

Can this have more than one call in flight? If not maybe add a comment similar
to one on SendData.

[xunjieli, 2015/11/13 23:41:45]

Done.

+  int ReadData(IOBuffer* buf, int buf_len);
+
+  // Sends data. This should not be called again until OnDataSent is invoked.
+  void SendData(IOBuffer* data, int length, bool end_stream);
+
+  // If there is |stream_request_|, cancel it. If |stream_| is established,
+  // cancel it.
+  void Cancel();

[mef, 2015/11/10 23:00:27]

What if BidirectionalStream is deleted without being canceled?

[xunjieli, 2015/11/13 23:41:44]

Hmm.. Then we probably should call cancel in that case. Done.

+
+  // TODO(xunjieli): implement a method to do flow control, and a method to ping
+  // remote end point.
+
+ private:
+  // BidirectionalStreamJob::Delegate implementation:
+
+  void OnFailed(Error error) override;
+
+  void OnRequestHeadersSent() override;
+
+  void OnHeaders(const SpdyHeaderBlock& response_headers) override;
+
+  void OnReadCompleted(int bytes_read) override;
+
+  void OnDataSent() override;
+
+  void OnTrailers(const SpdyHeaderBlock& trailers) override;
+
+  void OnClose(int status) override;
+
+  // HttpStreamRequest::Delegate implementation:
+
+  void OnStreamReady(const SSLConfig& used_ssl_config,
+                     const ProxyInfo& used_proxy_info,
+                     HttpStream* stream) override;
+  void OnBidirectionalStreamJobReady(const SSLConfig& used_ssl_config,
+                                     const ProxyInfo& used_proxy_info,
+                                     BidirectionalStreamJob* stream) override;
+  void OnWebSocketHandshakeStreamReady(
+      const SSLConfig& used_ssl_config,
+      const ProxyInfo& used_proxy_info,
+      WebSocketHandshakeStreamBase* stream) override;
+  void OnStreamFailed(int status,
+                      const SSLConfig& used_ssl_config,
+                      SSLFailureState ssl_failure_state) override;
+  void OnCertificateError(int status,
+                          const SSLConfig& used_ssl_config,
+                          const SSLInfo& ssl_info) override;
+  void OnNeedsProxyAuth(const HttpResponseInfo& response_info,
+                        const SSLConfig& used_ssl_config,
+                        const ProxyInfo& used_proxy_info,
+                        HttpAuthController* auth_controller) override;
+  void OnNeedsClientAuth(const SSLConfig& used_ssl_config,
+                         SSLCertRequestInfo* cert_info) override;
+  void OnHttpsProxyTunnelResponse(const HttpResponseInfo& response_info,
+                                  const SSLConfig& used_ssl_config,
+                                  const ProxyInfo& used_proxy_info,
+                                  HttpStream* stream) override;
+
+  const HttpRequestInfo request_info_;
+  RequestPriority priority_;
+  BoundNetLog net_log_;
+
+  Delegate* delegate_;
+
+  scoped_ptr<HttpStreamRequest> stream_request_;
+  scoped_ptr<BidirectionalStreamJob> stream_;

[mef, 2015/11/10 23:00:27]

should this be called |stream_job_| to avoid confusion with |this| being a
stream?

[xunjieli, 2015/11/13 23:41:44]

Done.

+
+  DISALLOW_COPY_AND_ASSIGN(BidirectionalStream);
+};
+
+}  // namespace net
+
+#endif  // NET_HTTP_BIDIRECTIONAL_STREAM_H_