Basic HTTP pipelining support

net/http/http_pipelined_connection.h

+// Copyright (c) 2011 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.
+//
+// This class manages all of the state for a single pipelined connection. It

[mmenke, 2011/08/03 21:09:39]

nit:  All this should go just before the class, rather than up here.

[James Simonsen, 2011/08/05 01:39:00]

Done.

+// tracks the order that HTTP requests are sent and enforces that the
+// subsequent reads occur in the appropriate order.
+//
+// If an error occurs related to pipelining, ERR_PIPELINE_EVICTION will be
+// returned to the client. This indicates the client should retry the request
+// without pipelining.
+
+#ifndef NET_HTTP_HTTP_PIPELINED_CONNECTION_H_
+#define NET_HTTP_HTTP_PIPELINED_CONNECTION_H_
+#pragma once
+
+#include <map>
+#include <queue>
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/task.h"
+#include "net/base/completion_callback.h"
+#include "net/base/net_log.h"
+#include "net/base/ssl_config_service.h"
+#include "net/base/upload_data_stream.h"
+#include "net/http/http_request_info.h"
+#include "net/proxy/proxy_info.h"
+
+namespace net {
+
+class ClientSocketHandle;
+class GrowableIOBuffer;
+class HttpPipelinedHost;
+class HttpPipelinedStream;
+class HttpRequestHeaders;
+class HttpResponseInfo;
+class HttpStreamParser;
+class IOBuffer;
+class SSLCertRequestInfo;
+class SSLInfo;
+
+class HttpPipelinedConnection {
+ public:
+  HttpPipelinedConnection(ClientSocketHandle* connection,
+                          HttpPipelinedHost* host,
+                          const SSLConfig& used_ssl_config,
+                          const ProxyInfo& used_proxy_info,
+                          const BoundNetLog& net_log,
+                          bool was_npn_negotiated);
+  ~HttpPipelinedConnection();
+
+  // The number of HTTP requests pending on this pipeline.
+  int depth() const { return stream_state_map_.size(); }
+
+  // True if this pipeline can accept new HTTP requests. False if a fatal error
+  // has occurred.
+  bool usable() const { return usable_; }
+
+  // True if this pipeline has bound one request is ready for additional

[mmenke, 2011/08/03 21:09:39]

nit:  "has bound one request and...".

[James Simonsen, 2011/08/05 01:39:00]

Done.

+  // requests.
+  bool active() const { return active_; }
+
+  const SSLConfig& used_ssl_config() const { return used_ssl_config_; }
+  const ProxyInfo& used_proxy_info() const { return used_proxy_info_; }
+  const NetLog::Source& source() const { return net_log_.source(); }
+  bool was_npn_negotiated() const { return was_npn_negotiated_; }
+
+  // HttpPipelinedStream uses these functions.
+
+  // Associates a HttpPipelinedStream with this connection. Returns a unique
+  // identifier.
+  int AddStream();
+
+  // Disassociates a previously associated HttpPipelinedStream.
+  void RemoveStream(int pipeline_id);
+
+  // Constructs a HttpStreamParser for the associated HttpPipelinedStream.
+  void InitializeParser(int pipeline_id,
+                        const HttpRequestInfo* request,
+                        const BoundNetLog& net_log);
+
+  // Indirect implementation of HttpStream used by our HttpPipelinedStreams.
+  int SendRequest(int pipeline_id,
+                  const std::string& request_line,
+                  const HttpRequestHeaders& headers,
+                  UploadDataStream* request_body,
+                  HttpResponseInfo* response,
+                  CompletionCallback* callback);
+
+  int ReadResponseHeaders(int pipeline_id,
+                          CompletionCallback* callback);
+
+  int ReadResponseBody(int pipeline_id,
+                       IOBuffer* buf, int buf_len,
+                       CompletionCallback* callback);
+
+  void Close(int pipeline_id,
+             bool not_reusable);
+
+  uint64 GetUploadProgress(int pipeline_id) const;
+
+  HttpResponseInfo* GetResponseInfo(int pipeline_id);
+
+  bool IsResponseBodyComplete(int pipeline_id) const;
+
+  bool CanFindEndOfResponse(int pipeline_id) const;
+
+  bool IsMoreDataBuffered(int pipeline_id) const;
+
+  bool IsConnectionReused(int pipeline_id) const;
+
+  void SetConnectionReused(int pipeline_id);
+
+  void GetSSLInfo(int pipeline_id,
+                  SSLInfo* ssl_info);
+
+  void GetSSLCertRequestInfo(int pipeline_id,
+                             SSLCertRequestInfo* cert_request_info);
+
+ private:
+  enum StreamState {
+    STREAM_CREATED,
+    STREAM_BOUND,
+    STREAM_SENT,
+    STREAM_CLOSED,
+  };
+  enum SendRequestState {
+    SEND_STATE_NEXT_REQUEST,
+    SEND_STATE_COMPLETE,
+    SEND_STATE_NONE,
+    SEND_STATE_UNUSABLE,
+  };
+  enum ReadHeadersState {
+    READ_STATE_NEXT_HEADERS,
+    READ_STATE_COMPLETE,
+    READ_STATE_STREAM_CLOSED,
+    READ_STATE_NONE,
+    READ_STATE_UNUSABLE,
+  };
+
+  struct DeferredSendRequest {
+    int pipeline_id;
+    std::string request_line;
+    HttpRequestHeaders headers;
+    UploadDataStream* request_body;
+    HttpResponseInfo* response;
+    CompletionCallback* callback;
+  };
+
+  // Called after the first request is processed, allowing the rest of this
+  // pipeline to fill up with any pending requests.
+  void FillPipeline();
+
+  int DoSendRequestLoop(int result);
+  void OnSendIOCallback(int result);
+  int DoSendNextRequest(int result);

[mmenke, 2011/08/03 21:09:39]

It'd great to have comments on what these functions are called in response to,
and what they actually do.

[James Simonsen, 2011/08/05 01:39:00]

Done.

+  int DoSendComplete(int result);
+  int DoEvictPendingSendRequests(int result);
+
+  int DoReadHeadersLoop(int result);
+  void OnReadIOCallback(int result);
+  int DoReadNextHeaders(int result);
+  int DoReadHeadersComplete(int result);
+  int DoStreamClosed();
+  int DoEvictPendingReadHeaders(int result);
+
+  void FireUserCallback(CompletionCallback* callback, int result);
+
+  HttpPipelinedHost* host_;
+  scoped_ptr<ClientSocketHandle> connection_;
+  SSLConfig used_ssl_config_;
+  ProxyInfo used_proxy_info_;
+  BoundNetLog net_log_;
+  bool was_npn_negotiated_;
+  scoped_refptr<GrowableIOBuffer> read_buf_;
+  int next_pipeline_id_;
+  bool active_;
+  bool usable_;
+  ScopedRunnableMethodFactory<HttpPipelinedConnection> method_factory_;
+
+  typedef std::map<int, StreamState> StreamStateMap;
+  StreamStateMap stream_state_map_;
+  typedef std::map<int, HttpStreamParser*> ParserMap;
+  ParserMap parser_map_;
+
+  std::queue<int> request_order_;
+
+  std::queue<DeferredSendRequest> deferred_request_queue_;
+  SendRequestState send_next_state_;
+  CompletionCallbackImpl<HttpPipelinedConnection> send_io_callback_;
+  CompletionCallback* send_user_callback_;
+
+  ReadHeadersState read_next_state_;
+  CompletionCallbackImpl<HttpPipelinedConnection> read_io_callback_;
+  CompletionCallback* read_user_callback_;
+  typedef std::map<int, CompletionCallback*> CallbackMap;
+  CallbackMap callback_map_;
+
+  DISALLOW_COPY_AND_ASSIGN(HttpPipelinedConnection);
+};
+
+}  // namespace net
+
+#endif  // NET_HTTP_HTTP_PIPELINED_CONNECTION_H_