Basic HTTP pipelining support

net/http/http_pipelined_host_pool.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.
+//
+// Manages all of the pipelining state for specific host with active pipelined
+// HTTP requests. Manages connection jobs, constructs pipelined streams, and
+// assigns requests to the least loaded pipelined connection.
+
+#ifndef NET_HTTP_HTTP_PIPELINED_HOST_POOL_H_
+#define NET_HTTP_HTTP_PIPELINED_HOST_POOL_H_
+#pragma once
+
+#include <map>
+
+#include <base/basictypes.h>
+
+namespace net {
+
+class HostPortPair;
+class HttpPipelinedHost;
+class HttpStreamFactory;
+
+class HttpPipelinedHostPool {
+ public:
+  explicit HttpPipelinedHostPool(HttpStreamFactory* factory);
+  ~HttpPipelinedHostPool();
+
+  // Returns the HttpPipelinedHost used for this origin, or a new one if none
+  // exists.
+  HttpPipelinedHost* GetOrCreatePipelinedHost(const HostPortPair& origin) {
+    return GetPipelinedHost(origin, true);
+  }
+
+  // Returns the HttpPipelinedHost used for this origin, or NULL if none exists.
+  HttpPipelinedHost* GetPipelinedHostIfExists(const HostPortPair& origin) {
+    return GetPipelinedHost(origin, false);
+  }
+
+  // Callbacks for HttpPipelinedHost.
+
+  // Called when a pipelined host has no outstanding pipelined connections.
+  void OnHostIdle(HttpPipelinedHost* host);
+
+  // Called when a pipelined host has newly available pipeline capacity.
+  void OnHostHasAdditionalCapacity(HttpPipelinedHost* host);
+
+ private:
+  HttpPipelinedHost* GetPipelinedHost(const HostPortPair& origin,
+                                      bool create_if_not_found);
+
+  HttpStreamFactory* factory_;
+  typedef std::map<const HostPortPair, HttpPipelinedHost*> HostMap;
+  HostMap host_map_;
+
+  DISALLOW_COPY_AND_ASSIGN(HttpPipelinedHostPool);
+};
+
+}  // namespace net
+
+#endif  // NET_HTTP_HTTP_PIPELINED_HOST_POOL_H_