Move core pieces of browser\renderer_host to src\content.

TBR=avi
Review URL: http://codereview.chromium.org/6532073

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@75489 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 100 insertions, 0 deletions

diff --git a/content/browser/renderer_host/resource_queue.h b/content/browser/renderer_host/resource_queue.h
new file mode 100644
index 0000000..4bf45d9
--- /dev/null
+++ b/content/browser/renderer_host/resource_queue.h
@@ -0,0 +1,100 @@
+// Copyright (c) 2009 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 CONTENT_BROWSER_RENDERER_HOST_RESOURCE_QUEUE_H_
+#define CONTENT_BROWSER_RENDERER_HOST_RESOURCE_QUEUE_H_
+#pragma once
+
+#include <map>
+#include <set>
+
+#include "base/basictypes.h"
+
+namespace net {
+class URLRequest;
+}  // namespace net
+
+class ResourceDispatcherHostRequestInfo;
+struct GlobalRequestID;
+
+// Makes decisions about delaying or not each net::URLRequest in the queue.
+// All methods are called on the IO thread.
+class ResourceQueueDelegate {
+ public:
+  // Should return true if it wants the |request| to not be started at this
+  // point. To start the delayed request, ResourceQueue::StartDelayedRequest
+  // should be used.
+  virtual bool ShouldDelayRequest(
+      net::URLRequest* request,
+      const ResourceDispatcherHostRequestInfo& request_info,
+      const GlobalRequestID& request_id) = 0;
+
+  // Called just before ResourceQueue shutdown. After that, the delegate
+  // should not use the ResourceQueue.
+  virtual void WillShutdownResourceQueue() = 0;
+
+ protected:
+  virtual ~ResourceQueueDelegate();
+};
+
+// Makes it easy to delay starting URL requests until specified conditions are
+// met.
+class ResourceQueue {
+ public:
+  typedef std::set<ResourceQueueDelegate*> DelegateSet;
+
+  // UI THREAD ONLY ------------------------------------------------------------
+
+  // Construct the queue. You must initialize it using Initialize.
+  ResourceQueue();
+  ~ResourceQueue();
+
+  // Initialize the queue with set of delegates it should ask for each incoming
+  // request.
+  void Initialize(const DelegateSet& delegates);
+
+  // IO THREAD ONLY ------------------------------------------------------------
+
+  // Must be called before destroying the queue. No other methods can be called
+  // after that.
+  void Shutdown();
+
+  // Takes care to start the |request| after all delegates allow that. If no
+  // delegate demands delaying the request it will be started immediately.
+  void AddRequest(net::URLRequest* request,
+                  const ResourceDispatcherHostRequestInfo& request_info);
+
+  // Tells the queue that the net::URLRequest object associated with
+  // |request_id| is no longer valid.
+  void RemoveRequest(const GlobalRequestID& request_id);
+
+  // A delegate should call StartDelayedRequest when it wants to allow the
+  // request to start. If it was the last delegate that demanded the request
+  // to be delayed, the request will be started.
+  void StartDelayedRequest(ResourceQueueDelegate* delegate,
+                           const GlobalRequestID& request_id);
+
+ private:
+  typedef std::map<GlobalRequestID, net::URLRequest*> RequestMap;
+  typedef std::map<GlobalRequestID, DelegateSet> InterestedDelegatesMap;
+
+  // The registered delegates. Will not change after the queue has been
+  // initialized.
+  DelegateSet delegates_;
+
+  // Stores net::URLRequest objects associated with each GlobalRequestID. This
+  // helps decoupling the queue from ResourceDispatcherHost.
+  RequestMap requests_;
+
+  // Maps a GlobalRequestID to the set of delegates that want to prevent the
+  // associated request from starting yet.
+  InterestedDelegatesMap interested_delegates_;
+
+  // True when we are shutting down.
+  bool shutdown_;
+
+  DISALLOW_COPY_AND_ASSIGN(ResourceQueue);
+};
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_RESOURCE_QUEUE_H_