Implement ResourceQueue, an object that makes it easy to delay starting

chrome/browser/renderer_host/resource_dispatcher_host.h

 // 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.
 
 // This is the browser side of the resource dispatcher, it receives requests
 // from the child process (i.e. [Renderer, Plugin, Worker]ProcessHost), and
 // dispatches them to URLRequests. It then fowards the messages from the
 // URLRequests back to the correct process for handling.
 //
 // See http://dev.chromium.org/developers/design-documents/multi-process-resource-loading
 
 #ifndef CHROME_BROWSER_RENDERER_HOST_RESOURCE_DISPATCHER_HOST_H_
 #define CHROME_BROWSER_RENDERER_HOST_RESOURCE_DISPATCHER_HOST_H_
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 #include "base/observer_list.h"
 #include "base/process.h"
 #include "base/timer.h"
 #include "chrome/common/child_process_info.h"
 #include "chrome/browser/privacy_blacklist/blocked_response.h"
+#include "chrome/browser/renderer_host/resource_queue.h"
 #include "ipc/ipc_message.h"
 #include "net/url_request/url_request.h"
 #include "webkit/glue/resource_type.h"
 
 class CrossSiteResourceHandler;
 class DownloadFileManager;
 class DownloadRequestManager;
 class LoginHandler;
 class PluginService;
 class ResourceDispatcherHostRequestInfo;
 class ResourceHandler;
 class SafeBrowsingService;
 class SaveFileManager;
 class SocketStreamDispatcherHost;
 class SSLClientAuthHandler;
 class UserScriptListener;
 class URLRequestContext;
 class WebKitThread;
+struct GlobalRequestID;
 struct ViewHostMsg_Resource_Request;
 struct ViewMsg_ClosePage_Params;
 
 class ResourceDispatcherHost : public URLRequest::Delegate {
  public:
   // Implemented by the client of ResourceDispatcherHost to receive messages in
   // response to a resource load.  The messages are intended to be forwarded to
   // the ResourceDispatcher in the child process via an IPC channel that the
   // client manages.
   //
@@ skipping 25 matching lines @@
     virtual void OnRequestStarted(ResourceDispatcherHost* resource_dispatcher,
                                   URLRequest* request) = 0;
     virtual void OnResponseCompleted(
         ResourceDispatcherHost* resource_dispatcher,
         URLRequest* request) = 0;
     virtual void OnReceivedRedirect(ResourceDispatcherHost* resource_dispatcher,
                                     URLRequest* request,
                                     const GURL& new_url) = 0;
   };
 
-  // Uniquely identifies a URLRequest.
-  struct GlobalRequestID {
-    GlobalRequestID() : child_id(-1), request_id(-1) {
-    }
-    GlobalRequestID(int child_id, int request_id)
-        : child_id(child_id),
-          request_id(request_id) {
-    }
-
-    int child_id;
-    int request_id;
-
-    bool operator<(const GlobalRequestID& other) const {
-      if (child_id == other.child_id)
-        return request_id < other.request_id;
-      return child_id < other.child_id;
-    }
-  };
-
   ResourceDispatcherHost();
   ~ResourceDispatcherHost();
 
   void Initialize();
 
   // Puts the resource dispatcher host in an inactive state (unable to begin
   // new requests).  Cancels all pending requests.
   void Shutdown();
 
   // Returns true if the message was a resource message that was processed.
@@ skipping 124 matching lines @@
 
   // Adds an observer.  The observer will be called on the IO thread.  To
   // observe resource events on the UI thread, subscribe to the
   // NOTIFY_RESOURCE_* notifications of the notification service.
   void AddObserver(Observer* obs);
 
   // Removes an observer.
   void RemoveObserver(Observer* obs);
 
   // Retrieves a URLRequest.  Must be called from the IO thread.
-  URLRequest* GetURLRequest(GlobalRequestID request_id) const;
+  URLRequest* GetURLRequest(const GlobalRequestID& request_id) const;
 
   // Notifies our observers that a request has been cancelled.
   void NotifyResponseCompleted(URLRequest* request, int process_unique_id);
 
   void RemovePendingRequest(int process_unique_id, int request_id);
 
   // Causes all new requests for the route identified by
   // |process_unique_id| and |route_id| to be blocked (not being
   // started) until ResumeBlockedRequestsForRoute or
   // CancelBlockedRequestsForRoute is called.
@@ skipping 144 matching lines @@
 
   // Returns true if the message passed in is a resource related message.
   static bool IsResourceDispatcherHostMessage(const IPC::Message&);
 
   PendingRequestList pending_requests_;
 
   // A timer that periodically calls UpdateLoadStates while pending_requests_
   // is not empty.
   base::RepeatingTimer<ResourceDispatcherHost> update_load_states_timer_;
 
+  // Handles the resource requests from the moment we want to start them.
+  ResourceQueue resource_queue_;
+
   // We own the download file writing thread and manager
   scoped_refptr<DownloadFileManager> download_file_manager_;
 
   // Determines whether a download is allowed.
   scoped_refptr<DownloadRequestManager> download_request_manager_;
 
   // We own the save file manager.
   scoped_refptr<SaveFileManager> save_file_manager_;
 
   scoped_refptr<UserScriptListener> user_script_listener_;
@@ skipping 46 matching lines @@
   // to the source of the message.
   Receiver* receiver_;
 
   // Keeps track of elements blocked by the Privacy Blacklist.
   chrome::BlockedResponse blocked_;
 
   DISALLOW_COPY_AND_ASSIGN(ResourceDispatcherHost);
 };
 
 #endif  // CHROME_BROWSER_RENDERER_HOST_RESOURCE_DISPATCHER_HOST_H_