Component updater on-demand logic with ResourceThrottle

chrome/browser/component_updater/component_updater_service.h

 // Copyright (c) 2012 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 CHROME_BROWSER_COMPONENT_UPDATER_COMPONENT_UPDATER_SERVICE_H_
 #define CHROME_BROWSER_COMPONENT_UPDATER_COMPONENT_UPDATER_SERVICE_H_
 
 #include <string>
 #include <vector>
 
 #include "base/version.h"
 #include "url/gurl.h"
 
 namespace base {
 class DictionaryValue;
 class FilePath;
 }
 
 namespace net {
 class URLRequestContextGetter;
+class URLRequest;
+}
+
+namespace content {
+class ResourceThrottle;
 }
 
 class ComponentPatcher;
 
 // Component specific installers must derive from this class and implement
 // OnUpdateError() and Install(). A valid instance of this class must be
 // given to ComponentUpdateService::RegisterComponent().
 class ComponentInstaller {
  public :
   // Called by the component updater on the UI thread when there was a
@@ skipping 150 matching lines @@
   // will not be canceled.
   virtual Status Stop() = 0;
 
   // Add component to be checked for updates. You can call this method
   // before calling Start().
   virtual Status RegisterComponent(const CrxComponent& component) = 0;
 
   // Returns a list of registered components.
   virtual void GetComponents(std::vector<CrxComponentInfo>* components) = 0;
 
+  // Returns a resource throttler. It imeans that a component will be downloaded

[Sorin Jianu, 2013/10/30 21:02:44]

imeans

[Sorin Jianu, 2013/10/30 22:09:13]

small nit, maybe say "resource throttle" instead of "resource throttler".

[cpu_(ooo_6.6-7.5), 2013/10/31 04:38:26]

Done.

+  // and installed before the resource is untrottled. Note that is this called

[waffles, 2013/10/30 21:11:20]

also, untrottled -> unthrottled

[cpu_(ooo_6.6-7.5), 2013/10/31 04:38:26]

Done.

+  // from the IO thread.
+  virtual content::ResourceThrottle* GetResourceThrottle(

[Sorin Jianu, 2013/10/30 22:09:13]

Since now this is part of the public interface of the class, how do we address
one of the past concerns: devs abusing this interface and calling ondemand
aggressively to get ahead of the queue?

[cpu_(ooo_6.6-7.5), 2013/10/31 04:38:26]

For it to work it requires a fair bit of infrastructure. It is not something one
can do by accident, but we could also friend the current client which besides
tests should be the only caller.

+      net::URLRequest* request, const char* crx_id) = 0;
+
   virtual ~ComponentUpdateService() {}
 
   // TODO(waffles): Remove PNaCl as a friend once an alternative on-demand
   // trigger is available.
   friend class ComponentsUI;
   friend class PnaclComponentInstaller;

[waffles, 2013/10/30 21:11:20]

Is the plan to remove this friendship and the old PNaCl on-demand flow in a
separate changelist?

[cpu_(ooo_6.6-7.5), 2013/10/31 04:38:26]

Yes, possibly in this change-list.

   friend class OnDemandTester;
 
  private:
   // Ask the component updater to do an update check for a previously
   // registered component, immediately. If an update or check is already
   // in progress, returns |kInProgress|.
   // There is no guarantee that the item will actually be updated,
   // since an update may not be available. Listeners for the component will
   // know the outcome of the check.
   virtual Status OnDemandUpdate(const std::string& component_id) = 0;
 };
 
 // Creates the component updater. You must pass a valid |config| allocated on
 // the heap which the component updater will own.
 ComponentUpdateService* ComponentUpdateServiceFactory(
     ComponentUpdateService::Configurator* config);
 
 #endif  // CHROME_BROWSER_COMPONENT_UPDATER_COMPONENT_UPDATER_SERVICE_H_