components/precache/content/precache_manager.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef COMPONENTS_PRECACHE_CONTENT_PRECACHE_MANAGER_H_
   6 #define COMPONENTS_PRECACHE_CONTENT_PRECACHE_MANAGER_H_
   7
   8 #include <list>
   9
  10 #include "base/callback.h"
  11 #include "base/compiler_specific.h"
  12 #include "base/memory/ref_counted.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/memory/weak_ptr.h"
  15 #include "components/keyed_service/core/keyed_service.h"
  16 #include "components/precache/core/precache_fetcher.h"
  17 #include "url/gurl.h"
  18
  19 namespace base {
  20 class Time;
  21 }
  22
  23 namespace content {
  24 class BrowserContext;
  25 }
  26
  27 namespace precache {
  28
  29 class PrecacheDatabase;
  30 class URLListProvider;
  31
  32 // Class that manages all precaching-related activities. Owned by the
  33 // BrowserContext that it is constructed for. Use
  34 // PrecacheManagerFactory::GetForBrowserContext to get an instance of this
  35 // class. All methods must be called on the UI thread unless indicated
  36 // otherwise.
  37 // TODO(sclittle): Delete precache history when browsing history is deleted.
  38 // http://crbug.com/326549
  39 class PrecacheManager : public KeyedService,
  40                         public PrecacheFetcher::PrecacheDelegate,
  41                         public base::SupportsWeakPtr<PrecacheManager> {
  42  public:
  43   typedef base::Closure PrecacheCompletionCallback;
  44
  45   explicit PrecacheManager(content::BrowserContext* browser_context);
  46   virtual ~PrecacheManager();
  47
  48   // Returns true if precaching is enabled as part of a field trial or by the
  49   // command line flag. This method can be called on any thread.
  50   static bool IsPrecachingEnabled();
  51
  52   // Returns true if precaching is allowed for the browser context.
  53   bool IsPrecachingAllowed();
  54
  55   // Starts precaching resources that the user is predicted to fetch in the
  56   // future. If precaching is already currently in progress, then this method
  57   // does nothing. The |precache_completion_callback| will be run when
  58   // precaching finishes, but will not be run if precaching is canceled.
  59   void StartPrecaching(
  60       const PrecacheCompletionCallback& precache_completion_callback,
  61       URLListProvider* url_list_provider);
  62
  63   // Cancels precaching if it is in progress.
  64   void CancelPrecaching();
  65
  66   // Returns true if precaching is currently in progress, or false otherwise.
  67   bool IsPrecaching() const;
  68
  69   // Update precache-related metrics in response to a URL being fetched.
  70   void RecordStatsForFetch(const GURL& url,
  71                            const base::Time& fetch_time,
  72                            int64 size,
  73                            bool was_cached);
  74
  75  private:
  76   // From KeyedService.
  77   virtual void Shutdown() override;
  78
  79   // From PrecacheFetcher::PrecacheDelegate.
  80   virtual void OnDone() override;
  81
  82   void OnURLsReceived(const std::list<GURL>& urls);
  83
  84   // The browser context that owns this PrecacheManager.
  85   content::BrowserContext* browser_context_;
  86
  87   // The PrecacheFetcher used to precache resources. Should only be used on the
  88   // UI thread.
  89   scoped_ptr<PrecacheFetcher> precache_fetcher_;
  90
  91   // The callback that will be run if precaching finishes without being
  92   // canceled.
  93   PrecacheCompletionCallback precache_completion_callback_;
  94
  95   // The PrecacheDatabase for tracking precache metrics. Should only be used on
  96   // the DB thread.
  97   scoped_refptr<PrecacheDatabase> precache_database_;
  98
  99   // Flag indicating whether or not precaching is currently in progress.
 100   bool is_precaching_;
 101
 102   DISALLOW_COPY_AND_ASSIGN(PrecacheManager);
 103 };
 104
 105 }  // namespace precache
 106
 107 #endif  // COMPONENTS_PRECACHE_CONTENT_PRECACHE_MANAGER_H_