components/suggestions/image_manager.h

   1 // Copyright 2014 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_SUGGESTIONS_IMAGE_MANAGER_H_
   6 #define COMPONENTS_SUGGESTIONS_IMAGE_MANAGER_H_
   7
   8 #include <map>
   9 #include <string>
  10 #include <vector>
  11
  12 #include "base/basictypes.h"
  13 #include "base/callback.h"
  14 #include "base/containers/hash_tables.h"
  15 #include "base/memory/scoped_ptr.h"
  16 #include "base/memory/weak_ptr.h"
  17 #include "base/threading/thread_checker.h"
  18 #include "components/leveldb_proto/proto_database.h"
  19 #include "components/suggestions/image_fetcher_delegate.h"
  20 #include "components/suggestions/proto/suggestions.pb.h"
  21 #include "ui/gfx/image/image_skia.h"
  22 #include "url/gurl.h"
  23
  24 namespace net {
  25 class URLRequestContextGetter;
  26 }
  27
  28 namespace suggestions {
  29
  30 class ImageData;
  31 class ImageFetcher;
  32 class SuggestionsProfile;
  33
  34 // A class used to fetch server images asynchronously and manage the caching
  35 // layer (both in memory and on disk).
  36 class ImageManager : public ImageFetcherDelegate {
  37  public:
  38   typedef std::vector<ImageData> ImageDataVector;
  39
  40   ImageManager(scoped_ptr<ImageFetcher> image_fetcher,
  41                scoped_ptr<leveldb_proto::ProtoDatabase<ImageData> > database,
  42                const base::FilePath& database_dir);
  43   ~ImageManager() override;
  44
  45   virtual void Initialize(const SuggestionsProfile& suggestions);
  46
  47   // Should be called from the UI thread.
  48   virtual void GetImageForURL(
  49       const GURL& url,
  50       base::Callback<void(const GURL&, const SkBitmap*)> callback);
  51
  52  protected:
  53   // Perform additional tasks when an image has been fetched.
  54   void OnImageFetched(const GURL& url, const SkBitmap* bitmap) override;
  55
  56  private:
  57   friend class MockImageManager;
  58   friend class ImageManagerTest;
  59   FRIEND_TEST_ALL_PREFIXES(ImageManagerTest, InitializeTest);
  60   FRIEND_TEST_ALL_PREFIXES(ImageManagerTest, GetImageForURLNetworkCacheHit);
  61   FRIEND_TEST_ALL_PREFIXES(ImageManagerTest,
  62                            GetImageForURLNetworkCacheNotInitialized);
  63
  64   // Used for testing.
  65   ImageManager();
  66
  67   typedef std::vector<base::Callback<void(const GURL&, const SkBitmap*)> >
  68       CallbackVector;
  69   typedef base::hash_map<std::string, SkBitmap> ImageMap;
  70
  71   // State related to an image fetch (associated website url, image_url,
  72   // pending callbacks).
  73   struct ImageCacheRequest {
  74     ImageCacheRequest();
  75     ~ImageCacheRequest();
  76
  77     GURL url;
  78     GURL image_url;
  79     // Queue for pending callbacks, which may accumulate while the request is in
  80     // flight.
  81     CallbackVector callbacks;
  82   };
  83
  84   typedef std::map<const GURL, ImageCacheRequest> ImageCacheRequestMap;
  85
  86   // Looks up image URL for |url|. If found, writes the result to |image_url|
  87   // and returns true. Otherwise just returns false.
  88   bool GetImageURL(const GURL& url, GURL* image_url);
  89
  90   void QueueCacheRequest(
  91       const GURL& url, const GURL& image_url,
  92       base::Callback<void(const GURL&, const SkBitmap*)> callback);
  93
  94   void ServeFromCacheOrNetwork(
  95       const GURL& url, const GURL& image_url,
  96       base::Callback<void(const GURL&, const SkBitmap*)> callback);
  97
  98   // Will return false if no bitmap was found corresponding to |url|, else
  99   // return true and call |callback| with the found bitmap.
 100   bool ServeFromCache(
 101       const GURL& url,
 102       base::Callback<void(const GURL&, const SkBitmap*)> callback);
 103
 104   // Returns null if the |url| had no entry in the cache.
 105   SkBitmap* GetBitmapFromCache(const GURL& url);
 106
 107   // Save the image bitmap in the cache and in the database.
 108   void SaveImage(const GURL& url, const SkBitmap& bitmap);
 109
 110   // Database callback methods.
 111   // Will initiate loading the entries.
 112   void OnDatabaseInit(bool success);
 113   // Will transfer the loaded |entries| in memory (|image_map_|).
 114   void OnDatabaseLoad(bool success, scoped_ptr<ImageDataVector> entries);
 115   void OnDatabaseSave(bool success);
 116
 117   // Take entries from the database and put them in the local cache.
 118   void LoadEntriesInCache(scoped_ptr<ImageDataVector> entries);
 119
 120   void ServePendingCacheRequests();
 121
 122   // Map from URL to image URL. Should be kept up to date when a new
 123   // SuggestionsProfile is available.
 124   std::map<GURL, GURL> image_url_map_;
 125
 126   // Map from website URL to request information, used for pending cache
 127   // requests while the database hasn't loaded.
 128   ImageCacheRequestMap pending_cache_requests_;
 129
 130   // Holding the bitmaps in memory, keyed by website URL string.
 131   ImageMap image_map_;
 132
 133   scoped_ptr<ImageFetcher> image_fetcher_;
 134
 135   scoped_ptr<leveldb_proto::ProtoDatabase<ImageData> > database_;
 136
 137   bool database_ready_;
 138
 139   base::ThreadChecker thread_checker_;
 140
 141   base::WeakPtrFactory<ImageManager> weak_ptr_factory_;
 142
 143   DISALLOW_COPY_AND_ASSIGN(ImageManager);
 144 };
 145
 146 }  // namespace suggestions
 147
 148 #endif  // COMPONENTS_SUGGESTIONS_IMAGE_MANAGER_H_