[Thumbnails DB] Allow setting last_requested time when accessing favicons.

components/history/core/browser/thumbnail_database.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 COMPONENTS_HISTORY_CORE_BROWSER_THUMBNAIL_DATABASE_H_
 #define COMPONENTS_HISTORY_CORE_BROWSER_THUMBNAIL_DATABASE_H_
 
 #include <vector>
 
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "components/history/core/browser/history_types.h"
 #include "sql/connection.h"
 #include "sql/init_status.h"
 #include "sql/meta_table.h"
 #include "sql/statement.h"
 
 namespace base {
 class FilePath;
 class RefCountedMemory;
 class Time;
 }
 
 namespace history {
 
 class HistoryBackendClient;
 
+// The minimum number of days after which last_requested field gets updated.
+// All earlier updates are ignored.
+static const int kFaviconUpdateLastRequestedAfterDays = 14;
+
 // This database interface is owned by the history backend and runs on the
 // history thread. It is a totally separate component from history partially
 // because we may want to move it to its own thread in the future. The
 // operations we will do on this database will be slow, but we can tolerate
 // higher latency (it's OK for thumbnails to come in slower than the rest
 // of the data). Moving this to a separate thread would not block potentially
 // higher priority history operations.
 class ThumbnailDatabase {
  public:
   explicit ThumbnailDatabase(HistoryBackendClient* backend_client);
@@ skipping 41 matching lines @@
                          std::vector<FaviconBitmap>* favicon_bitmaps);
 
   // Gets the last updated time, bitmap data, and pixel size of the favicon
   // bitmap at |bitmap_id|. Returns true if successful.
   bool GetFaviconBitmap(FaviconBitmapID bitmap_id,
                         base::Time* last_updated,
                         base::Time* last_requested,
                         scoped_refptr<base::RefCountedMemory>* png_icon_data,
                         gfx::Size* pixel_size);
 
-  // Adds a bitmap component at |pixel_size| for the favicon with |icon_id|.
-  // Only favicons representing a .ico file should have multiple favicon bitmaps
-  // per favicon.
+  // Adds a bitmap component of |type| at |pixel_size| for the favicon with
+  // |icon_id|. Only favicons representing a .ico file should have multiple
+  // favicon bitmaps per favicon.
   // |icon_data| is the png encoded data.
-  // The |time| indicates the access time, and is used to detect when the
-  // favicon should be refreshed.
+  // The |type| indicates how the lifetime of this icon should be managed.
+  // The |time| is used for lifetime management of the bitmap (should be Now()).
   // |pixel_size| is the pixel dimensions of |icon_data|.
   // Returns the id of the added bitmap or 0 if unsuccessful.
   FaviconBitmapID AddFaviconBitmap(
       favicon_base::FaviconID icon_id,
       const scoped_refptr<base::RefCountedMemory>& icon_data,
+      FaviconBitmapType type,
       base::Time time,
       const gfx::Size& pixel_size);
 
   // Sets the bitmap data and the last updated time for the favicon bitmap at
-  // |bitmap_id|.
+  // |bitmap_id|. Should not be called for bitmaps of type ON_DEMAND as they
+  // should never get updated (the call silently changes the type to ON_VISIT).
   // Returns true if successful.
   bool SetFaviconBitmap(FaviconBitmapID bitmap_id,
                         scoped_refptr<base::RefCountedMemory> bitmap_data,
                         base::Time time);
 
-  // Sets the last updated time for the favicon bitmap at |bitmap_id|.
-  // Returns true if successful.
+  // Sets the last_updated time for the favicon bitmap at |bitmap_id|. Should
+  // not be called for bitmaps of type ON_DEMAND as last_updated time is only
+  // tracked for ON_VISIT bitmaps (the call silently changes the type to
+  // ON_VISIT). Returns true if successful.
   bool SetFaviconBitmapLastUpdateTime(FaviconBitmapID bitmap_id,
                                       base::Time time);
 
-  // Sets the last requested time for the favicon bitmap at |bitmap_id|.
-  // Returns true if successful.
-  bool SetFaviconBitmapLastRequestedTime(FaviconBitmapID bitmap_id,
-                                         base::Time time);
-
   // Deletes the favicon bitmap with |bitmap_id|.
   // Returns true if successful.
   bool DeleteFaviconBitmap(FaviconBitmapID bitmap_id);
 
   // Favicons ------------------------------------------------------------------
 
   // Sets the the favicon as out of date. This will set |last_updated| for all
   // of the bitmaps for |icon_id| to be out of date.
   bool SetFaviconOutOfDate(favicon_base::FaviconID icon_id);
 
+  // Mark all bitmaps of type ON_DEMAND at |icon_url| as requested at |time|.
+  // This postpones their automatic eviction from the database. Not all calls
+  // end up in a write into the DB:
+  // - it is no-op if the bitmaps are not of type ON_DEMAND;
+  // - the updates of the "last requested time" have limited frequency for each
+  //   particular bitmap (e.g. once per week). This limits the overhead of
+  //   cache management for on-demand favicons.
+  // Returns true if successful.
+  bool TouchOnDemandFavicon(const GURL& icon_url, base::Time time);
+
   // Returns the id of the entry in the favicon database with the specified url
   // and icon type.
   // Returns 0 if no entry exists for the specified url.
   favicon_base::FaviconID GetFaviconIDForFaviconURL(
       const GURL& icon_url,
       favicon_base::IconType icon_type);
 
   // Gets the icon_url, icon_type and sizes for the specified |icon_id|.
   bool GetFaviconHeader(favicon_base::FaviconID icon_id,
                         GURL* icon_url,
                         favicon_base::IconType* icon_type);
 
   // Adds favicon with |icon_url|, |icon_type| and |favicon_sizes| to the
   // favicon db, returning its id.
   favicon_base::FaviconID AddFavicon(const GURL& icon_url,
                                      favicon_base::IconType icon_type);
 
   // Adds a favicon with a single bitmap. This call is equivalent to calling
-  // AddFavicon and AddFaviconBitmap.
+  // AddFavicon and AddFaviconBitmap of type |type|.
   favicon_base::FaviconID AddFavicon(
       const GURL& icon_url,
       favicon_base::IconType icon_type,
       const scoped_refptr<base::RefCountedMemory>& icon_data,
+      FaviconBitmapType type,
       base::Time time,
       const gfx::Size& pixel_size);
 
   // Delete the favicon with the provided id. Returns false on failure
   bool DeleteFavicon(favicon_base::FaviconID id);
 
   // Icon Mapping --------------------------------------------------------------
   //
   // Returns true if there is a matched icon mapping for the given page and
   // icon type.
@@ skipping 99 matching lines @@
 
   sql::Connection db_;
   sql::MetaTable meta_table_;
 
   HistoryBackendClient* backend_client_;
 };
 
 }  // namespace history
 
 #endif  // COMPONENTS_HISTORY_CORE_BROWSER_THUMBNAIL_DATABASE_H_