Implement a first pass at thumbnail store storage to disk, including a unit test for the new behavior.

TEST=covered by unittest
BUG=none

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@17670 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 47 insertions, 10 deletions

diff --git a/chrome/browser/thumbnail_store.h b/chrome/browser/thumbnail_store.h
index bfff59a..46b6ae0 100644
--- a/chrome/browser/thumbnail_store.h
+++ b/chrome/browser/thumbnail_store.h
@@ -5,11 +5,16 @@
 #ifndef CHROME_BROWSER_THUMBNAIL_STORE_H_
 #define CHROME_BROWSER_THUMBNAIL_STORE_H_
 
+#include <map>
 #include <vector>
 
 #include "base/file_path.h"
+#include "base/message_loop.h"
+#include "base/ref_counted.h"
+#include "testing/gtest/include/gtest/gtest_prod.h"
 
 class GURL;
+class Pickle;
 class SkBitmap;
 struct ThumbnailScore;
 namespace base {
@@ -18,7 +23,7 @@ class Time;
 
 // This storage interface provides storage for the thumbnails used
 // by the new_tab_ui.
-class ThumbnailStore {
+class ThumbnailStore : public base::RefCountedThreadSafe<ThumbnailStore> {
  public:
   ThumbnailStore();
   ~ThumbnailStore();
@@ -26,34 +31,66 @@ class ThumbnailStore {
   // Must be called after creation but before other methods are called.
   // file_path is a directory where a new database should be created
   // or the location of an existing databse.
-  // If false is returned, no other methods should be called.
-  bool Init(const FilePath& file_path);
+  void Init(const FilePath& file_path);
 
-  // Stores the given thumbnail and score with the associated url.
+  // Stores the given thumbnail and score with the associated url in the cache.
+  // If write_to_disk is true, the thumbnail data is written to disk on the
+  // file_thread.
   bool SetPageThumbnail(const GURL& url,
-                        const SkBitmap& thumbnail,
+                        SkBitmap& thumbnail,
                         const ThumbnailScore& score,
-                        const base::Time& time);
+                        bool write_to_disk);
 
   // Retrieves the thumbnail and score for the given url.
   // Returns false if there is not data for the given url or some other
   // error occurred.
   bool GetPageThumbnail(const GURL& url,
-                        SkBitmap** thumbnail,
-                        ThumbnailScore& score);
+                        SkBitmap* thumbnail,
+                        ThumbnailScore* score);
 
  private:
+  FRIEND_TEST(ThumbnailStoreTest, RetrieveFromCache);
+  FRIEND_TEST(ThumbnailStoreTest, RetrieveFromDisk);
+
+  // Data structure used to store thumbnail data in memory.
+  typedef std::map<GURL, std::pair<SkBitmap, ThumbnailScore> > Cache;
+
   // The location of the thumbnail store.
   FilePath file_path_;
 
+  // Read all thumbnail data from the specified FilePath into a Cache object.
+  // Done on the file_thread and returns to OnDiskDataAvailable on the thread
+  // owning the specified MessageLoop.
+  void GetAllThumbnailsFromDisk(FilePath filepath, MessageLoop* cb_loop);
+
+  // Read the thumbnail data from the given file and stores it in the
+  // out parameters GURL, SkBitmap, and ThumbnailScore.
+  bool GetPageThumbnailFromDisk(const FilePath& file,
+                                GURL* url,
+                                SkBitmap* thumbnail,
+                                ThumbnailScore* score) const;
+
+  // Once thumbnail data from the disk is available from the file_thread,
+  // this function is invoked on the main thread.  It takes ownership of the
+  // Cache* passed in and retains this Cache* for the lifetime of the object.
+  void OnDiskDataAvailable(ThumbnailStore::Cache* cache);
+
+  // Write thumbnail data to disk for a given url.
+  bool WriteThumbnailToDisk(const GURL& url) const;
+
   // Pack the given ThumbnailScore into the given Pickle.
-  void PackScore(const ThumbnailScore& score, Pickle& packed);
+  void PackScore(const ThumbnailScore& score, Pickle* packed) const;
 
   // Unpack a ThumbnailScore from a given Pickle and associated iterator.
   // Returns false is a ThumbnailScore could not be unpacked.
-  bool UnpackScore(ThumbnailScore* score, const Pickle& packed, void*& iter);
+  bool UnpackScore(ThumbnailScore* score, const Pickle& packed,
+                   void*& iter) const;
 
   DISALLOW_COPY_AND_ASSIGN(ThumbnailStore);
+
+  // The Cache maintained by the object.
+  scoped_ptr<ThumbnailStore::Cache> cache_;
+  bool cache_initialized_;
 };
 
 #endif  // CHROME_BROWSER_THUMBNAIL_STORE_H_