Preload the visited link db on the file thread.

chrome/browser/visitedlink_master.h

 // Copyright (c) 2006-2008 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_VISITEDLINK_MASTER_H__
 #define CHROME_BROWSER_VISITEDLINK_MASTER_H__
 
 #if defined(OS_WIN)
 #include <windows.h>
 #endif
@@ skipping 59 matching lines @@
   // testing except when you want to test the rebuild process explicitly.
   VisitedLinkMaster(Listener* listener,
                     HistoryService* history_service,
                     bool suppress_rebuild,
                     const FilePath& filename,
                     int32 default_table_size);
   virtual ~VisitedLinkMaster();
 
   // Must be called immediately after object creation. Nothing else will work
   // until this is called. Returns true on success, false means that this
-  // object won't work.
+  // object won't work. You can also use InitFromFile() and InitFromScratch()
+  // if you need more control over loading the visited link information.
   bool Init();
 
+  // Try to load the table from the database file. If the file doesn't exist or
+  // is corrupt, this will return failure.
+  bool InitFromFile();
+
+  // Creates a new empty table, call if InitFromFile() fails. Normally, when
+  // |suppress_rebuild| is false, the table will be rebuilt from history,
+  // keeping us in sync.
+  bool InitFromScratch();
+
   base::SharedMemory* shared_memory() { return shared_memory_; }
 
   // Adds a URL to the table.
   void AddURL(const GURL& url);
 
   // Adds a set of URLs to the table.
   void AddURLs(const std::vector<GURL>& url);
 
   // Deletes the specified URLs from the table.
   void DeleteURLs(const std::set<GURL>& urls);
@@ skipping 67 matching lines @@
   // inserted fingerprint or null_hash_ on failure.
   Hash TryToAddURL(const GURL& url);
 
   // File I/O functions
   // ------------------
 
   // Writes the entire table to disk, returning true on success. It will leave
   // the table file open and the handle to it in file_
   bool WriteFullTable();
 
-  // Try to load the table from the database file. If the file doesn't exist or
-  // is corrupt, this will return failure.
-  bool InitFromFile();
-
   // Reads the header of the link coloring database from disk. Assumes the
   // file pointer is at the beginning of the file and that there are no pending
   // asynchronous I/O operations.
   //
   // Returns true on success and places the size of the table in num_entries
   // and the number of nonzero fingerprints in used_count. This will fail if
   // the version of the file is not the current version of the database.
   bool ReadFileHeader(FILE* hfile, int32* num_entries, int32* used_count,
                       uint8 salt[LINK_SALT_LENGTH]);
 
@@ skipping 31 matching lines @@
   // deleted_since_rebuild_ list, the caller must update this itself if there
   // is an update pending.
   void DeleteFingerprintsFromCurrentTable(
       const std::set<Fingerprint>& fingerprints);
 
   // Removes the indicated fingerprint from the table. If the update_file flag
   // is set, the changes will also be written to disk. Returns true if the
   // fingerprint was deleted, false if it was not in the table to delete.
   bool DeleteFingerprint(Fingerprint fingerprint, bool update_file);
 
-  // Creates a new empty table, call if InitFromFile() fails. Normally, when
-  // |suppress_rebuild| is false, the table will be rebuilt from history,
-  // keeping us in sync. When |suppress_rebuild| is true, the new table will be
-  // empty and we will not consult history. This is used when clearing the
-  // database and for unit tests.
-  bool InitFromScratch(bool suppress_rebuild);
-
   // Allocates the Fingerprint structure and length. When init_to_empty is set,
   // the table will be filled with 0s and used_items_ will be set to 0 as well.
   // If the flag is not set, these things are untouched and it is the
   // responsibility of the caller to fill them (like when we are reading from
   // a file).
   bool CreateURLTable(int32 num_entries, bool init_to_empty);
 
   // A wrapper for CreateURLTable, this will allocate a new table, initialized
   // to empty. The caller is responsible for saving the shared memory pointer
   // and handles before this call (they will be replaced with new ones) and
@@ skipping 138 matching lines @@
   int32 used_count = 0;
   for (int32 i = 0; i < table_length_; i++) {
     if (hash_table_[i])
       used_count++;
   }
   DCHECK_EQ(used_count, used_items_);
 }
 #endif
 
 #endif  // CHROME_BROWSER_VISITEDLINK_MASTER_H__