Deprecate version 5 of the favicon database.

components/history/core/browser/thumbnail_database.cc

 // 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.
 
 #include "components/history/core/browser/thumbnail_database.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/bind.h"
@@ skipping 61 matching lines @@
 // For this database, schema migrations are deprecated after two
 // years.  This means that the oldest non-deprecated version should be
 // two years old or greater (thus the migrations to get there are
 // older).  Databases containing deprecated versions will be cleared
 // at startup.  Since this database is a cache, losing old data is not
 // fatal (in fact, very old data may be expired immediately at startup
 // anyhow).
 
 // Version 7: 911a634d/r209424 by qsr@chromium.org on 2013-07-01
 // Version 6: 610f923b/r152367 by pkotwicz@chromium.org on 2012-08-20
 // Version 5: e2ee8ae9/r105004 by groby@chromium.org on 2011-10-12

[Scott Hess - ex-Googler, 2015/03/24 19:28:25]

Mark this line (deprecated).

[Roger McFarlane (Chromium), 2015/03/24 22:26:57]

Done.

 // Version 4: 5f104d76/r77288 by sky@chromium.org on 2011-03-08 (deprecated)
 // Version 3: 09911bf3/r15 by initial.commit on 2008-07-26 (deprecated)
 
 // Version number of the database.
 // NOTE(shess): When changing the version, add a new golden file for
 // the new version and a test to verify that Init() works with it.
 const int kCurrentVersionNumber = 7;
 const int kCompatibleVersionNumber = 7;
-const int kDeprecatedVersionNumber = 4;  // and earlier.
+const int kDeprecatedVersionNumber = 5;  // and earlier.
 
 void FillIconMapping(const sql::Statement& statement,
                      const GURL& page_url,
                      IconMapping* icon_mapping) {
   icon_mapping->mapping_id = statement.ColumnInt64(0);
   icon_mapping->icon_id = statement.ColumnInt64(1);
   icon_mapping->icon_type =
       static_cast<favicon_base::IconType>(statement.ColumnInt(2));
   icon_mapping->icon_url = GURL(statement.ColumnString(3));
   icon_mapping->page_url = page_url;
@@ skipping 329 matching lines @@
     // creating the recover virtual table for corrupt.meta.  The table
     // may not exist, or the database may be too far gone.  Either
     // way, unclear how to resolve.
     sql::Recovery::Rollback(recovery.Pass());
     RecordRecoveryEvent(RECOVERY_EVENT_FAILED_META_VERSION);
     return;
   }
 
   // This code may be able to fetch version information that the regular
   // deprecation path cannot.
-  // NOTE(shess): v5 and v6 are currently not deprecated in the normal Init()
-  // path, but are deprecated in the recovery path in the interest of keeping
+  // NOTE(shess,rogerm): v6 is not currently deprecated in the normal Init()
+  // path, but is deprecated in the recovery path in the interest of keeping
   // the code simple.  http://crbug.com/327485 for numbers.
   DCHECK_LE(kDeprecatedVersionNumber, 6);
   if (version <= 6) {
     sql::Recovery::Unrecoverable(recovery.Pass());
     RecordRecoveryEvent(RECOVERY_EVENT_DEPRECATED);
     return;
   }
 
   // Earlier versions have been handled or deprecated, later versions should be
   // impossible.
@@ skipping 780 matching lines @@
   }
 
   if (cur_version < 7 && !db_.DoesColumnExist("favicons", "sizes")) {
     LOG(ERROR) << "Raze because of missing favicon.sizes";
     RecordInvalidStructure(STRUCTURE_EVENT_VERSION5);
 
     db_.RazeAndClose();
     return sql::INIT_FAILURE;
   }
 
-  if (cur_version == 5) {
-    ++cur_version;
-    if (!UpgradeToVersion6())
-      return CantUpgradeToVersion(cur_version);
-  }
-
   if (cur_version == 6) {
     ++cur_version;
     if (!UpgradeToVersion7())
       return CantUpgradeToVersion(cur_version);
   }
 
   LOG_IF(WARNING, cur_version < kCurrentVersionNumber) <<
       "Thumbnail database version " << cur_version << " is too old to handle.";
 
   // Initialization is complete.
@@ skipping 17 matching lines @@
   return sql::INIT_OK;
 }
 
 sql::InitStatus ThumbnailDatabase::CantUpgradeToVersion(int cur_version) {
   LOG(WARNING) << "Unable to update to thumbnail database to version " <<
                cur_version << ".";
   db_.Close();
   return sql::INIT_FAILURE;
 }
 
-bool ThumbnailDatabase::UpgradeToVersion6() {
-  // Move bitmap data from favicons to favicon_bitmaps.
-  bool success =
-      db_.Execute("INSERT INTO favicon_bitmaps (icon_id, last_updated, "
-                  "image_data, width, height)"
-                  "SELECT id, last_updated, image_data, 0, 0 FROM favicons") &&
-      db_.Execute("CREATE TABLE temp_favicons ("
-                  "id INTEGER PRIMARY KEY,"
-                  "url LONGVARCHAR NOT NULL,"
-                  "icon_type INTEGER DEFAULT 1,"
-                  // default icon_type FAVICON to be consistent with
-                  // past migration.
-                  "sizes LONGVARCHAR)") &&
-      db_.Execute("INSERT INTO temp_favicons (id, url, icon_type) "
-                  "SELECT id, url, icon_type FROM favicons") &&
-      db_.Execute("DROP TABLE favicons") &&
-      db_.Execute("ALTER TABLE temp_favicons RENAME TO favicons");
-  // NOTE(shess): v7 will re-create the index.
-  if (!success)
-    return false;
-
-  meta_table_.SetVersionNumber(6);
-  meta_table_.SetCompatibleVersionNumber(std::min(6, kCompatibleVersionNumber));
-  return true;
-}
-
 bool ThumbnailDatabase::UpgradeToVersion7() {
   // Sizes column was never used, remove it.
   bool success =
       db_.Execute("CREATE TABLE temp_favicons ("
                   "id INTEGER PRIMARY KEY,"
                   "url LONGVARCHAR NOT NULL,"
                   // default icon_type FAVICON to be consistent with
                   // past migration.
                   "icon_type INTEGER DEFAULT 1)") &&
       db_.Execute("INSERT INTO temp_favicons (id, url, icon_type) "
                   "SELECT id, url, icon_type FROM favicons") &&
       db_.Execute("DROP TABLE favicons") &&
       db_.Execute("ALTER TABLE temp_favicons RENAME TO favicons") &&
       db_.Execute("CREATE INDEX IF NOT EXISTS favicons_url ON favicons(url)");
 
   if (!success)
     return false;
 
   meta_table_.SetVersionNumber(7);
   meta_table_.SetCompatibleVersionNumber(std::min(7, kCompatibleVersionNumber));
   return true;
 }
 
 bool ThumbnailDatabase::IsFaviconDBStructureIncorrect() {
   return !db_.IsSQLValid("SELECT id, url, icon_type FROM favicons");
 }
 
 }  // namespace history