[Activity Log] when extension is uninstalled, delete data about it

chrome/browser/extensions/activity_log/counting_policy.cc

 // Copyright 2013 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.
 
 // A policy for storing activity log data to a database that performs
 // aggregation to reduce the size of the database.  The database layout is
 // nearly the same as FullStreamUIPolicy, which stores a complete log, with a
 // few changes:
 //   - a "count" column is added to track how many log records were merged
 //     together into this row
@@ skipping 547 matching lines @@
       return;
     }
   }
 
   // Clean up unused strings from the strings and urls table to really delete
   // the urls and page titles. Should be called even if an error occured when
   // removing a URL as there may some things to clean up.
   CleanStringTables(db);
 }
 
+void CountingPolicy::DoRemoveExtensionData(const std::string& extension_id) {
+  if (extension_id.empty())
+    return;
+
+  sql::Connection* db = GetDatabaseConnection();
+  if (!db) {
+    LOG(ERROR) << "Unable to connect to database";
+    return;
+  }
+
+  // Make sure any queued in memory are sent to the database before cleaning.
+  activity_database()->AdviseFlush(ActivityDatabase::kFlushImmediately);
+
+  std::string sql_str = base::StringPrintf(
+      "DELETE FROM %s WHERE extension_id_x=?", kTableName);
+  sql::Statement statement(
+      db->GetCachedStatement(sql::StatementID(SQL_FROM_HERE), sql_str.c_str()));
+  int64 id;
+  if (string_table_.StringToInt(db, extension_id, &id)) {

[felt, 2013/09/09 14:31:08]

Michael, can you check this if-statement? Is the else clause needed for safety,
or can we be sure this won't happen?

[mvrable, 2013/09/09 17:39:44]

The else clause is not needed.  All writes to the database will use an integer
ID and not a string.

[felt, 2013/09/09 21:19:44]

Thanks, changed to a return.

+    statement.BindInt64(0, id);
+  } else {
+    statement.BindString(0, extension_id);
+  }
+  if (!statement.Run()) {
+    LOG(ERROR) << "Removing URLs for extension "
+               << extension_id << "from database failed: "
+               << statement.GetSQLStatement();
+  }
+  CleanStringTables(db);
+}
+
 void CountingPolicy::DoDeleteDatabase() {
   sql::Connection* db = GetDatabaseConnection();
   if (!db) {
     LOG(ERROR) << "Unable to connect to database";
     return;
   }
 
   queued_actions_.clear();
 
   // Not wrapped in a transaction because a late failure shouldn't undo a
@@ skipping 52 matching lines @@
                  page_url,
                  arg_url,
                  days_ago),
       callback);
 }
 
 void CountingPolicy::RemoveURLs(const std::vector<GURL>& restrict_urls) {
   ScheduleAndForget(this, &CountingPolicy::DoRemoveURLs, restrict_urls);
 }
 
+void CountingPolicy::RemoveExtensionData(const std::string& extension_id) {
+  ScheduleAndForget(this, &CountingPolicy::DoRemoveExtensionData, extension_id);
+}
+
 void CountingPolicy::DeleteDatabase() {
   ScheduleAndForget(this, &CountingPolicy::DoDeleteDatabase);
 }
 
 void CountingPolicy::OnDatabaseFailure() {
   queued_actions_.clear();
 }
 
 void CountingPolicy::OnDatabaseClose() {
   delete this;
@@ skipping 32 matching lines @@
   return true;
 }
 
 void CountingPolicy::Close() {
   // The policy object should have never been created if there's no DB thread.
   DCHECK(BrowserThread::IsMessageLoopValid(BrowserThread::DB));
   ScheduleAndForget(activity_database(), &ActivityDatabase::Close);
 }
 
 }  // namespace extensions