Bug 858674 - 'Tweak SQLite pragmas on mobile devices for space savings'. r=khuey.

dom/indexedDB/IDBFactory.cpp

@@ -300,21 +300,41 @@ IDBFactory::GetConnection(const nsAString& aDatabaseFilePath,
   rv = ss->OpenDatabaseWithFileURL(dbFileUrl, getter_AddRefs(connection));
   NS_ENSURE_SUCCESS(rv, nullptr);
 
-  // Turn on foreign key constraints and recursive triggers.
-  // The "INSERT OR REPLACE" statement doesn't fire the update trigger,
-  // instead it fires only the insert trigger. This confuses the update
-  // refcount function. This behavior changes with enabled recursive triggers,
-  // so the statement fires the delete trigger first and then the insert
-  // trigger.
-  rv = connection->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
-    "PRAGMA foreign_keys = ON; "
-    "PRAGMA recursive_triggers = ON;"
-  ));
+  rv = SetDefaultPragmas(connection);
   NS_ENSURE_SUCCESS(rv, nullptr);
 
   return connection.forget();
 }
 
+// static
+nsresult
+IDBFactory::SetDefaultPragmas(mozIStorageConnection* aConnection)
+{
+  NS_ASSERTION(aConnection, "Null connection!");
+
+  nsresult rv = aConnection->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
+    // We use foreign keys in lots of places.
+    "PRAGMA foreign_keys = ON; "
+
+    // The "INSERT OR REPLACE" statement doesn't fire the update trigger,
+    // instead it fires only the insert trigger. This confuses the update
+    // refcount function. This behavior changes with enabled recursive triggers,
+    // so the statement fires the delete trigger first and then the insert
+    // trigger.
+    "PRAGMA recursive_triggers = ON; "
+
+#if defined(MOZ_WIDGET_ANDROID) || defined(MOZ_WIDGET_GONK)
+    // Switch the journaling mode to TRUNCATE to avoid changing the directory
+    // structure at the conclusion of every transaction for devices with slower
+    // file systems.
+    "PRAGMA journal_mode = TRUNCATE; "
+#endif
+  ));
+  NS_ENSURE_SUCCESS(rv, NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR);
+
+  return NS_OK;
+}
+
 inline
 bool
 IgnoreWhitespace(PRUnichar c)

dom/indexedDB/IDBFactory.h

@@ -80,6 +80,9 @@ public:
   GetConnection(const nsAString& aDatabaseFilePath,
                 const nsACString& aOrigin);
 
+  static nsresult
+  SetDefaultPragmas(mozIStorageConnection* aConnection);
+
   static nsresult
   LoadDatabaseInformation(mozIStorageConnection* aConnection,
                           nsIAtom* aDatabaseId,

dom/indexedDB/OpenDatabaseHelper.cpp

@@ -36,7 +36,7 @@ MOZ_STATIC_ASSERT(JS_STRUCTURED_CLONE_VERSION == 1,
                   "Need to update the major schema version.");
 
 // Major schema version. Bump for almost everything.
-const uint32_t kMajorSchemaVersion = 12;
+const uint32_t kMajorSchemaVersion = 13;
 
 // Minor schema version. Should almost always be 0 (maybe bump on release
 // branches if we have to).
@@ -1323,6 +1323,33 @@ UpgradeSchemaFrom11_0To12_0(mozIStorageConnection* aConnection)
   return NS_OK;
 }
 
+nsresult
+UpgradeSchemaFrom12_0To13_0(mozIStorageConnection* aConnection,
+                            bool* aVacuumNeeded)
+{
+  nsresult rv;
+
+#if defined(MOZ_WIDGET_ANDROID) || defined(MOZ_WIDGET_GONK)
+  int32_t defaultPageSize;
+  rv = aConnection->GetDefaultPageSize(&defaultPageSize);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Enable auto_vacuum mode and update the page size to the platform default.
+  nsAutoCString upgradeQuery("PRAGMA auto_vacuum = FULL; PRAGMA page_size = ");
+  upgradeQuery.AppendInt(defaultPageSize);
+
+  rv = aConnection->ExecuteSimpleSQL(upgradeQuery);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  *aVacuumNeeded = true;
+#endif
+
+  rv = aConnection->SetSchemaVersion(MakeSchemaVersion(13, 0));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
 class VersionChangeEventsRunnable;
 
 class SetVersionHelper : public AsyncConnectionHelper,
@@ -1814,6 +1841,9 @@ OpenDatabaseHelper::CreateDatabaseConnection(
   }
   NS_ENSURE_SUCCESS(rv, rv);
 
+  rv = IDBFactory::SetDefaultPragmas(connection);
+  NS_ENSURE_SUCCESS(rv, rv);
+
   rv = connection->EnableModule(NS_LITERAL_CSTRING("filesystem"));
   NS_ENSURE_SUCCESS(rv, rv);
 
@@ -1836,6 +1866,17 @@ OpenDatabaseHelper::CreateDatabaseConnection(
   bool vacuumNeeded = false;
 
   if (schemaVersion != kSQLiteSchemaVersion) {
+#if defined(MOZ_WIDGET_ANDROID) || defined(MOZ_WIDGET_GONK)
+    if (!schemaVersion) {
+      // Have to do this before opening a transaction.
+      rv = connection->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
+        // Turn on auto_vacuum mode to reclaim disk space on mobile devices.
+        "PRAGMA auto_vacuum = FULL; "
+      ));
+      NS_ENSURE_SUCCESS(rv, NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR);
+    }
+#endif
+
     mozStorageTransaction transaction(connection, false,
                                   mozIStorageConnection::TRANSACTION_IMMEDIATE);
 
@@ -1863,7 +1904,7 @@ OpenDatabaseHelper::CreateDatabaseConnection(
     }
     else  {
       // This logic needs to change next time we change the schema!
-      MOZ_STATIC_ASSERT(kSQLiteSchemaVersion == int32_t((12 << 4) + 0),
+      MOZ_STATIC_ASSERT(kSQLiteSchemaVersion == int32_t((13 << 4) + 0),
                         "Need upgrade code from schema version increase.");
 
       while (schemaVersion != kSQLiteSchemaVersion) {
@@ -1892,6 +1933,9 @@ OpenDatabaseHelper::CreateDatabaseConnection(
         else if (schemaVersion == MakeSchemaVersion(11, 0)) {
           rv = UpgradeSchemaFrom11_0To12_0(connection);
         }
+        else if (schemaVersion == MakeSchemaVersion(12, 0)) {
+          rv = UpgradeSchemaFrom12_0To13_0(connection, &vacuumNeeded);
+        }
         else {
           NS_WARNING("Unable to open IndexedDB database, no upgrade path is "
                      "available!");
@@ -1906,7 +1950,7 @@ OpenDatabaseHelper::CreateDatabaseConnection(
       NS_ASSERTION(schemaVersion == kSQLiteSchemaVersion, "Huh?!");
     }
 
-    rv = transaction.Commit();    
+    rv = transaction.Commit();
     if (rv == NS_ERROR_FILE_NO_DEVICE_SPACE) {
       // mozstorage translates SQLITE_FULL to NS_ERROR_FILE_NO_DEVICE_SPACE,
       // which we know better as NS_ERROR_DOM_INDEXEDDB_QUOTA_ERR.
@@ -1916,18 +1960,10 @@ OpenDatabaseHelper::CreateDatabaseConnection(
   }
 
   if (vacuumNeeded) {
-    rv = connection->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
-      "VACUUM;"
-    ));
+    rv = connection->ExecuteSimpleSQL(NS_LITERAL_CSTRING("VACUUM;"));
     NS_ENSURE_SUCCESS(rv, rv);
   }
 
-  // Turn on foreign key constraints.
-  rv = connection->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
-    "PRAGMA foreign_keys = ON;"
-  ));
-  NS_ENSURE_SUCCESS(rv, rv);
-
   connection.forget(aConnection);
   return NS_OK;
 }
@@ -2469,6 +2505,21 @@ DeleteDatabaseHelper::DoDatabaseWork(mozIStorageConnection* aConnection)
     }
   }
 
+  nsCOMPtr<nsIFile> dbJournalFile;
+  rv = directory->Clone(getter_AddRefs(dbJournalFile));
+  NS_ENSURE_SUCCESS(rv, NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR);
+
+  rv = dbJournalFile->Append(filename + NS_LITERAL_STRING(".sqlite-journal"));
+  NS_ENSURE_SUCCESS(rv, NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR);
+
+  rv = dbJournalFile->Exists(&exists);
+  NS_ENSURE_SUCCESS(rv, NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR);
+
+  if (exists) {
+    rv = dbJournalFile->Remove(false);
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR);
+  }
+
   nsCOMPtr<nsIFile> fmDirectory;
   rv = directory->Clone(getter_AddRefs(fmDirectory));
   NS_ENSURE_SUCCESS(rv, NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR);