Use an atomic implementation on sqlite for insertIfNotExist()

lib/private/db/adaptersqlite.php

@@ -19,11 +19,13 @@ class AdapterSqlite extends Adapter {
 	}
 
 	public function insertIfNotExist($table, $input) {
-		// NOTE: For SQLite we have to use this clumsy approach
-		// otherwise all fieldnames used must have a unique key.
-		$query = 'SELECT COUNT(*) FROM `' . $table . '` WHERE ';
-		$inserts = array();
-		foreach ($input as $key => $value) {
+		$fieldList = '`' . implode('`,`', array_keys($input)) . '`';
+		$query = "INSERT INTO `$table` ($fieldList) SELECT "
+			. str_repeat('?,', count($input)-1).'? '
+			. " WHERE NOT EXISTS (SELECT 1 FROM `$table` WHERE ";
+
+		$inserts = array_values($input);
+		foreach($input as $key => $value) {
 			$query .= '`' . $key . '`';
 			if (is_null($value)) {
 				$query .= ' IS NULL AND ';
@@ -33,34 +35,10 @@ class AdapterSqlite extends Adapter {
 			}
 		}
 		$query = substr($query, 0, strlen($query) - 5);
+		$query .= ')';
 
 		try {
-			$stmt = $this->conn->prepare($query);
-			$result = $stmt->execute($inserts);
-		} catch(\Doctrine\DBAL\DBALException $e) {
-			$entry = 'DB Error: "'.$e->getMessage() . '"<br />';
-			$entry .= 'Offending command was: ' . $query . '<br />';
-			\OC_Log::write('core', $entry, \OC_Log::FATAL);
-			$l = \OC::$server->getL10N('lib');
-			throw new \OC\HintException(
-				$l->t('Database Error'),
-				$l->t('Please contact your system administrator.'),
-				0,
-				$e
-			);
-		}
-
-		if ($stmt->fetchColumn() === '0') {
-			$query = 'INSERT INTO `' . $table . '` (`'
-				. implode('`,`', array_keys($input)) . '`) VALUES('
-				. str_repeat('?,', count($input)-1).'? ' . ')';
-		} else {
-			return 0; //no rows updated
-		}
-
-		try {
-			$statement = $this->conn->prepare($query);
-			$result = $statement->execute(array_values($input));
+			return $this->conn->executeUpdate($query, $inserts);
 		} catch(\Doctrine\DBAL\DBALException $e) {
 			$entry = 'DB Error: "'.$e->getMessage() . '"<br />';
 			$entry .= 'Offending command was: ' . $query.'<br />';
@@ -73,7 +51,5 @@ class AdapterSqlite extends Adapter {
 				$e
 			);
 		}
-
-		return $result;
 	}
 }