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- <?php
- /**
- * @file
- * Database interface code for PostgreSQL database servers.
- */
- /**
- * @addtogroup database
- * @{
- */
- /**
- * The name by which to obtain a lock for retrieving the next insert id.
- */
- define('POSTGRESQL_NEXTID_LOCK', 1000);
- class DatabaseConnection_pgsql extends DatabaseConnection {
- public function __construct(array $connection_options = array()) {
- // This driver defaults to transaction support, except if explicitly passed FALSE.
- $this->transactionSupport = !isset($connection_options['transactions']) || ($connection_options['transactions'] !== FALSE);
- // Transactional DDL is always available in PostgreSQL,
- // but we'll only enable it if standard transactions are.
- $this->transactionalDDLSupport = $this->transactionSupport;
- // Default to TCP connection on port 5432.
- if (empty($connection_options['port'])) {
- $connection_options['port'] = 5432;
- }
- // PostgreSQL in trust mode doesn't require a password to be supplied.
- if (empty($connection_options['password'])) {
- $connection_options['password'] = NULL;
- }
- // If the password contains a backslash it is treated as an escape character
- // http://bugs.php.net/bug.php?id=53217
- // so backslashes in the password need to be doubled up.
- // The bug was reported against pdo_pgsql 1.0.2, backslashes in passwords
- // will break on this doubling up when the bug is fixed, so check the version
- //elseif (phpversion('pdo_pgsql') < 'version_this_was_fixed_in') {
- else {
- $connection_options['password'] = str_replace('\\', '\\\\', $connection_options['password']);
- }
- $this->connectionOptions = $connection_options;
- $dsn = 'pgsql:host=' . $connection_options['host'] . ' dbname=' . $connection_options['database'] . ' port=' . $connection_options['port'];
- // Allow PDO options to be overridden.
- $connection_options += array(
- 'pdo' => array(),
- );
- $connection_options['pdo'] += array(
- // Prepared statements are most effective for performance when queries
- // are recycled (used several times). However, if they are not re-used,
- // prepared statements become inefficient. Since most of Drupal's
- // prepared queries are not re-used, it should be faster to emulate
- // the preparation than to actually ready statements for re-use. If in
- // doubt, reset to FALSE and measure performance.
- PDO::ATTR_EMULATE_PREPARES => TRUE,
- // Convert numeric values to strings when fetching.
- PDO::ATTR_STRINGIFY_FETCHES => TRUE,
- );
- parent::__construct($dsn, $connection_options['username'], $connection_options['password'], $connection_options['pdo']);
- // Force PostgreSQL to use the UTF-8 character set by default.
- $this->exec("SET NAMES 'UTF8'");
- // Execute PostgreSQL init_commands.
- if (isset($connection_options['init_commands'])) {
- $this->exec(implode('; ', $connection_options['init_commands']));
- }
- }
- public function prepareQuery($query) {
- // mapConditionOperator converts LIKE operations to ILIKE for consistency
- // with MySQL. However, Postgres does not support ILIKE on bytea (blobs)
- // fields.
- // To make the ILIKE operator work, we type-cast bytea fields into text.
- // @todo This workaround only affects bytea fields, but the involved field
- // types involved in the query are unknown, so there is no way to
- // conditionally execute this for affected queries only.
- return parent::prepareQuery(preg_replace('/ ([^ ]+) +(I*LIKE|NOT +I*LIKE) /i', ' ${1}::text ${2} ', $query));
- }
- public function query($query, array $args = array(), $options = array()) {
- $options += $this->defaultOptions();
- // The PDO PostgreSQL driver has a bug which
- // doesn't type cast booleans correctly when
- // parameters are bound using associative
- // arrays.
- // See http://bugs.php.net/bug.php?id=48383
- foreach ($args as &$value) {
- if (is_bool($value)) {
- $value = (int) $value;
- }
- }
- try {
- if ($query instanceof DatabaseStatementInterface) {
- $stmt = $query;
- $stmt->execute(NULL, $options);
- }
- else {
- $this->expandArguments($query, $args);
- $stmt = $this->prepareQuery($query);
- $stmt->execute($args, $options);
- }
- switch ($options['return']) {
- case Database::RETURN_STATEMENT:
- return $stmt;
- case Database::RETURN_AFFECTED:
- return $stmt->rowCount();
- case Database::RETURN_INSERT_ID:
- return $this->lastInsertId($options['sequence_name']);
- case Database::RETURN_NULL:
- return;
- default:
- throw new PDOException('Invalid return directive: ' . $options['return']);
- }
- }
- catch (PDOException $e) {
- if ($options['throw_exception']) {
- // Add additional debug information.
- if ($query instanceof DatabaseStatementInterface) {
- $e->query_string = $stmt->getQueryString();
- }
- else {
- $e->query_string = $query;
- }
- $e->args = $args;
- throw $e;
- }
- return NULL;
- }
- }
- public function queryRange($query, $from, $count, array $args = array(), array $options = array()) {
- return $this->query($query . ' LIMIT ' . (int) $count . ' OFFSET ' . (int) $from, $args, $options);
- }
- public function queryTemporary($query, array $args = array(), array $options = array()) {
- $tablename = $this->generateTemporaryTableName();
- $this->query('CREATE TEMPORARY TABLE {' . $tablename . '} AS ' . $query, $args, $options);
- return $tablename;
- }
- public function driver() {
- return 'pgsql';
- }
- public function databaseType() {
- return 'pgsql';
- }
- public function mapConditionOperator($operator) {
- static $specials;
- // Function calls not allowed in static declarations, thus this method.
- if (!isset($specials)) {
- $specials = array(
- // In PostgreSQL, 'LIKE' is case-sensitive. For case-insensitive LIKE
- // statements, we need to use ILIKE instead.
- 'LIKE' => array('operator' => 'ILIKE'),
- 'NOT LIKE' => array('operator' => 'NOT ILIKE'),
- );
- }
- return isset($specials[$operator]) ? $specials[$operator] : NULL;
- }
- /**
- * Retrieve the next id in a sequence.
- *
- * PostgreSQL has built in sequences. We'll use these instead of inserting
- * and updating a sequences table.
- */
- public function nextId($existing = 0) {
- // Retrieve the name of the sequence. This information cannot be cached
- // because the prefix may change, for example, like it does in simpletests.
- $sequence_name = $this->makeSequenceName('sequences', 'value');
- // When PostgreSQL gets a value too small then it will lock the table,
- // retry the INSERT and if it's still too small then alter the sequence.
- $id = $this->query("SELECT nextval('" . $sequence_name . "')")->fetchField();
- if ($id > $existing) {
- return $id;
- }
- // PostgreSQL advisory locks are simply locks to be used by an
- // application such as Drupal. This will prevent other Drupal processes
- // from altering the sequence while we are.
- $this->query("SELECT pg_advisory_lock(" . POSTGRESQL_NEXTID_LOCK . ")");
- // While waiting to obtain the lock, the sequence may have been altered
- // so lets try again to obtain an adequate value.
- $id = $this->query("SELECT nextval('" . $sequence_name . "')")->fetchField();
- if ($id > $existing) {
- $this->query("SELECT pg_advisory_unlock(" . POSTGRESQL_NEXTID_LOCK . ")");
- return $id;
- }
- // Reset the sequence to a higher value than the existing id.
- $this->query("ALTER SEQUENCE " . $sequence_name . " RESTART WITH " . ($existing + 1));
- // Retrieve the next id. We know this will be as high as we want it.
- $id = $this->query("SELECT nextval('" . $sequence_name . "')")->fetchField();
- $this->query("SELECT pg_advisory_unlock(" . POSTGRESQL_NEXTID_LOCK . ")");
- return $id;
- }
- public function utf8mb4IsActive() {
- return TRUE;
- }
- public function utf8mb4IsSupported() {
- return TRUE;
- }
- }
- /**
- * @} End of "addtogroup database".
- */
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