cms/drupal/includes/database/mysql/database.inc
changeset 541 e756a8c72c3d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cms/drupal/includes/database/mysql/database.inc	Fri Sep 08 12:04:06 2017 +0200
@@ -0,0 +1,256 @@
+<?php
+
+/**
+ * @file
+ * Database interface code for MySQL database servers.
+ */
+
+/**
+ * @addtogroup database
+ * @{
+ */
+
+class DatabaseConnection_mysql extends DatabaseConnection {
+
+  /**
+   * Flag to indicate if the cleanup function in __destruct() should run.
+   *
+   * @var boolean
+   */
+  protected $needsCleanup = FALSE;
+
+  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);
+
+    // MySQL never supports transactional DDL.
+    $this->transactionalDDLSupport = FALSE;
+
+    $this->connectionOptions = $connection_options;
+
+    $charset = 'utf8';
+    // Check if the charset is overridden to utf8mb4 in settings.php.
+    if ($this->utf8mb4IsActive()) {
+      $charset = 'utf8mb4';
+    }
+
+    // The DSN should use either a socket or a host/port.
+    if (isset($connection_options['unix_socket'])) {
+      $dsn = 'mysql:unix_socket=' . $connection_options['unix_socket'];
+    }
+    else {
+      // Default to TCP connection on port 3306.
+      $dsn = 'mysql:host=' . $connection_options['host'] . ';port=' . (empty($connection_options['port']) ? 3306 : $connection_options['port']);
+    }
+    // Character set is added to dsn to ensure PDO uses the proper character
+    // set when escaping. This has security implications. See
+    // https://www.drupal.org/node/1201452 for further discussion.
+    $dsn .= ';charset=' . $charset;
+    $dsn .= ';dbname=' . $connection_options['database'];
+    // Allow PDO options to be overridden.
+    $connection_options += array(
+      'pdo' => array(),
+    );
+    $connection_options['pdo'] += array(
+      // So we don't have to mess around with cursors and unbuffered queries by default.
+      PDO::MYSQL_ATTR_USE_BUFFERED_QUERY => TRUE,
+      // Because MySQL's prepared statements skip the query cache, because it's dumb.
+      PDO::ATTR_EMULATE_PREPARES => TRUE,
+    );
+    if (defined('PDO::MYSQL_ATTR_MULTI_STATEMENTS')) {
+      // An added connection option in PHP 5.5.21+ to optionally limit SQL to a
+      // single statement like mysqli.
+      $connection_options['pdo'] += array(PDO::MYSQL_ATTR_MULTI_STATEMENTS => FALSE);
+    }
+
+    parent::__construct($dsn, $connection_options['username'], $connection_options['password'], $connection_options['pdo']);
+
+    // Force MySQL to use the UTF-8 character set. Also set the collation, if a
+    // certain one has been set; otherwise, MySQL defaults to 'utf8_general_ci'
+    // for UTF-8.
+    if (!empty($connection_options['collation'])) {
+      $this->exec('SET NAMES ' . $charset . ' COLLATE ' . $connection_options['collation']);
+    }
+    else {
+      $this->exec('SET NAMES ' . $charset);
+    }
+
+    // Set MySQL init_commands if not already defined.  Default Drupal's MySQL
+    // behavior to conform more closely to SQL standards.  This allows Drupal
+    // to run almost seamlessly on many different kinds of database systems.
+    // These settings force MySQL to behave the same as postgresql, or sqlite
+    // in regards to syntax interpretation and invalid data handling.  See
+    // http://drupal.org/node/344575 for further discussion. Also, as MySQL 5.5
+    // changed the meaning of TRADITIONAL we need to spell out the modes one by
+    // one.
+    $connection_options += array(
+      'init_commands' => array(),
+    );
+    $connection_options['init_commands'] += array(
+      'sql_mode' => "SET sql_mode = 'REAL_AS_FLOAT,PIPES_AS_CONCAT,ANSI_QUOTES,IGNORE_SPACE,STRICT_TRANS_TABLES,STRICT_ALL_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER'",
+    );
+    // Execute initial commands.
+    foreach ($connection_options['init_commands'] as $sql) {
+      $this->exec($sql);
+    }
+  }
+
+  public function __destruct() {
+    if ($this->needsCleanup) {
+      $this->nextIdDelete();
+    }
+  }
+
+  public function queryRange($query, $from, $count, array $args = array(), array $options = array()) {
+    return $this->query($query . ' LIMIT ' . (int) $from . ', ' . (int) $count, $args, $options);
+  }
+
+  public function queryTemporary($query, array $args = array(), array $options = array()) {
+    $tablename = $this->generateTemporaryTableName();
+    $this->query('CREATE TEMPORARY TABLE {' . $tablename . '} Engine=MEMORY ' . $query, $args, $options);
+    return $tablename;
+  }
+
+  public function driver() {
+    return 'mysql';
+  }
+
+  public function databaseType() {
+    return 'mysql';
+  }
+
+  public function mapConditionOperator($operator) {
+    // We don't want to override any of the defaults.
+    return NULL;
+  }
+
+  public function nextId($existing_id = 0) {
+    $new_id = $this->query('INSERT INTO {sequences} () VALUES ()', array(), array('return' => Database::RETURN_INSERT_ID));
+    // This should only happen after an import or similar event.
+    if ($existing_id >= $new_id) {
+      // If we INSERT a value manually into the sequences table, on the next
+      // INSERT, MySQL will generate a larger value. However, there is no way
+      // of knowing whether this value already exists in the table. MySQL
+      // provides an INSERT IGNORE which would work, but that can mask problems
+      // other than duplicate keys. Instead, we use INSERT ... ON DUPLICATE KEY
+      // UPDATE in such a way that the UPDATE does not do anything. This way,
+      // duplicate keys do not generate errors but everything else does.
+      $this->query('INSERT INTO {sequences} (value) VALUES (:value) ON DUPLICATE KEY UPDATE value = value', array(':value' => $existing_id));
+      $new_id = $this->query('INSERT INTO {sequences} () VALUES ()', array(), array('return' => Database::RETURN_INSERT_ID));
+    }
+    $this->needsCleanup = TRUE;
+    return $new_id;
+  }
+
+  public function nextIdDelete() {
+    // While we want to clean up the table to keep it up from occupying too
+    // much storage and memory, we must keep the highest value in the table
+    // because InnoDB  uses an in-memory auto-increment counter as long as the
+    // server runs. When the server is stopped and restarted, InnoDB
+    // reinitializes the counter for each table for the first INSERT to the
+    // table based solely on values from the table so deleting all values would
+    // be a problem in this case. Also, TRUNCATE resets the auto increment
+    // counter.
+    try {
+      $max_id = $this->query('SELECT MAX(value) FROM {sequences}')->fetchField();
+      // We know we are using MySQL here, no need for the slower db_delete().
+      $this->query('DELETE FROM {sequences} WHERE value < :value', array(':value' => $max_id));
+    }
+    // During testing, this function is called from shutdown with the
+    // simpletest prefix stored in $this->connection, and those tables are gone
+    // by the time shutdown is called so we need to ignore the database
+    // errors. There is no problem with completely ignoring errors here: if
+    // these queries fail, the sequence will work just fine, just use a bit
+    // more database storage and memory.
+    catch (PDOException $e) {
+    }
+  }
+
+  /**
+   * Overridden to work around issues to MySQL not supporting transactional DDL.
+   */
+  protected function popCommittableTransactions() {
+    // Commit all the committable layers.
+    foreach (array_reverse($this->transactionLayers) as $name => $active) {
+      // Stop once we found an active transaction.
+      if ($active) {
+        break;
+      }
+
+      // If there are no more layers left then we should commit.
+      unset($this->transactionLayers[$name]);
+      if (empty($this->transactionLayers)) {
+        if (!PDO::commit()) {
+          throw new DatabaseTransactionCommitFailedException();
+        }
+      }
+      else {
+        // Attempt to release this savepoint in the standard way.
+        try {
+          $this->query('RELEASE SAVEPOINT ' . $name);
+        }
+        catch (PDOException $e) {
+          // However, in MySQL (InnoDB), savepoints are automatically committed
+          // when tables are altered or created (DDL transactions are not
+          // supported). This can cause exceptions due to trying to release
+          // savepoints which no longer exist.
+          //
+          // To avoid exceptions when no actual error has occurred, we silently
+          // succeed for MySQL error code 1305 ("SAVEPOINT does not exist").
+          if ($e->errorInfo[1] == '1305') {
+            // If one SAVEPOINT was released automatically, then all were.
+            // Therefore, clean the transaction stack.
+            $this->transactionLayers = array();
+            // We also have to explain to PDO that the transaction stack has
+            // been cleaned-up.
+            PDO::commit();
+          }
+          else {
+            throw $e;
+          }
+        }
+      }
+    }
+  }
+
+  public function utf8mb4IsConfigurable() {
+    return TRUE;
+  }
+
+  public function utf8mb4IsActive() {
+    return isset($this->connectionOptions['charset']) && $this->connectionOptions['charset'] === 'utf8mb4';
+  }
+
+  public function utf8mb4IsSupported() {
+    // Ensure that the MySQL driver supports utf8mb4 encoding.
+    $version = $this->getAttribute(PDO::ATTR_CLIENT_VERSION);
+    if (strpos($version, 'mysqlnd') !== FALSE) {
+      // The mysqlnd driver supports utf8mb4 starting at version 5.0.9.
+      $version = preg_replace('/^\D+([\d.]+).*/', '$1', $version);
+      if (version_compare($version, '5.0.9', '<')) {
+        return FALSE;
+      }
+    }
+    else {
+      // The libmysqlclient driver supports utf8mb4 starting at version 5.5.3.
+      if (version_compare($version, '5.5.3', '<')) {
+        return FALSE;
+      }
+    }
+
+    // Ensure that the MySQL server supports large prefixes and utf8mb4.
+    try {
+      $this->query("CREATE TABLE {drupal_utf8mb4_test} (id VARCHAR(255), PRIMARY KEY(id(255))) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci ROW_FORMAT=DYNAMIC ENGINE=INNODB");
+    }
+    catch (Exception $e) {
+      return FALSE;
+    }
+    $this->query("DROP TABLE {drupal_utf8mb4_test}");
+    return TRUE;
+  }
+}
+
+
+/**
+ * @} End of "addtogroup database".
+ */