Connection.php in Drupal 10

Namespace

Drupal\sqlite\Driver\Database\sqlite

File

core/modules/sqlite/src/Driver/Database/sqlite/Connection.php

<?php

namespace Drupal\sqlite\Driver\Database\sqlite;

use Drupal\Core\Database\DatabaseNotFoundException;
use Drupal\Core\Database\Connection as DatabaseConnection;
use Drupal\Core\Database\StatementInterface;

/**
 * SQLite implementation of \Drupal\Core\Database\Connection.
 */
class Connection extends DatabaseConnection {

  /**
   * Error code for "Unable to open database file" error.
   */
  const DATABASE_NOT_FOUND = 14;

  /**
   * {@inheritdoc}
   */
  protected $statementWrapperClass = NULL;

  /**
   * Whether or not the active transaction (if any) will be rolled back.
   *
   * @var bool
   */
  protected $willRollback;

  /**
   * A map of condition operators to SQLite operators.
   *
   * We don't want to override any of the defaults.
   */
  protected static $sqliteConditionOperatorMap = [
    'LIKE' => [
      'postfix' => " ESCAPE '\\'",
    ],
    'NOT LIKE' => [
      'postfix' => " ESCAPE '\\'",
    ],
    'LIKE BINARY' => [
      'postfix' => " ESCAPE '\\'",
      'operator' => 'GLOB',
    ],
    'NOT LIKE BINARY' => [
      'postfix' => " ESCAPE '\\'",
      'operator' => 'NOT GLOB',
    ],
  ];

  /**
   * All databases attached to the current database.
   *
   * This is used to allow prefixes to be safely handled without locking the
   * table.
   *
   * @var array
   */
  protected $attachedDatabases = [];

  /**
   * Whether or not a table has been dropped this request.
   *
   * The destructor will only try to get rid of unnecessary databases if there
   * is potential of them being empty.
   *
   * This variable is set to public because Schema needs to
   * access it. However, it should not be manually set.
   *
   * @var bool
   */
  public $tableDropped = FALSE;

  /**
   * {@inheritdoc}
   */
  protected $transactionalDDLSupport = TRUE;

  /**
   * {@inheritdoc}
   */
  protected $identifierQuotes = [
    '"',
    '"',
  ];

  /**
   * Constructs a \Drupal\sqlite\Driver\Database\sqlite\Connection object.
   */
  public function __construct(\PDO $connection, array $connection_options) {
    parent::__construct($connection, $connection_options);

    // Empty prefix means query the main database -- no need to attach anything.
    $prefix = $this->connectionOptions['prefix'] ?? '';
    if ($prefix !== '') {
      $this
        ->attachDatabase($prefix);

      // Add a ., so queries become prefix.table, which is proper syntax for
      // querying an attached database.
      $prefix .= '.';
    }

    // Regenerate the prefix.
    $this
      ->setPrefix($prefix);
  }

  /**
   * {@inheritdoc}
   */
  public static function open(array &$connection_options = []) {

    // Allow PDO options to be overridden.
    $connection_options += [
      'pdo' => [],
    ];
    $connection_options['pdo'] += [
      \PDO::ATTR_ERRMODE => \PDO::ERRMODE_EXCEPTION,
      // Convert numeric values to strings when fetching.
      \PDO::ATTR_STRINGIFY_FETCHES => TRUE,
    ];
    try {
      $pdo = new \PDO('sqlite:' . $connection_options['database'], '', '', $connection_options['pdo']);
    } catch (\PDOException $e) {
      if ($e
        ->getCode() == static::DATABASE_NOT_FOUND) {
        throw new DatabaseNotFoundException($e
          ->getMessage(), $e
          ->getCode(), $e);
      }

      // SQLite doesn't have a distinct error code for access denied, so don't
      // deal with that case.
      throw $e;
    }

    // Create functions needed by SQLite.
    $pdo
      ->sqliteCreateFunction('if', [
      __CLASS__,
      'sqlFunctionIf',
    ]);
    $pdo
      ->sqliteCreateFunction('greatest', [
      __CLASS__,
      'sqlFunctionGreatest',
    ]);
    $pdo
      ->sqliteCreateFunction('least', [
      __CLASS__,
      'sqlFunctionLeast',
    ]);
    $pdo
      ->sqliteCreateFunction('pow', 'pow', 2);
    $pdo
      ->sqliteCreateFunction('exp', 'exp', 1);
    $pdo
      ->sqliteCreateFunction('length', 'strlen', 1);
    $pdo
      ->sqliteCreateFunction('md5', 'md5', 1);
    $pdo
      ->sqliteCreateFunction('concat', [
      __CLASS__,
      'sqlFunctionConcat',
    ]);
    $pdo
      ->sqliteCreateFunction('concat_ws', [
      __CLASS__,
      'sqlFunctionConcatWs',
    ]);
    $pdo
      ->sqliteCreateFunction('substring', [
      __CLASS__,
      'sqlFunctionSubstring',
    ], 3);
    $pdo
      ->sqliteCreateFunction('substring_index', [
      __CLASS__,
      'sqlFunctionSubstringIndex',
    ], 3);
    $pdo
      ->sqliteCreateFunction('rand', [
      __CLASS__,
      'sqlFunctionRand',
    ]);
    $pdo
      ->sqliteCreateFunction('regexp', [
      __CLASS__,
      'sqlFunctionRegexp',
    ]);

    // SQLite does not support the LIKE BINARY operator, so we overload the
    // non-standard GLOB operator for case-sensitive matching. Another option
    // would have been to override another non-standard operator, MATCH, but
    // that does not support the NOT keyword prefix.
    $pdo
      ->sqliteCreateFunction('glob', [
      __CLASS__,
      'sqlFunctionLikeBinary',
    ]);

    // Create a user-space case-insensitive collation with UTF-8 support.
    $pdo
      ->sqliteCreateCollation('NOCASE_UTF8', [
      'Drupal\\Component\\Utility\\Unicode',
      'strcasecmp',
    ]);

    // Set SQLite init_commands if not already defined. Enable the Write-Ahead
    // Logging (WAL) for SQLite. See https://www.drupal.org/node/2348137 and
    // https://www.sqlite.org/wal.html.
    $connection_options += [
      'init_commands' => [],
    ];
    $connection_options['init_commands'] += [
      'wal' => "PRAGMA journal_mode=WAL",
    ];

    // Execute sqlite init_commands.
    if (isset($connection_options['init_commands'])) {
      $pdo
        ->exec(implode('; ', $connection_options['init_commands']));
    }
    return $pdo;
  }

  /**
   * Destructor for the SQLite connection.
   *
   * We prune empty databases on destruct, but only if tables have been
   * dropped. This is especially needed when running the test suite, which
   * creates and destroy databases several times in a row.
   */
  public function __destruct() {
    if ($this->tableDropped && !empty($this->attachedDatabases)) {
      foreach ($this->attachedDatabases as $prefix) {

        // Check if the database is now empty, ignore the internal SQLite tables.
        try {
          $count = $this
            ->query('SELECT COUNT(*) FROM ' . $prefix . '.sqlite_master WHERE type = :type AND name NOT LIKE :pattern', [
            ':type' => 'table',
            ':pattern' => 'sqlite_%',
          ])
            ->fetchField();

          // We can prune the database file if it doesn't have any tables.
          if ($count == 0 && $this->connectionOptions['database'] != ':memory:' && file_exists($this->connectionOptions['database'] . '-' . $prefix)) {

            // Detach the database.
            $this
              ->query('DETACH DATABASE :schema', [
              ':schema' => $prefix,
            ]);

            // Destroy the database file.
            unlink($this->connectionOptions['database'] . '-' . $prefix);
          }
        } catch (\Exception $e) {

          // Ignore the exception and continue. There is nothing we can do here
          // to report the error or fail safe.
        }
      }
    }
    parent::__destruct();
  }

  /**
   * {@inheritdoc}
   */
  public function attachDatabase(string $database) : void {

    // Only attach the database once.
    if (!isset($this->attachedDatabases[$database])) {

      // In memory database use ':memory:' as database name. According to
      // http://www.sqlite.org/inmemorydb.html it will open a unique database so
      // attaching it twice is not a problem.
      $database_file = $this->connectionOptions['database'] !== ':memory:' ? $this->connectionOptions['database'] . '-' . $database : $this->connectionOptions['database'];
      $this
        ->query('ATTACH DATABASE :database_file AS :database', [
        ':database_file' => $database_file,
        ':database' => $database,
      ]);
      $this->attachedDatabases[$database] = $database;
    }
  }

  /**
   * Gets all the attached databases.
   *
   * @return array
   *   An array of attached database names.
   *
   * @see \Drupal\sqlite\Driver\Database\sqlite\Connection::__construct()
   */
  public function getAttachedDatabases() {
    return $this->attachedDatabases;
  }

  /**
   * SQLite compatibility implementation for the IF() SQL function.
   */
  public static function sqlFunctionIf($condition, $expr1, $expr2 = NULL) {
    return $condition ? $expr1 : $expr2;
  }

  /**
   * SQLite compatibility implementation for the GREATEST() SQL function.
   */
  public static function sqlFunctionGreatest() {
    $args = func_get_args();
    foreach ($args as $v) {
      if (!isset($v)) {
        unset($args);
      }
    }
    if (count($args)) {
      return max($args);
    }
    else {
      return NULL;
    }
  }

  /**
   * SQLite compatibility implementation for the LEAST() SQL function.
   */
  public static function sqlFunctionLeast() {

    // Remove all NULL, FALSE and empty strings values but leaves 0 (zero) values.
    $values = array_filter(func_get_args(), 'strlen');
    return count($values) < 1 ? NULL : min($values);
  }

  /**
   * SQLite compatibility implementation for the CONCAT() SQL function.
   */
  public static function sqlFunctionConcat() {
    $args = func_get_args();
    return implode('', $args);
  }

  /**
   * SQLite compatibility implementation for the CONCAT_WS() SQL function.
   *
   * @see http://dev.mysql.com/doc/refman/5.6/en/string-functions.html#function_concat-ws
   */
  public static function sqlFunctionConcatWs() {
    $args = func_get_args();
    $separator = array_shift($args);

    // If the separator is NULL, the result is NULL.
    if ($separator === FALSE || is_null($separator)) {
      return NULL;
    }

    // Skip any NULL values after the separator argument.
    $args = array_filter($args, function ($value) {
      return !is_null($value);
    });
    return implode($separator, $args);
  }

  /**
   * SQLite compatibility implementation for the SUBSTRING() SQL function.
   */
  public static function sqlFunctionSubstring($string, $from, $length) {
    return substr($string, $from - 1, $length);
  }

  /**
   * SQLite compatibility implementation for the SUBSTRING_INDEX() SQL function.
   */
  public static function sqlFunctionSubstringIndex($string, $delimiter, $count) {

    // If string is empty, simply return an empty string.
    if (empty($string)) {
      return '';
    }
    $end = 0;
    for ($i = 0; $i < $count; $i++) {
      $end = strpos($string, $delimiter, $end + 1);
      if ($end === FALSE) {
        $end = strlen($string);
      }
    }
    return substr($string, 0, $end);
  }

  /**
   * SQLite compatibility implementation for the RAND() SQL function.
   */
  public static function sqlFunctionRand($seed = NULL) {
    if (isset($seed)) {
      mt_srand($seed);
    }
    return mt_rand() / mt_getrandmax();
  }

  /**
   * SQLite compatibility implementation for the REGEXP SQL operator.
   *
   * The REGEXP operator is natively known, but not implemented by default.
   *
   * @see http://www.sqlite.org/lang_expr.html#regexp
   */
  public static function sqlFunctionRegexp($pattern, $subject) {

    // preg_quote() cannot be used here, since $pattern may contain reserved
    // regular expression characters already (such as ^, $, etc). Therefore,
    // use a rare character as PCRE delimiter.
    $pattern = '#' . addcslashes($pattern, '#') . '#i';
    return preg_match($pattern, $subject);
  }

  /**
   * SQLite compatibility implementation for the LIKE BINARY SQL operator.
   *
   * SQLite supports case-sensitive LIKE operations through the
   * 'case_sensitive_like' PRAGMA statement, but only for ASCII characters, so
   * we have to provide our own implementation with UTF-8 support.
   *
   * @see https://sqlite.org/pragma.html#pragma_case_sensitive_like
   * @see https://sqlite.org/lang_expr.html#like
   */
  public static function sqlFunctionLikeBinary($pattern, $subject) {

    // Replace the SQL LIKE wildcard meta-characters with the equivalent regular
    // expression meta-characters and escape the delimiter that will be used for
    // matching.
    $pattern = str_replace([
      '%',
      '_',
    ], [
      '.*?',
      '.',
    ], preg_quote($pattern, '/'));
    return preg_match('/^' . $pattern . '$/', $subject);
  }
  public function queryRange($query, $from, $count, array $args = [], array $options = []) {
    return $this
      ->query($query . ' LIMIT ' . (int) $from . ', ' . (int) $count, $args, $options);
  }
  public function driver() {
    return 'sqlite';
  }
  public function databaseType() {
    return 'sqlite';
  }

  /**
   * Overrides \Drupal\Core\Database\Connection::createDatabase().
   *
   * @param string $database
   *   The name of the database to create.
   *
   * @throws \Drupal\Core\Database\DatabaseNotFoundException
   */
  public function createDatabase($database) {

    // Verify the database is writable.
    $db_directory = new \SplFileInfo(dirname($database));
    if (!$db_directory
      ->isDir() && !\Drupal::service('file_system')
      ->mkdir($db_directory
      ->getPathName(), 0755, TRUE)) {
      throw new DatabaseNotFoundException('Unable to create database directory ' . $db_directory
        ->getPathName());
    }
  }
  public function mapConditionOperator($operator) {
    return static::$sqliteConditionOperatorMap[$operator] ?? NULL;
  }

  /**
   * {@inheritdoc}
   */
  public function prepareStatement(string $query, array $options, bool $allow_row_count = FALSE) : StatementInterface {
    if (isset($options['return'])) {
      @trigger_error('Passing "return" option to ' . __METHOD__ . '() is deprecated in drupal:9.4.0 and is removed in drupal:11.0.0. For data manipulation operations, use dynamic queries instead. See https://www.drupal.org/node/3185520', E_USER_DEPRECATED);
    }
    try {
      $query = $this
        ->preprocessStatement($query, $options);
      $statement = new Statement($this->connection, $this, $query, $options['pdo'] ?? [], $allow_row_count);
    } catch (\Exception $e) {
      $this
        ->exceptionHandler()
        ->handleStatementException($e, $query, $options);
    }
    return $statement;
  }
  public function nextId($existing_id = 0) {
    $this
      ->startTransaction();

    // We can safely use literal queries here instead of the slower query
    // builder because if a given database breaks here then it can simply
    // override nextId. However, this is unlikely as we deal with short strings
    // and integers and no known databases require special handling for those
    // simple cases. If another transaction wants to write the same row, it will
    // wait until this transaction commits.
    $stmt = $this
      ->prepareStatement('UPDATE {sequences} SET [value] = GREATEST([value], :existing_id) + 1', [], TRUE);
    $args = [
      ':existing_id' => $existing_id,
    ];
    try {
      $stmt
        ->execute($args);
    } catch (\Exception $e) {
      $this
        ->exceptionHandler()
        ->handleExecutionException($e, $stmt, $args, []);
    }
    if ($stmt
      ->rowCount() === 0) {
      $this
        ->query('INSERT INTO {sequences} ([value]) VALUES (:existing_id + 1)', $args);
    }

    // The transaction gets committed when the transaction object gets destroyed
    // because it gets out of scope.
    return $this
      ->query('SELECT [value] FROM {sequences}')
      ->fetchField();
  }

  /**
   * {@inheritdoc}
   */
  public function getFullQualifiedTableName($table) {
    $prefix = $this
      ->tablePrefix($table);

    // Don't include the SQLite database file name as part of the table name.
    return $prefix . $table;
  }

  /**
   * {@inheritdoc}
   */
  public static function createConnectionOptionsFromUrl($url, $root) {
    $database = parent::createConnectionOptionsFromUrl($url, $root);

    // A SQLite database path with two leading slashes indicates a system path.
    // Otherwise the path is relative to the Drupal root.
    $url_components = parse_url($url);
    if ($url_components['path'][0] === '/') {
      $url_components['path'] = substr($url_components['path'], 1);
    }
    if ($url_components['path'][0] === '/' || $url_components['path'] === ':memory:') {
      $database['database'] = $url_components['path'];
    }
    else {
      $database['database'] = $root . '/' . $url_components['path'];
    }

    // User credentials and system port are irrelevant for SQLite.
    unset($database['username'], $database['password'], $database['port']);
    return $database;
  }

  /**
   * {@inheritdoc}
   */
  public static function createUrlFromConnectionOptions(array $connection_options) {
    if (!isset($connection_options['driver'], $connection_options['database'])) {
      throw new \InvalidArgumentException("As a minimum, the connection options array must contain at least the 'driver' and 'database' keys");
    }
    $db_url = 'sqlite://localhost/' . $connection_options['database'] . '?module=sqlite';
    if (isset($connection_options['prefix']) && $connection_options['prefix'] !== '') {
      $db_url .= '#' . $connection_options['prefix'];
    }
    return $db_url;
  }

}

Classes

Name	Description
Connection	SQLite implementation of \Drupal\Core\Database\Connection.