cms/drupal/includes/database/sqlite/database.inc
changeset 541 e756a8c72c3d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cms/drupal/includes/database/sqlite/database.inc	Fri Sep 08 12:04:06 2017 +0200
@@ -0,0 +1,527 @@
+<?php
+
+/**
+ * @file
+ * Database interface code for SQLite embedded database engine.
+ */
+
+/**
+ * @addtogroup database
+ * @{
+ */
+
+include_once DRUPAL_ROOT . '/includes/database/prefetch.inc';
+
+/**
+ * Specific SQLite implementation of DatabaseConnection.
+ */
+class DatabaseConnection_sqlite extends DatabaseConnection {
+
+  /**
+   * Whether this database connection supports savepoints.
+   *
+   * Version of sqlite lower then 3.6.8 can't use savepoints.
+   * See http://www.sqlite.org/releaselog/3_6_8.html
+   *
+   * @var boolean
+   */
+  protected $savepointSupport = FALSE;
+
+  /**
+   * Whether or not the active transaction (if any) will be rolled back.
+   *
+   * @var boolean
+   */
+  protected $willRollback;
+
+  /**
+   * 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 = array();
+
+  /**
+   * 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 DatabaseSchema_sqlite needs to
+   * access it. However, it should not be manually set.
+   *
+   * @var boolean
+   */
+  var $tableDropped = FALSE;
+
+  public function __construct(array $connection_options = array()) {
+    // We don't need a specific PDOStatement class here, we simulate it below.
+    $this->statementClass = NULL;
+
+    // This driver defaults to transaction support, except if explicitly passed FALSE.
+    $this->transactionSupport = $this->transactionalDDLSupport = !isset($connection_options['transactions']) || $connection_options['transactions'] !== FALSE;
+
+    $this->connectionOptions = $connection_options;
+
+    // Allow PDO options to be overridden.
+    $connection_options += array(
+      'pdo' => array(),
+    );
+    $connection_options['pdo'] += array(
+      // Convert numeric values to strings when fetching.
+      PDO::ATTR_STRINGIFY_FETCHES => TRUE,
+    );
+    parent::__construct('sqlite:' . $connection_options['database'], '', '', $connection_options['pdo']);
+
+    // Attach one database for each registered prefix.
+    $prefixes = $this->prefixes;
+    foreach ($prefixes as $table => &$prefix) {
+      // Empty prefix means query the main database -- no need to attach anything.
+      if (!empty($prefix)) {
+        // Only attach the database once.
+        if (!isset($this->attachedDatabases[$prefix])) {
+          $this->attachedDatabases[$prefix] = $prefix;
+          $this->query('ATTACH DATABASE :database AS :prefix', array(':database' => $connection_options['database'] . '-' . $prefix, ':prefix' => $prefix));
+        }
+
+        // Add a ., so queries become prefix.table, which is proper syntax for
+        // querying an attached database.
+        $prefix .= '.';
+      }
+    }
+    // Regenerate the prefixes replacement table.
+    $this->setPrefix($prefixes);
+
+    // Detect support for SAVEPOINT.
+    $version = $this->query('SELECT sqlite_version()')->fetchField();
+    $this->savepointSupport = (version_compare($version, '3.6.8') >= 0);
+
+    // Create functions needed by SQLite.
+    $this->sqliteCreateFunction('if', array($this, 'sqlFunctionIf'));
+    $this->sqliteCreateFunction('greatest', array($this, 'sqlFunctionGreatest'));
+    $this->sqliteCreateFunction('pow', 'pow', 2);
+    $this->sqliteCreateFunction('length', 'strlen', 1);
+    $this->sqliteCreateFunction('md5', 'md5', 1);
+    $this->sqliteCreateFunction('concat', array($this, 'sqlFunctionConcat'));
+    $this->sqliteCreateFunction('substring', array($this, 'sqlFunctionSubstring'), 3);
+    $this->sqliteCreateFunction('substring_index', array($this, 'sqlFunctionSubstringIndex'), 3);
+    $this->sqliteCreateFunction('rand', array($this, 'sqlFunctionRand'));
+
+    // Execute sqlite init_commands.
+    if (isset($connection_options['init_commands'])) {
+      $this->exec(implode('; ', $connection_options['init_commands']));
+    }
+  }
+
+  /**
+   * Destructor for the SQLite connection.
+   *
+   * We prune empty databases on destruct, but only if tables have been
+   * dropped. This is especially needed when running the test suite, which
+   * creates and destroy databases several times in a row.
+   */
+  public function __destruct() {
+    if ($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 ' . $prefix . '.sqlite_master WHERE type = :type AND name NOT LIKE :pattern', array(':type' => 'table', ':pattern' => 'sqlite_%'))->fetchField();
+
+          // We can prune the database file if it doesn't have any tables.
+          if ($count == 0) {
+            // Detach the database.
+            $this->query('DETACH DATABASE :schema', array(':schema' => $prefix));
+            // Destroy the database file.
+            unlink($this->connectionOptions['database'] . '-' . $prefix);
+          }
+        }
+        catch (Exception $e) {
+          // Ignore the exception and continue. There is nothing we can do here
+          // to report the error or fail safe.
+        }
+      }
+    }
+  }
+
+  /**
+   * SQLite compatibility implementation for the IF() SQL function.
+   */
+  public function sqlFunctionIf($condition, $expr1, $expr2 = NULL) {
+    return $condition ? $expr1 : $expr2;
+  }
+
+  /**
+   * SQLite compatibility implementation for the GREATEST() SQL function.
+   */
+  public function sqlFunctionGreatest() {
+    $args = func_get_args();
+    foreach ($args as $k => $v) {
+      if (!isset($v)) {
+        unset($args);
+      }
+    }
+    if (count($args)) {
+      return max($args);
+    }
+    else {
+      return NULL;
+    }
+  }
+
+  /**
+   * SQLite compatibility implementation for the CONCAT() SQL function.
+   */
+  public function sqlFunctionConcat() {
+    $args = func_get_args();
+    return implode('', $args);
+  }
+
+  /**
+   * SQLite compatibility implementation for the SUBSTRING() SQL function.
+   */
+  public function sqlFunctionSubstring($string, $from, $length) {
+    return substr($string, $from - 1, $length);
+  }
+
+  /**
+   * SQLite compatibility implementation for the SUBSTRING_INDEX() SQL function.
+   */
+  public function sqlFunctionSubstringIndex($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, $end);
+  }
+
+  /**
+   * SQLite compatibility implementation for the RAND() SQL function.
+   */
+  public function sqlFunctionRand($seed = NULL) {
+    if (isset($seed)) {
+      mt_srand($seed);
+    }
+    return mt_rand() / mt_getrandmax();
+  }
+
+  /**
+   * SQLite-specific implementation of DatabaseConnection::prepare().
+   *
+   * We don't use prepared statements at all at this stage. We just create
+   * a DatabaseStatement_sqlite object, that will create a PDOStatement
+   * using the semi-private PDOPrepare() method below.
+   */
+  public function prepare($query, $options = array()) {
+    return new DatabaseStatement_sqlite($this, $query, $options);
+  }
+
+  /**
+   * NEVER CALL THIS FUNCTION: YOU MIGHT DEADLOCK YOUR PHP PROCESS.
+   *
+   * This is a wrapper around the parent PDO::prepare method. However, as
+   * the PDO SQLite driver only closes SELECT statements when the PDOStatement
+   * destructor is called and SQLite does not allow data change (INSERT,
+   * UPDATE etc) on a table which has open SELECT statements, you should never
+   * call this function and keep a PDOStatement object alive as that can lead
+   * to a deadlock. This really, really should be private, but as
+   * DatabaseStatement_sqlite needs to call it, we have no other choice but to
+   * expose this function to the world.
+   */
+  public function PDOPrepare($query, array $options = array()) {
+    return parent::prepare($query, $options);
+  }
+
+  public function queryRange($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()) {
+    // Generate a new temporary table name and protect it from prefixing.
+    // SQLite requires that temporary tables to be non-qualified.
+    $tablename = $this->generateTemporaryTableName();
+    $prefixes = $this->prefixes;
+    $prefixes[$tablename] = '';
+    $this->setPrefix($prefixes);
+
+    $this->query('CREATE TEMPORARY TABLE ' . $tablename . ' AS ' . $query, $args, $options);
+    return $tablename;
+  }
+
+  public function driver() {
+    return 'sqlite';
+  }
+
+  public function databaseType() {
+    return 'sqlite';
+  }
+
+  public function mapConditionOperator($operator) {
+    // We don't want to override any of the defaults.
+    static $specials = array(
+      'LIKE' => array('postfix' => " ESCAPE '\\'"),
+      'NOT LIKE' => array('postfix' => " ESCAPE '\\'"),
+    );
+    return isset($specials[$operator]) ? $specials[$operator] : NULL;
+  }
+
+  public function prepareQuery($query) {
+    return $this->prepare($this->prefixTables($query));
+  }
+
+  public function nextId($existing_id = 0) {
+    $transaction = $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->query('UPDATE {sequences} SET value = GREATEST(value, :existing_id) + 1', array(
+      ':existing_id' => $existing_id,
+    ));
+    if (!$stmt->rowCount()) {
+      $this->query('INSERT INTO {sequences} (value) VALUES (:existing_id + 1)', array(
+        ':existing_id' => $existing_id,
+      ));
+    }
+    // The transaction gets committed when the transaction object gets destroyed
+    // because it gets out of scope.
+    return $this->query('SELECT value FROM {sequences}')->fetchField();
+  }
+
+  public function rollback($savepoint_name = 'drupal_transaction') {
+    if ($this->savepointSupport) {
+      return parent::rollBack($savepoint_name);
+    }
+
+    if (!$this->inTransaction()) {
+      throw new DatabaseTransactionNoActiveException();
+    }
+    // A previous rollback to an earlier savepoint may mean that the savepoint
+    // in question has already been rolled back.
+    if (!in_array($savepoint_name, $this->transactionLayers)) {
+      return;
+    }
+
+    // We need to find the point we're rolling back to, all other savepoints
+    // before are no longer needed.
+    while ($savepoint = array_pop($this->transactionLayers)) {
+      if ($savepoint == $savepoint_name) {
+        // Mark whole stack of transactions as needed roll back.
+        $this->willRollback = TRUE;
+        // If it is the last the transaction in the stack, then it is not a
+        // savepoint, it is the transaction itself so we will need to roll back
+        // the transaction rather than a savepoint.
+        if (empty($this->transactionLayers)) {
+          break;
+        }
+        return;
+      }
+    }
+    if ($this->supportsTransactions()) {
+      PDO::rollBack();
+    }
+  }
+
+  public function pushTransaction($name) {
+    if ($this->savepointSupport) {
+      return parent::pushTransaction($name);
+    }
+    if (!$this->supportsTransactions()) {
+      return;
+    }
+    if (isset($this->transactionLayers[$name])) {
+      throw new DatabaseTransactionNameNonUniqueException($name . " is already in use.");
+    }
+    if (!$this->inTransaction()) {
+      PDO::beginTransaction();
+    }
+    $this->transactionLayers[$name] = $name;
+  }
+
+  public function popTransaction($name) {
+    if ($this->savepointSupport) {
+      return parent::popTransaction($name);
+    }
+    if (!$this->supportsTransactions()) {
+      return;
+    }
+    if (!$this->inTransaction()) {
+      throw new DatabaseTransactionNoActiveException();
+    }
+
+    // Commit everything since SAVEPOINT $name.
+    while($savepoint = array_pop($this->transactionLayers)) {
+      if ($savepoint != $name) continue;
+
+      // If there are no more layers left then we should commit or rollback.
+      if (empty($this->transactionLayers)) {
+        // If there was any rollback() we should roll back whole transaction.
+        if ($this->willRollback) {
+          $this->willRollback = FALSE;
+          PDO::rollBack();
+        }
+        elseif (!PDO::commit()) {
+          throw new DatabaseTransactionCommitFailedException();
+        }
+      }
+      else {
+        break;
+      }
+    }
+  }
+
+  public function utf8mb4IsActive() {
+    return TRUE;
+  }
+
+  public function utf8mb4IsSupported() {
+    return TRUE;
+  }
+
+}
+
+/**
+ * Specific SQLite implementation of DatabaseConnection.
+ *
+ * See DatabaseConnection_sqlite::PDOPrepare() for reasons why we must prefetch
+ * the data instead of using PDOStatement.
+ *
+ * @see DatabaseConnection_sqlite::PDOPrepare()
+ */
+class DatabaseStatement_sqlite extends DatabaseStatementPrefetch implements Iterator, DatabaseStatementInterface {
+
+  /**
+   * SQLite specific implementation of getStatement().
+   *
+   * The PDO SQLite layer doesn't replace numeric placeholders in queries
+   * correctly, and this makes numeric expressions (such as COUNT(*) >= :count)
+   * fail. We replace numeric placeholders in the query ourselves to work
+   * around this bug.
+   *
+   * See http://bugs.php.net/bug.php?id=45259 for more details.
+   */
+  protected function getStatement($query, &$args = array()) {
+    if (count($args)) {
+      // Check if $args is a simple numeric array.
+      if (range(0, count($args) - 1) === array_keys($args)) {
+        // In that case, we have unnamed placeholders.
+        $count = 0;
+        $new_args = array();
+        foreach ($args as $value) {
+          if (is_float($value) || is_int($value)) {
+            if (is_float($value)) {
+              // Force the conversion to float so as not to loose precision
+              // in the automatic cast.
+              $value = sprintf('%F', $value);
+            }
+            $query = substr_replace($query, $value, strpos($query, '?'), 1);
+          }
+          else {
+            $placeholder = ':db_statement_placeholder_' . $count++;
+            $query = substr_replace($query, $placeholder, strpos($query, '?'), 1);
+            $new_args[$placeholder] = $value;
+          }
+        }
+        $args = $new_args;
+      }
+      else {
+        // Else, this is using named placeholders.
+        foreach ($args as $placeholder => $value) {
+          if (is_float($value) || is_int($value)) {
+            if (is_float($value)) {
+              // Force the conversion to float so as not to loose precision
+              // in the automatic cast.
+              $value = sprintf('%F', $value);
+            }
+
+            // We will remove this placeholder from the query as PDO throws an
+            // exception if the number of placeholders in the query and the
+            // arguments does not match.
+            unset($args[$placeholder]);
+            // PDO allows placeholders to not be prefixed by a colon. See
+            // http://marc.info/?l=php-internals&m=111234321827149&w=2 for
+            // more.
+            if ($placeholder[0] != ':') {
+              $placeholder = ":$placeholder";
+            }
+            // When replacing the placeholders, make sure we search for the
+            // exact placeholder. For example, if searching for
+            // ':db_placeholder_1', do not replace ':db_placeholder_11'.
+            $query = preg_replace('/' . preg_quote($placeholder) . '\b/', $value, $query);
+          }
+        }
+      }
+    }
+
+    return $this->dbh->PDOPrepare($query);
+  }
+
+  public function execute($args = array(), $options = array()) {
+    try {
+      $return = parent::execute($args, $options);
+    }
+    catch (PDOException $e) {
+      if (!empty($e->errorInfo[1]) && $e->errorInfo[1] === 17) {
+        // The schema has changed. SQLite specifies that we must resend the query.
+        $return = parent::execute($args, $options);
+      }
+      else {
+        // Rethrow the exception.
+        throw $e;
+      }
+    }
+
+    // In some weird cases, SQLite will prefix some column names by the name
+    // of the table. We post-process the data, by renaming the column names
+    // using the same convention as MySQL and PostgreSQL.
+    $rename_columns = array();
+    foreach ($this->columnNames as $k => $column) {
+      // In some SQLite versions, SELECT DISTINCT(field) will return "(field)"
+      // instead of "field".
+      if (preg_match("/^\((.*)\)$/", $column, $matches)) {
+        $rename_columns[$column] = $matches[1];
+        $this->columnNames[$k] = $matches[1];
+        $column = $matches[1];
+      }
+
+      // Remove "table." prefixes.
+      if (preg_match("/^.*\.(.*)$/", $column, $matches)) {
+        $rename_columns[$column] = $matches[1];
+        $this->columnNames[$k] = $matches[1];
+      }
+    }
+    if ($rename_columns) {
+      // DatabaseStatementPrefetch already extracted the first row,
+      // put it back into the result set.
+      if (isset($this->currentRow)) {
+        $this->data[0] = &$this->currentRow;
+      }
+
+      // Then rename all the columns across the result set.
+      foreach ($this->data as $k => $row) {
+        foreach ($rename_columns as $old_column => $new_column) {
+          $this->data[$k][$new_column] = $this->data[$k][$old_column];
+          unset($this->data[$k][$old_column]);
+        }
+      }
+
+      // Finally, extract the first row again.
+      $this->currentRow = $this->data[0];
+      unset($this->data[0]);
+    }
+
+    return $return;
+  }
+}
+
+/**
+ * @} End of "addtogroup database".
+ */