diff core/lib/Drupal/Core/Database/Transaction.php @ 0:4c8ae668cc8c

Initial import (non-working)

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/core/lib/Drupal/Core/Database/Transaction.php	Wed Nov 29 16:09:58 2017 +0000
@@ -0,0 +1,97 @@
+<?php
+
+namespace Drupal\Core\Database;
+
+/**
+ * A wrapper class for creating and managing database transactions.
+ *
+ * Not all databases or database configurations support transactions. For
+ * example, MySQL MyISAM tables do not. It is also easy to begin a transaction
+ * and then forget to commit it, which can lead to connection errors when
+ * another transaction is started.
+ *
+ * This class acts as a wrapper for transactions. To begin a transaction,
+ * simply instantiate it. When the object goes out of scope and is destroyed
+ * it will automatically commit. It also will check to see if the specified
+ * connection supports transactions. If not, it will simply skip any transaction
+ * commands, allowing user-space code to proceed normally. The only difference
+ * is that rollbacks won't actually do anything.
+ *
+ * In the vast majority of cases, you should not instantiate this class
+ * directly. Instead, call ->startTransaction(), from the appropriate connection
+ * object.
+ */
+class Transaction {
+
+  /**
+   * The connection object for this transaction.
+   *
+   * @var \Drupal\Core\Database\Connection
+   */
+  protected $connection;
+
+  /**
+   * A boolean value to indicate whether this transaction has been rolled back.
+   *
+   * @var bool
+   */
+  protected $rolledBack = FALSE;
+
+  /**
+   * The name of the transaction.
+   *
+   * This is used to label the transaction savepoint. It will be overridden to
+   * 'drupal_transaction' if there is no transaction depth.
+   */
+  protected $name;
+
+  public function __construct(Connection $connection, $name = NULL) {
+    $this->connection = $connection;
+    // If there is no transaction depth, then no transaction has started. Name
+    // the transaction 'drupal_transaction'.
+    if (!$depth = $connection->transactionDepth()) {
+      $this->name = 'drupal_transaction';
+    }
+    // Within transactions, savepoints are used. Each savepoint requires a
+    // name. So if no name is present we need to create one.
+    elseif (!$name) {
+      $this->name = 'savepoint_' . $depth;
+    }
+    else {
+      $this->name = $name;
+    }
+    $this->connection->pushTransaction($this->name);
+  }
+
+  public function __destruct() {
+    // If we rolled back then the transaction would have already been popped.
+    if (!$this->rolledBack) {
+      $this->connection->popTransaction($this->name);
+    }
+  }
+
+  /**
+   * Retrieves the name of the transaction or savepoint.
+   */
+  public function name() {
+    return $this->name;
+  }
+
+  /**
+   * Rolls back the current transaction.
+   *
+   * This is just a wrapper method to rollback whatever transaction stack we are
+   * currently in, which is managed by the connection object itself. Note that
+   * logging (preferable with watchdog_exception()) needs to happen after a
+   * transaction has been rolled back or the log messages will be rolled back
+   * too.
+   *
+   * @see \Drupal\Core\Database\Connection::rollBack()
+   * @see watchdog_exception()
+   */
+  public function rollBack() {
+    $this->rolledBack = TRUE;
+    $this->connection->rollBack($this->name);
+  }
+
+}