[ticket/11880] migration helper file

PHPBB3-11880

phpBB/phpbb/db/migration/helper.php

@@ -0,0 +1,82 @@
+<?php
+/**
+*
+* @package db
+* @copyright (c) 2014 phpBB Group
+* @license http://opensource.org/licenses/gpl-license.php GNU Public License
+*
+*/
+
+namespace phpbb\db\migration;
+
+/**
+* The migrator is responsible for applying new migrations in the correct order.
+*
+* @package db
+*/
+class helper
+{
+	/**
+	 * Get the schema steps from an array of schema changes
+	 *
+	 * This splits up $schema_changes into individual changes so that the
+	 * changes can be chunked
+	 *
+	 * @param array $schema_changes from migration
+	 * @return array
+	 */
+	public function get_schema_steps($schema_changes)
+	{
+		$steps = array();
+
+		// Nested level of data (only supports 1/2 currently)
+		$nested_level = array(
+			'drop_tables'		=> 1,
+			'add_tables'		=> 1,
+			'change_columns'	=> 2,
+			'add_columns'		=> 2,
+			'drop_keys'			=> 2,
+			'drop_columns'		=> 2,
+			'add_primary_keys'	=> 2, // perform_schema_changes only uses one level, but second is in the function
+			'add_unique_index'	=> 2,
+			'add_index'			=> 2,
+		);
+
+		foreach ($nested_level as $change_type => $data_depth)
+		{
+			if (!empty($schema_changes[$change_type]))
+			{
+				foreach ($schema_changes[$change_type] as $key => $value)
+				{
+					if ($data_depth === 1)
+					{
+						$steps[] = array(
+							'dbtools.perform_schema_changes', array(array(
+									$change_type	=> array(
+									$value,
+								),
+							)),
+						);
+					}
+					else if ($data_depth === 2)
+					{
+						foreach ($value as $key2 => $value2)
+						{
+							$steps[] = array(
+								'dbtools.perform_schema_changes', array(array(
+									$change_type	=> array(
+										$key => array(
+											$key2	=> $value2,
+										),
+									),
+								)),
+							);
+						}
+					}
+				}
+			}
+		}
+
+		return $steps;
+	}
+}