1 files changed, 740 insertions, 0 deletions
diff --git a/phpBB/includes/db/migrator.php b/phpBB/includes/db/migrator.php
new file mode 100644
index 0000000000..9d7cede95b
--- /dev/null
+++ b/phpBB/includes/db/migrator.php
@@ -0,0 +1,740 @@
+<?php
+/**
+*
+* @package db
+* @copyright (c) 2011 phpBB Group
+* @license http://opensource.org/licenses/gpl-license.php GNU Public License
+*
+*/
+
+/**
+* @ignore
+*/
+if (!defined('IN_PHPBB'))
+{
+	exit;
+}
+
+/**
+* The migrator is responsible for applying new migrations in the correct order.
+*
+* @package db
+*/
+class phpbb_db_migrator
+{
+	/** @var phpbb_config */
+	protected $config;
+
+	/** @var phpbb_db_driver */
+	protected $db;
+
+	/** @var phpbb_db_tools */
+	protected $db_tools;
+
+	/** @var string */
+	protected $table_prefix;
+
+	/** @var string */
+	protected $phpbb_root_path;
+
+	/** @var string */
+	protected $php_ext;
+
+	/** @var string */
+	protected $migrations_table;
+
+	/**
+	* State of all migrations
+	*
+	* (SELECT * FROM migrations table)
+	*
+	* @var array
+	*/
+	protected $migration_state = array();
+
+	/**
+	* Array of all migrations available to be run
+	*
+	* @var array
+	*/
+	protected $migrations = array();
+
+	/**
+	* 'name,' 'class,' and 'state' of the last migration run
+	*
+	* 'effectively_installed' set and set to true if the migration was effectively_installed
+	*
+	* @var array
+	*/
+	public $last_run_migration = false;
+
+	/**
+	* Constructor of the database migrator
+	*/
+	public function __construct(phpbb_config $config, phpbb_db_driver $db, phpbb_db_tools $db_tools, $migrations_table, $phpbb_root_path, $php_ext, $table_prefix, $tools)
+	{
+		$this->config = $config;
+		$this->db = $db;
+		$this->db_tools = $db_tools;
+
+		$this->migrations_table = $migrations_table;
+
+		$this->phpbb_root_path = $phpbb_root_path;
+		$this->php_ext = $php_ext;
+
+		$this->table_prefix = $table_prefix;
+
+		foreach ($tools as $tool)
+		{
+			$this->tools[$tool->get_name()] = $tool;
+		}
+
+		$this->load_migration_state();
+	}
+
+	/**
+	* Loads all migrations and their application state from the database.
+	*
+	* @return null
+	*/
+	public function load_migration_state()
+	{
+		$this->migration_state = array();
+
+		// prevent errors in case the table does not exist yet
+		$this->db->sql_return_on_error(true);
+
+		$sql = "SELECT *
+			FROM " . $this->migrations_table;
+		$result = $this->db->sql_query($sql);
+
+		if (!$this->db->sql_error_triggered)
+		{
+			while ($migration = $this->db->sql_fetchrow($result))
+			{
+				$this->migration_state[$migration['migration_name']] = $migration;
+
+				$this->migration_state[$migration['migration_name']]['migration_depends_on'] = unserialize($migration['migration_depends_on']);
+			}
+		}
+
+		$this->db->sql_freeresult($result);
+
+		$this->db->sql_return_on_error(false);
+	}
+
+	/**
+	* Sets the list of available migration class names to the given array.
+	*
+	* @param array $class_names An array of migration class names
+	* @return null
+	*/
+	public function set_migrations($class_names)
+	{
+		$this->migrations = $class_names;
+	}
+
+	/**
+	* Runs a single update step from the next migration to be applied.
+	*
+	* The update step can either be a schema or a (partial) data update. To
+	* check if update() needs to be called again use the finished() method.
+	*
+	* @return null
+	*/
+	public function update()
+	{
+		foreach ($this->migrations as $name)
+		{
+			if (!isset($this->migration_state[$name]) ||
+				!$this->migration_state[$name]['migration_schema_done'] ||
+				!$this->migration_state[$name]['migration_data_done'])
+			{
+				if (!$this->try_apply($name))
+				{
+					continue;
+				}
+				else
+				{
+					return;
+				}
+			}
+		}
+	}
+
+	/**
+	* Attempts to apply a step of the given migration or one of its dependencies
+	*
+	* @param	string	The class name of the migration
+	* @return	bool	Whether any update step was successfully run
+	*/
+	protected function try_apply($name)
+	{
+		if (!class_exists($name))
+		{
+			return false;
+		}
+
+		$migration = $this->get_migration($name);
+
+		$state = (isset($this->migration_state[$name])) ?
+			$this->migration_state[$name] :
+			array(
+				'migration_depends_on'	=> $migration->depends_on(),
+				'migration_schema_done' => false,
+				'migration_data_done'	=> false,
+				'migration_data_state'	=> '',
+				'migration_start_time'	=> 0,
+				'migration_end_time'	=> 0,
+			);
+
+		foreach ($state['migration_depends_on'] as $depend)
+		{
+			if (!isset($this->migration_state[$depend]) ||
+				!$this->migration_state[$depend]['migration_schema_done'] ||
+				!$this->migration_state[$depend]['migration_data_done'])
+			{
+				return $this->try_apply($depend);
+			}
+		}
+
+		$this->last_run_migration = array(
+			'name'	=> $name,
+			'class'	=> $migration,
+			'state'	=> $state,
+		);
+
+		if (!isset($this->migration_state[$name]))
+		{
+			if ($migration->effectively_installed())
+			{
+				$state = array(
+					'migration_depends_on'	=> $migration->depends_on(),
+					'migration_schema_done' => true,
+					'migration_data_done'	=> true,
+					'migration_data_state'	=> '',
+					'migration_start_time'	=> 0,
+					'migration_end_time'	=> 0,
+				);
+
+				$this->last_run_migration['effectively_installed'] = true;
+			}
+			else
+			{
+				$state['migration_start_time'] = time();
+			}
+		}
+
+		if (!$state['migration_schema_done'])
+		{
+			$this->apply_schema_changes($migration->update_schema());
+			$state['migration_schema_done'] = true;
+		}
+		else if (!$state['migration_data_done'])
+		{
+			try
+			{
+				$result = $this->process_data_step($migration->update_data(), $state['migration_data_state']);
+
+				$state['migration_data_state'] = ($result === true) ? '' : $result;
+				$state['migration_data_done'] = ($result === true);
+				$state['migration_end_time'] = ($result === true) ? time() : 0;
+			}
+			catch (phpbb_db_migration_exception $e)
+			{
+				// Revert the schema changes
+				$this->revert($name);
+
+				// Rethrow exception
+				throw $e;
+			}
+		}
+
+		$this->set_migration_state($name, $state);
+
+		return true;
+	}
+
+	/**
+	* Runs a single revert step from the last migration installed
+	*
+	* YOU MUST ADD/SET ALL MIGRATIONS THAT COULD BE DEPENDENT ON THE MIGRATION TO REVERT TO BEFORE CALLING THIS METHOD!
+	* The revert step can either be a schema or a (partial) data revert. To
+	* check if revert() needs to be called again use the migration_state() method.
+	*
+	* @param string $migration String migration name to revert (including any that depend on this migration)
+	* @return null
+	*/
+	public function revert($migration)
+	{
+		if (!isset($this->migration_state[$migration]))
+		{
+			// Not installed
+			return;
+		}
+
+		foreach ($this->migration_state as $name => $state)
+		{
+			if (!empty($state['migration_depends_on']) && in_array($migration, $state['migration_depends_on']))
+			{
+				$this->revert($name);
+			}
+		}
+
+		$this->try_revert($migration);
+	}
+
+	/**
+	* Attempts to revert a step of the given migration or one of its dependencies
+	*
+	* @param	string	The class name of the migration
+	* @return	bool	Whether any update step was successfully run
+	*/
+	protected function try_revert($name)
+	{
+		if (!class_exists($name))
+		{
+			return false;
+		}
+
+		$migration = $this->get_migration($name);
+
+		$state = $this->migration_state[$name];
+
+		$this->last_run_migration = array(
+			'name'	=> $name,
+			'class'	=> $migration,
+		);
+
+		if ($state['migration_data_done'])
+		{
+			if ($state['migration_data_state'] !== 'revert_data')
+			{
+				$result = $this->process_data_step($migration->update_data(), $state['migration_data_state'], true);
+
+				$state['migration_data_state'] = ($result === true) ? 'revert_data' : $result;
+			}
+			else
+			{
+				$result = $this->process_data_step($migration->revert_data(), '', false);
+
+				$state['migration_data_state'] = ($result === true) ? '' : $result;
+				$state['migration_data_done'] = ($result === true) ? false : true;
+			}
+
+			$this->set_migration_state($name, $state);
+		}
+		else
+		{
+			$this->apply_schema_changes($migration->revert_schema());
+
+			$sql = 'DELETE FROM ' . $this->migrations_table . "
+				WHERE migration_name = '" . $this->db->sql_escape($name) . "'";
+			$this->db->sql_query($sql);
+
+			unset($this->migration_state[$name]);
+		}
+
+		return true;
+	}
+
+	/**
+	* Apply schema changes from a migration
+	*
+	* Just calls db_tools->perform_schema_changes
+	*
+	* @param array $schema_changes from migration
+	*/
+	protected function apply_schema_changes($schema_changes)
+	{
+		$this->db_tools->perform_schema_changes($schema_changes);
+	}
+
+	/**
+	* Process the data step of the migration
+	*
+	* @param array $steps The steps to run
+	* @param bool|string $state Current state of the migration
+	* @param bool $revert true to revert a data step
+	* @return bool|string migration state. True if completed, serialized array if not finished
+	*/
+	protected function process_data_step($steps, $state, $revert = false)
+	{
+		$state = ($state) ? unserialize($state) : false;
+
+		foreach ($steps as $step_identifier => $step)
+		{
+			$last_result = false;
+			if ($state)
+			{
+				// Continue until we reach the step that matches the last step called
+				if ($state['step'] != $step_identifier)
+				{
+					continue;
+				}
+
+				// We send the result from last time to the callable function
+				$last_result = $state['result'];
+
+				// Set state to false since we reached the point we were at
+				$state = false;
+			}
+
+			try
+			{
+				// Result will be null or true if everything completed correctly
+				$result = $this->run_step($step, $last_result, $revert);
+				if ($result !== null && $result !== true)
+				{
+					return serialize(array(
+						'result'	=> $result,
+						'step'		=> $step_identifier,
+					));
+				}
+			}
+			catch (phpbb_db_migration_exception $e)
+			{
+				// We should try rolling back here
+				foreach ($steps as $reverse_step_identifier => $reverse_step)
+				{
+					// If we've reached the current step we can break because we reversed everything that was run
+					if ($reverse_step_identifier == $step_identifier)
+					{
+						break;
+					}
+
+					// Reverse the step that was run
+					$result = $this->run_step($reverse_step, false, !$revert);
+				}
+
+				// rethrow the exception
+				throw $e;
+			}
+		}
+
+		return true;
+	}
+
+	/**
+	* Run a single step
+	*
+	* An exception should be thrown if an error occurs
+	*
+	* @param mixed $step Data step from migration
+	* @param mixed $last_result Result to pass to the callable (only for 'custom' method)
+	* @param bool $reverse False to install, True to attempt uninstallation by reversing the call
+	* @return null
+	*/
+	protected function run_step($step, $last_result = false, $reverse = false)
+	{
+		$callable_and_parameters = $this->get_callable_from_step($step, $last_result, $reverse);
+
+		if ($callable_and_parameters === false)
+		{
+			return;
+		}
+
+		$callable = $callable_and_parameters[0];
+		$parameters = $callable_and_parameters[1];
+
+		return call_user_func_array($callable, $parameters);
+	}
+
+	/**
+	* Get a callable statement from a data step
+	*
+	* @param array $step Data step from migration
+	* @param mixed $last_result Result to pass to the callable (only for 'custom' method)
+	* @param bool $reverse False to install, True to attempt uninstallation by reversing the call
+	* @return array Array with parameters for call_user_func_array(), 0 is the callable, 1 is parameters
+	*/
+	protected function get_callable_from_step(array $step, $last_result = false, $reverse = false)
+	{
+		$type = $step[0];
+		$parameters = $step[1];
+
+		$parts = explode('.', $type);
+
+		$class = $parts[0];
+		$method = false;
+
+		if (isset($parts[1]))
+		{
+			$method = $parts[1];
+		}
+
+		switch ($class)
+		{
+			case 'if':
+				if (!isset($parameters[0]))
+				{
+					throw new phpbb_db_migration_exception('MIGRATION_INVALID_DATA_MISSING_CONDITION', $step);
+				}
+
+				if (!isset($parameters[1]))
+				{
+					throw new phpbb_db_migration_exception('MIGRATION_INVALID_DATA_MISSING_STEP', $step);
+				}
+
+				$condition = $parameters[0];
+
+				if (!$condition)
+				{
+					return false;
+				}
+
+				$step = $parameters[1];
+
+				return $this->get_callable_from_step($step);
+			break;
+			case 'custom':
+				if (!is_callable($parameters[0]))
+				{
+					throw new phpbb_db_migration_exception('MIGRATION_INVALID_DATA_CUSTOM_NOT_CALLABLE', $step);
+				}
+
+				return array(
+					$parameters[0],
+					array($last_result),
+				);
+			break;
+
+			default:
+				if (!$method)
+				{
+					throw new phpbb_db_migration_exception('MIGRATION_INVALID_DATA_UNKNOWN_TYPE', $step);
+				}
+
+				if (!isset($this->tools[$class]))
+				{
+					throw new phpbb_db_migration_exception('MIGRATION_INVALID_DATA_UNDEFINED_TOOL', $step);
+				}
+
+				if (!method_exists(get_class($this->tools[$class]), $method))
+				{
+					throw new phpbb_db_migration_exception('MIGRATION_INVALID_DATA_UNDEFINED_METHOD', $step);
+				}
+
+				// Attempt to reverse operations
+				if ($reverse)
+				{
+					array_unshift($parameters, $method);
+
+					return array(
+						array($this->tools[$class], 'reverse'),
+						$parameters,
+					);
+				}
+
+				return array(
+					array($this->tools[$class], $method),
+					$parameters,
+				);
+			break;
+		}
+	}
+
+	/**
+	* Insert/Update migration row into the database
+	*
+	* @param string $name Name of the migration
+	* @param array $state
+	* @return null
+	*/
+	protected function set_migration_state($name, $state)
+	{
+		$migration_row = $state;
+		$migration_row['migration_depends_on'] = serialize($state['migration_depends_on']);
+
+		if (isset($this->migration_state[$name]))
+		{
+			$sql = 'UPDATE ' . $this->migrations_table . '
+				SET ' . $this->db->sql_build_array('UPDATE', $migration_row) . "
+				WHERE migration_name = '" . $this->db->sql_escape($name) . "'";
+			$this->db->sql_query($sql);
+		}
+		else
+		{
+			$migration_row['migration_name'] = $name;
+			$sql = 'INSERT INTO ' . $this->migrations_table . '
+				' . $this->db->sql_build_array('INSERT', $migration_row);
+			$this->db->sql_query($sql);
+		}
+
+		$this->migration_state[$name] = $state;
+
+		$this->last_run_migration['state'] = $state;
+	}
+
+	/**
+	* Checks if a migration's dependencies can even theoretically be satisfied.
+	*
+	* @param string	$name The class name of the migration
+	* @return bool|string False if fulfillable, string of missing migration name if unfulfillable
+	*/
+	public function unfulfillable($name)
+	{
+		if (isset($this->migration_state[$name]))
+		{
+			return false;
+		}
+
+		if (!class_exists($name))
+		{
+			return $name;
+		}
+
+		$migration = $this->get_migration($name);
+		$depends = $migration->depends_on();
+
+		foreach ($depends as $depend)
+		{
+			$unfulfillable = $this->unfulfillable($depend);
+			if ($unfulfillable !== false)
+			{
+				return $unfulfillable;
+			}
+		}
+
+		return false;
+	}
+
+	/**
+	* Checks whether all available, fulfillable migrations have been applied.
+	*
+	* @return bool Whether the migrations have been applied
+	*/
+	public function finished()
+	{
+		foreach ($this->migrations as $name)
+		{
+			if (!isset($this->migration_state[$name]))
+			{
+				// skip unfulfillable migrations, but fulfillables mean we
+				// are not finished yet
+				if ($this->unfulfillable($name) !== false)
+				{
+					continue;
+				}
+				return false;
+			}
+
+			$migration = $this->migration_state[$name];
+
+			if (!$migration['migration_schema_done'] || !$migration['migration_data_done'])
+			{
+				return false;
+			}
+		}
+
+		return true;
+	}
+
+	/**
+	* Gets a migration state (whether it is installed and to what extent)
+	*
+	* @param string $migration String migration name to check if it is installed
+	* @return bool|array False if the migration has not at all been installed, array
+	*/
+	public function migration_state($migration)
+	{
+		if (!isset($this->migration_state[$migration]))
+		{
+			return false;
+		}
+
+		return $this->migration_state[$migration];
+	}
+
+	/**
+	* Helper to get a migration
+	*
+	* @param string $name Name of the migration
+	* @return phpbb_db_migration
+	*/
+	protected function get_migration($name)
+	{
+		return new $name($this->config, $this->db, $this->db_tools, $this->phpbb_root_path, $this->php_ext, $this->table_prefix);
+	}
+
+	/**
+	* This function adds all migrations sent to it to the migrations table
+	*
+	* THIS SHOULD NOT GENERALLY BE USED! THIS IS FOR THE PHPBB INSTALLER.
+	* THIS WILL THROW ERRORS IF MIGRATIONS ALREADY EXIST IN THE TABLE, DO NOT CALL MORE THAN ONCE!
+	*
+	* @param array $migrations Array of migrations (names) to add to the migrations table
+	* @return null
+	*/
+	public function populate_migrations($migrations)
+	{
+		foreach ($migrations as $name)
+		{
+			if ($this->migration_state($name) === false)
+			{
+				$state = array(
+					'migration_depends_on'	=> $name::depends_on(),
+					'migration_schema_done' => true,
+					'migration_data_done'	=> true,
+					'migration_data_state'	=> '',
+					'migration_start_time'	=> time(),
+					'migration_end_time'	=> time(),
+				);
+				$this->set_migration_state($name, $state);
+			}
+		}
+	}
+
+	/**
+	* Load migration data files from a directory
+	*
+	* @param phpbb_extension_finder $finder
+	* @param string $path Path to migration data files
+	* @param bool $check_fulfillable If TRUE (default), we will check
+	* 	if all of the migrations are fulfillable after loading them.
+	* 	If FALSE, we will not check. You SHOULD check at least once
+	* 	to prevent errors (if including multiple directories, check
+	* 	with the last call to prevent throwing errors unnecessarily).
+	* @return array Array of migration names
+	*/
+	public function load_migrations(phpbb_extension_finder $finder, $path, $check_fulfillable = true)
+	{
+		if (!is_dir($path))
+		{
+			throw new phpbb_db_migration_exception('DIRECTORY INVALID', $path);
+		}
+
+		$migrations = array();
+
+		$files = $finder
+			->extension_directory("/")
+			->find_from_paths(array('/' => $path));
+		foreach ($files as $file)
+		{
+			$migrations[$file['path'] . $file['filename']] = '';
+		}
+		$migrations = $finder->get_classes_from_files($migrations);
+
+		foreach ($migrations as $migration)
+		{
+			if (!in_array($migration, $this->migrations))
+			{
+				$this->migrations[] = $migration;
+			}
+		}
+
+		if ($check_fulfillable)
+		{
+			foreach ($this->migrations as $name)
+			{
+				$unfulfillable = $this->unfulfillable($name);
+				if ($unfulfillable !== false)
+				{
+					throw new phpbb_db_migration_exception('MIGRATION_NOT_FULFILLABLE', $name, $unfulfillable);
+				}
+			}
+		}
+
+		return $this->migrations;
+	}
+}