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php-phpbb/phpBB/includes/db/migrator.php
Nathan Guse f56e400cd3 [feature/migrations] Comments
PHPBB3-9737
2013-01-09 16:44:09 -06:00

551 lines
12 KiB
PHP

<?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' and 'class' of the last migration run
*
* @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();
$sql = "SELECT *
FROM " . $this->migrations_table;
$result = $this->db->sql_query($sql);
while ($migration = $this->db->sql_fetchrow($result))
{
$this->migration_state[$migration['migration_name']] = $migration;
}
$this->db->sql_freeresult($result);
}
/**
* 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;
}
/**
* Load migration data files from a directory
*
* This does not loop through sub-directories.
* Migration data files loaded with this function MUST contain
* ONLY ONE class in them (or an exception will be thrown).
*
* @param string $path Path to migration data files
* @param bool $check_fulfillable If TRUE (default), we will check
* if all of the migrations are fulfillable after loading them.
* If FALSE, we will not check. You SHOULD check at least once
* to prevent errors (if including multiple directories, check
* with the last call to prevent throwing errors unnecessarily).
* @return array Array of migrations with names
*/
public function load_migrations($path, $check_fulfillable = true)
{
$handle = opendir($path);
while (($file = readdir($handle)) !== false)
{
if (strpos($file, '_') !== 0 && strrpos($file, '.' . $this->php_ext) === (strlen($file) - strlen($this->php_ext) - 1))
{
// We try to find what class existed by comparing the classes declared before and after including the file.
$declared_classes = get_declared_classes();
include ($path . $file);
$added_classes = array_diff(get_declared_classes(), $declared_classes);
if (
// If two classes have been added and phpbb_db_migration is one of them, we've only added one real migration
!(sizeof($added_classes) == 2 && in_array('phpbb_db_migration', $added_classes)) &&
// Otherwise there should only be one class added
sizeof($added_classes) != 1
)
{
throw new phpbb_db_migration_exception('MIGRATION DATA FILE INVALID', $path . $file);
}
$name = array_pop($added_classes);
if (!in_array($name, $this->migrations))
{
$this->migrations[] = $name;
}
}
}
if ($check_fulfillable)
{
foreach ($this->migrations as $name)
{
if ($this->unfulfillable($name))
{
throw new phpbb_db_migration_exception('MIGRATION NOT FULFILLABLE', $name);
}
}
}
return $this->migrations;
}
/**
* Runs a single update step from the next migration to be applied.
*
* The update step can either be a schema or a (partial) data update. To
* check if update() needs to be called again use the finished() method.
*
* @return null
*/
public function update()
{
foreach ($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_schema_done' => false,
'migration_data_done' => false,
'migration_data_state' => '',
'migration_start_time' => 0,
'migration_end_time' => 0,
);
$depends = $migration->depends_on();
foreach ($depends 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' => $migration,
);
if (!isset($this->migration_state[$name]))
{
$state['migration_start_time'] = time();
$this->insert_migration($name, $state);
}
if (!$state['migration_schema_done'])
{
$this->apply_schema_changes($migration->update_schema());
$state['migration_schema_done'] = true;
}
else
{
$result = $this->process_data_step($migration, $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;
}
$sql = 'UPDATE ' . $this->migrations_table . '
SET ' . $this->db->sql_build_array('UPDATE', $state) . "
WHERE migration_name = '" . $this->db->sql_escape($name) . "'";
$this->db->sql_query($sql);
$this->migration_state[$name] = $state;
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 phpbb_db_migration $migration
* @param bool|string $state Current state of the migration
* @return bool|string migration state. True if completed, serialized array if not finished
*/
protected function process_data_step($migration, $state)
{
$state = ($state) ? unserialize($state) : false;
$steps = $migration->update_data();
foreach ($steps as $step)
{
$last_result = false;
if ($state)
{
// Continue until we reach the step that matches the last step called
if ($state['step'] != $step)
{
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, $last_result);
if ($result !== null && $result !== true)
{
return serialize(array(
'result' => $result,
'step' => $step,
));
}
}
catch (phpbb_db_migration_exception $e)
{
// We should try rolling back here
var_dump($step);
echo $e;
die();
}
}
return true;
}
/**
* Run a single step
*
* An exception should be thrown if an error occurs
*
* @param mixed $step Data step from migration
* @param mixed $last_result Result to pass to the callable (only for 'custom' method)
* @return null
*/
protected function run_step($step, $last_result = false)
{
$callable_and_parameters = $this->get_callable_from_step($step, $last_result);
$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 mixed $step Data step from migration
* @param mixed $last_result Result to pass to the callable (only for 'custom' method)
* @return array Array with parameters for call_user_func_array(), 0 is the callable, 1 is parameters
*/
public function get_callable_from_step($step, $last_result = 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];
$step = $parameters[1];
$callable_and_parameters = $this->get_callable_from_step($step);
$callable = $callable_and_parameters[0];
$sub_parameters = $callable_and_parameters[1];
return array(
function ($condition) use ($callable, $sub_parameters) {
return call_user_func_array($callable, $sub_parameters);
},
array($condition),
);
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', $step);
}
return array(
array($this->tools[$class], $method),
$parameters,
);
break;
}
}
/**
* Insert migration row into the database
*
* @param string $name Name of the migration
* @param array $state
* @return null
*/
protected function insert_migration($name, $state)
{
$migration_row = $state;
$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;
}
/**
* Checks if a migration's dependencies can even theoretically be satisfied.
*
* @param string $name The class name of the migration
* @return bool Whether the migration cannot be fulfilled
*/
public function unfulfillable($name)
{
if (isset($this->migration_state[$name]))
{
return false;
}
if (!class_exists($name))
{
return true;
}
$migration = $this->get_migration($name);
$depends = $migration->depends_on();
foreach ($depends as $depend)
{
if ($this->unfulfillable($depend))
{
return true;
}
}
return false;
}
/**
* Checks whether all available, fulfillable migrations have been applied.
*
* @return bool Whether the migrations have been applied
*/
public function finished()
{
foreach ($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))
{
continue;
}
return false;
}
$migration = $this->migration_state[$name];
if (!$migration['migration_schema_done'] || !$migration['migration_data_done'])
{
return false;
}
}
return true;
}
/**
* 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);
}
}