<?php
/**
* CakePHP(tm) : Rapid Development Framework (https://cakephp.org)
* Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
*
* Licensed under The MIT License
* For full copyright and license information, please see the LICENSE.txt
* Redistributions of files must retain the above copyright notice.
*
* @copyright Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
* @link https://cakephp.org CakePHP(tm) Project
* @since 3.6.0
* @license https://opensource.org/licenses/mit-license.php MIT License
*/
namespace Cake\Database;
use Cake\Cache\Cache;
use Cake\Database\Connection;
use RuntimeException;
/**
* Schema Cache.
*
* This tool is intended to be used by deployment scripts so that you
* can prevent thundering herd effects on the metadata cache when new
* versions of your application are deployed, or when migrations
* requiring updated metadata are required.
*
* @link https://en.wikipedia.org/wiki/Thundering_herd_problem About the thundering herd problem
*/
class SchemaCache
{
/**
* Schema
*
* @var \Cake\Database\Schema\CachedCollection
*/
protected $_schema;
/**
* Constructor
*
* @param string|\Cake\Datasource\ConnectionInterface $connection Connection name to get the schema for or a connection instance
*/
public function __construct($connection)
{
$this->_schema = $this->getSchema($connection);
}
/**
* Build metadata.
*
* @param string|null $name The name of the table to build cache data for.
* @return array Returns a list build table caches
*/
public function build($name = null)
{
$tables = [$name];
if (empty($name)) {
$tables = $this->_schema->listTables();
}
foreach ($tables as $table) {
$this->_schema->describe($table, ['forceRefresh' => true]);
}
return $tables;
}
/**
* Clear metadata.
*
* @param string|null $name The name of the table to clear cache data for.
* @return array Returns a list of cleared table caches
*/
public function clear($name = null)
{
$tables = [$name];
if (empty($name)) {
$tables = $this->_schema->listTables();
}
$configName = $this->_schema->getCacheMetadata();
foreach ($tables as $table) {
$key = $this->_schema->cacheKey($table);
Cache::delete($key, $configName);
}
return $tables;
}
/**
* Helper method to get the schema collection.
*
* @param \Cake\Database\Connection $connection Connection object
* @return \Cake\Database\Schema\Collection|\Cake\Database\Schema\CachedCollection
* @throws \RuntimeException If given connection object is not compatible with schema caching
*/
public function getSchema(Connection $connection)
{
if (!method_exists($connection, 'schemaCollection')) {
throw new RuntimeException('The given connection object is not compatible with schema caching, as it does not implement a "schemaCollection()" method.');
}
$config = $connection->config();
if (empty($config['cacheMetadata'])) {
$connection->cacheMetadata(true);
}
return $connection->getSchemaCollection();
}
}