box-o-sand/php-practice/web-cake/html/cake/libs/model/connection_manager.php

296 lines
7.9 KiB
PHP

<?php
/**
* Datasource connection manager
*
* Provides an interface for loading and enumerating connections defined in app/config/database.php
*
* PHP versions 4 and 5
*
* CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
* Copyright 2005-2010, Cake Software Foundation, Inc. (http://cakefoundation.org)
*
* Licensed under The MIT License
* Redistributions of files must retain the above copyright notice.
*
* @copyright Copyright 2005-2010, Cake Software Foundation, Inc. (http://cakefoundation.org)
* @link http://cakephp.org CakePHP(tm) Project
* @package cake
* @subpackage cake.cake.libs.model
* @since CakePHP(tm) v 0.10.x.1402
* @license MIT License (http://www.opensource.org/licenses/mit-license.php)
*/
require LIBS . 'model' . DS . 'datasources' . DS . 'datasource.php';
include_once CONFIGS . 'database.php';
/**
* Manages loaded instances of DataSource objects
*
* @package cake
* @subpackage cake.cake.libs.model
*/
class ConnectionManager extends Object {
/**
* Holds a loaded instance of the Connections object
*
* @var DATABASE_CONFIG
* @access public
*/
var $config = null;
/**
* Holds instances DataSource objects
*
* @var array
* @access protected
*/
var $_dataSources = array();
/**
* Contains a list of all file and class names used in Connection settings
*
* @var array
* @access protected
*/
var $_connectionsEnum = array();
/**
* Constructor.
*
*/
function __construct() {
if (class_exists('DATABASE_CONFIG')) {
$this->config =& new DATABASE_CONFIG();
$this->_getConnectionObjects();
}
}
/**
* Gets a reference to the ConnectionManger object instance
*
* @return object Instance
* @access public
* @static
*/
function &getInstance() {
static $instance = array();
if (!$instance) {
$instance[0] =& new ConnectionManager();
}
return $instance[0];
}
/**
* Gets a reference to a DataSource object
*
* @param string $name The name of the DataSource, as defined in app/config/database.php
* @return object Instance
* @access public
* @static
*/
function &getDataSource($name) {
$_this =& ConnectionManager::getInstance();
if (!empty($_this->_dataSources[$name])) {
$return =& $_this->_dataSources[$name];
return $return;
}
if (empty($_this->_connectionsEnum[$name])) {
trigger_error(sprintf(__("ConnectionManager::getDataSource - Non-existent data source %s", true), $name), E_USER_ERROR);
$null = null;
return $null;
}
$conn = $_this->_connectionsEnum[$name];
$class = $conn['classname'];
if ($_this->loadDataSource($name) === null) {
trigger_error(sprintf(__("ConnectionManager::getDataSource - Could not load class %s", true), $class), E_USER_ERROR);
$null = null;
return $null;
}
$_this->_dataSources[$name] =& new $class($_this->config->{$name});
$_this->_dataSources[$name]->configKeyName = $name;
$return =& $_this->_dataSources[$name];
return $return;
}
/**
* Gets the list of available DataSource connections
*
* @return array List of available connections
* @access public
* @static
*/
function sourceList() {
$_this =& ConnectionManager::getInstance();
return array_keys($_this->_dataSources);
}
/**
* Gets a DataSource name from an object reference.
*
* **Warning** this method may cause fatal errors in PHP4.
*
* @param object $source DataSource object
* @return string Datasource name, or null if source is not present
* in the ConnectionManager.
* @access public
* @static
*/
function getSourceName(&$source) {
$_this =& ConnectionManager::getInstance();
foreach ($_this->_dataSources as $name => $ds) {
if ($ds == $source) {
return $name;
}
}
return '';
}
/**
* Loads the DataSource class for the given connection name
*
* @param mixed $connName A string name of the connection, as defined in app/config/database.php,
* or an array containing the filename (without extension) and class name of the object,
* to be found in app/models/datasources/ or cake/libs/model/datasources/.
* @return boolean True on success, null on failure or false if the class is already loaded
* @access public
* @static
*/
function loadDataSource($connName) {
$_this =& ConnectionManager::getInstance();
if (is_array($connName)) {
$conn = $connName;
} else {
$conn = $_this->_connectionsEnum[$connName];
}
if (class_exists($conn['classname'])) {
return false;
}
if (!empty($conn['parent'])) {
$_this->loadDataSource($conn['parent']);
}
$conn = array_merge(array('plugin' => null, 'classname' => null, 'parent' => null), $conn);
$class = "{$conn['plugin']}.{$conn['classname']}";
if (!App::import('Datasource', $class, !is_null($conn['plugin']))) {
trigger_error(sprintf(__('ConnectionManager::loadDataSource - Unable to import DataSource class %s', true), $class), E_USER_ERROR);
return null;
}
return true;
}
/**
* Return a list of connections
*
* @return array An associative array of elements where the key is the connection name
* (as defined in Connections), and the value is an array with keys 'filename' and 'classname'.
* @access public
* @static
*/
function enumConnectionObjects() {
$_this =& ConnectionManager::getInstance();
return $_this->_connectionsEnum;
}
/**
* Dynamically creates a DataSource object at runtime, with the given name and settings
*
* @param string $name The DataSource name
* @param array $config The DataSource configuration settings
* @return object A reference to the DataSource object, or null if creation failed
* @access public
* @static
*/
function &create($name = '', $config = array()) {
$_this =& ConnectionManager::getInstance();
if (empty($name) || empty($config) || array_key_exists($name, $_this->_connectionsEnum)) {
$null = null;
return $null;
}
$_this->config->{$name} = $config;
$_this->_connectionsEnum[$name] = $_this->__connectionData($config);
$return =& $_this->getDataSource($name);
return $return;
}
/**
* Gets a list of class and file names associated with the user-defined DataSource connections
*
* @return void
* @access protected
* @static
*/
function _getConnectionObjects() {
$connections = get_object_vars($this->config);
if ($connections != null) {
foreach ($connections as $name => $config) {
$this->_connectionsEnum[$name] = $this->__connectionData($config);
}
} else {
$this->cakeError('missingConnection', array(array('code' => 500, 'className' => 'ConnectionManager')));
}
}
/**
* Returns the file, class name, and parent for the given driver.
*
* @return array An indexed array with: filename, classname, plugin and parent
* @access private
*/
function __connectionData($config) {
if (!isset($config['datasource'])) {
$config['datasource'] = 'dbo';
}
$filename = $classname = $parent = $plugin = null;
if (!empty($config['driver'])) {
$parent = $this->__connectionData(array('datasource' => $config['datasource']));
$parentSource = preg_replace('/_source$/', '', $parent['filename']);
list($plugin, $classname) = pluginSplit($config['driver']);
if ($plugin) {
$source = Inflector::underscore($classname);
} else {
$source = $parentSource . '_' . $config['driver'];
$classname = Inflector::camelize(strtolower($source));
}
$filename = $parentSource . DS . $source;
} else {
list($plugin, $classname) = pluginSplit($config['datasource']);
if ($plugin) {
$filename = Inflector::underscore($classname);
} else {
$filename = Inflector::underscore($config['datasource']);
}
if (substr($filename, -7) != '_source') {
$filename .= '_source';
}
$classname = Inflector::camelize(strtolower($filename));
}
return compact('filename', 'classname', 'parent', 'plugin');
}
/**
* Destructor.
*
* @access private
*/
function __destruct() {
if (Configure::read('Session.save') == 'database' && function_exists('session_write_close')) {
session_write_close();
}
}
}