path: root/lib/class/dba.class.php

<?php
/* vim:set tabstop=8 softtabstop=8 shiftwidth=8 noexpandtab: */
/**
 * Dba Class
 *
 *
 * LICENSE: GNU General Public License, version 2 (GPLv2)
 * Copyright (c) 2001 - 2011 Ampache.org All Rights Reserved
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License v2
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * @package	Ampache
 * @copyright	2001 - 2011 Ampache.org
 * @license	http://opensource.org/licenses/gpl-2.0 GPLv2
 * @link	http://www.ampache.org/
 */

/* Make sure they aren't directly accessing it */
if (!defined('INIT_LOADED') || INIT_LOADED != '1') { exit; }

/**
 * Dba Class
 *
 * This is the database abstraction class
 * It duplicates the functionality of mysql_???
 * with a few exceptions, the row and assoc will always
 * return an array, simplifying checking on the far end
 * it will also auto-connect as needed, and has a default
 * database simplifying queries in most cases.
 *
 * @package	Ampache
 * @copyright	2001 - 2011 Ampache.org
 * @license	http://opensource.org/licenses/gpl-2.0 GPLv2
 * @link	http://www.ampache.org/
 */
class Dba {

	public static $stats = array('query'=>0);

	private static $_default_db;
	private static $_sql;
	private static $config;

	/**
	 * constructor
	 * This does nothing with the DBA class
	 */
	private function __construct() {

		// Rien a faire

	} // construct

	/**
	 * query
	 * This is the meat of the class this does a query, it emulates
	 * The mysql_query function
	 */
	public static function query($sql) {

		// Run the query
		$resource = mysql_query($sql,self::dbh());
		debug_event('Query',$sql,'6');

		// Save the query, to make debug easier
		self::$_sql = $sql;
		self::$stats['query']++;

		// Do a little error checking here and try to recover from some forms of failure
		if (!$resource) {
			switch (mysql_errno(self::dbh())) {
				case '2006':
				case '2013':
				case '2055':
					debug_event('DBH','Lost connection to database server, trying to re-connect and hope nobody noticed','1');
					self::disconnect();
					// Try again
					$resource = mysql_query($sql,self::dbh());
					break;
				default:
					debug_event('DBH',mysql_error(self::dbh()) . ' ['. mysql_errno(self::dbh()) . ']','1');
					break;
			} // end switch on error #
		} // if failed query

		return $resource;

	} // query

	/**
	 * read
	 * This is a wrapper for query, it's so that in the future if we ever wanted
	 * to split reads and writes we could
	 */
	public static function read($sql) {

		return self::query($sql);

	} // read

	/**
	 * write
	 * This is a wrapper for a write query, it is so that we can split out reads and
	 * writes if we want to
	 */
	public static function write($sql) {

		return self::query($sql);

	} // write

	/**
	 * escape
	 * This runs a escape on a variable so that it can be safely inserted
	 * into the sql
	 */
	public static function escape($var) {

		$string = mysql_real_escape_string($var,self::dbh());

		return $string;

	} // escape

	/**
	 * fetch_assoc
	 * This emulates the mysql_fetch_assoc and takes a resource result
	 * we force it to always return an array, albit an empty one
	 */
	public static function fetch_assoc($resource) {

		$result = mysql_fetch_assoc($resource);

		if (!$result) {
			return array();
		}

		return $result;

	} // fetch_assoc

	/**
	 * fetch_row
	 * This emulates the mysql_fetch_row and takes a resource result
	 * we force it to always return an array, albit an empty one
	 */
	public static function fetch_row($resource) {

		$result = mysql_fetch_row($resource);

		if (!$result) {
			return array();
		}

		return $result;

	} // fetch_row

	/**
	 * num_rows
	 * This emulates the mysql_num_rows function which is really
	 * just a count of rows returned by our select statement, this
	 * doesn't work for updates or inserts
	 */
	public static function num_rows($resource) {

		$result = mysql_num_rows($resource);

		if (!$result) {
			return '0';
		}

		return $result;
	} // num_rows

	/**
	 * finish
	 * This closes a result handle and clears the memory associated with it
	 */
	public static function finish($resource) {

		// Clear the result memory
		mysql_free_result($resource);

	} // finish

	/**
	 * affected_rows
	 * This emulates the mysql_affected_rows function
	 */
	public static function affected_rows($resource) {

		$result = mysql_affected_rows($resource);

		if (!$result) {
			return '0';
		}

		return $result;

	} // affected_rows

	/**
	 * _connect
	 * This connects to the database, used by the DBH function
	 */
	private static function _connect($db_name) {

		if (self::$_default_db == $db_name) {
			$username = Config::get('database_username');
			$hostname = Config::get('database_hostname');
			$password = Config::get('database_password');
			$database = Config::get('database_name');
		}
		else {
			// Do this later
		}


		$dbh = mysql_connect($hostname,$username,$password);
		if (!$dbh) { debug_event('Database','Error unable to connect to database' . mysql_error(),'1'); }

		$data = self::translate_to_mysqlcharset(Config::get('site_charset'));

		if (function_exists('mysql_set_charset')) {
			if (!$charset = mysql_set_charset($data['charset'],$dbh)) {
				debug_event('Database','Error unable to set MySQL Connection charset to ' . $data['charset'] . ' this may cause issues...','1');
			}
		}
		else {
			$sql = "SET NAMES " . mysql_real_escape_string($data['charset']);
			$charset = mysql_query($sql,$dbh);
			if (mysql_error($dbh)) { debug_event('Database','Error unable to set MySQL Connection charset to ' . $data['charset'] . ' using SET NAMES, you may have issues','1'); }

		}
		if (!$charset) { debug_event('Database','Error unable to set connection charset, function missing or set failed','1'); }

		$select_db = mysql_select_db($database,$dbh);
		if (!$select_db) { debug_event('Database','Error unable to select ' . $database . ' error ' . mysql_error(),'1'); }

		if (Config::get('sql_profiling')) {
			mysql_query('set profiling=1', $dbh);
			mysql_query('set profiling_history_size=50', $dbh);
			mysql_query('set query_cache_type=0', $dbh);
		}
		return $dbh;

	} // _connect

	/**
	 * show_profile
	 * This function is used for debug, helps with profiling
	 */
	public static function show_profile() {

		if (Config::get('sql_profiling')) {
			print '<br/>Profiling data: <br/>';
			$res = Dba::read('show profiles');
			print '<table>';
			while ($r = Dba::fetch_row($res)) {
				print '<tr><td>' . implode('</td><td>', $r) . '</td></tr>';
			}
			print '</table>';
		}
	} // show_profile

	/**
	 * dbh
	 * This is called by the class to return the database handle
	 * for the specified database, if none is found it connects
	 */
	public static function dbh($database='') {

		if (!$database) { $database = self::$_default_db; }

		// Assign the Handle name that we are going to store
		$handle = 'dbh_' . $database;

		if (!is_resource(Config::get($handle))) {
			$dbh = self::_connect($database);
			Config::set($handle,$dbh,1);
			return $dbh;
		}
		else {
			return Config::get($handle);
		}


	} // dbh

	/**
	 * disconnect
	 * This nukes the dbh connection based, this isn't used very often...
	 */
	public static function disconnect($database='') {

		if (!$database) { $database = self::$_default_db; }

		$handle = 'dbh_' . $database;

		// Try to close it correctly
		mysql_close(Config::get($handle));

		// Nuke it
		Config::set($handle,false,1);

		return true;

	} // disconnect

	/**
	 * insert_id
	 * This emulates the mysql_insert_id function, it takes
	 * an optional database target
	 */
	public static function insert_id() {

		$id = mysql_insert_id(self::dbh());
		return $id;

	} // insert_id

	/**
	 * error
	 * this returns the error of the db
	 */
	public static function error() {

		return mysql_error();

	} // error

	/**
	 * auto_init
	 * This is the auto init function it sets up the config class
	 * and also sets the default database
	 */
	public static function _auto_init() {

		self::$_default_db = Config::get('database_name');

		return true;

	} // auto_init

	/**
	 * translate_to_mysqlcharset
	 * This translates the specified charset to a mysqlcharset, stupid ass mysql
	 * demands that it's charset list is different!
	 */
	public static function translate_to_mysqlcharset($charset) {

		// MySQL translte real charset names into fancy smancy MySQL land names
		switch (strtoupper($charset)) {
			case 'CP1250':
			case 'WINDOWS-1250':
				$target_charset = 'cp1250';
				$target_collation = 'cp1250_general_ci';
				break;
			case 'ISO-8859':
			case 'ISO-8859-2':
				$target_charset = 'latin2';
				$target_collation = 'latin2_general_ci';
				break;
			case 'ISO-8859-1':
			case 'CP1252':
			case 'WINDOWS-1252':
				$target_charset = 'latin1';
				$target_collation = 'latin1_general_ci';
				break;
			case 'EUC-KR':
				$target_charset = 'euckr';
				$target_collation = 'euckr_korean_ci';
				break;
			case 'CP932':
				$target_charset = 'sjis';
				$target_collation = 'sjis_japanese_ci';
				break;
			case 'KOI8-U':
				$target_charset = 'koi8u';
				$target_collation = 'koi8u_general_ci';
				break;
			case 'KOI8-R':
				$target_charset = 'koi8r';
				$target_collation = 'koi8r_general_ci';
				break;
			default;
			case 'UTF-8':
				$target_charset = 'utf8';
				$target_collation = 'utf8_unicode_ci';
				break;
		} // end mysql charset translation

		return array('charset'=>$target_charset,'collation'=>$target_collation);

	} // translate_to_mysqlcharset

	/**
	 * reset_db_charset
	 * This cruises through the database and trys to set the charset to the current
	 * site charset, this is an admin function that can be run by an administrator
	 * this can mess up data if you switch between charsets that are not overlapping
	 * a catalog verify must be re-run to correct them
	 */
	public static function reset_db_charset() {

		$translated_charset = self::translate_to_mysqlcharset(Config::get('site_charset'));
		$target_charset = $translated_charset['charset'];
		$target_collation = $translated_charset['collation'];

		// Alter the charset for the entire database
		$sql = "ALTER DATABASE `" . Config::get('database_name') . "` DEFAULT CHARACTER SET $target_charset COLLATE $target_collation";
		$db_results = Dba::write($sql);

		$sql = "SHOW TABLES";
		$db_results = Dba::read($sql);

		// Go through the tables!
		while ($row = Dba::fetch_row($db_results)) {
			$sql = "DESCRIBE `" . $row['0'] . "`";
			$describe_results = Dba::read($sql);

			// Change the tables default charset and colliation
			$sql = "ALTER TABLE `" . $row['0'] . "`  DEFAULT CHARACTER SET $target_charset COLLATE $target_collation";
			$alter_table = Dba::write($sql);

			// Itterate through the columns of the table
			while ($table = Dba::fetch_assoc($describe_results)) {
				if (
				(strpos($table['Type'], 'varchar') !== false) ||
				(strpos($table['Type'], 'enum') !== false) ||
				(strpos($table['Table'],'text') !== false)) {
					$sql = "ALTER TABLE `" . $row['0'] . "` MODIFY `" . $table['Field'] . "` " . $table['Type'] . " CHARACTER SET " . $target_charset;
					$charset_results = Dba::write($sql);
					if (!$charset_results) {
						debug_event('CHARSET','Unable to update the charset of ' . $table['Field'] . '.' . $table['Type'] . ' to ' . $target_charset,'3');
					} // if it fails
				} // if its a varchar
			} // end columns

		} // end tables


	} // reset_db_charset

} // dba class

?>