<?php
/**
 *  
 * @author  Benjamin Gillissen <hide@address.com>
 * 
 *	**************************************************************

	Copyright (C) 2009  Benjamin Gillissen
	
	This program is free software; you can redistribute it and/or
	modify it under the terms of the GNU General Public License
	as published by the Free Software Foundation; either version 2
	of the License, or (at your option) any later version.
	
	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 at:
	http://www.gnu.org/copyleft/gpl.html

 *	**************************************************************
 */

class chrono {
	
	private static $chronos, $start;
	
	public function __construct(){ }
	
	public static function init($ref){
		if ( ! CORE::isphpModLoaded('bcmath') ){
			if ( ! CORE::LoadphpMod('bcmath') ){ 
				errors::raise('Missing PHP extention, ask your admin to reinstall php with the bcmath support', CORE_LOG_ALERT, 'CHRONO');
			}
		}
		if ( isset(self::$chronos[$ref]) ){ unset(self::$chronos[$ref]); }
		self::$chronos[$ref]['elapsed'] = 0;
		self::reqstart();
	}

	public static function isinit($ref){ return isset(self::$chronos[$ref]); }
	
	public static function reqstart(){ 
		if ( !isset(self::$start) ){ self::$start = self::get_microtime(); }
	}
	
	public static function start($ref){
		if ( ! isset(self::$chronos[$ref]) ){ return; } //no init
		if ( isset(self::$chronos[$ref]['startat']) ){ return; } //already started
		self::$chronos[$ref]['startat'] = self::get_microtime();
		self::$chronos[$ref]['pausekey'] = CORE::hash(NULL, 5);
		return self::$chronos[$ref]['pausekey'];
	}
	
	public static function pause($ref, $key=NULL){
		if ( ! isset(self::$chronos[$ref]) ){ return; }	//no init
		if ( ! isset(self::$chronos[$ref]['startat']) ){ return; } //not started, or paused
		if ( self::$chronos[$ref]['pausekey'] !== $key ){ return; }	//not good context!
		$elapsed = bcsub(self::get_microtime(), self::$chronos[$ref]['startat'], 4);
		self::$chronos[$ref]['elapsed'] = bcadd(self::$chronos[$ref]['elapsed'], $elapsed, 4);
		unset(self::$chronos[$ref]['startat'], self::$chronos[$ref]['pausekey']);
	}
	
	public static function stop($ref){
		if ( ! isset(self::$chronos[$ref]) ){ return 0; }	//no init
		if ( isset(self::$chronos[$ref]['startat']) ){ self::pause($ref, self::$chronos[$ref]['pausekey']);	}//started
		return self::$chronos[$ref]['elapsed']; //in ms
	}
	
	public static function stopall(){
		$tot['time'] = bcsub(self::get_microtime(), self::$start, 4);
		$tot['ref'] = 'tot';
		$buf=0;
		foreach(self::$chronos as  $ref => $val){
			$b['ref'] = $ref;
			$b['time'] = self::stop($ref);
			if ( $b['time'] != 0 ){ $o[] = $b; }
			//$buf = bcadd($b['time'], $buf, 4);
		}
		//$other = Array( 'ref'=> 'other', 'time' => bcsub($tot['time'], $buf, 4) );
		//$o[] = $other;
		$o[] = $tot;
		//echo '<pre>'.print_r($o, TRUE).'</pre>';
		return $o;
	}
	
	public static function get_microtime(){
		list($usec, $sec) = explode(" ", microtime());
		return bcadd($usec, $sec, 4);
	}
}