<?php

// drop-in class for multi-section timing and reporting functions, with millisecond precision.  Useful for internal micro-benchmarking
// Usage example:
// $sw = new Stopwatch();
// $sw->start( 'section 1' );
// $sw->start( 'section 2' );
// $sw->start( 'section n...' );
// $sw->stop();
// echo 'Stopwatch timings: ' . $sw->toString();
// requires PHP5
class Stopwatch{

	private $marks = array(); // array of timestamp marks
	private $sections = array(); // array of times between each mark (calculated when stop() is called)
	private $total = 0; // total time for all sections
	
	// start a new named stopwatch section.  use this to start the stopwatch, and call repeatedly for each new section
	public function start( $section ){
		$this->marks[ $section ] = microtime( true );
	}
	
	// call when the end of the final section is reached.  closes off the last session, and calculates session times
	public function stop(){
		$this->start( 'END' );
		$previousSection = false;
		foreach( $this->marks as $section => $mark )
		{	
			if( $previousSection !== false )
			{
				$elapsed = $mark - $this->marks[ $previousSection ];
				$this->sections[ $previousSection ] = $elapsed;
				$this->total += $elapsed;
			}
			$previousSection = $section;
		}
	}
	
	// get total time
	public function getTotal(){
		return $this->total;
	}
	
	// get time for a particular section
	public function getTime( $name ){
		return array_key_exists( $name, $this->sections ) ? $this->sections[ $name ] : 0;
	}

	// return summary of all sections, as a string
	public function toString(){
		$ret = '';
		foreach( $this->sections as $section => $time )
			$ret .= "$section:$time ";
		$ret .= 'TOTAL:' . $this->getTotal();
		return $ret;
	}
}

?>