php记录程序执行时间microtime

/**
 * 记录程序程序时间---只能记录连续的调用改函数
 * @param		$time_key		记录的key，多次执行可以指定同一个key
 * @return		none				没有返回值，直接获取全局变量$time_arr，如果是在方法中调用需要先global一次
 **/
function showExecuTime($time_key = '') {
	global $time_arr,$time_start,$time_end,$time_num;
	$time_now = microtime(true);
	if ( !$time_num ) {
		$time_num = 0;
	}
	$time_num++;
	if ( $time_num%2 == 1 ) {
		$time_start = $time_now;
	} else {
		$time_end = $time_now;
	}
	if ( $time_num %2 == 0 && $time_start && $time_end ) {
		$time = $time_end - $time_start;
		if ( $time_key ) {
			$time_arr[$time_key] += $time;
		} else {
			$time_arr[] = $time;
		}
		$time_arr['total'] += $time;
	}
}

/**
 * 记录程序程序时间---可以多次交叉的调用
 * @param		$time_key		记录的key，多次执行可以指定同一个key
 * @return		none				没有返回值，直接获取全局变量$time_arr，如果是在方法中调用需要先global一次
 **/
function showExecuTime($time_key = '') {
	global $time_arr,$time_key_arr,$time_num;
	$time_now = microtime(true);
	if ( !$time_key ) {
		if ( !$time_num ) {
			$time_num = 0;
		}
		$time_num++;
		$time_key = floor(($time_num+1)/2) - 1;
	}
	// 记录本次是开始时间还是结束时间
	if ( !isset($time_key_arr[$time_key])) {
		$time_key_arr[$time_key]['num'] = 0;
	}
	$time_key_arr[$time_key]['num']++;
	if ( $time_key_arr[$time_key]['num']%2 == 1 ) {
		$time_key_arr[$time_key]['time_start'] = $time_now;
	} else {
		$time_key_arr[$time_key]['time_end'] = $time_now;
	}
	
	// 如果连续记录2次，计算结果
	if ( $time_key_arr[$time_key]['num'] %2 == 0 && $time_key_arr[$time_key]['time_start'] && $time_key_arr[$time_key]['time_end'] ) {
		$time = $time_key_arr[$time_key]['time_end'] - $time_key_arr[$time_key]['time_start'];
		$time_arr[$time_key] += $time;
		$time_arr['total'] += $time;
	}
}

showExecuTime('all');
showExecuTime();
sleep(1);
showExecuTime('all');//////
sleep(1);
showExecuTime();
sleep(1);
showExecuTime();
sleep(1);
showExecuTime();
showExecuTime('a');
sleep(1);
showExecuTime('a');
// showExecuTime('all');//////
print_r($time_arr);
print_r($time_key_arr);