README

目的

在优化过程中，我们需要检查不同操作所花费的时间。如果我们放置了很多 microtime 代码块，这很快就会变得混乱。

StopWatch 的目的是提供一种记录不同代码块所用时间的整洁方式。

支持的版本

上面的构建已经在 PHP 版本 5.3、5.4、5.5、5.6、7.0 和 HHVM 上进行了测试。详细信息请查看 .travis.yml 文件。

示例

示例文件夹中有示例。以下是几个示例

简单的计时器（文件 example/simplewatch.php）

以下示例展示了 StopWatch 的最简单用法。

<?php

/*
 * This example shows simple use of Stopwatch. For simple use, we need just four steps:
 *   - Create instance of StopWatch,
 *   - Call `start()` method to start the timer,
 *   - Call `stop()` method to stop the watch, and
 *   - Call `getTime()` method to get the time between start and stop.
 */

// Load Composer auto loader
require_once "../vendor/autoload.php";

use Phpreboot\Stopwatch\StopWatch;

// Create an instance of StopWatch
$stopWatch = new StopWatch();

// Start the watch to start timer,
$stopWatch->start();

$iteration = 0;

for ($i = 0; $i < 10000; $i++) {
    for ($j = 0; $j < 10000; $j++) {
        $iteration++;
    }
}

// Stop the watch.
$stopWatch->stop();

// By default, it will return time in seconds
$time = $stopWatch->getTime();

printf("Time taken for %d iterations was %f seconds.\n", $iteration, $time);

暂停示例（文件 example/pausedemo.php）

此示例展示了在多个时间段内测量时间。我们简单地暂停计时器以停止计时，并在稍后再次启动。此步骤可以重复多次。

<?php

/*
 * The example shows how to pause the timer for measuring time at different stages.
 * Once watch is started, we can call `pause` method to pause the watch.
 * If watch is paused, we can start it again to start timer. In that case, time will be added to timer.
 */

// Load Composer auto loader
require_once "../vendor/autoload.php";

use Phpreboot\Stopwatch\StopWatch;

// Create an instance of StopWatch
$stopWatch = new StopWatch();

$innerIterator = 0;

for ($i = 1; $i <= 10; $i++) {
    printf("Iteration %d starting.\n", $i);

    $stopWatch->start();
    for ($j = 0; $j < 1000; $j++) {
        $innerIterator++;
    }
    $stopWatch->pause();

    printf("Iteration %d watch stopped, not other task is starting..\n", $i);

    for ($k = 0; $k < 1000; $k++) {
        $timeWaster = $k;
    }
}

printf("Time taken by first loop (\$j), for %d iterations was: %f seconds.\n", $innerIterator, $stopWatch->getTime());

多计时器示例（文件 example/multiDemo.php）

在多个时间段内测量时间很有用，但有时我们需要多个独立的计时器。以下示例展示了我们如何拥有多个计时器。

<?php

/*
 * This example shows using multiple stop watches in the same program.
 * If we want to use multiple watches, we must provide unique name all of them.
 * Steps involved are:
 *   - Add watches by any of following methods
 *     - Call `addWatch` multiple times, with name of watch as parameter, or
 *     - Call `addWatches` and pass an array of name of watches as parameter.
 *   - Further operation is same as in `simplewatch` and `pauseDemo` example. However this time, we need to pass
 *     watch name to all the methods.
 */

// Load Composer auto loader
require_once "../vendor/autoload.php";
use Phpreboot\Stopwatch\StopWatch;

// Create an instance of StopWatch
$stopWatch = new StopWatch();

// Initialize the watches.
$stopWatch->addWatches(["a", "b", "c"]);
// We could also use
// $stopWatch->addWatch("a");
// $stopWatch->addWatch("b");
// $stopWatch->addWatch("c");

$operatorA = 0;
$operatorB = 0;
$operatorC = 0;

for ($i = 1; $i <= 10; $i++) {
    // Following code block represent one operation, which needs to be measured.
    $stopWatch->start("a");
    for ($a = 0; $a < 10000; $a++) {
        $operatorA++;
    }
    $stopWatch->pause("a");

    // Following code block represent another operation, which needs to be measured separately.
    $stopWatch->start("b");
    for ($b = 0; $b < 10000; $b++) {
        $operatorB++;
    }
    $stopWatch->pause("b");

    // One more operation, independent of above operations needs to be measured.
    $stopWatch->start("c");
    for ($c = 0; $c < 10000; $c++) {
        $operatorC++;
    }
    $stopWatch->pause("c");
}

printf("Time taken in block 'a': %f seconds.\n", $stopWatch->getTime("a"));
printf("Time taken in block 'b': %f seconds.\n", $stopWatch->getTime("b"));
printf("Time taken in block 'c': %f seconds.\n", $stopWatch->getTime("c"));