让我们来看看这个类和方法:
class Test {
protected $storage;
public function rng() {
$random = random_bytes(100);
$this->storage = $random;
}
}
使用PHP7的random_bytes()函数计算一些随机字节,并且不返回结果;它只存储在一个属性中。
让我们看一下上述方法略有不同的版本:
class Test {
protected $storage;
public function rng() {
$random = random_bytes(100);
$this->storage = $random;
return $random;
}
}
这次,返回结果。我想知道在返回值时是否有任何性能损失。
答案 0 :(得分:3)
测试脚本#1:不返回值
<?php
class Test {
protected $storage;
public function rng() {
$random = random_bytes(100);
$this->storage = $random;
}
}
$instance = new Test;
$start = microtime(true);
for ($i = 0; $i < 10000; $i++) {
$instance->rng();
}
$end = microtime(true);
$diff = $end - $start;
printf('Not returning: %.25f', $diff);
print PHP_EOL;
测试脚本#2:返回值
<?php
class Test {
protected $storage;
public function rng() {
$random = random_bytes(100);
$this->storage = $random;
return $random;
}
}
$instance = new Test;
$start = microtime(true);
for ($i = 0; $i < 10000; $i++) {
$instance->rng();
}
$end = microtime(true);
$diff = $end - $start;
printf('Returning: %.25f', $diff);
print PHP_EOL;
结果:
$ php -f functions-returning-values-benchmark.php
Not returning: 0.0937850475311279296875000
$ php -f functions-returning-values-benchmark.php
Not returning: 0.0939409732818603515625000
$ php -f functions-returning-values-benchmark.php
Not returning: 0.0953028202056884765625000
$ php -f functions-returning-values-benchmark.php
Returning: 0.0947949886322021484375000
$ php -f functions-returning-values-benchmark.php
Returning: 0.0930099487304687500000000
$ php -f functions-returning-values-benchmark.php
Returning: 0.0935621261596679687500000
没有性能受损。
在运行PHP 7.0.7的AWS Debian Jessie t2.micro实例(1vCore,1 GiB RAM)上测试。