CakeFest 2024: The Official CakePHP Conference

PHP 回调

可以将 PHP 闭包分配给函数指针类型的原生变量,或将其作为函数参数传递。

<?php
$zend
= FFI::cdef("
typedef int (*zend_write_func_t)(const char *str, size_t str_length);
extern zend_write_func_t zend_write;
"
);

echo
"Hello World 1!\n";

$orig_zend_write = clone $zend->zend_write;
$zend->zend_write = function($str, $len) {
global
$orig_zend_write;
$orig_zend_write("{\n\t", 3);
$ret = $orig_zend_write($str, $len);
$orig_zend_write("}\n", 2);
return
$ret;
};
echo
"Hello World 2!\n";
$zend->zend_write = $orig_zend_write;
echo
"Hello World 3!\n";
?>

以上示例会输出:

Hello World 1!
{
        Hello World 2!
}
Hello World 3!
虽然这样可以运行,但并非所有的 libffi 平台都支持这个功能,而且效率不高,并且在请求结束时会泄漏资源。
小技巧

因此,建议尽量减少使用 PHP 回调函数。

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