[转]自己写PHP扩展之创建一个类，php一个类

原文：http://www.imsiren.com/archives/572

比如我们要创建一个类..PHP代码如下

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 class Person { public $name; public $age; public function __construct() { echo "construct is running! "; } public function __destruct() { echo " destruct is running!"; } public function getproperty($key) { echo $this->$key; } public function setproperty($key,$val) { $this->$key = $val; } }

用PHP来做,很简单..
那么用PHP扩展来写该怎么做?
OK.
1.在php_siren.h里面声明类

1 2 3 4 PHP_METHOD(Person,__construct); PHP_METHOD(Person,__destruct); PHP_METHOD(Person,setproperty); PHP_METHOD(Person,getproperty);

PHP_METHOD宏.
PHP_METHOD 等于ZEND_METHOD
这个宏接受两个参数,第一个是类名,第二个是类的方法

1 2 3 4 #define ZEND_METHOD(classname, name) ZEND_NAMED_FUNCTION(ZEND_MN(classname##_##name)) #define INTERNAL_FUNCTION_PARAMETERS int ht, zval *return_value, zval **return_value_ptr, zval *this_ptr, int return_v alue_used TSRMLS_DC //最后等于 void name(int ht, zval *return_value, zval **return_value_ptr, zval *this_ptr, int return_v alue_used TSRMLS_DC )

这个宏是用来声明我们的方法…
2.设置接收的参数
我们的方法如果需要接受参数.那么就要执行

1 2 3 ZEND_BEGIN_ARG_INFO_EX(arg_person_info,0,0,2) ZEND_ARG_INFO(0,name) ZEND_END_ARG_INFO()

详细讲这几个宏之前先看看zend_arg_info

1 2 3 4 5 6 7 8 9 10 11 typedef struct _zend_arg_info { const char *name; //参数名称 zend_uint name_len;//长度 const char *class_name; //所属类名 zend_uint class_name_len; //类名长度 zend_bool array_type_hint; zend_bool allow_null; //允许为空 zend_bool pass_by_reference; //引用传值 zend_bool return_reference; //引用返回 int required_num_args; //参数个数 } zend_arg_info;

ZEND_BEGIN_ARG_INFO_EX定义在Zend/zend_API.h

1 2 3 #define ZEND_BEGIN_ARG_INFO_EX(name, pass_rest_by_reference, return_reference, required_num_args) \ static const zend_arg_info name[] = { \ { NULL, 0, NULL, 0, 0, 0, pass_rest_by_reference, return_reference, required_num_args },

很明显声明一个zend_arg_info的数组name,然后初始化结构体的值
ZEND_ARG_INFO(0,name)的定义如下

1	`#define ZEND_ARG_INFO(pass_by_ref, name) { #name, sizeof(#name)-1, NULL, 0, 0, 0, pass_by_ref, 0, 0 },`

这三个宏执行代码等于

1 2 3 static const zend_arg_info name[] = { { NULL, 0, NULL, 0, 0, 0, pass_rest_by_reference, return_reference, required_num_args }, { #name, sizeof(#name)-1, NULL, 0, 0, 0, pass_by_ref, 0, 0 }, };

3.创建zend_function_entry结构数组

1 2 3 4 5 6 7 const zend_function_entry person_functions[]={ PHP_ME(Person,__construct,NULL,ZEND_ACC_PUBLIC|ZEND_ACC_CTOR) PHP_ME(Person,__destruct,NULL,ZEND_ACC_PUBLIC|ZEND_ACC_DTOR) PHP_ME(Person,getproperty,arg_person_info,ZEND_ACC_PUBLIC) PHP_ME(Person,setproperty,arg_person_info,ZEND_ACC_PUBLIC) PHP_FE_END };

zend_function_entry定义如下

1 2 3 4 5 6 7 typedef struct _zend_function_entry { const char *fname; //函数名称 void (*handler)(INTERNAL_FUNCTION_PARAMETERS); const struct _zend_arg_info *arg_info;//参数 zend_uint num_args;//参数个数 zend_uint flags;//标示PUBLIC ?PRIVATE ?PROTECTED } zend_function_entry;

PHP_ME宏接收四个参数
1 类名,
2 方法名,
3 zend_arg_info 的参数列表,

ZEND_ACC_PUBLIC ZEND_ACC_PRIVATE ZEND_ACC_PROTECTED是我们类里面的三个访问权限
ZEND_ACC_CTOR标示构造函数
ZEND_ACC_DTOR标示析构函数
4.修改PHP_MINIT_FUNCTION
前面我们说过 PHP_MINIT_FUNCTION是在模块启动的时候执行的函数
首先创建一个全局指针 zend_class_entry *person_ce;
在PHP_MINIT_FUNCTION加入如下代码

1 2 3 4 zend_class_entry person; INIT_CLASS_ENTRY(person,"Person",person_functions); person_ce=zend_register_internal_class_ex(&person,NULL,NULL TSRMLS_CC); zend_declare_property_null(person_ce,ZEND_STRL("name"),ZEND_ACC_PUBLIC TSRMLS_CC);

1行创建一个zend_class_entry对象person.
zend_class_entry这个结构体前面也讲过 PHP内核研究之类的实现
2行初始化zend_class_entry 它执行了如下代码

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 { \ int _len = class_name_len; \ class_container.name = zend_strndup(class_name, _len); \ class_container.name_length = _len; \ class_container.builtin_functions = functions; \ class_container.constructor = NULL; \ class_container.destructor = NULL; \ class_container.clone = NULL; \ class_container.serialize = NULL; \ class_container.unserialize = NULL; \ class_container.create_object = NULL; \ class_container.interface_gets_implemented = NULL; \ class_container.get_static_method = NULL; \ class_container.__call = handle_fcall; \ class_container.__callstatic = NULL; \ class_container.__tostring = NULL; \ class_container.__get = handle_propget; \ class_container.__set = handle_propset; \ class_container.__unset = handle_propunset; \ class_container.__isset = handle_propisset; \ class_container.serialize_func = NULL; \ class_container.unserialize_func = NULL; \ class_container.serialize = NULL; \ class_container.unserialize = NULL; \ class_container.parent = NULL; \ class_container.num_interfaces = 0; \ class_container.interfaces = NULL; \ class_container.get_iterator = NULL; \ class_container.iterator_funcs.funcs = NULL; \ class_container.module = NULL; \ }

可以对应文章>> PHP内核研究之类的实现来分析
zend_declare_property_null(person_ce,ZEND_STRL(“name”),ZEND_ACC_PUBLIC TSRMLS_CC);
创建一个值为NULL的属性
第一个参数是类名,第二个参数是属性名称,第三个参数是属性名的长度,因为ZEND_STRL宏定义了长度,所以这里不用再传递长度.
第四个参数是属性的访问权限.
还有其他几个函数用来创建不同类型的属性

1 2 3 4 5 6 7 zend_declare_property_bool zend_declare_property_double zend_declare_property_ex zend_declare_property_long zend_declare_property_null zend_declare_property_string zend_declare_property_stringl

5.创建 php_siren.h头文件中的方法体

1 2 3 4 5 6 7 8 9 10 11 12 PHP_METHOD(Person,__construct){ php_printf("construct is running "); } PHP_METHOD(Person,__destruct){ php_printf("destruct is running "); } PHP_METHOD(Person,setproperty){ } PHP_METHOD(Person,getproperty){ }