深入PHP内核之面向对象总结
很久以前看过的，今天总结一下
一、PHP中创建一个类
在PHP中创建一个简单的类是这样的：
<?php $obj = new test($url) ?>
二、zend_class_entry结构
zend_class_entry是内核中定义的一个结构体，是PHP中类与对象的基础结构类型。
struct _zend_class_entry {
char type; // 类型：ZEND_INTERNAL_CLASS / ZEND_USER_CLASS
char *name;// 类名称
zend_uint name_length; // 即sizeof(name) - 1
struct _zend_class_entry *parent; // 继承的父类
int refcount; // 引用数
zend_bool constants_updated;
zend_uint ce_flags; // ZEND_ACC_IMPLICIT_ABSTRACT_CLASS: 类存在abstract方法
// ZEND_ACC_EXPLICIT_ABSTRACT_CLASS: 在类名称前加了abstract关键字
// ZEND_ACC_FINAL_CLASS
// ZEND_ACC_INTERFACE
HashTable function_table; // 方法
HashTable default_properties; // 默认属性
HashTable properties_info; // 属性信息
HashTable default_static_members;// 类本身所具有的静态变量
HashTable *static_members; // type == ZEND_USER_CLASS时，取&default_static_members;
// type == ZEND_INTERAL_CLASS时，设为NULL
HashTable constants_table; // 常量
struct _zend_function_entry *builtin_functions;// 方法定义入口
union _zend_function *constructor;
union _zend_function *destructor;
union _zend_function *clone;
/* 魔术方法 */
union _zend_function *__get;
union _zend_function *__set;
union _zend_function *__unset;
union _zend_function *__isset;
union _zend_function *__call;
union _zend_function *__tostring;
union _zend_function *serialize_func;
union _zend_function *unserialize_func;
zend_class_iterator_funcs iterator_funcs;// 迭代
/* 类句柄 */
zend_object_value (*create_object)(zend_class_entry *class_type TSRMLS_DC);
zend_object_iterator *(*get_iterator)(zend_class_entry *ce, zval *object,
intby_ref TSRMLS_DC);
/* 类声明的接口 */
int(*interface_gets_implemented)(zend_class_entry *iface,
zend_class_entry *class_type TSRMLS_DC);
/* 序列化回调函数指针 */
int(*serialize)(zval *object， unsignedchar**buffer, zend_uint *buf_len,
zend_serialize_data *data TSRMLS_DC);
int(*unserialize)(zval **object, zend_class_entry *ce, constunsignedchar*buf,
zend_uint buf_len, zend_unserialize_data *data TSRMLS_DC);
zend_class_entry **interfaces; // 类实现的接口
zend_uint num_interfaces; // 类实现的接口数
char *filename; // 类的存放文件地址 绝对地址
zend_uint line_start; // 类定义的开始行
zend_uint line_end; // 类定义的结束行
char *doc_comment;
zend_uint doc_comment_len;
struct _zend_module_entry *module; // 类所在的模块入口：EG(current_module)
};
二、访问控制
//fn_flags代表可以在定义方法时使用，zend_property_info.flags代表可以在定义属性时使用，ce_flags代表在定义zend_class_entry时候可用 //ZEND_ACC_CTOR 构造函数掩码 , ZEND_ACC_DTOR 析构函数掩码 //ZEND_ACC_STATIC static函数掩码 //ZEND_ACC_ABSTRACT abstract函数掩码 #define ZEND_ACC_STATIC 0x01 /* fn_flags, zend_property_info.flags */ #define ZEND_ACC_ABSTRACT 0x02 /* fn_flags */ #define ZEND_ACC_FINAL 0x04 /* fn_flags */ #define ZEND_ACC_IMPLEMENTED_ABSTRACT 0x08 /* fn_flags */ #define ZEND_ACC_IMPLICIT_ABSTRACT_CLASS 0x10 /* ce_flags */ #define ZEND_ACC_EXPLICIT_ABSTRACT_CLASS 0x20 /* ce_flags */ #define ZEND_ACC_FINAL_CLASS 0x40 /* ce_flags */ #define ZEND_ACC_INTERFACE 0x80 /* ce_flags */ #define ZEND_ACC_INTERACTIVE 0x10 /* fn_flags */ #define ZEND_ACC_PUBLIC 0x100 /* fn_flags, zend_property_info.flags */ #define ZEND_ACC_PROTECTED 0x200 /* fn_flags, zend_property_info.flags */ #define ZEND_ACC_PRIVATE 0x400 /* fn_flags, zend_property_info.flags */ #define ZEND_ACC_PPP_MASK (ZEND_ACC_PUBLIC | ZEND_ACC_PROTECTED | ZEND_ACC_PRIVATE) #define ZEND_ACC_CHANGED 0x800 /* fn_flags, zend_property_info.flags */ #define ZEND_ACC_IMPLICIT_PUBLIC 0x1000 /* zend_property_info.flags; unused (1) */ #define ZEND_ACC_CTOR 0x2000 /* fn_flags */ #define ZEND_ACC_DTOR 0x4000 /* fn_flags */ #define ZEND_ACC_CLONE 0x8000 /* fn_flags */ #define ZEND_ACC_ALLOW_STATIC 0x10000 /* fn_flags */ #define ZEND_ACC_SHADOW 0x20000 /* fn_flags */ #define ZEND_ACC_DEPRECATED 0x40000 /* fn_flags */ #define ZEND_ACC_CLOSURE 0x100000 /* fn_flags */ #define ZEND_ACC_CALL_VIA_HANDLER 0x200000 /* fn_flags */
三、申明和更新类中的属性
ZEND_API int zend_declare_class_constant(zend_class_entry *ce, const char *name, size_t name_length, zval *value TSRMLS_DC); ZEND_API int zend_declare_class_constant_null(zend_class_entry *ce, const char *name, size_t name_length TSRMLS_DC); ZEND_API int zend_declare_class_constant_long(zend_class_entry *ce, const char *name, size_t name_length, long value TSRMLS_DC); ZEND_API int zend_declare_class_constant_bool(zend_class_entry *ce, const char *name, size_t name_length, zend_bool value TSRMLS_DC); ZEND_API int zend_declare_class_constant_double(zend_class_entry *ce, const char *name, size_t name_length, double value TSRMLS_DC); ZEND_API int zend_declare_class_constant_stringl(zend_class_entry *ce, const char *name, size_t name_length, const char *value, size_t value_length TSRMLS_DC); ZEND_API int zend_declare_class_constant_string(zend_class_entry *ce, const char *name, size_t name_length, const char *value TSRMLS_DC); ZEND_API void zend_update_property_null(zend_class_entry *scope, zval *object, char *name, int name_length TSRMLS_DC); ZEND_API void zend_update_property_bool(zend_class_entry *scope, zval *object, char *name, int name_length, long value TSRMLS_DC); ZEND_API void zend_update_property_long(zend_class_entry *scope, zval *object, char *name, int name_length, long value TSRMLS_DC); ZEND_API void zend_update_property_double(zend_class_entry *scope, zval *object, char *name, int name_length, double value TSRMLS_DC); ZEND_API void zend_update_property_string(zend_class_entry *scope, zval *object, char *name, int name_length, const char *value TSRMLS_DC); ZEND_API void zend_update_property_stringl(zend_class_entry *scope, zval *object, char *name, int name_length, const char *value, int value_length TSRMLS_DC); ZEND_API int zend_update_static_property_null(zend_class_entry *scope, char *name, int name_length TSRMLS_DC); ZEND_API int zend_update_static_property_bool(zend_class_entry *scope, char *name, int name_length, long value TSRMLS_DC); ZEND_API int zend_update_static_property_long(zend_class_entry *scope, char *name, int name_length, long value TSRMLS_DC); ZEND_API int zend_update_static_property_double(zend_class_entry *scope, char *name, int name_length, double value TSRMLS_DC); ZEND_API int zend_update_static_property_string(zend_class_entry *scope, char *name, int name_length, const char *value TSRMLS_DC); ZEND_API int zend_update_static_property_stringl(zend_class_entry *scope, char *name, int name_length, const char *value, int value_length TSRMLS_DC);
动态添加属性
#define add_property_long(__arg, __key, __n) add_property_long_ex(__arg, __key, strlen(__key)+1, __n TSRMLS_CC) #define add_property_null(__arg, __key) add_property_null_ex(__arg, __key, strlen(__key) + 1 TSRMLS_CC) #define add_property_bool(__arg, __key, __b) add_property_bool_ex(__arg, __key, strlen(__key)+1, __b TSRMLS_CC) #define add_property_resource(__arg, __key, __r) add_property_resource_ex(__arg, __key, strlen(__key)+1, __r TSRMLS_CC) #define add_property_double(__arg, __key, __d) add_property_double_ex(__arg, __key, strlen(__key)+1, __d TSRMLS_CC) #define add_property_string(__arg, __key, __str, __duplicate) add_property_string_ex(__arg, __key, strlen(__key)+1, __str, __duplicate TSRMLS_CC) #define add_property_stringl(__arg, __key, __str, __length, __duplicate) add_property_stringl_ex(__arg, __key, strlen(__key)+1, __str, __length, __duplicate TSRMLS_CC) #define add_property_zval(__arg, __key, __value) add_property_zval_ex(__arg, __key, strlen(__key)+1, __value TSRMLS_CC)
四、一些其它的宏
#define INIT_CLASS_ENTRY(class_container, class_name, functions) INIT_OVERLOADED_CLASS_ENTRY(class_container, class_name, functions, NULL, NULL, NULL)
#define INIT_OVERLOADED_CLASS_ENTRY(class_container, class_name, functions, handle_fcall, handle_propget, handle_propset) INIT_OVERLOADED_CLASS_ENTRY_EX(class_container, class_name, sizeof(class_name)-1, functions, handle_fcall, handle_propget, handle_propset, NULL, NULL)
define INIT_CLASS_ENTRY_EX(class_container, class_name, class_name_len, functions) INIT_OVERLOADED_CLASS_ENTRY_EX(class_container, class_name, class_name_len, functions, NULL, NULL, NULL, NULL, NULL)
define INIT_OVERLOADED_CLASS_ENTRY_EX(class_container, class_name, class_name_len, functions, handle_fcall, handle_propget, handle_propset, handle_propunset, handle_propisset) {
const char *cl_name = class_name;
int _len = class_name_len;
class_container.name = zend_new_interned_string(cl_name, _len+1, 0 TSRMLS_CC);
if (class_container.name == cl_name) {
class_container.name = zend_strndup(cl_name, _len);
}
class_container.name_length = _len;
INIT_CLASS_ENTRY_INIT_METHODS(class_container, functions, handle_fcall, handle_propget, handle_propset, handle_propunset, handle_propisset) \
}
#define INIT_CLASS_ENTRY_INIT_METHODS(class_container, functions, handle_fcall, handle_propget, handle_propset, handle_propunset, handle_propisset) {
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.traits = NULL;
class_container.num_traits = 0;
class_container.trait_aliases = NULL;
class_container.trait_precedences = NULL;
class_container.interfaces = NULL;
class_container.get_iterator = NULL;
class_container.iterator_funcs.funcs = NULL;
class_container.info.internal.module = NULL;
class_container.info.internal.builtin_functions = functions;
}
五、PHP_METHOD
PHP_METHOD(test,__construct); PHP_METHOD(test,__destruct); PHP_METHOD(test,setproperty); PHP_METHOD(test,getproperty);
内核中的定义
#define PHP_METHOD ZEND_METHOD #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 //等价于 void name(int ht, zval *return_value, zval **return_value_ptr, zval *this_ptr, int return_v alue_used TSRMLS_DC )
六、zend_arg_info
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;
接受参数.那么就要执行
ZEND_BEGIN_ARG_INFO(test___construct_arginfo, 0)
ZEND_ARG_INFO(0, url)
ZEND_END_ARG_INFO()
ZEND_BEGIN_ARG_INFO_EX定义在Zend/zend_API.h
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 },
ZEND_ARG_INFO(0,url)的定义如下
#define ZEND_ARG_INFO(pass_by_ref, name) { #name, sizeof(#name)-1, NULL, 0, 0, 0, pass_by_ref, 0, 0 },
最终是这样的
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 },
};
七、定义一个类
1、申明
static zend_class_entry *test_ce;
2、添加方法
const zend_function_entry test_methods[] = {
PHP_ME(test, __construct, test___construct_arginfo, ZEND_ACC_PUBLIC | ZEND_ACC_CTOR)
PHP_ME(test, __destruct, NULL, ZEND_ACC_PUBLIC | ZEND_ACC_DTOR)
PHP_ME(test, __toString, NULL, ZEND_ACC_PUBLIC)
PHP_ME(test, getMeta, NULL, ZEND_ACC_PUBLIC)
PHP_ME(test, setMeta, NULL, ZEND_ACC_PUBLIC)
{ NULL, NULL, NULL }
};
//ZEND_ACC_CTOR标示构造函数
//ZEND_ACC_DTOR标示析构函数
3、PHP_MINIT_FUNCTION中初始化
PHP_MINIT_FUNCTION(test)
{
/*定义一个temp class*/
zend_class_entry ce;
/*初始化这个class，第二个参数是class name, 第三个参数是class methods*/
INIT_CLASS_ENTRY(ce, "test", test_methods);
/*注册这个class到zend engine*/
test_ce = zend_register_internal_class(&ce TSRMLS_CC);
return SUCCESS;
}
4、定义参数
ZEND_BEGIN_ARG_INFO(test___construct_arginfo, 0)
ZEND_ARG_INFO(0, url)
ZEND_END_ARG_INFO()
5、具体方法
static PHP_METHOD(test, __construct) {
char *url;
int url_len;
if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s", &url, &url_len, &age) == FAILURE) {
return;
}
zval *obj;
obj = getThis();
zend_update_property_stringl(test_ce, obj, "url", sizeof("url") -1, url, url_len TSRMLS_CC);
}
6、在PHP中访问
<?php
$c = new test('http://test.com');
?>
可以参考的文章
http://www.phpinternalsbook.com/classes_objects/simple_classes.html
- 作者：踏雪无痕
- 出处：http://www.cnblogs.com/chenpingzhao/
- 本文版权归作者和博客园共有，如需转载，请联系 pingzhao1990#163.com
