深入PHP內核之面向對象總結

很久以前看過的，今天總結一下

一、PHP中創建一個類

在PHP中創建一個簡單的類是這樣的：

<?php

$obj = new test($url)

?>

二、zend_class_entry結構

zend_class_entry是內核中定義的一個結構體，是PHP中類與對象的基礎結構類型。

struct _zend_class_entry {

char type; // 類型：ZEND_INTERNAL_CLASS / ZEND_USER_CLASS

char *name;// 類名稱

zend_uint name_length; // 即sizeof(name) - 1

struct　_zend_class_entry *parent; // 繼承的父類

int　refcount; // 引用數

zend_bool constants_updated;

zend_uint ce_flags; // ZEND_ACC_IMPLICIT_ABSTRACT_CLASS: 類存在abstract方法

// ZEND_ACC_EXPLICIT_ABSTRACT_CLASS: 在類名稱前加了abstract關鍵字

// ZEND_ACC_FINAL_CLASS

// ZEND_ACC_INTERFACE

HashTable function_table; // 方法

HashTable default_properties; // 默認屬性

HashTable properties_info; // 屬性信息

HashTable default_static_members;// 類本身所具有的靜態變量

HashTable *static_members; // type == ZEND_USER_CLASS時，取&default_static_members;

// type == ZEND_INTERAL_CLASS時，設為NULL

HashTable constants_table; // 常量

struct _zend_function_entry *builtin_functions;// 方法定義入口

union _zend_function *constructor;

union _zend_function *destructor;

union _zend_function *clone;

/* 魔術方法 */

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

/* 類句柄 */

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);

/* 類聲明的接口 */

int(*interface_gets_implemented)(zend_class_entry *iface,

zend_class_entry *class_type TSRMLS_DC);

/* 序列化回調函數指針 */

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; // 類實現的接口

zend_uint num_interfaces; // 類實現的接口數

char *filename; // 類的存放文件地址 絕對地址

zend_uint line_start; // 類定義的開始行

zend_uint line_end; // 類定義的結束行

char *doc_comment;

zend_uint doc_comment_len;

struct _zend_module_entry *module; // 類所在的模塊入口：EG(current_module)

};

二、訪問控制

//fn_flags代表可以在定義方法時使用，zend_property_info.flags代表可以在定義屬性時使用，ce_flags代表在定義zend_class_entry時候可用

//ZEND_ACC_CTOR 構造函數掩碼 , ZEND_ACC_DTOR 析構函數掩碼

//ZEND_ACC_STATIC static函數掩碼

//ZEND_ACC_ABSTRACT abstract函數掩碼

#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、申明和更新類中的屬性

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);

動態添加屬性

#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);

內核中的定義

#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

//等價於

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; //參數名稱

zend_uint name_len;//長度

const char *class_name; //所屬類名

zend_uint class_name_len; //類名長度

zend_bool array_type_hint;

zend_bool allow_null; //允許為空

zend_bool pass_by_reference; //引用傳值

zend_bool return_reference; //引用返回

int required_num_args; //參數個數

} zend_arg_info;

接受參數.那麼就要執行　

ZEND_BEGIN_ARG_INFO(test___construct_arginfo, 0)

ZEND_ARG_INFO(0, url)

ZEND_END_ARG_INFO()

ZEND_BEGIN_ARG_INFO_EX定義在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)的定義如下

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

最終是這樣的

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、定義一個類

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標示構造函數

//ZEND_ACC_DTOR標示析構函數

3、PHP_MINIT_FUNCTION中初始化

PHP_MINIT_FUNCTION(test)

{

/*定義一個temp class*/

zend_class_entry ce;

/*初始化這個class，第二個參數是class name, 第三個參數是class methods*/

INIT_CLASS_ENTRY(ce, "test", test_methods);

/*注冊這個class到zend engine*/

test_ce = zend_register_internal_class(&ce TSRMLS_CC);

return SUCCESS;

}

4、定義參數

ZEND_BEGIN_ARG_INFO(test___construct_arginfo, 0)

ZEND_ARG_INFO(0, url)

ZEND_END_ARG_INFO()

5、具體方法

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中訪問

<?php

$c = new test('http://test.com');

?>