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');

?>