用C实现PHP扩展类的步骤

前面简单介绍了用C语言实现PHP扩展的步骤，见用C开发PHP扩展的步骤，那个是扩展一个函数，这里讲述一下如何用C扩展类。

准备实现的类如下：

[php]
class Rectangle{
    private $_width;
    private $_height;
    public function __construct($width, $height){
        $this->_width = $width;
        $this->_height = $height;
    }
    public function clone(){
        return new Rectangle($this->_width, $this->_height);
    }
    public function setWidth($width){
        $this->_width = $width;
    }
    public function setHeight($height){
        $this->_height = $height;
    }
    public function getWidth(){
        return $this->_width;
    }
    public function getHeight(){
        return $this->_height;
    }
    public function getArea(){
        return $this->_width * $this->_height;
    }
    public function getCircle(){
        return ($this->_width + $this->_height) * 2;
    }
}

实现类扩展的步骤如下：（首先下载PHP源码，这里使用的是php-5.2.8）

1，建立扩展骨架

[php]
cd php-5.2.8/ext
./ext_skel --extname=class_ext

2，修改编译参数
[php]
cd php-5.2.8/ext/class_ext
vi config.m4
去掉PHP_ARG_ENABLE(class_ext, whether to enable class_ext support,和
[ --enable-class_ext Enable class_ext support])两行前面的dnl，修改后为：

[php]
dnl Otherwise use enable:
PHP_ARG_ENABLE(class_ext, whether to enable class_ext support,
dnl Make sure that the comment is aligned:
[ --enable-class_ext           Enable class_ext support])

3，编写C代码

[php]
cd php-5.2.8/ext/class_ext
vi php_class_ext.h
#在 PHP_FUNCTION(confirm_class_ext_compiled); 后面增加申明函数;

[php]
PHP_METHOD(Rectangle,__construct);
PHP_METHOD(Rectangle,clone);
PHP_METHOD(Rectangle,setWidth);
PHP_METHOD(Rectangle,setHeight);
PHP_METHOD(Rectangle,getWidth);
PHP_METHOD(Rectangle,getHeight);
PHP_METHOD(Rectangle,getArea);
PHP_METHDO(Rectangle,getCircle);

[php]
vi class_ext.c
#申明方法的参数，注册到函数表中

[php]
ZEND_BEGIN_ARG_INFO(arg_construct,2)
ZEND_ARG_INFO(0, width)
ZEND_ARG_INFO(0, height)
ZEND_END_ARG_INFO()

ZEND_BEGIN_ARG_INFO(arg_set_width,1)
ZEND_ARG_INFO(0, width)
ZEND_END_ARG_INFO()

ZEND_BEGIN_ARG_INFO(arg_set_height,1)
ZEND_ARG_INFO(0, height)
ZEND_END_ARG_INFO()

const zend_function_entry class_ext_functions[] = {
    PHP_FE(confirm_class_ext_compiled, NULL)
    PHP_ME(Rectangle, __construct, arg_construct, ZEND_ACC_CTOR|ZEND_ACC_PUBLIC)
    PHP_ME(Rectangle, clone, NULL, ZEND_ACC_PUBLIC)
    PHP_ME(Rectangle, setWidth, NULL, ZEND_ACC_PUBLIC)
    PHP_ME(Rectangle, setHeight, NULL, ZEND_ACC_PUBLIC)
    PHP_ME(Rectangle, getWidth, NULL, ZEND_ACC_PUBLIC)
    PHP_ME(Rectangle, getHeight, NULL, ZEND_ACC_PUBLIC)
    PHP_ME(Rectangle, getArea, NULL, ZEND_ACC_PUBLIC)
    PHP_ME(Rectangle, getCircle, NULL, ZEND_ACC_PUBLIC)
    {NULL, NULL, NULL} /* Must be the last line in class_ext_functions[] */
};
[php]
#其中ZEND_ACC_CTOR表示构造函数，ZEND_ACC_PUBLIC表示访问权限为PUBLIC。
[php]
#接下来，在模块初始化函数中注册并初始化类

[php]
zend_class_entry *Rectangle_ce; //zend内部类结构变量
PHP_MINIT_FUNCTION(class_ext)
{
    zend_class_entry Rectangle;
    INIT_CLASS_ENTRY(Rectanble, "Rectangle", class_ext_functions); //第二个参数为类名，第三个参数为类的函数列表
    Rectangle_ce = zend_register_internal_class_ex(&Rectangle, NULL, NULL TSRMLS_CC); //注册类
    zend_declare_property_null(Rectangle_ce, ZEND_STRL("_width"), ZEND_ACC_PRIVATE TSRMLS_CC); //初始化类的属性_width
    zend_declare_property_null(Rectangle_ce, ZEND_STRL("_height"), ZEND_ACC_PRIVATE TSRMLS_CC); //初始化类的属性_height
    return SUCCESS;
}
[php]
#在文件最后增加类的成员函数的具体实现代码
[php]
PHP_METHOD(Rectangle, __construct)
{
    long width,height;
    if(zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "ll", &width, &height) == FAILURE){ //获取构造函数的两个函数参数_width和_height
        WRONG_PARAM_COUNT;
    }
    if( width <= 0 ) {
        width = 1; //如果_width为0，则赋默认值1
    }
    if( height <= 0 ) {
        height = 1; //如果_height为0，则赋默认值1
    }
    zend_update_property_long(Z_OBJCE_P(getThis()), getThis(), ZEND_STRL("_width"), width TSRMLS_CC); //更新类成员变量_width的值
    zend_update_property_long(Z_OBJCE_P(getThis()), getThis(), ZEND_STRL("_height"), height TSRMLS_CC); //更新类成员变量_height的值
    RETURN_TRUE;
}

PHP_METHOD(Rectangle, clone)
{
    zval *clone_obj;
    zval *width,*height;
    MAKE_STD_ZVAL(clone_obj);
    object_init_ex(clone_obj, Rectangle_ce); //初始化对象，对象所属的类为Rectangle_ce
    width = zend_read_property(Z_OBJCE_P(getThis()), getThis(), ZEND_STRL("_width"), 0 TSRMLS_CC); //获取类成员变量_width的值
    height = zend_read_property(Z_OBJCE_P(getThis()), getThis(), ZEND_STRL("_height"), 0 TSRMLS_CC); //获取类成员变量_height的值
    zend_update_property_long(Z_OBJCE_P(getThis()), getThis(), ZEND_STRL("_width"), width TSRMLS_CC); //更新Rectangle_ce类对象clone_obj的属性值_width
    zend_update_property_lo

补充：Web开发 , php ,