php内核之数组

1、zend_hash_num_elements 获取数组元素个数。宏定义如下：

#define zend_hash_num_elements(ht) 
    (ht)->nNumOfElements

2、ZEND_HASH_FOREACH_KEY_VAL 遍历数组键值。使用方法：

ZEND_HASH_FOREACH_KEY_VAL(Z_ARRVAL_P(array), num_key, string_key, entry) {
            // code
} ZEND_HASH_FOREACH_END();

　ZEND_HASH_FOREACH_KEY_VAL是个宏函数：

#define ZEND_HASH_FOREACH_KEY_VAL(ht, _h, _key, _val) 
    ZEND_HASH_FOREACH(ht, 0); 
    _h = _p->h; 
    _key = _p->key; 
    _val = _z;

　  继续展开 ZEND_HASH_FOREACH：

#define ZEND_HASH_FOREACH(_ht, indirect) do { 
        Bucket *_p = (_ht)->arData; 
        Bucket *_end = _p + (_ht)->nNumUsed; 
        for (; _p != _end; _p++) { 
            zval *_z = &_p->val; 
            if (indirect && Z_TYPE_P(_z) == IS_INDIRECT) { 
                _z = Z_INDIRECT_P(_z); 
            } 
            if (UNEXPECTED(Z_TYPE_P(_z) == IS_UNDEF)) continue;

ZEND_HASH_FOREACH_END展开：

#define ZEND_HASH_FOREACH_END() 
        } 
    } while (0)

  

ZEND_HASH_FOREACH_KEY_VAL(Z_ARRVAL_P(array), num_key, string_key, entry) {
             // code
} ZEND_HASH_FOREACH_END();
完全展开：

do { 
    Bucket *_p = (_ht)->arData;  // Z_ARRVAL_P(array) ---> ht ---> _ht
    Bucket *_end = _p + (_ht)->nNumUsed;  // 起始地址+偏移地址
    for (; _p != _end; _p++) { 
        zval *_z = &_p->val; 
        if (indirect && Z_TYPE_P(_z) == IS_INDIRECT) { 
            _z = Z_INDIRECT_P(_z); 
        } 
        if (UNEXPECTED(Z_TYPE_P(_z) == IS_UNDEF)) continue;
        _h = _p->h;  // zend_ulong num_key ---> _h
        _key = _p->key; // zend_string *string_key ---> _key
        _val = _z; // zval *entry ---> _val
        {
           //code
        } 
    } 
} while (0)