php内核之数组

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

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

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

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

　ZEND_HASH_FOREACH_KEY_VAL是个宏函数：

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

　继续展开 ZEND_HASH_FOREACH：

1 #define ZEND_HASH_FOREACH(_ht, indirect) do { 
2         Bucket *_p = (_ht)->arData; 
3         Bucket *_end = _p + (_ht)->nNumUsed; 
4         for (; _p != _end; _p++) { 
5             zval *_z = &_p->val; 
6             if (indirect && Z_TYPE_P(_z) == IS_INDIRECT) { 
7                 _z = Z_INDIRECT_P(_z); 
8             } 
9             if (UNEXPECTED(Z_TYPE_P(_z) == IS_UNDEF)) continue;

ZEND_HASH_FOREACH_END展开：

1 #define ZEND_HASH_FOREACH_END() 
2         } 
3     } 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：

 1 do { 
 2     Bucket *_p = (_ht)->arData;  // Z_ARRVAL_P(array) ---> ht ---> _ht
 3     Bucket *_end = _p + (_ht)->nNumUsed;  // 起始地址+偏移地址
 4     for (; _p != _end; _p++) { 
 5         zval *_z = &_p->val; 
 6         if (indirect && Z_TYPE_P(_z) == IS_INDIRECT) { 
 7             _z = Z_INDIRECT_P(_z); 
 8         } 
 9         if (UNEXPECTED(Z_TYPE_P(_z) == IS_UNDEF)) continue;
10         _h = _p->h;  // zend_ulong num_key ---> _h
11         _key = _p->key; // zend_string *string_key ---> _key
12         _val = _z; // zval *entry ---> _val
13         {
14            //code
15         } 
16     } 
17 } while (0)