PHP源代码数组统计count分析

//文件4：ext/standard/array.c
PHP_FUNCTION(count)
{
zval *array;
long mode = COUNT_NORMAL;

if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "z|l", &array, &mode) == FAILURE) {
return;
}

switch (Z_TYPE_P(array)) {
case IS_NULL:
RETURN_LONG(0);
break;
case IS_ARRAY:
RETURN_LONG (php_count_recursive (array, mode TSRMLS_CC));
break;
.....

//php_count_recursive的实现
static int php_count_recursive(zval *array, long mode TSRMLS_DC) /* {{{ */
{
long cnt = 0;
zval **element;

if (Z_TYPE_P(array) == IS_ARRAY) {
//错误处理
if (Z_ARRVAL_P(array)->nApplyCount > 1) {
php_error_docref(NULL TSRMLS_CC, E_WARNING, "recursion detected");
return 0;
}
//通过zend_hash_num_elements直接获得长度
cnt = zend_hash_num_elements(Z_ARRVAL_P(array));

//如果指定了需要重新统计，则会进入一次循环统计
if (mode == COUNT_RECURSIVE) {
HashPosition pos;

for (zend_hash_internal_pointer_reset_ex(Z_ARRVAL_P(array), &pos);
zend_hash_get_current_data_ex(Z_ARRVAL_P(array), (void **) &element, &pos) == SUCCESS;
zend_hash_move_forward_ex(Z_ARRVAL_P(array), &pos)
) {
Z_ARRVAL_P(array)->nApplyCount++;
cnt += php_count_recursive(*element, COUNT_RECURSIVE TSRMLS_CC);
Z_ARRVAL_P(array)->nApplyCount--;
}
}
}

return cnt;
}

//文件5：zend/zend_hash.c
//zend_hash_num_elements的实现
ZEND_API int zend_hash_num_elements(const HashTable *ht)
{
IS_CONSISTENT(ht);

return ht->nNumOfElements;
}