php内置函数分析array_count_values()

PHP_FUNCTION(array_count_values)
{
    zval    *input,        /* Input array */ 
            *entry,        /* An entry in the input array */
            *tmp;
    HashTable *myht;

    if (zend_parse_parameters(ZEND_NUM_ARGS(), "a", &input) == FAILURE) {
        return;
    }

    /* Initialize return array */
    array_init(return_value);

    /* Go through input array and add values to the return array */
    myht = Z_ARRVAL_P(input);
    // 循环遍历数组
    ZEND_HASH_FOREACH_VAL(myht, entry) {
        ZVAL_DEREF(entry);
        /* 数组元素的值只能是字符串或整数 */
        if (Z_TYPE_P(entry) == IS_LONG) { // 数组元素值为整数
            if ((tmp = zend_hash_index_find(Z_ARRVAL_P(return_value), Z_LVAL_P(entry))) == NULL) { // 返回数组中不存在该键
                zval data;
                ZVAL_LONG(&data, 1); // 首次出现，+1
                zend_hash_index_update(Z_ARRVAL_P(return_value), Z_LVAL_P(entry), &data); // 添加到返回值数组
            } else {
                Z_LVAL_P(tmp)++; // 元素值出现次数+1
            }
        } else if (Z_TYPE_P(entry) == IS_STRING) { // 数组元素值为字符串
            if ((tmp = zend_symtable_find(Z_ARRVAL_P(return_value), Z_STR_P(entry))) == NULL) {
                zval data;
                ZVAL_LONG(&data, 1);
                zend_symtable_update(Z_ARRVAL_P(return_value), Z_STR_P(entry), &data);
            } else {
                Z_LVAL_P(tmp)++;
            }
        } else {
            // 数组元素的值非字符串或整数，则报warning错误。
            php_error_docref(NULL, E_WARNING, "Can only count STRING and INTEGER values!");
        }
    } ZEND_HASH_FOREACH_END();
}