array_get
先来看看php的实现：
function array_get($array, $key, $default = null)
{
if (is_null($key)) {
return $array;
}
if (isset($array[$key])) {
return $array[$key];
}
foreach (explode('.', $key) as $segment) {
if (! is_array($array) || ! array_key_exists($segment, $array)) {
return value($default);
}
$array = $array[$segment];
}
return $array;
}
用扩展实现如下(没有考虑key为空的情况):
PHP_FUNCTION(array_get)
{
zval *arr; // array
zend_string* strkey; // key
zval *defaultval = NULL; // default value
zval *retval;
HashTable *arrHashTable;
zval *dest_entry;
if (zend_parse_parameters(ZEND_NUM_ARGS(), "zS|z", &arr, &strkey, &defaultval) == FAILURE) {
return;
}
if ((retval = zend_hash_find(Z_ARRVAL_P(arr), strkey)) != NULL){
RETURN_ZVAL(retval, 1, 0);
}
// foreach
if (zend_memrchr(ZSTR_VAL(strkey), '.', ZSTR_LEN(strkey))) {
char *entry, *ptr, *seg;
HashTable *target = Z_ARRVAL_P(arr);
entry = estrndup(ZSTR_VAL(strkey), ZSTR_LEN(strkey));
if ((seg = php_strtok_r(entry, ".", &ptr))) {
do {
if (target == NULL || (retval = zend_symtable_str_find(target, seg, strlen(seg))) == NULL) {
break;
}
if (Z_TYPE_P(retval) == IS_ARRAY) {
target = Z_ARRVAL_P(retval);
} else {
target = NULL;
}
} while ((seg = php_strtok_r(NULL, ".", &ptr)));
}
efree(entry);
if (retval) {
RETURN_ZVAL(retval, 1, 0);
}
}
// end foreach
if (defaultval) {
// 如果有默认值，则返回默认值
RETURN_ZVAL(defaultval, 1, 0);
} else {
RETURN_NULL();
}
}
近期评论