PHP7 cas doesn't work

[bolknote]

Last php70-php-pecl-memcached.x86_64 from remi70 (3.0.0-dev):

$m = new \Memcached();
$m->addServer('127.0.0.1', 11211);

$m->delete('cas_test');
$cas_token = null;
$m->set('cas_test', 10);
$v = $m->get('cas_test', null, $cas_token);

var_dump($cas_token); // NULL
var_dump($v); // 10

var_dump($m->getResultCode()); // 10 (MEMCACHED_SERVER_ERROR)

$m->getDelayed(['cas_test'], true);
var_dump($m->fetchAll()[0]['cas']); // int(1057)

I think you should use 'gets' instead of 'get' if we ask cas token.

[TysonAndre]

It seems as though the CAS param was omitted from the PHP7 implementation. cas_token was passed to zend_parse_parameters in php_memc_get_impl in php5, but not in php7.

In php5 (with CAS return value): https://github.com/php-memcached-dev/php-memcached/blob/master/php_memcached.c#L570

/* {{{ -- php_memc_get_impl */
static void php_memc_get_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_key)
{
    char *key = NULL;
    int key_len = 0;
    char *server_key = NULL;
    int   server_key_len = 0;
    uint32_t flags = 0;
    uint64_t cas = 0;
    zval *cas_token = NULL;
    zval *udf_flags = NULL;
    zend_fcall_info fci = empty_fcall_info;
    zend_fcall_info_cache fcc = empty_fcall_info_cache;
    // other vars omitted

    if (by_key) {
        if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "ss|f!zz", &server_key,
                                  &server_key_len, &key, &key_len, &fci, &fcc, &cas_token, &udf_flags) == FAILURE) {
            return;
        }
    } else {
        if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s|f!zz", &key, &key_len,
                                  &fci, &fcc, &cas_token, &udf_flags) == FAILURE) {
            return;
        }
    }

In php7 (without CAS return value): https://github.com/php-memcached-dev/php-memcached/blob/php7/php_memcached.c#L1386

static
void php_memc_get_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_key)
{
    php_memc_get_ctx_t context = {};
    php_memc_keys_t keys = {0}; 
    zend_long get_flags = 0; 
    zend_string *key;
    zend_string *server_key = NULL;
    zend_bool mget_status;
    memcached_return status = MEMCACHED_SUCCESS;
    zend_fcall_info fci = empty_fcall_info;
    zend_fcall_info_cache fcc = empty_fcall_info_cache;
    MEMC_METHOD_INIT_VARS;

    if (by_key) {
        if (zend_parse_parameters(ZEND_NUM_ARGS(), "SS|f!l", &server_key, &key, &fci, &fcc, &get_flags) == FAILURE) {
            return;
        }
    } else {
        if (zend_parse_parameters(ZEND_NUM_ARGS(), "S|f!l", &key, &fci, &fcc, &get_flags) == FAILURE) {
            return;
        }
    }   

[TysonAndre]

Oh. This was mentioned in #214 (comment) .
They suggest using Memcached::GET_EXTENDED.

The API docs would need to be updated for get() as well.
See #229

[TysonAndre]

@bolknote , I assume you'd need to use something like this in any library that needs to work in multiple memcached versions. Not sure if this is completely correct, tell me if there are bugs.

<?php
/**
 * Utilities to deal with Memcached API breaking changes in 3.0 in Memcached->get() and Memcached->getMulti().
 * TODO getMulti
 */
class MemcachedUtil {
    /**
     * Returns data stored in cache at $key.
     *
     * @param Memcached $m
     * @param string $key
     * @param callable|null $v (Must be null for now, see https://github.com/php-memcached-dev/php-memcached/issues/248 )
     * @param int|string &$token token for CAS(returned by reference)
     * @return mixed|false the value in memcached, or false
     */
    public static function get_with_token($m, $key, $v = null, &$token = null) {
        if ($v !== null) {
             throw new Exception("Providing read-through callback may or may not have bugs in php7");
        }
        if (self::does_get_return_cas_by_reference($m)) {
            return $m->get($key, $v, $token);
        } else {
            // $values has fields value, cas, and flags
            $values = $m->get($key, $v, Memcached::GET_EXTENDED);
            if (is_array($values)) {
                $token = $values['cas'];
                return $values['value'];
            }
            return false;
        }
    }

    /**
     * @param Memcached $m
     * @return boolean Do get() and getMulti() return $token by reference, or do you have to pass Memcached::GET_EXTENDED as a bit flag in that position instead.
     */
    public static function does_get_return_cas_by_reference($m) {
        // TODO Logic for handling mocks
        static $returnsReference;
        if ($returnsReference === null) {
            // memcached < 3.0.0a1 (approx) returns the CAS token by reference.
            $returnsReference = version_compare(phpversion("memcached"), '3.0.0a1', '<');
        }
        return $returnsReference;
    }
}

EDIT: version_compare was in the wrong order

[bolknote]

Thank you! It works!