/**
* {@inheritdoc}
*/
public function replace($key, $value, $expire = 0)
{
$ttl = $this->ttl($expire);
/*
* Negative ttl behavior isn't properly documented & doesn't always
* appear to treat the value as non-existing. Let's play safe and just
* delete it right away!
*/
if ($ttl < 0) {
return $this->delete($key);
}
/*
* Redis supports passing set() an extended options array since >=2.6.12
* which allows for an easy and 1-request way to replace a value.
* That version already comes with Ubuntu 14.04. Ubuntu 12.04 (still
* widely used and in LTS) comes with an older version, however, so I
* want to support that too.
* Supporting both versions comes at a cost.
* I'll optimize for recent versions, which will get (in case of replace
* failure) 1 additional network request (for version info). Older
* versions will get 2 additional network requests: a failed replace
* (because the options are unknown) & a version check.
*/
if ($this->version === null || $this->supportsOptionsArray()) {
$options = array('xx');
if ($ttl > 0) {
/*
* Not adding 0 TTL to options:
* * HHVM (used to) interpret(s) wrongly & throw an exception
* * it's not needed anyway, for 0...
* @see https://github.com/facebook/hhvm/pull/4833
*/
$options['ex'] = $ttl;
}
// either we support options array or we haven't yet checked, in
// which case I'll assume a recent server is running
$result = $this->client->set($key, $value, $options);
if ($result !== false) {
return $result;
}
if ($this->supportsOptionsArray()) {
// failed execution, but not because our Redis version is too old
return false;
}
}
// workaround for old Redis versions
$this->client->watch($key);
$exists = $this->client->exists('key');
if (!$exists) {
/*
* HHVM Redis only got unwatch recently
* @see https://github.com/asgrim/hhvm/commit/bf5a259cece5df8a7617133c85043608d1ad5316
*/
if (method_exists($this->client, 'unwatch')) {
$this->client->unwatch();
} else {
// this should also kill the watch...
$this->client->multi()->discard();
}
return false;
}
// since we're watching the key, this will fail should it change in the
// meantime
$this->client->multi();
$this->client->set($key, $value, $ttl);
/** @var bool[] $return */
$return = (array) $this->client->exec();
return !in_array(false, $return);
}
