stream_socket_client() has the undocumented ability to open different persistent
streams by providing a path in the $address string. Previously we supported this
behaviour with a combination of "persistent" and "path" (see #139) but this can
be confusing, especially now that we support the redis:// scheme which uses the
path part of an URI string to specify a database number.
After this change, instead of using an URI string such as:
$parameters = 'tcp://127.0.0.1/first?persistent=1&database=5';
You should use the following ones:
$parameters = 'tcp://127.0.0.1?persistent=first&database=5';
$parameters = 'redis://127.0.0.1/5?persistent=first';
Avoiding "path" makes even more sense when using array connection parameters:
$parameters = [
'host' => '127.0.0.1',
'database' => 5,
'persistent' => 'first',
]
This feature is not supported when using UNIX domain sockets because the path
trick of stream_socket_client() does not play well with the actual path of the
socket file. The client will throw an InvalidArgumentException exception to
notify the user.
NOTE: unfortunately we have to disable the tests for persistent connections when
running under HHVM due to a bug in their implementation of get_resource_type()
preventing us to recognize a persistent stream from userland code.
The base abstract connection class now returns a bool to indicate when
the actual connect() operation has been performed on the underlying
resource. This return value is not part of the interface so extending
classes can decide to not return any value.
Status response objects are needed mostly to make it possible from the
client perspective to differentiate a status response with the payload
"OK" from a normale bulk reply containing "OK".
The biggest change is for commands returning +OK responses: these were
previously translated to TRUE (bool value), but they are now returned
as instances of Predis\Response\Status. Just to illustrate an example
of the possibilities with this change we will use SET since it is the
most widely used command returning +OK:
$response = $client->set('foo', 'bar');
echo $response; // 'OK'
$response == 'OK'; // TRUE
isset($response->ok); // TRUE
$response == true; // TRUE
$response === true; // FALSE
$response instanceof Predis\Response\ObjectInterface; // TRUE
$response instanceof Predis\Response\Status; // TRUE
For those checking responses returned by commands such as SET or PONG,
the breaking change basically lies in the usage of strict comparison:
doing $response === true will now evaluate to FALSE instead of TRUE.
By default Predis caches common status responses such as OK or QUEUED
to lower the memory usage when using pipelines or transactions.
Daniele Alessandri