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.
Daniele Alessandri