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.
We now have a base test case class for Predis (namely PredisTestCase)
grouping various commonly used utility methods shared by all of the
tests in the suite, greatly improving reusability.
Supporting this feature has been problematic and leaded to some ugly
code to make abstractions such as pipelines and transactions aware of
these kind of response objects. Furthermore, it was not possible to
add them to all the connection classes due to implementation limits.
For such reasons Predis do not support them globally anymore, but the
actual classes are still shipped within the library so that they can
be used to build custom stuff at a level lower than client (that is,
unless we decide to remove them for good before going stable).
This cannot be implemented for previous versions of PHP because we
need socket_import_stream() to extract the underlying socket resource
from the stream in order to be able to set the TCP_NODELAY flag.
Daniele Alessandri