This is more consistent with Predis\Client::executeRaw() and its more
explicit since simply "raw" as a method name was a bit too vague even
despite being nicely short.
Using PHP's "parse_str()" to parse the query string is slightly more
efficient then our own code especially when the number of fields in
the query string grows, with the additional benefit of supporting
arrays for values when brackets are present in fieldnames.
So after this commit, providing this URI string:
$string = 'tcp://127.0.0.1?metavars[]=foo&metavars[]=hoge';
Is equivalent to providing the following named array:
$array = [
'scheme' => 'tcp',
'host' => '127.0.0.1',
'metavars' => ['foo', 'hoge'],
];
Aside from this improvement, the URI parsing behavior has not changed.
These parameters are applied only to connections being created on the
fly when not part of the current pool. This condition usually happens
upon -MOVE or -ASK responses returned by Redis to redirect client to
different nodes.
Only named arrays are explicitly accepted now, but the old behaviour
of creating a connection parameters instance out of an URI string or
a named array is still available using the "create()" static method.
$array = ['host' => '127.0.0.1', 'timeout' => 1];
$uri = 'tcp://127.0.0.1?timeout=1';
$parameters = new ConnectionParameters($array); // Arrays only
$parameters = ConnectionParameters::create($array); // Arrays OK
$parameters = ConnectionParameters::create($uri); // Strings OK
The purpose of the change is to have a more concise constructor with a
well defined signature.
List of changes:
- The cluster connection can be initialized with a partial list of
nodes, the full slots map will be fetched from Redis itself using
the CLUSTER NODES command.
- The slots map can be optionally retrieved from Redis if the server
returns a -MOVE response, otherwise only the interested slot will
be permanently reassigned to the new target node.
- $cluster->connect() connects to a random connection in the pool
instead of forcing the connect operation on all the connections.
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.
This optimization is mostly useful since connection parameters can be
instantiated more than one time in a script when using clustering or
replication.
A profile is not needed to create instances of basic initialization
commands such as AUTH (authentication) and SELECT (database selection)
since they do not need prefixing and other stuff.
If needed, developers can still extend the base connection factory to
make it use a server profile and configure the client to use it using
options.
When sending raw commands their arguments are not filtered, responses
are not parsed and key prefixes are not applied. The client also does
not throw any exception on Redis errors regardless of its settings.
The first parameter takes the raw arguments of the command (included
its identifier) as defined by the Redis documentation while the second
optional parameter is always populated by reference to indicate when
Redis actually returned an error response.
$client->raw(['PING']); // "PONG"
$client->raw(['SET','foo','bar']); // "OK"
$client->raw(['GET','foo'], $err); // "bar", $err=FALSE
$client->raw(['LPUSH','foo',1], $err); // "WRONGTYPE...", $err=TRUE
Internally, this method creates instances of Predis\Command\RawCommand
that get passed to the underlying connection instance for execution as
if they were usual commands defined by Predis.
Raw commands work in both cluster and replication scenarios since they
are recognized by their command ID, but key prefixing is not supported
since it is done by the profile instance when instantiating commands.
Daniele Alessandri