The previous implementation was not good because we were exposing in the
public API an internal implementation detail of the base factory class,
furthermore it made Predis\Command\Factory::define() confusing. Having a
separate method to undefine commands in the factory is self-explanatory.
We also changed `Predis\Configuration\Option\Commands` accordingly when
a dictionary of $commandID => $classCommand is passed to the "commands"
client option and $classCommand is NULL.
A few minor changes (mostly cosmetic or documentation) were applied too.
From feedback to PR #644.
This change does not affect distribution but simply separates the two
concepts of connection ID (ip:port pair) and alias (value set via the
"alias" connection parameter), the method getConnectionByAlias() has
been added to reflect this change.
The method getConnectionBySlot() has also been added.
When using replication backends, now the role of a connection is not
defined by its alias but by the new connection parameter "role" that
can be set to "master", "slave" and (for redis-sentinel) "sentinel".
This also led to a redesign of how connections can be retrieved from
replication backends: the method getConnectionById() now retrieves a
connection only by its ID (ip:port pair), to get a connection by its
alias there is the new method getConnectionByAlias(). This method is
not supported by the redis-sentinel backend due to its dynamic nature
(connections are retrieved and initialized at runtime from sentinels)
but it is still possible to get a single connection from the pool by
using its ID. It is also possible to retrive a connection by its role
using the method getConnectionByRole().
NOTE: the "role" parameter is an hint for the internals of aggregate
connection backends so it is still possible that the actual role of
a connection changes during the execution of a script (e.g. a slave
gets promoted to the role of master): in this case the parameters of
that connection will not be changed as they are immutable, but the
method getConnectionByRole() will return the appropriate connection.
Predis\Client::getClientBy() has been updated with the addition of
"role" and "alias" as supported selectors.
This method improves the previous one, which worked only by picking a
connection by ID, allowing users to specify a selector type among the
following ones: "id", "key", "slot", "command". These selectors are
expanded internally to methods, invoked against the connection object
in use by the client, that follow the getConnectionByXXX() convention
already in use through the library:
id => getConnectionById()
key => getConnectionByKey()
slot => getConnectionBySlot()
command => getConnectionByCommand()
The underlying connection does not necessarily need to implement the
aggregate connection interface as the client relies on a duck-typing
approach by using method_exists().
This new method acts exactly like "getClientFor()" by returning a new
client instance for the specified node unless a callback is passed as
the second argument, in this case the callback is invoked and the new
client instance is passed to it. The value returned by the callback
is used as the return value of the "on()" method.
All option classes have been moved in the Predis\Configuration\Option
namespace and some have been optimized to have less impact on client
initialization timings.
Furthermore the accepted values for some options have been changed,
this is the complete list of accepted values:
- _aggregate_: callable returning an aggregate connection.
- cluster: string value ("predis", "redis"), callable returning an
aggregate connection.
- replication: string value ("predis", "sentinel"), callable returning
an aggregate connection.
- commands: command factory, named array mapping command IDs to PHP
classes, callable returning a command factory or a named array.
- connections: connection factory, callable returning a connection
factory, named array mapping connection schemes to PHP classes.
- _prefix_: string value, command processor, callable.
- _exceptions_: boolean value.
Note that the cluster and replication options now return a closure
acting as initializer instead of an aggregate connection.
This change reduces some unnecessary complexity in the library, Redis
commands do not change much after all. Developers can still implement
their own commands factory, inject new commands or override existing
ones. The "profile" client options has been renamed to "commands" and
it accepts instances of Predis\Command\FactoryInterface.
The test suite checks at runtime the version of the running instance
of Redis for integration tests to adapt itself automatically.
* Renamed SingleConnectionInterface to NodeConnectionInterface since
this name is better and makes even more sense in the context of
cluster and replication scenarios.
* Moved specialized aggregate connections (the ones implementing both
predis and redis cluster and master/slave replication) in a newly
created Predis\Connection\Aggregate sub-namespace.
* Removed the "Connection" part from names of aggregate connection
interfaces in the Predis\Connection\Aggregate sub-namespace.
* Changed "Composable" to "Composite" in the name of interfaces and
classes that can use pluggable protocol processors.
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.
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.
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.
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.
We also changed our wording to indentify this kind of abstraction so
instead of using "scripted commands" (kind of broken English) we now
use "scriptable commands".
We also changed some options for this class, the accepted ones are:
- "keys": string or array of strings for automatic WATCH.
- "cas": sets the check-and-set mode.
- "retry": number of attempts before giving up aborted transactions.
- "exceptions": sets whether exceptions should be thrown on error
responses (overrides the "exceptions" client option).
The "on_retry" option has been removed.
Only two options available for now, used to specify which kind of
pipeline object the client should use or return:
- "atomic": returns a pipeline wrapped in a MULTI / EXEC transaction
(class: Predis\Pipeline\Atomic).
- "fire-and-forget": returns a pipeline that does not read back
responses from the server (class: Predis\Pipeline\FireAndForget).
We might add more options in the future.
First of all we completely removed the concept of pipeline executors.
Now pipelines can be easily customized by extending our default class
Predis\Pipeline\Pipeline.
Tests coverage for the Predis\Pipeline namespace is decent but can be
definitely improved while test cases can be beautified.
Daniele Alessandri
Raza Mehdi