The main reason behind that code duplication was performance related
as we tried to reduce method calls when possible, even at the cost of
falling into the realm of early optimizations. Apparently we just lose
~400 req/sec on a 21000 req/sec basis ("SET foo bar") using PHP 5.5.3
(packaged by Ubuntu 13.10) on an Intel Q6600, so we will most likely
stick with this change for the sake of best practices.
Backported from v0.9-dev.
Client::pubSub() still works like usual by returning a new pub/sub
context, but it is now considered an alias of Client::pubSubLoop().
This change is necessary in preparation for the next major version
of Predis where Client::pubSub() will be used for the new PUBSUB
command introduced in Redis 2.8.
Previously the getClientFor() method in a subclass of Predis\Client
returned an instance of Predis\Client instead of a new instance of
the subclass. The new behaviour is more correct.
Connection classes should just handle, convert and return simple Redis
types while parsing and transforming structured replies should be done
by consumers (see Predis\Client or Predis\Transaction\MultiExecContext).
This actually makes more sense considering that parsing a complex response
with the associated command parser may require different actions. As an
example, the result of EXEC is a multibulk that holds the actual responses,
so we really need to parse each one of its elements and we should also
make sure that iterable multibulks are consumed. We already did that
previously, but it was weird knowing that command parsers were applied
by the connection class.
This also moves some duplicated logic away from each connection class
implementation which is a nice bonus.
When no server profile is specified, the connection factory will not push
any initialization command to the newly created connection object.
This change is mainly useful when using redis-cluster and also makes it
possible to easily inject commands such as "SCRIPT LOAD" at initialization
time by grouping everything into one common place simply by extending the
connection factory class.
Now Predis\Command\ScriptedCommand uses EVALSHA instead of EVAL internally
so that performances should be better since the client do not resend the
Lua script body on each call.
Plain EVALSHA commands are not affected and will return or throw the error.
The "throw_errors" connection parameter has been removed and replaced by the
new "exceptions" client option since exceptions on -ERR replies returned by
Redis are not generated by connection classes anymore but are thrown by the
client class and other abstractions such as pipeline contexts.
This change does not affect much people using the Predis\Client class (aside
from the different configuration) but gives much more flexibility to those
building their own pieces of code around the internal classes of Predis.
Now developers can pass a client object or an executable context (see
Predis\Transaction\MultiExecContext or Predis\Pipeline\PipelineContext)
interchangeably as parameters to their methods using the new interface
Predis\BasicCliantInterface.
These new interfaces will also allow us to easily create new client
classes aside from the standard Predis\Client one.
The reason for this change is that not every cluster implementation can support
this behaviour, think of Redis cluster for example. We moved the implementation
of this method in Predis\Connection\PredisCluster since it can still be useful.
Previously it was possible to create a new instance of Predis\Client using
the alias of a single connection in a cluster of connections. Now we added
the ability to do this also when using master/slave replication.
Daniele Alessandri
Alexandru Patranescu
Ondrej -onovy- Novy