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.
By raw we mean that input arguments are not filtered and responses are
not parsed, which means arguments must follow the command signature as
defined by Redis and complex responses are left untouched.
When instantiating an instance of `Predis\Command\RawCommand` you must
pass at least the command ID. You can pass further arguments in the
array or you can just set them later with `RawCommand::setArguments()`
but you cannot modify the command ID once instantiated.
$command = new Predis\Command\RawCommand(['SET', 'foo', 'bar']);
$response = $client->executeCommand($command);
While higher level abstractions built upon `Predis\Client` should just
use commands created by the profile in use, inner parts of the library
might use raw commands to provide certain functionalities making sure
that input and output of commands are always consistent, independent
of the profile.
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".
It was too broad in concept and not really that useful, so for now we
assume that only our base Predis\Profile\RedisProfile class can handle
command processing and we will decide later if we want to add a couple
of more methods to Predis\Profile\ProfileInterface.
While command classes define how the client should filter arguments or
parse responses, key prefixing depends on the actual command signature
as defined by Redis so it really is something that should be handled
separately as the norm.
Developers can define new handlers or override existing ones, but they
can still define the key prefixing logic inside their command classes
by implementing Predis\Command\PrefixableCommandInterface: the key
prefix processor will just use that by overriding any defined handler.
One test is currently marked as skipped because it makes
Redis crash when the specified MATCH pattern returns one
or more elements.
See http://redis.io/commands/scan for reference.
One test is currently marked as skipped because it makes
Redis crash when the specified MATCH pattern returns one
or more elements.
See http://redis.io/commands/scan for reference.
Actually this was already the case for certain commands, but some of them
was left unguarded for such cases. This commit also fixes#109.
The behaviour of silently skipping key prefixing when a command has no
arguments may change in the future so we added explicit tests as guards
for future changes. Predis\Command\Processor\KeyPrefixProcessor will
continue to skip key prefixing on empty arguments, regardless.
This method should have been part of the interface since start since
it is used through the library. We also do not specify a default value
for the index argument since it does not make much sense.
We previously used FALSE for that but in the end it does not make much
sense. Luckily for us this does not represent a breaking change since
existing code will keep to work, so we can safely push this change into
the next patch release.
Multibulk response iterators will not be passed anymore to the response
parser method of the command that generated the response. Pipeline and
transaction abstractions still consume interators returned as response
items.
This should make things a tiny bit faster (we are speaking about micro
optimizations anyway) but more importantly it results in a better
encapsulation.
This is needed because redis-cluster does not support the same commands
or operations that can be performed with our client-side managed predis
cluster.
For example redis-cluster does not support key tagging (that is, parts
of a key enclosed by {...} to hash only that specific part of a key)
and multiple-key operations suchs as MGET, MSET, SDIFF, SUNION or SINTER.
Some multiple-key operations can be performed anyway if the command has
only one key (e.g. "MGET foo" and "MSET foo bar" will not fail).
The reason for this change is to support the upcoming redis-cluster since
it has different behaviors compared to the client-side cluster implementation
provided by Predis. For example redis-cluster will not support key tags or
certain operations currently available with our client-side implementation.
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.
With a negative number Predis will count from the end of the arguments list
to calculate the actual number of keys that will be interpreted as elements
for `KEYS` by the underlying `EVAL` command.
Daniele Alessandri
Raphael Stolt