NAME¶
AnyEvent::Redis - Non-blocking Redis client
SYNOPSIS¶
use AnyEvent::Redis;
my $redis = AnyEvent::Redis->new(
host => '127.0.0.1',
port => 6379,
encoding => 'utf8',
on_error => sub { warn @_ },
on_cleanup => sub { warn "Connection closed: @_" },
);
# callback based
$redis->set( 'foo'=> 'bar', sub { warn "SET!" } );
$redis->get( 'foo', sub { my $value = shift } );
my ($key, $value) = ('list_key', 123);
$redis->lpush( $key, $value );
$redis->lpop( $key, sub { my $value = shift });
# condvar based
my $cv = $redis->lpop( $key );
$cv->cb(sub { my $value = $_[0]->recv });
DESCRIPTION¶
AnyEvent::Redis is a non-blocking (event-driven) Redis client.
This module is an AnyEvent user; you must install and use a supported event
loop.
ESTABLISHING A CONNECTION¶
To create a new connection, use the
new() method with the following
attributes:
- host => <HOSTNAME>
- Required. The hostname or literal address of the server.
- port => <PORT>
- Optional. The server port.
- encoding => <ENCODING>
- Optional. Encode and decode data (when storing and retrieving,
respectively) according to ENCODING ("utf8" is
recommended or see Encode::Supported for details on possible
ENCODING values).
Omit if you intend to handle raw binary data with this connection.
- on_error => $cb->($errmsg)
- Optional. Callback that will be fired if a connection or database-level
error occurs. The error message will be passed to the callback as the sole
argument.
- on_cleanup => $cb->($errmsg)
- Optional. Callback that will be fired if a connection error occurs. The
error message will be passed to the callback as the sole argument. After
this callback, errors will be reported for all outstanding requests.
METHODS¶
All methods supported by your version of Redis should be supported.
Normal commands¶
There are two alternative approaches for handling results from commands:
- •
- AnyEvent::CondVar based:
my $cv = $redis->command(
# arguments to command
);
# Then...
my $res;
eval {
# Could die()
$res = $cv->recv;
};
warn $@ if $@;
# or...
$cv->cb(sub {
my ($cv) = @_;
my ($result, $err) = $cv->recv
});
- •
- Callback:
$redis->command(
# arguments,
sub {
my ($result, $err) = @_;
});
(Callback is a wrapper around the $cv approach.)
Transactions (MULTI/EXEC)¶
Redis transactions begin with a "multi" command and end with an
"exec" command. Commands in between are not executed immediately
when they're sent. On receipt of the "exec", the server executes all
the saved commands atomically, and returns all their results as one bulk
reply.
After a transaction is finished, results for each individual command are
reported in the usual way. Thus, by the time any of these callbacks is called,
the entire transaction is finished for better or worse.
Results of the "exec" (containing all the other results) will be
returned as an array reference containing all of the individual results. This
may in some cases make callbacks on the individual commands unnecessary, or
vice versa. In this bulk reply, errors reported for each individual command
are represented by objects of class "AnyEvent::Redis::Error", which
will respond to a "->message" method call with that error
message.
It is not permitted to nest transactions. This module does not permit
subscription-related commands in a transaction.
Subscriptions¶
The subscription methods ("subscribe" and "psubscribe") must
be used with a callback:
my $cv = $redis->subscribe("test", sub {
my ($message, $channel[, $actual_channel]) = @_;
# ($actual_channel is provided for pattern subscriptions.)
});
The $cv condition will be met on unsubscribing from the channel.
Due to limitations of the Redis protocol the only valid commands on a connection
with an active subscription are subscribe and unsubscribe commands.
Common methods¶
- •
- get
- •
- set
- •
- hset
- •
- hget
- •
- lpush
- •
- lpop
The Redis command reference (<
http://redis.io/commands>) lists all
commands Redis supports.
REQUIREMENTS¶
This requires Redis >= 1.2.
COPYRIGHT¶
Tatsuhiko Miyagawa <miyagawa@bulknews.net> 2009-
LICENSE¶
This library is free software; you can redistribute it and/or modify it under
the same terms as Perl itself.
AUTHORS¶
Tatsuhiko Miyagawa
David Leadbeater
Chia-liang Kao
franck cuny
Lee Aylward
Joshua Barratt
Jeremy Zawodny
Leon Brocard
Michael S. Fischer
Chip Salzenberg
SEE ALSO¶
Redis, AnyEvent