NAME
AnyEvent::Redis::RipeRedis - Flexible non-blocking Redis client with reconnect feature
SYNOPSIS
use AnyEvent;
use AnyEvent::Redis::RipeRedis qw( :err_codes );
my $cv = AE::cv();
my $redis = AnyEvent::Redis::RipeRedis->new(
host => 'localhost',
port => '6379',
password => 'your_password',
encoding => 'utf8',
on_connect => sub {
print "Connected to Redis server\n";
},
on_disconnect => sub {
print "Disconnected from Redis server\n";
},
on_error => sub {
my $err_msg = shift;
my $err_code = shift;
warn "$err_msg. Error code: $err_code\n";
},
);
# Set value
$redis->set( 'foo', 'Some string', {
on_done => sub {
print "SET is done\n";
$cv->send();
},
on_error => sub {
my $err_msg = shift;
my $err_code = shift;
$cv->croak( "$err_msg. Error code: $err_code" );
}
} );
$cv->recv();
$redis->disconnect();
DESCRIPTION
AnyEvent::Redis::RipeRedis is the flexible non-blocking Redis client with reconnect feature. The client supports subscriptions, transactions and connection via UNIX-socket.
Requires Redis 1.2 or higher, and any supported event loop.
CONSTRUCTOR
new()
my $redis = AnyEvent::Redis::RipeRedis->new(
host => 'localhost',
port => '6379',
password => 'your_password',
database => 7,
lazy => 1,
connection_timeout => 5,
read_timeout => 5,
reconnect => 1,
encoding => 'utf8',
on_connect => sub {
print "Connected to Redis server\n";
},
on_disconnect => sub {
print "Disconnected from Redis server\n";
},
on_connect_error => sub {
my $err_msg = shift;
warn "$err_msg\n";
},
on_error => sub {
my $err_msg = shift;
my $err_code = shift;
warn "$err_msg. Error code: $err_code\n";
},
);
- host
-
Server hostname (default: 127.0.0.1)
- port
-
Server port (default: 6379)
- password
-
Authentication password. If the password is specified, then the
AUTH
command will be send immediately to the server after a connection and after every reconnection. - database
-
Database index. If the index is specified, then client will be switched to the specified database immediately after a connection and after every reconnection.
The default database index is
0
. - connection_timeout
-
If after this timeout the client could not connect to the server, the callback
on_error
is called with the error codeE_CANT_CONN
. The timeout must be specified in seconds and can contain a fractional part.my $redis = AnyEvent::Redis::RipeRedis->new( connection_timeout => 10.5, );
By default the client use kernel's connection timeout.
- read_timeout
-
If after this timeout the client do not received a response from the server to any command, the callback
on_error
is called with the error codeE_READ_TIMEDOUT
. The timeout must be specified in seconds and can contain a fractional part.my $redis = AnyEvent::Redis::RipeRedis->new( read_timeout => 0.5, );
Not set by default.
- lazy
-
If this parameter is set, then the connection will be established, when you will send the first command to the server. By default the connection establishes after calling of the method
new
. - reconnect
-
If the connection to the Redis server was lost and the parameter 'reconnect' is TRUE, then the client try to restore the connection, when executing a next command. The client try to reconnect only once and if it fails, then is called the
on_error
callback. If you need several attempts of the reconnection, just retry a command from theon_error
callback as many times, as you need. This feature made the client more responsive.By default is TRUE.
- encoding
-
Used for encode/decode strings during input/output operations.
Not set by default.
- on_connect => $cb->()
-
The callback
on_connect
is called, when the connection is successfully established.Not set by default.
- on_disconnect => $cb->()
-
The callback
on_disconnect
is called, when the connection is closed by any reason.Not set by default.
- on_connect_error => $cb->( $err_msg )
-
The callback
on_connect_error
is called, when the connection could not be established. If this collback isn't specified, then theon_error
callback is called with the error codeE_CANT_CONN
.Not set by default.
- on_error => $cb->( $err_msg, $err_code )
-
The callback
on_error
is called, if any error occurred. If the callback is not set, the client just print an error message toSTDERR
.
COMMAND EXECUTION
<command>( [ @args[, \%callbacks ] ] )
The full list of the Redis commands can be found here: http://redis.io/commands.
# Set value
$redis->set( 'foo', 'Some string' );
# Increment
$redis->incr( 'bar', {
on_done => sub {
my $data = shift;
print "$data\n";
},
} );
# Get list of values
$redis->lrange( 'list', 0, -1, {
on_done => sub {
my $data = shift;
foreach my $val ( @{$data} ) {
print "$val\n";
}
},
on_error => sub {
my $err_msg = shift;
my $err_code = shift;
$cv->croak( "$err_msg. Error code: $err_code" );
},
} );
- on_done => $cb->( [ $data ] )
-
The callback
on_done
is called, when the current operation is done. - on_error => $cb->( $err_msg, $err_code )
-
The callback
on_error
is called, if any error occurred. If the callback is not set, then theon_error
callback, that was specified in constructor, is called.
TRANSACTIONS
The detailed information abount the Redis transactions can be found here: http://redis.io/topics/transactions.
multi( [ \%callbacks ] )
Marks the start of a transaction block. Subsequent commands will be queued for atomic execution using EXEC
.
exec( [ \%callbacks ] )
Executes all previously queued commands in a transaction and restores the connection state to normal. When using WATCH
, EXEC
will execute commands only if the watched keys were not modified.
discard( [ \%callbacks ] )
Flushes all previously queued commands in a transaction and restores the connection state to normal.
If WATCH
was used, DISCARD
unwatches all keys.
watch( @keys[, \%callbacks ] )
Marks the given keys to be watched for conditional execution of a transaction.
unwatch( [ \%callbacks ] )
Forget about all watched keys.
SUBSCRIPTIONS
The detailed information about Redis Pub/Sub can be found here: http://redis.io/topics/pubsub
subscribe( @channels[, \%callbacks ] )
Subscribes the client to the specified channels.
Once the client enters the subscribed state it is not supposed to issue any other commands, except for additional SUBSCRIBE
, PSUBSCRIBE
, UNSUBSCRIBE
and PUNSUBSCRIBE
commands.
$redis->subscribe( qw( ch_foo ch_bar ), {
on_done => sub {
my $ch_name = shift;
my $subs_num = shift;
print "Subscribed: $ch_name. Active: $subs_num\n";
},
on_message => sub {
my $ch_name = shift;
my $msg = shift;
print "$ch_name: $msg\n";
},
on_error => sub {
my $err_msg = shift;
my $err_code = shift;
$cv->croak( "$err_msg. Error code: $err_code" );
},
} );
- on_done => $cb->( $ch_name, $sub_num )
-
The callback
on_done
is called, when the current subscription operation is done. - on_message => $cb->( $ch_name, $msg )
-
The callback
on_message
is called, when a published message is received. - on_error => $cb->( $err_msg, $err_code )
-
The callback
on_error
is called, if the subscription operation fails. If the callback is not set, then theon_error
callback, that was specified in constructor, is called.
psubscribe( @patterns[, \%callbacks ] )
Subscribes the client to the given patterns.
$redis->psubscribe( qw( info_* err_* ), {
on_done => sub {
my $ch_pattern = shift;
my $subs_num = shift;
print "Subscribed: $ch_pattern. Active: $subs_num\n";
},
on_message => sub {
my $ch_name = shift;
my $msg = shift;
my $ch_pattern = shift;
print "$ch_name ($ch_pattern): $msg\n";
},
on_error => sub {
my $err_msg = shift;
my $err_code = shift;
$cv->croak( "$err_msg. Error code: $err_code" );
},
} );
- on_done => $cb->( $ch_pattern, $sub_num )
-
The callback
on_done
is called, when the current subscription operation is done. - on_message => $cb->( $ch_name, $msg, $ch_pattern )
-
The callback
on_message
is called, when published message is received. - on_error => $cb->( $err_msg, $err_code )
-
The callback
on_error
is called, if the subscription operation fails. If the callback is not set, then theon_error
callback, that was specified in constructor, is called.
publish( $channel, $message[, \%callbacks ] )
Posts a message to the given channel.
unsubscribe( [ @channels ][, \%callbacks ] )
Unsubscribes the client from the given channels, or from all of them if none is given.
When no channels are specified, the client is unsubscribed from all the previously subscribed channels. In this case, a message for every unsubscribed channel will be sent to the client.
punsubscribe( [ @patterns ][, \%callbacks ] )
Unsubscribes the client from the given patterns, or from all of them if none is given.
When no patters are specified, the client is unsubscribed from all the previously subscribed patterns. In this case, a message for every unsubscribed pattern will be sent to the client.
CONNECTION VIA UNIX-SOCKET
Redis 2.2 and higher support connection via UNIX domain socket. To connect via a UNIX-socket in the parameter host
you have to specify unix/
, and in the parameter port
you have to specify the path to the socket.
my $redis = AnyEvent::Redis::RipeRedis->new(
host => 'unix/',
port => '/tmp/redis.sock',
);
LUA SCRIPTS EXECUTION
Redis 2.6 and higher support execution of Lua scripts on the server side. To execute a Lua script you can use one of the commands EVAL
or EVALSHA
, or you can use the special method eval_cached()
.
eval_cached( $script, $numkeys[, [ @keys, ][ @args, ]\%callbacks ] );
When you call the eval_cached()
method, the client first generate a SHA1 hash for a Lua script and cache it in memory. Then the client optimistically send the EVALSHA
command under the hood. If the NO_SCRIPT
error will be returned, the client send the EVAL
command.
If you call the eval_cached()
method with the same Lua script, client don't generate a SHA1 hash for this script repeatedly, it gets a hash from the cache.
$redis->eval_cached( 'return { KEYS[1], KEYS[2], ARGV[1], ARGV[2] }',
2, 'key1', 'key2', 'first', 'second', {
on_done => sub {
my $data = shift;
foreach my $val ( @{$data} ) {
print "$val\n";
}
}
} );
ERROR CODES
Every time when the calback on_error
is called, the current error code passed to it in the second argument. Error codes can be used for programmatic handling of errors.
AnyEvent::Redis::RipeRedis provides constants of error codes, that can be imported and used in expressions.
use AnyEvent::Redis::RipeRedis qw( :err_codes );
Error codes and constants corresponding to them:
1 - E_CANT_CONN
2 - E_LOADING_DATASET
3 - E_IO
4 - E_CONN_CLOSED_BY_REMOTE_HOST
5 - E_CONN_CLOSED_BY_CLIENT
6 - E_NO_CONN
9 - E_OPRN_ERROR
10 - E_UNEXPECTED_DATA
11 - E_NO_SCRIPT
12 - E_READ_TIMEDOUT
- E_CANT_CONN
-
Can't connect to the server. If this error occurred, the client abort all operations.
- E_LOADING_DATASET
-
Redis is loading the dataset in memory.
- E_IO
-
Input/Output operation error. If this error occurred, the client abort all operations and close the connection.
- E_CONN_CLOSED_BY_REMOTE_HOST
-
The connection closed by remote host. If this error occurred, the client abort all operations.
- E_CONN_CLOSED_BY_CLIENT
-
If in the client queue are uncompleted operations, when application calling method
disconnect()
or executing commandQUIT
, the client abort them with this error. - E_NO_CONN
-
No connection to the server. Error occurs, if at time of a command execution the connection has been closed by any reason and the parameter
reconnect
was set to FALSE. - E_OPRN_ERROR
-
Operation error. Usually returned by the the Redis server.
- E_UNEXPECTED_DATA
-
The client received unexpected data from the server. If this error occurred, the client abort all operations and close the connection.
- E_NO_SCRIPT
-
No matching script. Use the
EVAL
command. - E_READ_TIMEDOUT
-
Read timed out. If this error occurred, the client abort all operations and close the connection.
DISCONNECTION
When the connection to the server is no longer needed you can close it in three ways: call the method disconnect()
, send the QUIT
command or you can just "forget" any references to an AnyEvent::Redis::RipeRedis object, but in this case a client object is destroyed silently without calling any callbacks including the on_disconnect
callback to avoid an unexpected behavior.
disconnect()
The method for synchronous disconnection.
$redis->disconnect();
OTHER METHODS
connection_timeout( $seconds )
Get, set or reset to default the connection_timeout
of the client.
read_timeout( $seconds )
Get, set or disable the read_timeout
of the client.
reconnect( $boolean )
Enable or disable reconnection mode of the client.
encoding( $enc_name )
Get, set or disable the encoding
.
on_connect( $callback )
Get, set or disable the on_connect
callback.
on_disconnect( $callback )
Get, set or disable the on_disconnect
callback.
on_connect_error( $callback )
Get, set or disable the on_connect_error
callback.
on_error( $callback )
Get, set or disable the on_error
callback.
SEE ALSO
AnyEvent, AnyEvent::Redis, Redis, Redis::hiredis, RedisDB
AUTHOR
Eugene Ponizovsky, <ponizovsky@gmail.com>
Special thanks
Alexey Shrub
Vadim Vlasov
Konstantin Uvarin
COPYRIGHT AND LICENSE
Copyright (c) 2012-2013, Eugene Ponizovsky, <ponizovsky@gmail.com>. All rights reserved.
This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.