Redis - Perl binding for Redis database
version 1.971
## Defaults to $ENV{REDIS_SERVER} or 127.0.0.1:6379 my $redis = Redis->new; my $redis = Redis->new(server => 'redis.example.com:8080'); ## Set the connection name (requires Redis 2.6.9) my $redis = Redis->new( server => 'redis.example.com:8080', name => 'my_connection_name', ); my $generation = 0; my $redis = Redis->new( server => 'redis.example.com:8080', name => sub { "cache-$$-".++$generation }, ); ## Use UNIX domain socket my $redis = Redis->new(sock => '/path/to/socket'); ## Enable auto-reconnect ## Try to reconnect every 1s up to 60 seconds until success ## Die if you can't after that my $redis = Redis->new(reconnect => 60); ## Try each 100ms upto 2 seconds (every is in milisecs) my $redis = Redis->new(reconnect => 2, every => 100); ## Enable connection timeout (in seconds) my $redis = Redis->new(cnx_timeout => 60); ## Enable read timeout (in seconds) my $redis = Redis->new(read_timeout => 0.5); ## Enable write timeout (in seconds) my $redis = Redis->new(write_timeout => 1.2); ## Use all the regular Redis commands, they all accept a list of ## arguments ## See http://redis.io/commands for full list $redis->get('key'); $redis->set('key' => 'value'); $redis->sort('list', 'DESC'); $redis->sort(qw{list LIMIT 0 5 ALPHA DESC}); ## Add a coderef argument to run a command in the background $redis->sort(qw{list LIMIT 0 5 ALPHA DESC}, sub { my ($reply, $error) = @_; die "Oops, got an error: $error\n" if defined $error; print "$_\n" for @$reply; }); long_computation(); $redis->wait_all_responses; ## or $redis->wait_one_response(); ## Or run a large batch of commands in a pipeline my %hash = _get_large_batch_of_commands(); $redis->hset('h', $_, $hash{$_}, sub {}) for keys %hash; $redis->wait_all_responses; ## Publish/Subscribe $redis->subscribe( 'topic_1', 'topic_2', sub { my ($message, $topic, $subscribed_topic) = @_ ## $subscribed_topic can be different from topic if ## you use psubscribe() with wildcards } ); $redis->psubscribe('nasdaq.*', sub {...}); ## Blocks and waits for messages, calls subscribe() callbacks ## ... forever my $timeout = 10; $redis->wait_for_messages($timeout) while 1; ## ... until some condition my $keep_going = 1; ## other code will set to false to quit $redis->wait_for_messages($timeout) while $keep_going; $redis->publish('topic_1', 'message');
Pure perl bindings for http://redis.io/
This version supports protocol 2.x (multi-bulk) or later of Redis available at https://github.com/antirez/redis/.
This documentation lists commands which are exercised in test suite, but additional commands will work correctly since protocol specifies enough information to support almost all commands with same piece of code with a little help of AUTOLOAD.
AUTOLOAD
Usually, running a command will wait for a response. However, if you're doing large numbers of requests, it can be more efficient to use what Redis calls pipelining: send multiple commands to Redis without waiting for a response, then wait for the responses that come in.
To use pipelining, add a coderef argument as the last argument to a command method call:
$r->set('foo', 'bar', sub {});
Pending responses to pipelined commands are processed in a single batch, as soon as at least one of the following conditions holds:
A non-pipelined (synchronous) command is called on the same connection
A pub/sub subscription command (one of subscribe, unsubscribe, psubscribe, or punsubscribe) is about to be called on the same connection.
subscribe
unsubscribe
psubscribe
punsubscribe
One of "wait_all_responses" or "wait_one_response" methods is called explicitly.
The coderef you supply to a pipelined command method is invoked once the response is available. It takes two arguments, $reply and $error. If $error is defined, it contains the text of an error reply sent by the Redis server. Otherwise, $reply is the non-error reply. For almost all commands, that means it's undef, or a defined but non-reference scalar, or an array ref of any of those; but see "keys", "info", and "exec".
$reply
$error
undef
Note the contrast with synchronous commands, which throw an exception on receipt of an error reply, or return a non-error reply directly.
The fact that pipelined commands never throw an exception can be particularly useful for Redis transactions; see "exec".
There is no encoding feature anymore, it has been deprecated and finally removed. This module consider that any data sent to the Redis server is a raw octets string, even if it has utf8 flag set. And it doesn't do anything when getting data from the Redis server.
So, do you pre-encoding or post-decoding operation yourself if needed !
my $r = Redis->new; # $ENV{REDIS_SERVER} or 127.0.0.1:6379 my $r = Redis->new( server => '192.168.0.1:6379', debug => 0 ); my $r = Redis->new( server => '192.168.0.1:6379', encoding => undef ); my $r = Redis->new( sock => '/path/to/sock' ); my $r = Redis->new( reconnect => 60, every => 5000 ); my $r = Redis->new( password => 'boo' ); my $r = Redis->new( on_connect => sub { my ($redis) = @_; ... } ); my $r = Redis->new( name => 'my_connection_name' ); my $r = Redis->new( name => sub { "cache-for-$$" });
The server parameter specifies the Redis server we should connect to, via TCP. Use the 'IP:PORT' format. If no server option is present, we will attempt to use the REDIS_SERVER environment variable. If neither of those options are present, it defaults to '127.0.0.1:6379'.
server
REDIS_SERVER
Alternatively you can use the sock parameter to specify the path of the UNIX domain socket where the Redis server is listening.
sock
The REDIS_SERVER can be used for UNIX domain sockets too. The following formats are supported:
/path/to/sock
unix:/path/to/sock
127.0.0.1:11011
tcp:127.0.0.1:11011
The reconnect option enables auto-reconnection mode. If we cannot connect to the Redis server, or if a network write fails, we enter retry mode. We will try a new connection every every milliseconds (1000ms by default), up-to reconnect seconds.
reconnect
every
Be aware that read errors will always thrown an exception, and will not trigger a retry until the new command is sent.
If we cannot re-establish a connection after reconnect seconds, an exception will be thrown.
The cnx_timeout option enables connection timeout. The Redis client will wait at most that number of seconds (can be fractional) before giving up connecting to a server.
cnx_timeout
The read_timeout option enables read timeout. The Redis client will wait at most that number of seconds (can be fractional) before giving up when reading from the server.
read_timeout
The write_timeout option enables write timeout. The Redis client will wait at most that number of seconds (can be fractional) before giving up when reading from the server.
write_timeout
If your Redis server requires authentication, you can use the password attribute. After each established connection (at the start or when reconnecting), the Redis AUTH command will be send to the server. If the password is wrong, an exception will be thrown and reconnect will be disabled.
password
AUTH
You can also provide a code reference that will be immediately after each successful connection. The on_connect attribute is used to provide the code reference, and it will be called with the first parameter being the Redis object.
on_connect
You can also provide no_auto_connect_on_new in which case new won't call $obj->connect for you implicitly, you'll have to do that yourself. This is useful for figuring out how long connection setup takes so you can configure the cnx_timeout appropriately.
no_auto_connect_on_new
new
$obj->connect
You can also set a name for each connection. This can be very useful for debugging purposes, using the CLIENT LIST command. To set a connection name, use the name parameter. You can use both a scalar value or a CodeRef. If the latter, it will be called after each connection, with the Redis object, and it should return the connection name to use. If it returns a undefined value, Redis will not set the connection name.
CLIENT LIST
name
Please note that there are restrictions on the name you can set, the most important of which is, no spaces. See the CLIENT SETNAME documentation for all the juicy details. This feature is safe to use with all versions of Redis servers. If CLIENT SETNAME support is not available (Redis servers 2.6.9 and above only), the name parameter is ignored.
CLIENT SETNAME
The debug parameter enables debug information to STDERR, including all interactions with the server. You can also enable debug with the REDIS_DEBUG environment variable.
debug
REDIS_DEBUG
$r->connect();
Connects to the Redis server. This is done by default when the obect is constructed using new(), unless no_auto_connect_on_new has been set. See this option in the new() constructor.
new()
$r->quit;
Closes the connection to the server. The quit method does not support pipelined operation.
quit
$r->ping || die "no server?";
The ping method does not support pipelined operation.
ping
@clients = $r->client_list;
Returns list of clients connected to the server. See CLIENT LIST documentation for a description of the fields and their meaning.
my $connection_name = $r->client_getname;
Returns the name associated with this connection. See "client_setname" or the name parameter to "new" for ways to set this name.
$r->client_setname('my_connection_name');
Sets this connection name. See the CLIENT SETNAME documentation for restrictions on the connection name string. The most important one: no spaces.
Waits until all pending pipelined responses have been received, and invokes the pipeline callback for each one. See "PIPELINING".
Waits until the first pending pipelined response has been received, and invokes its callback. See "PIPELINING".
Warning: the behaviour of these commands when combined with pipelining is still under discussion, and you should NOT use them at the same time just now.
You can follow the discussion to see the open issues with this.
$r->multi;
$r->discard;
my @individual_replies = $r->exec;
exec has special behaviour when run in a pipeline: the $reply argument to the pipeline callback is an array ref whose elements are themselves [$reply, $error] pairs. This means that you can accurately detect errors yielded by any command in the transaction, and without any exceptions being thrown.
exec
[$reply, $error]
$r->set( foo => 'bar' ); $r->setnx( foo => 42 );
my $value = $r->get( 'foo' );
my @values = $r->mget( 'foo', 'bar', 'baz' );
$r->incr('counter'); $r->incrby('tripplets', 3);
$r->decr('counter'); $r->decrby('tripplets', 3);
$r->exists( 'key' ) && print "got key!";
$r->del( 'key' ) || warn "key doesn't exist";
$r->type( 'key' ); # = string
my @keys = $r->keys( '*glob_pattern*' ); my $keys = $r->keys( '*glob_pattern*' ); # count of matching keys
Note that synchronous keys calls in a scalar context return the number of matching keys (not an array ref of matching keys as you might expect). This does not apply in pipelined mode: assuming the server returns a list of keys, as expected, it is always passed to the pipeline callback as an array ref.
keys
my $key = $r->randomkey;
my $ok = $r->rename( 'old-key', 'new-key', $new );
my $nr_keys = $r->dbsize;
See also Redis::List for tie interface.
$r->rpush( $key, $value );
$r->lpush( $key, $value );
$r->llen( $key );
my @list = $r->lrange( $key, $start, $end );
my $ok = $r->ltrim( $key, $start, $end );
$r->lindex( $key, $index );
$r->lset( $key, $index, $value );
my $modified_count = $r->lrem( $key, $count, $value );
my $value = $r->lpop( $key );
my $value = $r->rpop( $key );
my $ok = $r->sadd( $key, $member );
my $n_elements = $r->scard( $key );
my @elements = $r->sdiff( $key1, $key2, ... ); my $elements = $r->sdiff( $key1, $key2, ... ); # ARRAY ref
my $ok = $r->sdiffstore( $dstkey, $key1, $key2, ... );
my @elements = $r->sinter( $key1, $key2, ... ); my $elements = $r->sinter( $key1, $key2, ... ); # ARRAY ref
my $ok = $r->sinterstore( $dstkey, $key1, $key2, ... );
my $bool = $r->sismember( $key, $member );
my @elements = $r->smembers( $key ); my $elements = $r->smembers( $key ); # ARRAY ref
my $ok = $r->smove( $srckey, $dstkey, $element );
my $element = $r->spop( $key );
my $element = $r->srandmember( $key );
$r->srem( $key, $member );
my @elements = $r->sunion( $key1, $key2, ... ); my $elements = $r->sunion( $key1, $key2, ... ); # ARRAY ref
my $ok = $r->sunionstore( $dstkey, $key1, $key2, ... );
Hashes in Redis cannot be nested as in perl, if you want to store a nested hash, you need to serialize the hash first. If you want to have a named hash, you can use Redis-hashes. You will find an example in the tests of this module t/01-basic.t
Sets the value to a key in a hash.
$r->hset('hashname', $key => $value); ## returns true on success
Gets the value to a key in a hash.
my $value = $r->hget('hashname', $key);
if($r->hexists('hashname', $key) { ## do something, the key exists } else { ## the key does not exist }
Deletes a key from a hash
if($r->hdel('hashname', $key)) { ## key is deleted } else { ## oops }
Adds an integer to a value. The integer is signed, so a negative integer decrements.
my $key = 'testkey'; $r->hset('hashname', $key => 1); ## value -> 1 my $increment = 1; ## has to be an integer $r->hincrby('hashname', $key => $increment); ## value -> 2 $increment = 5; $r->hincrby('hashname', $key => $increment); ## value -> 7 $increment = -1; $r->hincrby('hashname', $key => $increment); ## value -> 6
Adds a key to a hash unless it is not already set.
my $key = 'testnx'; $r->hsetnx('hashname', $key => 1); ## returns true $r->hsetnx('hashname', $key => 2); ## returns false because key already exists
Adds multiple keys to a hash.
$r->hmset('hashname', 'key1' => 'value1', 'key2' => 'value2'); ## returns true on success
Returns multiple keys of a hash.
my @values = $r->hmget('hashname', 'key1', 'key2');
Returns the whole hash.
my %hash = $r->hgetall('hashname');
Returns the keys of a hash.
my @keys = $r->hkeys('hashname');
Returns the values of a hash.
my @values = $r->hvals('hashname');
Returns the count of keys in a hash.
my $keycount = $r->hlen('hashname');
$r->sort("key BY pattern LIMIT start end GET pattern ASC|DESC ALPHA');
When one of "subscribe" or "psubscribe" is used, the Redis object will enter PubSub mode. When in PubSub mode only commands in this section, plus "quit", will be accepted.
If you plan on using PubSub and other Redis functions, you should use two Redis objects, one dedicated to PubSub and the other for regular commands.
All Pub/Sub commands receive a callback as the last parameter. This callback receives three arguments:
The published message.
The topic over which the message was sent.
The subscribed topic that matched the topic for the message. With "subscribe" these last two are the same, always. But with "psubscribe", this parameter tells you the pattern that matched.
See the Pub-Sub notes for more information about the messages you will receive on your callbacks after each "subscribe", "unsubscribe", "psubscribe" and "punsubscribe".
$r->publish($topic, $message);
Publishes the $message to the $topic.
$message
$topic
$r->subscribe( @topics_to_subscribe_to, my $savecallback = sub { my ($message, $topic, $subscribed_topic) = @_; ... }, );
Subscribe one or more topics. Messages published into one of them will be received by Redis, and the specified callback will be executed.
$r->unsubscribe(@topic_list, $savecallback);
Stops receiving messages via $savecallback for all the topics in @topic_list. WARNING: it is important that you give the same calleback that you used for subscribtion. The value of the CodeRef must be the same, as this is how internally the code identifies it.
$savecallback
@topic_list
my @topic_matches = ('prefix1.*', 'prefix2.*'); $r->psubscribe(@topic_matches, my $savecallback = sub { my ($m, $t, $s) = @_; ... });
Subscribes a pattern of topics. All messages to topics that match the pattern will be delivered to the callback.
my @topic_matches = ('prefix1.*', 'prefix2.*'); $r->punsubscribe(@topic_matches, $savecallback);
Stops receiving messages via $savecallback for all the topics pattern matches in @topic_list. WARNING: it is important that you give the same calleback that you used for subscribtion. The value of the CodeRef must be the same, as this is how internally the code identifies it.
if ($r->is_subscriber) { say "We are in Pub/Sub mode!" }
Returns true if we are in Pub/Sub mode.
my $keep_going = 1; ## Set to false somewhere to leave the loop my $timeout = 5; $r->wait_for_messages($timeout) while $keep_going;
Blocks, waits for incoming messages and delivers them to the appropriate callbacks.
Requires a single parameter, the number of seconds to wait for messages. Use 0 to wait for ever. If a positive non-zero value is used, it will return after that amount of seconds without a single notification.
Please note that the timeout is not a commitment to return control to the caller at most each timeout seconds, but more a idle timeout, were control will return to the caller if Redis is idle (as in no messages were received during the timeout period) for more than timeout seconds.
timeout
The "wait_for_messages" call returns the number of messages processed during the run.
$r->save;
$r->bgsave;
$r->lastsave;
$r->eval($lua_script, $num_keys, $key1, ..., $arg1, $arg2);
Executes a Lua script server side.
Note that this commands sends the Lua script every time you call it. See "evalsha" and "script_load" for an alternative.
$r->eval($lua_script_sha1, $num_keys, $key1, ..., $arg1, $arg2);
Executes a Lua script cached on the server side by its SHA1 digest.
See "script_load".
my ($sha1) = $r->script_load($lua_script);
Cache Lua script, returns SHA1 digest that can be used with "evalsha".
my ($exists1, $exists2, ...) = $r->script_exists($scrip1_sha, $script2_sha, ...);
Given a list of SHA1 digests, returns a list of booleans, one for each SHA1, that report the existence of each script in the server cache.
$r->script_kill;
Kills the currently running script.
$r->script_flush;
Flush the Lua scripts cache.
my $info_hash = $r->info;
The info method is unique in that it decodes the server's response into a hashref, if possible. This decoding happens in both synchronous and pipelined modes.
info
$r->shutdown;
The shutdown method does not support pipelined operation.
shutdown
my $nr_items = $r->slowlog("len"); my @last_ten_items = $r->slowlog("get", 10);
The slowlog command gives access to the server's slow log.
slowlog
$r->select( $dbindex ); # 0 for new clients
$r->move( $key, $dbindex );
$r->flushdb;
$r->flushall;
The following persons contributed to this project (alphabetical order):
Aaron Crane (pipelining and AUTOLOAD caching support)
Dirk Vleugels
Flavio Poletti
Jeremy Zawodny
sunnavy at bestpractical.com
Thiago Berlitz Rondon
Ulrich Habel
Ivan Kruglov
Pedro Melo <melo@cpan.org>
Damien Krotkine <dams@cpan.org>
This software is Copyright (c) 2013 by Pedro Melo, Damien Krotkine.
This is free software, licensed under:
The Artistic License 2.0 (GPL Compatible)
To install Redis, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Redis
CPAN shell
perl -MCPAN -e shell install Redis
For more information on module installation, please visit the detailed CPAN module installation guide.