=head1 NAME AnyEvent::RipeRedis - Flexible non-blocking Redis client =head1 SYNOPSIS use AnyEvent; use AnyEvent::RipeRedis; my $redis = AnyEvent::RipeRedis->new( host => 'localhost', port => 6379, password => 'yourpass', ); my $cv = AE::cv; $redis->set( 'foo', 'bar', sub { my $err = $_[1]; if ( defined $err ) { warn $err->message . "\n"; $cv->send; return; } $redis->get( 'foo', sub { my $reply = shift; my $err = shift; if ( defined $err ) { warn $err->message . "\n"; $cv->send; return; } print "$reply\n"; $cv->send; } ); } ); $cv->recv; =head1 DESCRIPTION AnyEvent::RipeRedis is flexible non-blocking Redis client. Supports subscriptions, transactions and can automaticaly restore connection after failure. Requires Redis 1.2 or higher, and any supported event loop. =head1 CONSTRUCTOR =head2 new( %params ) my $redis = AnyEvent::RipeRedis->new( host => 'localhost', port => 6379, password => 'yourpass', database => 7, connection_timeout => 5, read_timeout => 5, lazy => 1, reconnect_interval => 5, on_connect => sub { # handling... }, on_disconnect => sub { # handling... }, on_error => sub { my $err = shift; # error handling... }, ); =over =item host => $host Server hostname (default: 127.0.0.1) =item port => $port Server port (default: 6379) =item password => $password If the password is specified, the C<AUTH> command is sent to the server after connection. =item database => $index Database index. If the index is specified, the client switches to the specified database after connection. You can also switch to another database after connection by using C<SELECT> command. The client remembers last selected database after reconnection and switches to it automaticaly. The default database index is C<0>. =item utf8 => $boolean If enabled, all strings will be converted to UTF-8 before sending to the server, and all results will be decoded from UTF-8. Enabled by default. =item connection_timeout => $fractional_seconds Specifies connection timeout. If the client could not connect to the server after specified timeout, the C<on_error> callback is called with the C<E_CANT_CONN> error. The timeout specifies in seconds and can contain a fractional part. connection_timeout => 10.5, By default the client use kernel's connection timeout. =item read_timeout => $fractional_seconds Specifies read timeout. If the client could not receive a reply from the server after specified timeout, the client close connection and call the C<on_error> callback with the C<E_READ_TIMEDOUT> error. The timeout is specifies in seconds and can contain a fractional part. read_timeout => 3.5, Not set by default. =item lazy => $boolean If enabled, the connection establishes at time when you will send the first command to the server. By default the connection establishes after calling of the C<new> method. Disabled by default. =item reconnect => $boolean If the connection to the server was lost and the parameter C<reconnect> is TRUE (default), the client will try to restore the connection when you execute next command. The client will try to reconnect only once and, if attempt fails, the error object is passed to command callback. If you need several attempts of the reconnection, you must retry a command from the callback as many times, as you need. Such behavior allows to control reconnection procedure. Enabled by default. =item reconnect_interval => $fractional_seconds If the parameter is specified, the client will try to reconnect only after this interval. Commands executed between reconnections will be queued. reconnect_interval => 5, Not set by default. =item handle_params => \%params Specifies L<AnyEvent::Handle> parameters. handle_params => { autocork => 1, linger => 60, } Enabling of the C<autocork> parameter can improve performance. See documentation on L<AnyEvent::Handle> for more information. =item on_connect => $cb->() The C<on_connect> callback is called when the connection is successfully established. Not set by default. =item on_disconnect => $cb->() The C<on_disconnect> callback is called when the connection is closed by any reason. Not set by default. =item on_error => $cb->( $err ) The C<on_error> callback is called when occurred an error, which was affected on entire client (e. g. connection error or authentication error). Also the C<on_error> callback is called on command errors if the command callback is not specified. If the C<on_error> callback is not specified, the client just print an error messages to C<STDERR>. =back =head1 COMMAND EXECUTION =head2 <command>( [ @args ] [, $cb->( $reply, $err ) ] ) To execute the command you must call specific method with corresponding name. The reply to the command is passed to the callback in first argument. If any error occurred during the command execution, the error object is passed to the callback in second argument. Error object is the instance of the class L<AnyEvent::RipeRedis::Error>. The command callback is optional. If it is not specified and any error occurred, the C<on_error> callback of the client is called. The full list of the Redis commands can be found here: L<http://redis.io/commands>. $redis->get( 'foo', sub { my $reply = shift; my $err = shift; if ( defined $err ) { my $err_msg = $err->message; my $err_code = $err->code; # error handling... return; } print "$reply\n"; } ); $redis->lrange( 'list', 0, -1, sub { my $reply = shift; my $err = shift; if ( defined $err ) { my $err_msg = $err->message; my $err_code = $err->code; # error handling... return; } foreach my $value ( @{$reply} ) { print "$value\n"; } } ); $redis->incr( 'counter' ); You can execute multi-word commands like this: $redis->client_getname( sub { my $reply = shift; my $err = shift; if ( defined $err ) { my $err_msg = $err->message; my $err_code = $err->code; # error handling... return; } print "$reply\n"; } ); =head2 execute( $command, [ @args ] [, $cb->( $reply, $err ) ] ) An alternative method to execute commands. In some cases it can be more convenient. $redis->execute( 'get', 'foo', sub { my $reply = shift; my $err = shift; if ( defined $err ) { my $err_msg = $err->message; my $err_code = $err->code; return; } print "$reply\n"; } ); =head1 TRANSACTIONS The detailed information about the Redis transactions can be found here: L<http://redis.io/topics/transactions>. =head2 multi( [ $cb->( $reply, $err ) ] ) Marks the start of a transaction block. Subsequent commands will be queued for atomic execution using C<EXEC>. =head2 exec( [ $cb->( $reply, $err ) ] ) Executes all previously queued commands in a transaction and restores the connection state to normal. When using C<WATCH>, C<EXEC> will execute commands only if the watched keys were not modified. If during a transaction at least one command fails, to the callback will be passed error object, and the reply will be contain nested error objects for every failed command. $redis->multi(); $redis->set( 'foo', 'string' ); $redis->incr('foo'); # causes an error $redis->exec( sub { my $reply = shift; my $err = shift; if ( defined $err ) { my $err_msg = $err->message(); my $err_code = $err->code(); if ( defined $reply ) { foreach my $nested_reply ( @{$reply} ) { if ( ref($nested_reply) eq 'AnyEvent::RipeRedis::Error' ) { my $nested_err_msg = $nested_reply->message(); my $nested_err_code = $nested_reply->code(); # error handling... } } return; } # error handling... return; } # reply handling... }, ); =head2 discard( [ $cb->( $reply, $err ) ] ) Flushes all previously queued commands in a transaction and restores the connection state to normal. If C<WATCH> was used, C<DISCARD> unwatches all keys. =head2 watch( @keys [, $cb->( $reply, $err ) ] ) Marks the given keys to be watched for conditional execution of a transaction. =head2 unwatch( [ $cb->( $reply, $err ) ] ) Forget about all watched keys. =head1 SUBSCRIPTIONS Once the client enters the subscribed state it is not supposed to issue any other commands, except for additional C<SUBSCRIBE>, C<PSUBSCRIBE>, C<UNSUBSCRIBE>, C<PUNSUBSCRIBE> and C<QUIT> commands. The detailed information about Redis Pub/Sub can be found here: L<http://redis.io/topics/pubsub> =head2 subscribe( @channels, ( $cb->( $msg, $channel ) | \%cbs ) ) Subscribes the client to the specified channels. Method can accept two callbacks: C<on_reply> and C<on_message>. The C<on_reply> callback is called when subscription to all specified channels will be activated. In first argument to the callback is passed the number of channels we are currently subscribed. If subscription to specified channels was lost, the C<on_reply> callback is called with the error object in the second argument. The C<on_message> callback is called on every published message. If the C<subscribe> method is called with one callback, this callback will be act as C<on_message> callback. $redis->subscribe( qw( foo bar ), { on_reply => sub { my $channels_num = shift; my $err = shift; if ( defined $err ) { # error handling... return; } # reply handling... }, on_message => sub { my $msg = shift; my $channel = shift; # message handling... }, } ); $redis->subscribe( qw( foo bar ), sub { my $msg = shift; my $channel = shift; # message handling... } ); =head2 psubscribe( @patterns, ( $cb->( $msg, $pattern, $channel ) | \%cbs ) ) Subscribes the client to the given patterns. See C<subscribe()> method for details. $redis->psubscribe( qw( foo_* bar_* ), { on_reply => sub { my $channels_num = shift; my $err = shift; if ( defined $err ) { # error handling... return; } # reply handling... }, on_message => sub { my $msg = shift; my $pattern = shift; my $channel = shift; # message handling... }, } ); $redis->psubscribe( qw( foo_* bar_* ), sub { my $msg = shift; my $pattern = shift; my $channel = shift; # message handling... } ); =head2 publish( $channel, $message [, $cb->( $reply, $err ) ] ) Posts a message to the given channel. =head2 unsubscribe( [ @channels ] [, $cb->( $reply, $err ) ] ) Unsubscribes the client from the given channels, or from all of them if none is given. In first argument to the callback is passed the number of channels we are currently subscribed or zero if we were unsubscribed from all channels. $redis->unsubscribe( qw( foo bar ), sub { my $channels_num = shift; my $err = shift; if ( defined $err ) { # error handling... return; } # reply handling... } ); =head2 punsubscribe( [ @patterns ] [, $cb->( $reply, $err ) ] ) Unsubscribes the client from the given patterns, or from all of them if none is given. See C<unsubscribe()> method for details. $redis->punsubscribe( qw( foo_* bar_* ), sub { my $channels_num = shift; my $err = shift; if ( defined $err ) { # error handling... return; } # reply handling... } ); =head1 CONNECTION VIA UNIX-SOCKET Redis 2.2 and higher support connection via UNIX domain socket. To connect via a UNIX-socket in the parameter C<host> you have to specify C<unix/>, and in the parameter C<port> you have to specify the path to the socket. my $redis = AnyEvent::RipeRedis->new( host => 'unix/', port => '/tmp/redis.sock', ); =head1 LUA SCRIPTS EXECUTION Redis 2.6 and higher support execution of Lua scripts on the server side. To execute a Lua script you can send one of the commands C<EVAL> or C<EVALSHA>, or use the special method C<eval_cached()>. =head2 eval_cached( $script, $keys_num [, @keys ] [, @args ] [, $cb->( $reply, $err ) ] ] ); When you call the C<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 C<EVALSHA> command under the hood. If the C<E_NO_SCRIPT> error will be returned, the client send the C<EVAL> command. If you call the C<eval_cached()> method with the same Lua script, client don not generate a SHA1 hash for this script repeatedly, it gets a hash from the cache instead. $redis->eval_cached( 'return { KEYS[1], KEYS[2], ARGV[1], ARGV[2] }', 2, 'key1', 'key2', 'first', 'second', sub { my $reply = shift; my $err = shift; if ( defined $err ) { # error handling... return; } foreach my $value ( @{$reply} ) { print "$value\n"; } } ); Be care, passing a different Lua scripts to C<eval_cached()> method every time cause memory leaks. If Lua script returns multi-bulk reply with at least one error reply, to the callback will be passed error object, and the reply will be contain nested error objects. $redis->eval_cached( "return { 'foo', redis.error_reply( 'Error.' ) }", 0, sub { my $reply = shift; my $err = shift; if ( defined $err ) { my $err_msg = $err->message; my $err_code = $err->code; if ( defined $reply ) { foreach my $nested_reply ( @{$reply} ) { if ( ref($nested_reply) eq 'AnyEvent::RipeRedis::Error' ) { my $nested_err_msg = $nested_reply->message(); my $nested_err_code = $nested_reply->code(); # error handling... } } } # error handling... return; } # reply handling... } ); =head1 ERROR CODES Every error object, passed to callback, contain error code, which can be used for programmatic handling of errors. AnyEvent::RipeRedis provides constants for error codes. They can be imported and used in expressions. use AnyEvent::RipeRedis qw( :err_codes ); =over =item E_CANT_CONN Can't connect to the server. All operations were aborted. =item E_LOADING_DATASET Redis is loading the dataset in memory. =item E_IO Input/Output operation error. The connection to the Redis server was closed and all operations were aborted. =item E_CONN_CLOSED_BY_REMOTE_HOST The connection closed by remote host. All operations were aborted. =item E_CONN_CLOSED_BY_CLIENT Connection closed by client prematurely. Uncompleted operations were aborted. =item E_NO_CONN No connection to the Redis server. Connection was lost by any reason on previous operation. =item E_OPRN_ERROR Operation error. For example, wrong number of arguments for a command. =item E_UNEXPECTED_DATA The client received unexpected reply from the server. The connection to the Redis server was closed and all operations were aborted. =item E_READ_TIMEDOUT Read timed out. The connection to the Redis server was closed and all operations were aborted. =back Error codes available since Redis 2.6. =over =item E_NO_SCRIPT No matching script. Use the C<EVAL> command. =item E_BUSY Redis is busy running a script. You can only call C<SCRIPT KILL> or C<SHUTDOWN NOSAVE>. =item E_NOT_BUSY No scripts in execution right now. =item E_MASTER_DOWN Link with MASTER is down and slave-serve-stale-data is set to 'no'. =item E_MISCONF Redis is configured to save RDB snapshots, but is currently not able to persist on disk. Commands that may modify the data set are disabled. Please check Redis logs for details about the error. =item E_READONLY You can't write against a read only slave. =item E_OOM Command not allowed when used memory > 'maxmemory'. =item E_EXEC_ABORT Transaction discarded because of previous errors. =back Error codes available since Redis 2.8. =over =item E_NO_AUTH Authentication required. =item E_WRONG_TYPE Operation against a key holding the wrong kind of value. =item E_NO_REPLICAS Not enough good slaves to write. =item E_BUSY_KEY Target key name already exists. =back Error codes available since Redis 3.0. =over =item E_CROSS_SLOT Keys in request don't hash to the same slot. =item E_TRY_AGAIN Multiple keys request during rehashing of slot. =item E_ASK Redirection required. For more information see: L<http://redis.io/topics/cluster-spec> =item E_MOVED Redirection required. For more information see: L<http://redis.io/topics/cluster-spec> =item E_CLUSTER_DOWN The cluster is down or hash slot not served. =back =head1 DISCONNECTION When the connection to the server is no longer needed you can close it in three ways: call the method C<disconnect()>, send the C<QUIT> command or you can just "forget" any references to an AnyEvent::RipeRedis object, but in this case the client object is destroyed without calling any callbacks, including the C<on_disconnect> callback, to avoid an unexpected behavior. =head2 disconnect() The method for synchronous disconnection. All uncompleted operations will be aborted. =head2 quit( [ $cb->( $reply, $err ) ] ) The method for asynchronous disconnection. =head1 OTHER METHODS =head2 info( [ $section ] [, $cb->( $reply, $err ) ] ) Gets and parses information and statistics about the server. The result is passed to callback as a hash reference. More information about C<INFO> command can be found here: L<http://redis.io/commands/info> =head2 host() Gets current host of the client. =head2 port() Gets current port of the client. =head2 select( $index, [, $cb->( $reply, $err ) ] ) Selects the database by numeric index. =head2 database() Gets selected database index. =head2 utf8( [ $boolean ] ) Enables or disables UTF-8 mode. =head2 connection_timeout( [ $fractional_seconds ] ) Gets or sets the C<connection_timeout> of the client. The C<undef> value resets the C<connection_timeout> to default value. =head2 read_timeout( [ $fractional_seconds ] ) Gets or sets the C<read_timeout> of the client. =head2 reconnect( [ $boolean ] ) Enables or disables reconnection mode of the client. =head2 reconnect_interval( [ $fractional_seconds ] ) Gets or sets C<reconnect_interval> of the client. =head2 on_connect( [ $callback ] ) Gets or sets the C<on_connect> callback. =head2 on_disconnect( [ $callback ] ) Gets or sets the C<on_disconnect> callback. =head2 on_error( [ $callback ] ) Gets or sets the C<on_error> callback. =head1 SEE ALSO L<AnyEvent::RipeRedis::Cluster>, L<AnyEvent>, L<Redis::hiredis>, L<Redis>, L<RedisDB> =head1 AUTHOR Eugene Ponizovsky, E<lt>ponizovsky@gmail.comE<gt> Sponsored by SMS Online, E<lt>dev.opensource@sms-online.comE<gt> =head2 Special thanks =over =item * Alexey Shrub =item * Vadim Vlasov =item * Konstantin Uvarin =item * Ivan Kruglov =back =head1 COPYRIGHT AND LICENSE Copyright (c) 2012-2017, Eugene Ponizovsky, SMS Online. All rights reserved. This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.