# RubyRedis is an alternative implementatin of Ruby client library written
# by Salvatore Sanfilippo.
#
# The aim of this library is to create an alternative client library that is
# much simpler and does not implement every command explicitly but uses
# method_missing instead.
require 'socket'
require 'set'
begin
if (RUBY_VERSION >= '1.9')
require 'timeout'
RedisTimer = Timeout
else
require 'system_timer'
RedisTimer = SystemTimer
end
rescue LoadError
RedisTimer = nil
end
class RedisClient
BulkCommands = {
"set"=>true, "setnx"=>true, "rpush"=>true, "lpush"=>true, "lset"=>true,
"lrem"=>true, "sadd"=>true, "srem"=>true, "sismember"=>true,
"echo"=>true, "getset"=>true, "smove"=>true
}
ConvertToBool = lambda{|r| r == 0 ? false : r}
ReplyProcessor = {
"exists" => ConvertToBool,
"sismember"=> ConvertToBool,
"sadd"=> ConvertToBool,
"srem"=> ConvertToBool,
"smove"=> ConvertToBool,
"move"=> ConvertToBool,
"setnx"=> ConvertToBool,
"del"=> ConvertToBool,
"renamenx"=> ConvertToBool,
"expire"=> ConvertToBool,
"keys" => lambda{|r| r.split(" ")},
"info" => lambda{|r|
info = {}
r.each_line {|kv|
k,v = kv.split(":",2).map{|x| x.chomp}
info[k.to_sym] = v
}
info
}
}
Aliases = {
"flush_db" => "flushdb",
"flush_all" => "flushall",
"last_save" => "lastsave",
"key?" => "exists",
"delete" => "del",
"randkey" => "randomkey",
"list_length" => "llen",
"push_tail" => "rpush",
"push_head" => "lpush",
"pop_tail" => "rpop",
"pop_head" => "lpop",
"list_set" => "lset",
"list_range" => "lrange",
"list_trim" => "ltrim",
"list_index" => "lindex",
"list_rm" => "lrem",
"set_add" => "sadd",
"set_delete" => "srem",
"set_count" => "scard",
"set_member?" => "sismember",
"set_members" => "smembers",
"set_intersect" => "sinter",
"set_intersect_store" => "sinterstore",
"set_inter_store" => "sinterstore",
"set_union" => "sunion",
"set_union_store" => "sunionstore",
"set_diff" => "sdiff",
"set_diff_store" => "sdiffstore",
"set_move" => "smove",
"set_unless_exists" => "setnx",
"rename_unless_exists" => "renamenx"
}
def initialize(opts={})
@host = opts[:host] || '127.0.0.1'
@port = opts[:port] || 6379
@db = opts[:db] || 0
@timeout = opts[:timeout] || 0
connect_to_server
end
def to_s
"Redis Client connected to #{@host}:#{@port} against DB #{@db}"
end
def connect_to_server
@sock = connect_to(@host,@port,@timeout == 0 ? nil : @timeout)
call_command(["select",@db]) if @db != 0
end
def connect_to(host, port, timeout=nil)
# We support connect() timeout only if system_timer is availabe
# or if we are running against Ruby >= 1.9
# Timeout reading from the socket instead will be supported anyway.
if @timeout != 0 and RedisTimer
begin
sock = TCPSocket.new(host, port, 0)
rescue Timeout::Error
@sock = nil
raise Timeout::Error, "Timeout connecting to the server"
end
else
sock = TCPSocket.new(host, port, 0)
end
# If the timeout is set we set the low level socket options in order
# to make sure a blocking read will return after the specified number
# of seconds. This hack is from memcached ruby client.
if timeout
secs = Integer(timeout)
usecs = Integer((timeout - secs) * 1_000_000)
optval = [secs, usecs].pack("l_2")
sock.setsockopt Socket::SOL_SOCKET, Socket::SO_RCVTIMEO, optval
sock.setsockopt Socket::SOL_SOCKET, Socket::SO_SNDTIMEO, optval
end
sock
end
def method_missing(*argv)
call_command(argv)
end
def call_command(argv)
# this wrapper to raw_call_command handle reconnection on socket
# error. We try to reconnect just one time, otherwise let the error
# araise.
connect_to_server if !@sock
begin
raw_call_command(argv)
rescue Errno::ECONNRESET
@sock.close
connect_to_server
raw_call_command(argv)
end
end
def raw_call_command(argv)
bulk = nil
argv[0] = argv[0].to_s.downcase
argv[0] = Aliases[argv[0]] if Aliases[argv[0]]
if BulkCommands[argv[0]]
bulk = argv[-1].to_s
argv[-1] = bulk.length
end
@sock.write(argv.join(" ")+"\r\n")
@sock.write(bulk+"\r\n") if bulk
# Post process the reply if needed
processor = ReplyProcessor[argv[0]]
processor ? processor.call(read_reply) : read_reply
end
def select(*args)
raise "SELECT not allowed, use the :db option when creating the object"
end
def [](key)
get(key)
end
def []=(key,value)
set(key,value)
end
def sort(key, opts={})
cmd = []
cmd << "SORT #{key}"
cmd << "BY #{opts[:by]}" if opts[:by]
cmd << "GET #{[opts[:get]].flatten * ' GET '}" if opts[:get]
cmd << "#{opts[:order]}" if opts[:order]
cmd << "LIMIT #{opts[:limit].join(' ')}" if opts[:limit]
call_command(cmd)
end
def incr(key,increment=nil)
call_command(increment ? ["incrby",key,increment] : ["incr",key])
end
def decr(key,decrement=nil)
call_command(decrement ? ["decrby",key,decrement] : ["decr",key])
end
def read_reply
# We read the first byte using read() mainly because gets() is
# immune to raw socket timeouts.
begin
rtype = @sock.read(1)
rescue Errno::EAGAIN
# We want to make sure it reconnects on the next command after the
# timeout. Otherwise the server may reply in the meantime leaving
# the protocol in a desync status.
@sock = nil
raise Errno::EAGAIN, "Timeout reading from the socket"
end
raise Errno::ECONNRESET,"Connection lost" if !rtype
line = @sock.gets
case rtype
when "-"
raise "-"+line.strip
when "+"
line.strip
when ":"
line.to_i
when "$"
bulklen = line.to_i
return nil if bulklen == -1
data = @sock.read(bulklen)
@sock.read(2) # CRLF
data
when "*"
objects = line.to_i
return nil if bulklen == -1
res = []
objects.times {
res << read_reply
}
res
else
raise "Protocol error, got '#{rtype}' as initial reply byte"
end
end
end
) is private.
