client-libraries/ruby_2/rubyredis.rb

   1 # RubyRedis is an alternative implementatin of Ruby client library written
   2 # by Salvatore Sanfilippo.
   3 #
   4 # The aim of this library is to create an alternative client library that is
   5 # much simpler and does not implement every command explicitly but uses
   6 # method_missing instead.
   7
   8 require 'socket'
   9
  10 class RedisClient
  11     BulkCommands = {
  12         "set"=>true, "setnx"=>true, "rpush"=>true, "lpush"=>true, "lset"=>true,
  13         "lrem"=>true, "sadd"=>true, "srem"=>true, "sismember"=>true,
  14         "echo"=>true, "getset"=>true, "smove"=>true
  15     }
  16
  17     def initialize(opts={})
  18         opts = {:host => 'localhost', :port => '6379', :db => 0}.merge(opts)
  19         @host = opts[:host]
  20         @port = opts[:port]
  21         @db = opts[:db]
  22         @sock = connect_to_server
  23         call_command(["select",@db]) if @db != 0
  24     end
  25
  26     def to_s
  27         "Redis Client connected to #{@host}:#{@port} against DB #{@db}"
  28     end
  29
  30     def connect_to_server
  31         TCPSocket.new(@host, @port, 0)
  32     end
  33
  34     def method_missing(*argv)
  35         call_command(argv)
  36     end
  37
  38     def call_command(argv)
  39         bulk = nil
  40         argv[0] = argv[0].to_s.downcase
  41         if BulkCommands[argv[0]]
  42             bulk = argv[-1]
  43             argv[-1] = bulk.length
  44         end
  45         @sock.write(argv.join(" ")+"\r\n")
  46         @sock.write(bulk+"\r\n") if bulk
  47         read_reply
  48     end
  49
  50     def select(*args)
  51         raise "SELECT not allowed, use the :db option when creating the object"
  52     end
  53
  54     def [](key)
  55         get(key)
  56     end
  57
  58     def []=(key,value)
  59         set(key,value)
  60     end
  61
  62     def read_reply
  63         line = @sock.gets
  64         case line[0..0]
  65         when "-"
  66             raise line.strip
  67         when "+"
  68             line[1..-1].strip
  69         when ":"
  70             line[1..-1].to_i
  71         when "$"
  72             bulklen = line[1..-1].to_i
  73             return nil if bulklen == -1
  74             data = @sock.read(bulklen)
  75             @sock.read(2) # CRLF
  76             data
  77         when "*"
  78             objects = line[1..-1].to_i
  79             return nil if bulklen == -1
  80             res = []
  81             objects.times {
  82                 res << read_reply
  83             }
  84             res
  85         end
  86     end
  87 end