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         connect_to_server
  23     end
  24
  25     def to_s
  26         "Redis Client connected to #{@host}:#{@port} against DB #{@db}"
  27     end
  28
  29     def connect_to_server
  30         @sock = TCPSocket.new(@host, @port, 0)
  31         call_command(["select",@db]) if @db != 0
  32     end
  33
  34     def method_missing(*argv)
  35         call_command(argv)
  36     end
  37
  38     def call_command(argv)
  39         # this wrapper to raw_call_command handle reconnection on socket
  40         # error. We try to reconnect just one time, otherwise let the error
  41         # araise.
  42         begin
  43             raw_call_command(argv)
  44         rescue Errno::ECONNRESET
  45             @sock.close
  46             connect_to_server
  47             raw_call_command(argv)
  48         end
  49     end
  50
  51     def raw_call_command(argv)
  52         bulk = nil
  53         argv[0] = argv[0].to_s.downcase
  54         if BulkCommands[argv[0]]
  55             bulk = argv[-1]
  56             argv[-1] = bulk.length
  57         end
  58         @sock.write(argv.join(" ")+"\r\n")
  59         @sock.write(bulk+"\r\n") if bulk
  60         read_reply
  61     end
  62
  63     def select(*args)
  64         raise "SELECT not allowed, use the :db option when creating the object"
  65     end
  66
  67     def [](key)
  68         get(key)
  69     end
  70
  71     def []=(key,value)
  72         set(key,value)
  73     end
  74
  75     def read_reply
  76         line = @sock.gets
  77         raise Errno::ECONNRESET,"Connection lost" if !line
  78         case line[0..0]
  79         when "-"
  80             raise line.strip
  81         when "+"
  82             line[1..-1].strip
  83         when ":"
  84             line[1..-1].to_i
  85         when "$"
  86             bulklen = line[1..-1].to_i
  87             return nil if bulklen == -1
  88             data = @sock.read(bulklen)
  89             @sock.read(2) # CRLF
  90             data
  91         when "*"
  92             objects = line[1..-1].to_i
  93             return nil if bulklen == -1
  94             res = []
  95             objects.times {
  96                 res << read_reply
  97             }
  98             res
  99         end
 100     end
 101 end