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     ConvertToBool = lambda{|r| r == 0 ? false : r}
  18
  19     ReplyProcessor = {
  20         "exists" => ConvertToBool,
  21         "sismember"=> ConvertToBool,
  22         "sadd"=> ConvertToBool,
  23         "srem"=> ConvertToBool,
  24         "smove"=> ConvertToBool,
  25         "move"=> ConvertToBool,
  26         "setnx"=> ConvertToBool,
  27         "del"=> ConvertToBool,
  28         "renamenx"=> ConvertToBool,
  29         "expire"=> ConvertToBool,
  30         "keys" => lambda{|r| r.split(" ")},
  31         "info" => lambda{|r|
  32             info = {}
  33             r.each_line {|kv|
  34                 k,v = kv.split(':', 2)
  35                 k,v = k.chomp, v = v.chomp
  36                 info[k.to_sym] = v
  37             }
  38             info
  39         }
  40     }
  41
  42     def initialize(opts={})
  43         opts = {:host => 'localhost', :port => '6379', :db => 0}.merge(opts)
  44         @host = opts[:host]
  45         @port = opts[:port]
  46         @db = opts[:db]
  47         connect_to_server
  48     end
  49
  50     def to_s
  51         "Redis Client connected to #{@host}:#{@port} against DB #{@db}"
  52     end
  53
  54     def connect_to_server
  55         @sock = TCPSocket.new(@host, @port, 0)
  56         call_command(["select",@db]) if @db != 0
  57     end
  58
  59     def method_missing(*argv)
  60         call_command(argv)
  61     end
  62
  63     def call_command(argv)
  64         # this wrapper to raw_call_command handle reconnection on socket
  65         # error. We try to reconnect just one time, otherwise let the error
  66         # araise.
  67         begin
  68             raw_call_command(argv)
  69         rescue Errno::ECONNRESET
  70             @sock.close
  71             connect_to_server
  72             raw_call_command(argv)
  73         end
  74     end
  75
  76     def raw_call_command(argv)
  77         bulk = nil
  78         argv[0] = argv[0].to_s.downcase
  79         if BulkCommands[argv[0]]
  80             bulk = argv[-1].to_s
  81             argv[-1] = bulk.length
  82         end
  83         @sock.write(argv.join(" ")+"\r\n")
  84         @sock.write(bulk+"\r\n") if bulk
  85
  86         # Post process the reply if needed
  87         processor = ReplyProcessor[argv[0]]
  88         processor ? processor.call(read_reply) : read_reply
  89     end
  90
  91     def select(*args)
  92         raise "SELECT not allowed, use the :db option when creating the object"
  93     end
  94
  95     def [](key)
  96         get(key)
  97     end
  98
  99     def []=(key,value)
 100         set(key,value)
 101     end
 102
 103     def read_reply
 104         line = @sock.gets
 105         raise Errno::ECONNRESET,"Connection lost" if !line
 106         case line[0..0]
 107         when "-"
 108             raise line.strip
 109         when "+"
 110             line[1..-1].strip
 111         when ":"
 112             line[1..-1].to_i
 113         when "$"
 114             bulklen = line[1..-1].to_i
 115             return nil if bulklen == -1
 116             data = @sock.read(bulklen)
 117             @sock.read(2) # CRLF
 118             data
 119         when "*"
 120             objects = line[1..-1].to_i
 121             return nil if bulklen == -1
 122             res = []
 123             objects.times {
 124                 res << read_reply
 125             }
 126             res
 127         end
 128     end
 129 end