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