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