Class: Redis

Inherits:
Object
  • Object
show all
Defined in:
lib/redis_ext/pipeline.rb,
lib/redis_ext/redis.rb

Overview

require “redis”

Direct Known Subclasses

Pipeline

Defined Under Namespace

Classes: Pipeline

Constant Summary collapse

OK = 
"OK".freeze
MINUS = 
"-".freeze
PLUS = 
"+".freeze
COLON = 
":".freeze
DOLLAR = 
"$".freeze
ASTERISK = 
"*".freeze
BULK_COMMANDS = 
{
  "set"       => true,
  "setnx"     => true,
  "rpush"     => true,
  "lpush"     => true,
  "lset"      => true,
  "lrem"      => true,
  "sadd"      => true,
  "srem"      => true,
  "sismember" => true,
  "echo"      => true,
  "getset"    => true,
  "smove"     => true
}
BOOLEAN_PROCESSOR = 
lambda{|r| r == 1 }
REPLY_PROCESSOR = 
{
  "exists"    => BOOLEAN_PROCESSOR,
  "sismember" => BOOLEAN_PROCESSOR,
  "sadd"      => BOOLEAN_PROCESSOR,
  "srem"      => BOOLEAN_PROCESSOR,
  "smove"     => BOOLEAN_PROCESSOR,
  "move"      => BOOLEAN_PROCESSOR,
  "setnx"     => BOOLEAN_PROCESSOR,
  "del"       => BOOLEAN_PROCESSOR,
  "renamenx"  => BOOLEAN_PROCESSOR,
  "expire"    => BOOLEAN_PROCESSOR,
  "keys"      => lambda{|r| r.split(" ")},
  "info"      => lambda{|r|
    info = {}
    r.each_line {|kv|
      k,v = kv.split(":",2).map{|x| x.chomp}
      info[k.to_sym] = v
    }
    info
  }
}
ALIASES = 
{
  "flush_db"             => "flushdb",
  "flush_all"            => "flushall",
  "last_save"            => "lastsave",
  "key?"                 => "exists",
  "delete"               => "del",
  "randkey"              => "randomkey",
  "list_length"          => "llen",
  "push_tail"            => "rpush",
  "push_head"            => "lpush",
  "pop_tail"             => "rpop",
  "pop_head"             => "lpop",
  "list_set"             => "lset",
  "list_range"           => "lrange",
  "list_trim"            => "ltrim",
  "list_index"           => "lindex",
  "list_rm"              => "lrem",
  "set_add"              => "sadd",
  "set_delete"           => "srem",
  "set_count"            => "scard",
  "set_member?"          => "sismember",
  "set_members"          => "smembers",
  "set_intersect"        => "sinter",
  "set_intersect_store"  => "sinterstore",
  "set_inter_store"      => "sinterstore",
  "set_union"            => "sunion",
  "set_union_store"      => "sunionstore",
  "set_diff"             => "sdiff",
  "set_diff_store"       => "sdiffstore",
  "set_move"             => "smove",
  "set_unless_exists"    => "setnx",
  "rename_unless_exists" => "renamenx",
  "type?"                => "type"
}
DISABLED_COMMANDS = 
{
  "monitor" => true,
  "sync"    => true
}

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ Redis

Returns a new instance of Redis.



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# File 'lib/redis_ext/redis.rb', line 103

def initialize(options = {})
  @host    =  options[:host]    || '127.0.0.1'
  @port    = (options[:port]    || 6379).to_i
  @db      = (options[:db]      || 0).to_i
  @timeout = (options[:timeout] || 5).to_i
  @password = options[:password]
  @logger  =  options[:logger]

  @logger.info { self.to_s } if @logger
  connect_to_server
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(*argv) ⇒ Object 



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# File 'lib/redis_ext/redis.rb', line 158

def method_missing(*argv)
  call_command(argv)
end

Instance Method Details

#[](key) ⇒ Object 



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# File 'lib/redis_ext/redis.rb', line 218

def [](key)
  self.get(key)
end

#[]=(key, value) ⇒ Object 



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# File 'lib/redis_ext/redis.rb', line 222

def []=(key,value)
  set(key,value)
end

#call_command(argv) ⇒ Object 



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# File 'lib/redis_ext/redis.rb', line 162

def call_command(argv)
  @logger.debug { argv.inspect } if @logger

  # this wrapper to raw_call_command handle reconnection on socket
  # error. We try to reconnect just one time, otherwise let the error
  # araise.
  connect_to_server if !@sock

  begin
    raw_call_command(argv.dup)
  rescue Errno::ECONNRESET, Errno::EPIPE
    @sock.close
    @sock = nil
    connect_to_server
    raw_call_command(argv.dup)
  end
end

#connect_to(host, port, timeout = nil) ⇒ Object 



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# File 'lib/redis_ext/redis.rb', line 129

def connect_to(host, port, timeout=nil)
  # We support connect() timeout only if system_timer is availabe
  # or if we are running against Ruby >= 1.9
  # Timeout reading from the socket instead will be supported anyway.
  if @timeout != 0 and RedisTimer
    begin
      sock = TCPSocket.new(host, port)
    rescue Timeout::Error
      @sock = nil
      raise Timeout::Error, "Timeout connecting to the server"
    end
  else
    sock = TCPSocket.new(host, port)
  end
  sock.setsockopt Socket::IPPROTO_TCP, Socket::TCP_NODELAY, 1

  # If the timeout is set we set the low level socket options in order
  # to make sure a blocking read will return after the specified number
  # of seconds. This hack is from memcached ruby client.
  if timeout
    secs   = Integer(timeout)
    usecs  = Integer((timeout - secs) * 1_000_000)
    optval = [secs, usecs].pack("l_2")
    sock.setsockopt Socket::SOL_SOCKET, Socket::SO_RCVTIMEO, optval
    sock.setsockopt Socket::SOL_SOCKET, Socket::SO_SNDTIMEO, optval
  end
  sock
end

#connect_to_server ⇒ Object 



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# File 'lib/redis_ext/redis.rb', line 123

def connect_to_server
  @sock = connect_to(@host, @port, @timeout == 0 ? nil : @timeout)
  call_command(["auth",@password]) if @password
  call_command(["select",@db]) unless @db == 0
end

#decr(key, decrement = nil) ⇒ Object 



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# File 'lib/redis_ext/redis.rb', line 246

def decr(key,decrement = nil)
  call_command(decrement ? ["decrby",key,decrement] : ["decr",key])
end

#incr(key, increment = nil) ⇒ Object 



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# File 'lib/redis_ext/redis.rb', line 242

def incr(key, increment = nil)
  call_command(increment ? ["incrby",key,increment] : ["incr",key])
end

#mapped_mget(*keys) ⇒ Object

Similar to memcache.rb’s #get_multi, returns a hash mapping keys to values.



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# File 'lib/redis_ext/redis.rb', line 252

def mapped_mget(*keys)
  mget(*keys).inject({}) do |hash, value|
    key = keys.shift
    value.nil? ? hash : hash.merge(key => value)
  end
end

#pipelined {|pipeline| ... } ⇒ Object

Yields:

  • (pipeline) 


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# File 'lib/redis_ext/redis.rb', line 270

def pipelined(&block)
  pipeline = Pipeline.new self
  yield pipeline
  pipeline.execute
end

#quit ⇒ Object 



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# File 'lib/redis_ext/redis.rb', line 265

def quit
  call_command(['quit'])
rescue Errno::ECONNRESET
end

#raw_call_command(argvp) ⇒ Object 



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# File 'lib/redis_ext/redis.rb', line 180

def raw_call_command(argvp)
  pipeline = argvp[0].is_a?(Array)

  unless pipeline
    argvv = [argvp]
  else
    argvv = argvp
  end

  command = ''

  argvv.each do |argv|
    bulk = nil
    argv[0] = argv[0].to_s.downcase
    argv[0] = ALIASES[argv[0]] if ALIASES[argv[0]]
    raise "#{argv[0]} command is disabled" if DISABLED_COMMANDS[argv[0]]
    if BULK_COMMANDS[argv[0]] and argv.length > 1
      bulk = argv[-1].to_s
      argv[-1] = bulk.respond_to?(:bytesize) ? bulk.bytesize : bulk.size
    end
    command << "#{argv.join(' ')}\r\n"
    command << "#{bulk}\r\n" if bulk
  end

  @sock.write(command)

  results = argvv.map do |argv|
    processor = REPLY_PROCESSOR[argv[0]]
    processor ? processor.call(read_reply) : read_reply
  end

  return pipeline ? results : results[0]
end

#read_reply ⇒ Object

Raises:

  • (Errno::ECONNRESET) 


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# File 'lib/redis_ext/redis.rb', line 276

def read_reply
  # We read the first byte using read() mainly because gets() is
  # immune to raw socket timeouts.
  begin
    rtype = @sock.read(1)
  rescue Errno::EAGAIN
    # We want to make sure it reconnects on the next command after the
    # timeout. Otherwise the server may reply in the meantime leaving
    # the protocol in a desync status.
    @sock = nil
    raise Errno::EAGAIN, "Timeout reading from the socket"
  end

  raise Errno::ECONNRESET,"Connection lost" if !rtype
  line = @sock.gets
  case rtype
  when MINUS
    raise MINUS + line.strip
  when PLUS
    line.strip
  when COLON
    line.to_i
  when DOLLAR
    bulklen = line.to_i
    return nil if bulklen == -1
    data = @sock.read(bulklen)
    @sock.read(2) # CRLF
    data
  when ASTERISK
    objects = line.to_i
    return nil if bulklen == -1
    res = []
    objects.times {
      res << read_reply
    }
    res
  else
    raise "Protocol error, got '#{rtype}' as initial reply byte"
  end
end

#select(*args) ⇒ Object 



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# File 'lib/redis_ext/redis.rb', line 214

def select(*args)
  raise "SELECT not allowed, use the :db option when creating the object"
end

#server ⇒ Object 



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# File 'lib/redis_ext/redis.rb', line 119

def server
  "#{@host}:#{@port}"
end

#set(key, value, expiry = nil) ⇒ Object 



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# File 'lib/redis_ext/redis.rb', line 226

def set(key, value, expiry=nil)
  s = call_command([:set, key, value]) == OK
  expire(key, expiry) if s && expiry
  s
end

#sort(key, options = {}) ⇒ Object 



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# File 'lib/redis_ext/redis.rb', line 232

def sort(key, options = {})
  cmd = ["SORT"]
  cmd << key
  cmd << "BY #{options[:by]}" if options[:by]
  cmd << "GET #{[options[:get]].flatten * ' GET '}" if options[:get]
  cmd << "#{options[:order]}" if options[:order]
  cmd << "LIMIT #{options[:limit].join(' ')}" if options[:limit]
  call_command(cmd)
end

#to_s ⇒ Object 



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# File 'lib/redis_ext/redis.rb', line 115

def to_s
  "Redis Client connected to #{server} against DB #{@db}"
end

#type(key) ⇒ Object

Ruby defines a now deprecated type method so we need to override it here since it will never hit method_missing



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# File 'lib/redis_ext/redis.rb', line 261

def type(key)
  call_command(['type', key])
end