Module: EventMachine::Protocols::Redis

Includes:
EM::Deferrable
Defined in:
lib/em-redis/redis_protocol.rb

Defined Under Namespace

Classes: ParserError, ProtocolError, RedisError

Constant Summary collapse

OK =

constants

"OK".freeze
MINUS = 
"-".freeze
PLUS = 
"+".freeze
COLON = 
":".freeze
DOLLAR = 
"$".freeze
ASTERISK = 
"*".freeze
DELIM = 
"\r\n".freeze
BOOLEAN_PROCESSOR = 
lambda{|r| r == 1 }
REPLY_PROCESSOR = 
{
  "exists"    => BOOLEAN_PROCESSOR,
  "sismember" => BOOLEAN_PROCESSOR,
  "sadd"      => BOOLEAN_PROCESSOR,
  "srem"      => BOOLEAN_PROCESSOR,
  "smove"     => BOOLEAN_PROCESSOR,
  "zadd"      => BOOLEAN_PROCESSOR,
  "zrem"      => BOOLEAN_PROCESSOR,
  "move"      => BOOLEAN_PROCESSOR,
  "setnx"     => BOOLEAN_PROCESSOR,
  "del"       => BOOLEAN_PROCESSOR,
  "renamenx"  => BOOLEAN_PROCESSOR,
  "expire"    => BOOLEAN_PROCESSOR,
  "select"    => BOOLEAN_PROCESSOR, # not in redis gem
  "hset"      => BOOLEAN_PROCESSOR,
  "hdel"      => BOOLEAN_PROCESSOR,
  "hexists"   => BOOLEAN_PROCESSOR,
  "keys"      => lambda {|r|
    if r.is_a?(Array)
      r
    else
      r.split(" ")
    end
  },
  "info"      => lambda{|r|
    info = {}
    r.each_line {|kv|
      k,v = kv.split(":",2).map{|x| x.chomp}
      info[k.to_sym] = v
    }
    info
  }, 
  "hgetall"   => lambda{|r|
    Hash[*r]
  }
}
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",
  "zset_add"             => "zadd",
  "zset_count"           => "zcard",
  "zset_range_by_score"  => "zrangebyscore",
  "zset_reverse_range"   => "zrevrange",
  "zset_range"           => "zrange",
  "zset_delete"          => "zrem",
  "zset_score"           => "zscore",
  "zset_incr_by"         => "zincrby",
  "zset_increment_by"    => "zincrby",
  # these aliases aren't in redis gem
  "background_save"      => 'bgsave',
  "async_save"           => 'bgsave',
  "members"              => 'smembers',
  "decrement_by"         => "decrby",
  "decrement"            => "decr",
  "increment_by"         => "incrby",
  "increment"            => "incr",
  "set_if_nil"           => "setnx",
  "multi_get"            => "mget",
  "random_key"           => "randomkey",
  "random"               => "randomkey",
  "rename_if_nil"        => "renamenx",
  "tail_pop"             => "rpop",
  "pop"                  => "rpop",
  "head_pop"             => "lpop",
  "shift"                => "lpop",
  "list_remove"          => "lrem",
  "index"                => "lindex",
  "trim"                 => "ltrim",
  "list_range"           => "lrange",
  "range"                => "lrange",
  "list_len"             => "llen",
  "len"                  => "llen",
  "head_push"            => "lpush",
  "unshift"              => "lpush",
  "tail_push"            => "rpush",
  "push"                 => "rpush",
  "add"                  => "sadd",
  "set_remove"           => "srem",
  "set_size"             => "scard",
  "member?"              => "sismember",
  "intersect"            => "sinter",
  "intersect_and_store"  => "sinterstore",
  "members"              => "smembers",
  "exists?"              => "exists"
}
DISABLED_COMMANDS = 
{
  "monitor" => true,
  "sync"    => true
}

Class Method Summary collapse

Instance Method Summary collapse

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(*argv, &blk) ⇒ Object 



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# File 'lib/em-redis/redis_protocol.rb', line 251

def method_missing(*argv, &blk)
  call_command(argv, &blk)
end

Class Method Details

.connect(*args) ⇒ Object

em hooks



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# File 'lib/em-redis/redis_protocol.rb', line 304

def self.connect(*args)
  case args.length
  when 0
    options = {}
  when 1
    arg = args.shift
    case arg
    when Hash then options = arg
    when String then options = {:host => arg}
    else raise ArgumentError, 'first argument must be Hash or String'
    end
  when 2
    options = {:host => args[0], :port => args[1]}
  else
    raise ArgumentError, "wrong number of arguments (#{args.length} for 1)"
  end
  options[:host] ||= '127.0.0.1'
  options[:port]   = (options[:port] || 6379).to_i
  EM.connect options[:host], options[:port], self, options
end

Instance Method Details

#[]=(key, value) ⇒ Object 



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# File 'lib/em-redis/redis_protocol.rb', line 145

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

#auth(password, &blk) ⇒ Object 



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# File 'lib/em-redis/redis_protocol.rb', line 179

def auth(password, &blk)
  @password = password
  call_command(['auth', password], &blk)
end

#call_command(argv, &blk) ⇒ Object 



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# File 'lib/em-redis/redis_protocol.rb', line 265

def call_command(argv, &blk)
  argv = argv.dup

  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]]

  command = ""
  command << "*#{argv.size}\r\n"
  argv.each do |a|
    a = a.to_s
    command << "$#{get_size(a)}\r\n"
    command << a
    command << "\r\n"
  end

  @logger.debug { "*** sending: #{command}" } if @logger
  maybe_lock do
    @redis_callbacks << [REPLY_PROCESSOR[argv[0]], blk]
    send_data command
  end
end

#connection_completed ⇒ Object 



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# File 'lib/em-redis/redis_protocol.rb', line 347

def connection_completed
  @logger.debug { "Connected to #{@host}:#{@port}" } if @logger

  @redis_callbacks = []
  @previous_multibulks = []
  @multibulk_n     = false
  @reconnecting    = false
  @connected       = true

  succeed
end

#decr(key, decrement = nil, &blk) ⇒ Object 



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# File 'lib/em-redis/redis_protocol.rb', line 170

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

#dispatch_response(value) ⇒ Object 



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# File 'lib/em-redis/redis_protocol.rb', line 424

def dispatch_response(value)
  if @multibulk_n
    @multibulk_values << value
    @multibulk_n -= 1

    if @multibulk_n == 0
      value = @multibulk_values
      @multibulk_n,@multibulk_values = @previous_multibulks.pop
      if @multibulk_n
        dispatch_response(value)
        return
      end
    else
      return
    end
  end

  processor, blk = @redis_callbacks.shift
  value = processor.call(value) if processor
  blk.call(value) if blk
end

#errback(&blk) ⇒ Object Also known as: on_error 



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# File 'lib/em-redis/redis_protocol.rb', line 246

def errback(&blk)
  @error_callback = blk
end

#exec(&blk) ⇒ Object 



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# File 'lib/em-redis/redis_protocol.rb', line 207

def exec(&blk)
  call_command(['exec'], &blk)
end

#incr(key, increment = nil, &blk) ⇒ Object 



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# File 'lib/em-redis/redis_protocol.rb', line 166

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

#initialize(options = {}) ⇒ Object 



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# File 'lib/em-redis/redis_protocol.rb', line 325

def initialize(options = {})
  @host           = options[:host]
  @port           = options[:port]
  @db             = (options[:db] || 0).to_i
  @password       = options[:password]
  @logger         = options[:logger]
  @error_callback = lambda do |code|
    err = RedisError.new
    err.code = code
    raise err, "Redis server returned error code: #{code}"
  end

  # These commands should be first
  auth_and_select_db
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/em-redis/redis_protocol.rb', line 186

def mapped_mget(*keys)
  mget(*keys) do |response|
    result = {}
    response.each do |value|
      key = keys.shift
      result.merge!(key => value) unless value.nil?
    end
    yield result if block_given?
  end
end

#maybe_lock(&blk) ⇒ Object 



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# File 'lib/em-redis/redis_protocol.rb', line 255

def maybe_lock(&blk)
  if !EM.reactor_thread?
    EM.schedule { maybe_lock(&blk) }
  elsif @connected
    yield
  else
    callback { yield }
  end
end

#mset(*args, &blk) ⇒ Object 



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# File 'lib/em-redis/redis_protocol.rb', line 228

def mset(*args, &blk)
  hsh = args.pop if Hash === args.last
  if hsh
    call_command(hsh.to_a.flatten.unshift(:mset), &blk)
  else
    call_command(args.unshift(:mset), &blk)
  end
end

#msetnx(*args, &blk) ⇒ Object 



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# File 'lib/em-redis/redis_protocol.rb', line 237

def msetnx(*args, &blk)
  hsh = args.pop if Hash === args.last
  if hsh
    call_command(hsh.to_a.flatten.unshift(:msetnx), &blk)
  else
    call_command(args.unshift(:msetnx), &blk)
  end
end

#multi ⇒ Object

I’m not sure autocommit is a good idea. For example:

r.multi { r.set('a', 'b') { raise "kaboom" } }

will commit “a” and will stop EM



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# File 'lib/em-redis/redis_protocol.rb', line 215

def multi
  call_command(['multi'])
  if block_given?
    begin
      yield self
      exec
    rescue Exception => e
      discard
      raise e
    end
  end
end

#process_cmd(line) ⇒ Object 



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# File 'lib/em-redis/redis_protocol.rb', line 375

def process_cmd(line)
  @logger.debug { "*** processing #{line}" } if @logger
  # first character of buffer will always be the response type
  reply_type = line[0, 1]
  reply_args = line.slice(1..-3) # remove type character and \r\n
  case reply_type

  #e.g. -MISSING
  when MINUS
    @redis_callbacks.shift # throw away the cb?
    @error_callback.call(reply_args)
  # e.g. +OK
  when PLUS
    dispatch_response(reply_args)
  # e.g. $3\r\nabc\r\n
  # 'bulk' is more complex because it could be part of multi-bulk
  when DOLLAR
    data_len = Integer(reply_args)
    if data_len == -1 # expect no data; return nil
      dispatch_response(nil)
    elsif @buffer.size >= data_len + 2 # buffer is full of expected data
      dispatch_response(@buffer.slice!(0, data_len))
      @buffer.slice!(0,2) # tossing \r\n
    else # buffer isn't full or nil
      # TODO: don't control execution with exceptions
      raise ParserError
    end
  #e.g. :8
  when COLON
    dispatch_response(Integer(reply_args))
  #e.g. *2\r\n$1\r\na\r\n$1\r\nb\r\n 
  when ASTERISK
    multibulk_count = Integer(reply_args)
    if multibulk_count == -1 || multibulk_count == 0
      dispatch_response([])
    else
      if @multibulk_n
        @previous_multibulks << [@multibulk_n, @multibulk_values]
      end
      @multibulk_n = multibulk_count
      @multibulk_values = []
    end
  # Whu?
  else
    # TODO: get rid of this exception
    raise ProtocolError, "reply type not recognized: #{line.strip}"
  end
end

#quit(&blk) ⇒ Object 



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# File 'lib/em-redis/redis_protocol.rb', line 203

def quit(&blk)
  call_command(['quit'], &blk)
end

#receive_data(data) ⇒ Object

19Feb09 Switched to a custom parser, LineText2 is recursive and can cause

stack overflows when there is too much data.

include EM::P::LineText2



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# File 'lib/em-redis/redis_protocol.rb', line 362

def receive_data(data)
  (@buffer ||= '') << data
  while index = @buffer.index(DELIM)
    begin
      line = @buffer.slice!(0, index+2)
      process_cmd line
    rescue ParserError
      @buffer[0...0] = line
      break
    end
  end
end

#select(db, &blk) ⇒ Object 



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# File 'lib/em-redis/redis_protocol.rb', line 174

def select(db, &blk)
  @db = db.to_i
  call_command(['select', @db], &blk)
end

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



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# File 'lib/em-redis/redis_protocol.rb', line 149

def set(key, value, expiry=nil)
  call_command([:set, key, value]) do |s|
    yield s if block_given?
  end
  expire(key, expiry) if expiry
end

#sort(key, options = {}, &blk) ⇒ Object 



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# File 'lib/em-redis/redis_protocol.rb', line 156

def sort(key, options={}, &blk)
  cmd = ["SORT"]
  cmd << key
  cmd << ["BY", options[:by]] if options[:by]
  cmd << [options[:get]].flatten.map { |key| ["GET", key] } if options[:get]
  cmd << options[:order].split(/\s+/) if options[:order]
  cmd << ["LIMIT", options[:limit]] if options[:limit]
  call_command(cmd.flatten, &blk)
end

#type(key, &blk) ⇒ 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/em-redis/redis_protocol.rb', line 199

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

#unbind ⇒ Object 



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# File 'lib/em-redis/redis_protocol.rb', line 446

def unbind
  @logger.debug { "Disconnected" }  if @logger
  if @connected || @reconnecting
    EM.add_timer(1) do
      @logger.debug { "Reconnecting to #{@host}:#{@port}" }  if @logger
      reconnect @host, @port
      auth_and_select_db
    end
    @connected = false
    @reconnecting = true
    @deferred_status = nil
  else
    # TODO: get rid of this exception
    raise 'Unable to connect to redis server'
  end
end