Put redis library in lib/vendor/ and adjust LOAD_PATHuse-redis-rb-client

14 files changed, 2786 insertions, 13 deletions

diff --git a/lib/vendor/redis/lib/redis.rb b/lib/vendor/redis/lib/redis.rb
new file mode 100644
index 0000000..62dcab7
--- /dev/null
+++ b/lib/vendor/redis/lib/redis.rb
@@ -0,0 +1,2773 @@
+require "monitor"
+require "redis/errors"
+
+class Redis
+
+  def self.deprecate(message, trace = caller[0])
+    $stderr.puts "\n#{message} (in #{trace})"
+  end
+
+  attr :client
+
+  # @deprecated The preferred way to create a new client object is using `#new`.
+  #             This method does not actually establish a connection to Redis,
+  #             in contrary to what you might expect.
+  def self.connect(options = {})
+    new(options)
+  end
+
+  def self.current
+    @current ||= Redis.new
+  end
+
+  def self.current=(redis)
+    @current = redis
+  end
+
+  include MonitorMixin
+
+  # Create a new client instance
+  #
+  # @param [Hash] options
+  # @option options [String] :url (value of the environment variable REDIS_URL) a Redis URL, for a TCP connection: `redis://:[password]@[hostname]:[port]/[db]` (password, port and database are optional), for a unix socket connection: `unix://[path to Redis socket]`. This overrides all other options.
+  # @option options [String] :host ("127.0.0.1") server hostname
+  # @option options [Fixnum] :port (6379) server port
+  # @option options [String] :path path to server socket (overrides host and port)
+  # @option options [Float] :timeout (5.0) timeout in seconds
+  # @option options [Float] :connect_timeout (same as timeout) timeout for initial connect in seconds
+  # @option options [String] :password Password to authenticate against server
+  # @option options [Fixnum] :db (0) Database to select after initial connect
+  # @option options [Symbol] :driver Driver to use, currently supported: `:ruby`, `:hiredis`, `:synchrony`
+  # @option options [String] :id ID for the client connection, assigns name to current connection by sending `CLIENT SETNAME`
+  # @option options [Hash, Fixnum] :tcp_keepalive Keepalive values, if Fixnum `intvl` and `probe` are calculated based on the value, if Hash `time`, `intvl` and `probes` can be specified as a Fixnum
+  # @option options [Fixnum] :reconnect_attempts Number of attempts trying to connect
+  # @option options [Boolean] :inherit_socket (false) Whether to use socket in forked process or not
+  # @option options [Array] :sentinels List of sentinels to contact
+  # @option options [Symbol] :role (:master) Role to fetch via Sentinel, either `:master` or `:slave`
+  #
+  # @return [Redis] a new client instance
+  def initialize(options = {})
+    @options = options.dup
+    @original_client = @client = Client.new(options)
+    @queue = Hash.new { |h, k| h[k] = [] }
+
+    super() # Monitor#initialize
+  end
+
+  def synchronize
+    mon_synchronize { yield(@client) }
+  end
+
+  # Run code with the client reconnecting
+  def with_reconnect(val=true, &blk)
+    synchronize do |client|
+      client.with_reconnect(val, &blk)
+    end
+  end
+
+  # Run code without the client reconnecting
+  def without_reconnect(&blk)
+    with_reconnect(false, &blk)
+  end
+
+  # Test whether or not the client is connected
+  def connected?
+    @original_client.connected?
+  end
+
+  # Disconnect the client as quickly and silently as possible.
+  def close
+    @original_client.disconnect
+  end
+  alias disconnect! close
+
+  # Sends a command to Redis and returns its reply.
+  #
+  # Replies are converted to Ruby objects according to the RESP protocol, so
+  # you can expect a Ruby array, integer or nil when Redis sends one. Higher
+  # level transformations, such as converting an array of pairs into a Ruby
+  # hash, are up to consumers.
+  #
+  # Redis error replies are raised as Ruby exceptions.
+  def call(*command)
+    synchronize do |client|
+      client.call(command)
+    end
+  end
+
+  # Queues a command for pipelining.
+  #
+  # Commands in the queue are executed with the Redis#commit method.
+  #
+  # See http://redis.io/topics/pipelining for more details.
+  #
+  def queue(*command)
+    @queue[Thread.current.object_id] << command
+  end
+
+  # Sends all commands in the queue.
+  #
+  # See http://redis.io/topics/pipelining for more details.
+  #
+  def commit
+    synchronize do |client|
+      begin
+        client.call_pipelined(@queue[Thread.current.object_id])
+      ensure
+        @queue.delete(Thread.current.object_id)
+      end
+    end
+  end
+
+  # Authenticate to the server.
+  #
+  # @param [String] password must match the password specified in the
+  #   `requirepass` directive in the configuration file
+  # @return [String] `OK`
+  def auth(password)
+    synchronize do |client|
+      client.call([:auth, password])
+    end
+  end
+
+  # Change the selected database for the current connection.
+  #
+  # @param [Fixnum] db zero-based index of the DB to use (0 to 15)
+  # @return [String] `OK`
+  def select(db)
+    synchronize do |client|
+      client.db = db
+      client.call([:select, db])
+    end
+  end
+
+  # Ping the server.
+  #
+  # @return [String] `PONG`
+  def ping
+    synchronize do |client|
+      client.call([:ping])
+    end
+  end
+
+  # Echo the given string.
+  #
+  # @param [String] value
+  # @return [String]
+  def echo(value)
+    synchronize do |client|
+      client.call([:echo, value])
+    end
+  end
+
+  # Close the connection.
+  #
+  # @return [String] `OK`
+  def quit
+    synchronize do |client|
+      begin
+        client.call([:quit])
+      rescue ConnectionError
+      ensure
+        client.disconnect
+      end
+    end
+  end
+
+  # Asynchronously rewrite the append-only file.
+  #
+  # @return [String] `OK`
+  def bgrewriteaof
+    synchronize do |client|
+      client.call([:bgrewriteaof])
+    end
+  end
+
+  # Asynchronously save the dataset to disk.
+  #
+  # @return [String] `OK`
+  def bgsave
+    synchronize do |client|
+      client.call([:bgsave])
+    end
+  end
+
+  # Get or set server configuration parameters.
+  #
+  # @param [Symbol] action e.g. `:get`, `:set`, `:resetstat`
+  # @return [String, Hash] string reply, or hash when retrieving more than one
+  #   property with `CONFIG GET`
+  def config(action, *args)
+    synchronize do |client|
+      client.call([:config, action] + args) do |reply|
+        if reply.kind_of?(Array) && action == :get
+          Hashify.call(reply)
+        else
+          reply
+        end
+      end
+    end
+  end
+
+  # Return the number of keys in the selected database.
+  #
+  # @return [Fixnum]
+  def dbsize
+    synchronize do |client|
+      client.call([:dbsize])
+    end
+  end
+
+  def debug(*args)
+    synchronize do |client|
+      client.call([:debug] + args)
+    end
+  end
+
+  # Remove all keys from all databases.
+  #
+  # @return [String] `OK`
+  def flushall
+    synchronize do |client|
+      client.call([:flushall])
+    end
+  end
+
+  # Remove all keys from the current database.
+  #
+  # @return [String] `OK`
+  def flushdb
+    synchronize do |client|
+      client.call([:flushdb])
+    end
+  end
+
+  # Get information and statistics about the server.
+  #
+  # @param [String, Symbol] cmd e.g. "commandstats"
+  # @return [Hash<String, String>]
+  def info(cmd = nil)
+    synchronize do |client|
+      client.call([:info, cmd].compact) do |reply|
+        if reply.kind_of?(String)
+          reply = Hash[reply.split("\r\n").map do |line|
+            line.split(":", 2) unless line =~ /^(#|$)/
+          end.compact]
+
+          if cmd && cmd.to_s == "commandstats"
+            # Extract nested hashes for INFO COMMANDSTATS
+            reply = Hash[reply.map do |k, v|
+              v = v.split(",").map { |e| e.split("=") }
+              [k[/^cmdstat_(.*)$/, 1], Hash[v]]
+            end]
+          end
+        end
+
+        reply
+      end
+    end
+  end
+
+  # Get the UNIX time stamp of the last successful save to disk.
+  #
+  # @return [Fixnum]
+  def lastsave
+    synchronize do |client|
+      client.call([:lastsave])
+    end
+  end
+
+  # Listen for all requests received by the server in real time.
+  #
+  # There is no way to interrupt this command.
+  #
+  # @yield a block to be called for every line of output
+  # @yieldparam [String] line timestamp and command that was executed
+  def monitor(&block)
+    synchronize do |client|
+      client.call_loop([:monitor], &block)
+    end
+  end
+
+  # Synchronously save the dataset to disk.
+  #
+  # @return [String]
+  def save
+    synchronize do |client|
+      client.call([:save])
+    end
+  end
+
+  # Synchronously save the dataset to disk and then shut down the server.
+  def shutdown
+    synchronize do |client|
+      client.with_reconnect(false) do
+        begin
+          client.call([:shutdown])
+        rescue ConnectionError
+          # This means Redis has probably exited.
+          nil
+        end
+      end
+    end
+  end
+
+  # Make the server a slave of another instance, or promote it as master.
+  def slaveof(host, port)
+    synchronize do |client|
+      client.call([:slaveof, host, port])
+    end
+  end
+
+  # Interact with the slowlog (get, len, reset)
+  #
+  # @param [String] subcommand e.g. `get`, `len`, `reset`
+  # @param [Fixnum] length maximum number of entries to return
+  # @return [Array<String>, Fixnum, String] depends on subcommand
+  def slowlog(subcommand, length=nil)
+    synchronize do |client|
+      args = [:slowlog, subcommand]
+      args << length if length
+      client.call args
+    end
+  end
+
+  # Internal command used for replication.
+  def sync
+    synchronize do |client|
+      client.call([:sync])
+    end
+  end
+
+  # Return the server time.
+  #
+  # @example
+  #   r.time # => [ 1333093196, 606806 ]
+  #
+  # @return [Array<Fixnum>] tuple of seconds since UNIX epoch and
+  #   microseconds in the current second
+  def time
+    synchronize do |client|
+      client.call([:time]) do |reply|
+        reply.map(&:to_i) if reply
+      end
+    end
+  end
+
+  # Remove the expiration from a key.
+  #
+  # @param [String] key
+  # @return [Boolean] whether the timeout was removed or not
+  def persist(key)
+    synchronize do |client|
+      client.call([:persist, key], &Boolify)
+    end
+  end
+
+  # Set a key's time to live in seconds.
+  #
+  # @param [String] key
+  # @param [Fixnum] seconds time to live
+  # @return [Boolean] whether the timeout was set or not
+  def expire(key, seconds)
+    synchronize do |client|
+      client.call([:expire, key, seconds], &Boolify)
+    end
+  end
+
+  # Set the expiration for a key as a UNIX timestamp.
+  #
+  # @param [String] key
+  # @param [Fixnum] unix_time expiry time specified as a UNIX timestamp
+  # @return [Boolean] whether the timeout was set or not
+  def expireat(key, unix_time)
+    synchronize do |client|
+      client.call([:expireat, key, unix_time], &Boolify)
+    end
+  end
+
+  # Get the time to live (in seconds) for a key.
+  #
+  # @param [String] key
+  # @return [Fixnum] remaining time to live in seconds.
+  #
+  # In Redis 2.6 or older the command returns -1 if the key does not exist or if
+  # the key exist but has no associated expire.
+  #
+  # Starting with Redis 2.8 the return value in case of error changed:
+  #
+  #     - The command returns -2 if the key does not exist.
+  #     - The command returns -1 if the key exists but has no associated expire.
+  def ttl(key)
+    synchronize do |client|
+      client.call([:ttl, key])
+    end
+  end
+
+  # Set a key's time to live in milliseconds.
+  #
+  # @param [String] key
+  # @param [Fixnum] milliseconds time to live
+  # @return [Boolean] whether the timeout was set or not
+  def pexpire(key, milliseconds)
+    synchronize do |client|
+      client.call([:pexpire, key, milliseconds], &Boolify)
+    end
+  end
+
+  # Set the expiration for a key as number of milliseconds from UNIX Epoch.
+  #
+  # @param [String] key
+  # @param [Fixnum] ms_unix_time expiry time specified as number of milliseconds from UNIX Epoch.
+  # @return [Boolean] whether the timeout was set or not
+  def pexpireat(key, ms_unix_time)
+    synchronize do |client|
+      client.call([:pexpireat, key, ms_unix_time], &Boolify)
+    end
+  end
+
+  # Get the time to live (in milliseconds) for a key.
+  #
+  # @param [String] key
+  # @return [Fixnum] remaining time to live in milliseconds
+  # In Redis 2.6 or older the command returns -1 if the key does not exist or if
+  # the key exist but has no associated expire.
+  #
+  # Starting with Redis 2.8 the return value in case of error changed:
+  #
+  #     - The command returns -2 if the key does not exist.
+  #     - The command returns -1 if the key exists but has no associated expire.
+  def pttl(key)
+    synchronize do |client|
+      client.call([:pttl, key])
+    end
+  end
+
+  # Return a serialized version of the value stored at a key.
+  #
+  # @param [String] key
+  # @return [String] serialized_value
+  def dump(key)
+    synchronize do |client|
+      client.call([:dump, key])
+    end
+  end
+
+  # Create a key using the serialized value, previously obtained using DUMP.
+  #
+  # @param [String] key
+  # @param [String] ttl
+  # @param [String] serialized_value
+  # @return [String] `"OK"`
+  def restore(key, ttl, serialized_value)
+    synchronize do |client|
+      client.call([:restore, key, ttl, serialized_value])
+    end
+  end
+
+  # Transfer a key from the connected instance to another instance.
+  #
+  # @param [String] key
+  # @param [Hash] options
+  #   - `:host => String`: host of instance to migrate to
+  #   - `:port => Integer`: port of instance to migrate to
+  #   - `:db => Integer`: database to migrate to (default: same as source)
+  #   - `:timeout => Integer`: timeout (default: same as connection timeout)
+  # @return [String] `"OK"`
+  def migrate(key, options)
+    host = options[:host] || raise(RuntimeError, ":host not specified")
+    port = options[:port] || raise(RuntimeError, ":port not specified")
+    db = (options[:db] || client.db).to_i
+    timeout = (options[:timeout] || client.timeout).to_i
+
+    synchronize do |client|
+      client.call([:migrate, host, port, key, db, timeout])
+    end
+  end
+
+  # Delete one or more keys.
+  #
+  # @param [String, Array<String>] keys
+  # @return [Fixnum] number of keys that were deleted
+  def del(*keys)
+    synchronize do |client|
+      client.call([:del] + keys)
+    end
+  end
+
+  # Determine if a key exists.
+  #
+  # @param [String] key
+  # @return [Boolean]
+  def exists(key)
+    synchronize do |client|
+      client.call([:exists, key], &Boolify)
+    end
+  end
+
+  # Find all keys matching the given pattern.
+  #
+  # @param [String] pattern
+  # @return [Array<String>]
+  def keys(pattern = "*")
+    synchronize do |client|
+      client.call([:keys, pattern]) do |reply|
+        if reply.kind_of?(String)
+          reply.split(" ")
+        else
+          reply
+        end
+      end
+    end
+  end
+
+  # Move a key to another database.
+  #
+  # @example Move a key to another database
+  #   redis.set "foo", "bar"
+  #     # => "OK"
+  #   redis.move "foo", 2
+  #     # => true
+  #   redis.exists "foo"
+  #     # => false
+  #   redis.select 2
+  #     # => "OK"
+  #   redis.exists "foo"
+  #     # => true
+  #   redis.get "foo"
+  #     # => "bar"
+  #
+  # @param [String] key
+  # @param [Fixnum] db
+  # @return [Boolean] whether the key was moved or not
+  def move(key, db)
+    synchronize do |client|
+      client.call([:move, key, db], &Boolify)
+    end
+  end
+
+  def object(*args)
+    synchronize do |client|
+      client.call([:object] + args)
+    end
+  end
+
+  # Return a random key from the keyspace.
+  #
+  # @return [String]
+  def randomkey
+    synchronize do |client|
+      client.call([:randomkey])
+    end
+  end
+
+  # Rename a key. If the new key already exists it is overwritten.
+  #
+  # @param [String] old_name
+  # @param [String] new_name
+  # @return [String] `OK`
+  def rename(old_name, new_name)
+    synchronize do |client|
+      client.call([:rename, old_name, new_name])
+    end
+  end
+
+  # Rename a key, only if the new key does not exist.
+  #
+  # @param [String] old_name
+  # @param [String] new_name
+  # @return [Boolean] whether the key was renamed or not
+  def renamenx(old_name, new_name)
+    synchronize do |client|
+      client.call([:renamenx, old_name, new_name], &Boolify)
+    end
+  end
+
+  # Sort the elements in a list, set or sorted set.
+  #
+  # @example Retrieve the first 2 elements from an alphabetically sorted "list"
+  #   redis.sort("list", :order => "alpha", :limit => [0, 2])
+  #     # => ["a", "b"]
+  # @example Store an alphabetically descending list in "target"
+  #   redis.sort("list", :order => "desc alpha", :store => "target")
+  #     # => 26
+  #
+  # @param [String] key
+  # @param [Hash] options
+  #   - `:by => String`: use external key to sort elements by
+  #   - `:limit => [offset, count]`: skip `offset` elements, return a maximum
+  #   of `count` elements
+  #   - `:get => [String, Array<String>]`: single key or array of keys to
+  #   retrieve per element in the result
+  #   - `:order => String`: combination of `ASC`, `DESC` and optionally `ALPHA`
+  #   - `:store => String`: key to store the result at
+  #
+  # @return [Array<String>, Array<Array<String>>, Fixnum]
+  #   - when `:get` is not specified, or holds a single element, an array of elements
+  #   - when `:get` is specified, and holds more than one element, an array of
+  #   elements where every element is an array with the result for every
+  #   element specified in `:get`
+  #   - when `:store` is specified, the number of elements in the stored result
+  def sort(key, options = {})
+    args = []
+
+    by = options[:by]
+    args.concat(["BY", by]) if by
+
+    limit = options[:limit]
+    args.concat(["LIMIT"] + limit) if limit
+
+    get = Array(options[:get])
+    args.concat(["GET"].product(get).flatten) unless get.empty?
+
+    order = options[:order]
+    args.concat(order.split(" ")) if order
+
+    store = options[:store]
+    args.concat(["STORE", store]) if store
+
+    synchronize do |client|
+      client.call([:sort, key] + args) do |reply|
+        if get.size > 1 && !store
+          if reply
+            reply.each_slice(get.size).to_a
+          end
+        else
+          reply
+        end
+      end
+    end
+  end
+
+  # Determine the type stored at key.
+  #
+  # @param [String] key
+  # @return [String] `string`, `list`, `set`, `zset`, `hash` or `none`
+  def type(key)
+    synchronize do |client|
+      client.call([:type, key])
+    end
+  end
+
+  # Decrement the integer value of a key by one.
+  #
+  # @example
+  #   redis.decr("value")
+  #     # => 4
+  #
+  # @param [String] key
+  # @return [Fixnum] value after decrementing it
+  def decr(key)
+    synchronize do |client|
+      client.call([:decr, key])
+    end
+  end
+
+  # Decrement the integer value of a key by the given number.
+  #
+  # @example
+  #   redis.decrby("value", 5)
+  #     # => 0
+  #
+  # @param [String] key
+  # @param [Fixnum] decrement
+  # @return [Fixnum] value after decrementing it
+  def decrby(key, decrement)
+    synchronize do |client|
+      client.call([:decrby, key, decrement])
+    end
+  end
+
+  # Increment the integer value of a key by one.
+  #
+  # @example
+  #   redis.incr("value")
+  #     # => 6
+  #
+  # @param [String] key
+  # @return [Fixnum] value after incrementing it
+  def incr(key)
+    synchronize do |client|
+      client.call([:incr, key])
+    end
+  end
+
+  # Increment the integer value of a key by the given integer number.
+  #
+  # @example
+  #   redis.incrby("value", 5)
+  #     # => 10
+  #
+  # @param [String] key
+  # @param [Fixnum] increment
+  # @return [Fixnum] value after incrementing it
+  def incrby(key, increment)
+    synchronize do |client|
+      client.call([:incrby, key, increment])
+    end
+  end
+
+  # Increment the numeric value of a key by the given float number.
+  #
+  # @example
+  #   redis.incrbyfloat("value", 1.23)
+  #     # => 1.23
+  #
+  # @param [String] key
+  # @param [Float] increment
+  # @return [Float] value after incrementing it
+  def incrbyfloat(key, increment)
+    synchronize do |client|
+      client.call([:incrbyfloat, key, increment], &Floatify)
+    end
+  end
+
+  # Set the string value of a key.
+  #
+  # @param [String] key
+  # @param [String] value
+  # @param [Hash] options
+  #   - `:ex => Fixnum`: Set the specified expire time, in seconds.
+  #   - `:px => Fixnum`: Set the specified expire time, in milliseconds.
+  #   - `:nx => true`: Only set the key if it does not already exist.
+  #   - `:xx => true`: Only set the key if it already exist.
+  # @return [String, Boolean] `"OK"` or true, false if `:nx => true` or `:xx => true`
+  def set(key, value, options = {})
+    args = []
+
+    ex = options[:ex]
+    args.concat(["EX", ex]) if ex
+
+    px = options[:px]
+    args.concat(["PX", px]) if px
+
+    nx = options[:nx]
+    args.concat(["NX"]) if nx
+
+    xx = options[:xx]
+    args.concat(["XX"]) if xx
+
+    synchronize do |client|
+      if nx || xx
+        client.call([:set, key, value.to_s] + args, &BoolifySet)
+      else
+        client.call([:set, key, value.to_s] + args)
+      end
+    end
+  end
+
+  alias :[]= :set
+
+  # Set the time to live in seconds of a key.
+  #
+  # @param [String] key
+  # @param [Fixnum] ttl
+  # @param [String] value
+  # @return [String] `"OK"`
+  def setex(key, ttl, value)
+    synchronize do |client|
+      client.call([:setex, key, ttl, value.to_s])
+    end
+  end
+
+  # Set the time to live in milliseconds of a key.
+  #
+  # @param [String] key
+  # @param [Fixnum] ttl
+  # @param [String] value
+  # @return [String] `"OK"`
+  def psetex(key, ttl, value)
+    synchronize do |client|
+      client.call([:psetex, key, ttl, value.to_s])
+    end
+  end
+
+  # Set the value of a key, only if the key does not exist.
+  #
+  # @param [String] key
+  # @param [String] value
+  # @return [Boolean] whether the key was set or not
+  def setnx(key, value)
+    synchronize do |client|
+      client.call([:setnx, key, value.to_s], &Boolify)
+    end
+  end
+
+  # Set one or more values.
+  #
+  # @example
+  #   redis.mset("key1", "v1", "key2", "v2")
+  #     # => "OK"
+  #
+  # @param [Array<String>] args array of keys and values
+  # @return [String] `"OK"`
+  #
+  # @see #mapped_mset
+  def mset(*args)
+    synchronize do |client|
+      client.call([:mset] + args)
+    end
+  end
+
+  # Set one or more values.
+  #
+  # @example
+  #   redis.mapped_mset({ "f1" => "v1", "f2" => "v2" })
+  #     # => "OK"
+  #
+  # @param [Hash] hash keys mapping to values
+  # @return [String] `"OK"`
+  #
+  # @see #mset
+  def mapped_mset(hash)
+    mset(hash.to_a.flatten)
+  end
+
+  # Set one or more values, only if none of the keys exist.
+  #
+  # @example
+  #   redis.msetnx("key1", "v1", "key2", "v2")
+  #     # => true
+  #
+  # @param [Array<String>] args array of keys and values
+  # @return [Boolean] whether or not all values were set
+  #
+  # @see #mapped_msetnx
+  def msetnx(*args)
+    synchronize do |client|
+      client.call([:msetnx] + args, &Boolify)
+    end
+  end
+
+  # Set one or more values, only if none of the keys exist.
+  #
+  # @example
+  #   redis.mapped_msetnx({ "key1" => "v1", "key2" => "v2" })
+  #     # => true
+  #
+  # @param [Hash] hash keys mapping to values
+  # @return [Boolean] whether or not all values were set
+  #
+  # @see #msetnx
+  def mapped_msetnx(hash)
+    msetnx(hash.to_a.flatten)
+  end
+
+  # Get the value of a key.
+  #
+  # @param [String] key
+  # @return [String]
+  def get(key)
+    synchronize do |client|
+      client.call([:get, key])
+    end
+  end
+
+  alias :[] :get
+
+  # Get the values of all the given keys.
+  #
+  # @example
+  #   redis.mget("key1", "key1")
+  #     # => ["v1", "v2"]
+  #
+  # @param [Array<String>] keys
+  # @return [Array<String>] an array of values for the specified keys
+  #
+  # @see #mapped_mget
+  def mget(*keys, &blk)
+    synchronize do |client|
+      client.call([:mget] + keys, &blk)
+    end
+  end
+
+  # Get the values of all the given keys.
+  #
+  # @example
+  #   redis.mapped_mget("key1", "key2")
+  #     # => { "key1" => "v1", "key2" => "v2" }
+  #
+  # @param [Array<String>] keys array of keys
+  # @return [Hash] a hash mapping the specified keys to their values
+  #
+  # @see #mget
+  def mapped_mget(*keys)
+    mget(*keys) do |reply|
+      if reply.kind_of?(Array)
+        Hash[keys.zip(reply)]
+      else
+        reply
+      end
+    end
+  end
+
+  # Overwrite part of a string at key starting at the specified offset.
+  #
+  # @param [String] key
+  # @param [Fixnum] offset byte offset
+  # @param [String] value
+  # @return [Fixnum] length of the string after it was modified
+  def setrange(key, offset, value)
+    synchronize do |client|
+      client.call([:setrange, key, offset, value.to_s])
+    end
+  end
+
+  # Get a substring of the string stored at a key.
+  #
+  # @param [String] key
+  # @param [Fixnum] start zero-based start offset
+  # @param [Fixnum] stop zero-based end offset. Use -1 for representing
+  #   the end of the string
+  # @return [Fixnum] `0` or `1`
+  def getrange(key, start, stop)
+    synchronize do |client|
+      client.call([:getrange, key, start, stop])
+    end
+  end
+
+  # Sets or clears the bit at offset in the string value stored at key.
+  #
+  # @param [String] key
+  # @param [Fixnum] offset bit offset
+  # @param [Fixnum] value bit value `0` or `1`
+  # @return [Fixnum] the original bit value stored at `offset`
+  def setbit(key, offset, value)
+    synchronize do |client|
+      client.call([:setbit, key, offset, value])
+    end
+  end
+
+  # Returns the bit value at offset in the string value stored at key.
+  #
+  # @param [String] key
+  # @param [Fixnum] offset bit offset
+  # @return [Fixnum] `0` or `1`
+  def getbit(key, offset)
+    synchronize do |client|
+      client.call([:getbit, key, offset])
+    end
+  end
+
+  # Append a value to a key.
+  #
+  # @param [String] key
+  # @param [String] value value to append
+  # @return [Fixnum] length of the string after appending
+  def append(key, value)
+    synchronize do |client|
+      client.call([:append, key, value])
+    end
+  end
+
+  # Count the number of set bits in a range of the string value stored at key.
+  #
+  # @param [String] key
+  # @param [Fixnum] start start index
+  # @param [Fixnum] stop stop index
+  # @return [Fixnum] the number of bits set to 1
+  def bitcount(key, start = 0, stop = -1)
+    synchronize do |client|
+      client.call([:bitcount, key, start, stop])
+    end
+  end
+
+  # Perform a bitwise operation between strings and store the resulting string in a key.
+  #
+  # @param [String] operation e.g. `and`, `or`, `xor`, `not`
+  # @param [String] destkey destination key
+  # @param [String, Array<String>] keys one or more source keys to perform `operation`
+  # @return [Fixnum] the length of the string stored in `destkey`
+  def bitop(operation, destkey, *keys)
+    synchronize do |client|
+      client.call([:bitop, operation, destkey] + keys)
+    end
+  end
+
+  # Return the position of the first bit set to 1 or 0 in a string.
+  #
+  # @param [String] key
+  # @param [Fixnum] bit whether to look for the first 1 or 0 bit
+  # @param [Fixnum] start start index
+  # @param [Fixnum] stop stop index
+  # @return [Fixnum] the position of the first 1/0 bit.
+  #                  -1 if looking for 1 and it is not found or start and stop are given.
+  def bitpos(key, bit, start=nil, stop=nil)
+    if stop and not start
+      raise(ArgumentError, 'stop parameter specified without start parameter')
+    end
+
+    synchronize do |client|
+      command = [:bitpos, key, bit]
+      command << start if start
+      command << stop if stop
+      client.call(command)
+    end
+  end
+
+  # Set the string value of a key and return its old value.
+  #
+  # @param [String] key
+  # @param [String] value value to replace the current value with
+  # @return [String] the old value stored in the key, or `nil` if the key
+  #   did not exist
+  def getset(key, value)
+    synchronize do |client|
+      client.call([:getset, key, value.to_s])
+    end
+  end
+
+  # Get the length of the value stored in a key.
+  #
+  # @param [String] key
+  # @return [Fixnum] the length of the value stored in the key, or 0
+  #   if the key does not exist
+  def strlen(key)
+    synchronize do |client|
+      client.call([:strlen, key])
+    end
+  end
+
+  # Get the length of a list.
+  #
+  # @param [String] key
+  # @return [Fixnum]
+  def llen(key)
+    synchronize do |client|
+      client.call([:llen, key])
+    end
+  end
+
+  # Prepend one or more values to a list, creating the list if it doesn't exist
+  #
+  # @param [String] key
+  # @param [String, Array] value string value, or array of string values to push
+  # @return [Fixnum] the length of the list after the push operation
+  def lpush(key, value)
+    synchronize do |client|
+      client.call([:lpush, key, value])
+    end
+  end
+
+  # Prepend a value to a list, only if the list exists.
+  #
+  # @param [String] key
+  # @param [String] value
+  # @return [Fixnum] the length of the list after the push operation
+  def lpushx(key, value)
+    synchronize do |client|
+      client.call([:lpushx, key, value])
+    end
+  end
+
+  # Append one or more values to a list, creating the list if it doesn't exist
+  #
+  # @param [String] key
+  # @param [String] value
+  # @return [Fixnum] the length of the list after the push operation
+  def rpush(key, value)
+    synchronize do |client|
+      client.call([:rpush, key, value])
+    end
+  end
+
+  # Append a value to a list, only if the list exists.
+  #
+  # @param [String] key
+  # @param [String] value
+  # @return [Fixnum] the length of the list after the push operation
+  def rpushx(key, value)
+    synchronize do |client|
+      client.call([:rpushx, key, value])
+    end
+  end
+
+  # Remove and get the first element in a list.
+  #
+  # @param [String] key
+  # @return [String]
+  def lpop(key)
+    synchronize do |client|
+      client.call([:lpop, key])
+    end
+  end
+
+  # Remove and get the last element in a list.
+  #
+  # @param [String] key
+  # @return [String]
+  def rpop(key)
+    synchronize do |client|
+      client.call([:rpop, key])
+    end
+  end
+
+  # Remove the last element in a list, append it to another list and return it.
+  #
+  # @param [String] source source key
+  # @param [String] destination destination key
+  # @return [nil, String] the element, or nil when the source key does not exist
+  def rpoplpush(source, destination)
+    synchronize do |client|
+      client.call([:rpoplpush, source, destination])
+    end
+  end
+
+  def _bpop(cmd, args)
+    options = {}
+
+    case args.last
+    when Hash
+      options = args.pop
+    when Integer
+      # Issue deprecation notice in obnoxious mode...
+      options[:timeout] = args.pop
+    end
+
+    if args.size > 1
+      # Issue deprecation notice in obnoxious mode...
+    end
+
+    keys = args.flatten
+    timeout = options[:timeout] || 0
+
+    synchronize do |client|
+      command = [cmd, keys, timeout]
+      timeout += client.timeout if timeout > 0
+      client.call_with_timeout(command, timeout)
+    end
+  end
+
+  # Remove and get the first element in a list, or block until one is available.
+  #
+  # @example With timeout
+  #   list, element = redis.blpop("list", :timeout => 5)
+  #     # => nil on timeout
+  #     # => ["list", "element"] on success
+  # @example Without timeout
+  #   list, element = redis.blpop("list")
+  #     # => ["list", "element"]
+  # @example Blocking pop on multiple lists
+  #   list, element = redis.blpop(["list", "another_list"])
+  #     # => ["list", "element"]
+  #
+  # @param [String, Array<String>] keys one or more keys to perform the
+  #   blocking pop on
+  # @param [Hash] options
+  #   - `:timeout => Fixnum`: timeout in seconds, defaults to no timeout
+  #
+  # @return [nil, [String, String]]
+  #   - `nil` when the operation timed out
+  #   - tuple of the list that was popped from and element was popped otherwise
+  def blpop(*args)
+    _bpop(:blpop, args)
+  end
+
+  # Remove and get the last element in a list, or block until one is available.
+  #
+  # @param [String, Array<String>] keys one or more keys to perform the
+  #   blocking pop on
+  # @param [Hash] options
+  #   - `:timeout => Fixnum`: timeout in seconds, defaults to no timeout
+  #
+  # @return [nil, [String, String]]
+  #   - `nil` when the operation timed out
+  #   - tuple of the list that was popped from and element was popped otherwise
+  #
+  # @see #blpop
+  def brpop(*args)
+    _bpop(:brpop, args)
+  end
+
+  # Pop a value from a list, push it to another list and return it; or block
+  # until one is available.
+  #
+  # @param [String] source source key
+  # @param [String] destination destination key
+  # @param [Hash] options
+  #   - `:timeout => Fixnum`: timeout in seconds, defaults to no timeout
+  #
+  # @return [nil, String]
+  #   - `nil` when the operation timed out
+  #   - the element was popped and pushed otherwise
+  def brpoplpush(source, destination, options = {})
+    case options
+    when Integer
+      # Issue deprecation notice in obnoxious mode...
+      options = { :timeout => options }
+    end
+
+    timeout = options[:timeout] || 0
+
+    synchronize do |client|
+      command = [:brpoplpush, source, destination, timeout]
+      timeout += client.timeout if timeout > 0
+      client.call_with_timeout(command, timeout)
+    end
+  end
+
+  # Get an element from a list by its index.
+  #
+  # @param [String] key
+  # @param [Fixnum] index
+  # @return [String]
+  def lindex(key, index)
+    synchronize do |client|
+      client.call([:lindex, key, index])
+    end
+  end
+
+  # Insert an element before or after another element in a list.
+  #
+  # @param [String] key
+  # @param [String, Symbol] where `BEFORE` or `AFTER`
+  # @param [String] pivot reference element
+  # @param [String] value
+  # @return [Fixnum] length of the list after the insert operation, or `-1`
+  #   when the element `pivot` was not found
+  def linsert(key, where, pivot, value)
+    synchronize do |client|
+      client.call([:linsert, key, where, pivot, value])
+    end
+  end
+
+  # Get a range of elements from a list.
+  #
+  # @param [String] key
+  # @param [Fixnum] start start index
+  # @param [Fixnum] stop stop index
+  # @return [Array<String>]
+  def lrange(key, start, stop)
+    synchronize do |client|
+      client.call([:lrange, key, start, stop])
+    end
+  end
+
+  # Remove elements from a list.
+  #
+  # @param [String] key
+  # @param [Fixnum] count number of elements to remove. Use a positive
+  #   value to remove the first `count` occurrences of `value`. A negative
+  #   value to remove the last `count` occurrences of `value`. Or zero, to
+  #   remove all occurrences of `value` from the list.
+  # @param [String] value
+  # @return [Fixnum] the number of removed elements
+  def lrem(key, count, value)
+    synchronize do |client|
+      client.call([:lrem, key, count, value])
+    end
+  end
+
+  # Set the value of an element in a list by its index.
+  #
+  # @param [String] key
+  # @param [Fixnum] index
+  # @param [String] value
+  # @return [String] `OK`
+  def lset(key, index, value)
+    synchronize do |client|
+      client.call([:lset, key, index, value])
+    end
+  end
+
+  # Trim a list to the specified range.
+  #
+  # @param [String] key
+  # @param [Fixnum] start start index
+  # @param [Fixnum] stop stop index
+  # @return [String] `OK`
+  def ltrim(key, start, stop)
+    synchronize do |client|
+      client.call([:ltrim, key, start, stop])
+    end
+  end
+
+  # Get the number of members in a set.
+  #
+  # @param [String] key
+  # @return [Fixnum]
+  def scard(key)
+    synchronize do |client|
+      client.call([:scard, key])
+    end
+  end
+
+  # Add one or more members to a set.
+  #
+  # @param [String] key
+  # @param [String, Array<String>] member one member, or array of members
+  # @return [Boolean, Fixnum] `Boolean` when a single member is specified,
+  #   holding whether or not adding the member succeeded, or `Fixnum` when an
+  #   array of members is specified, holding the number of members that were
+  #   successfully added
+  def sadd(key, member)
+    synchronize do |client|
+      client.call([:sadd, key, member]) do |reply|
+        if member.is_a? Array
+          # Variadic: return integer
+          reply
+        else
+          # Single argument: return boolean
+          Boolify.call(reply)
+        end
+      end
+    end
+  end
+
+  # Remove one or more members from a set.
+  #
+  # @param [String] key
+  # @param [String, Array<String>] member one member, or array of members
+  # @return [Boolean, Fixnum] `Boolean` when a single member is specified,
+  #   holding whether or not removing the member succeeded, or `Fixnum` when an
+  #   array of members is specified, holding the number of members that were
+  #   successfully removed
+  def srem(key, member)
+    synchronize do |client|
+      client.call([:srem, key, member]) do |reply|
+        if member.is_a? Array
+          # Variadic: return integer
+          reply
+        else
+          # Single argument: return boolean
+          Boolify.call(reply)
+        end
+      end
+    end
+  end
+
+  # Remove and return a random member from a set.
+  #
+  # @param [String] key
+  # @return [String]
+  def spop(key)
+    synchronize do |client|
+      client.call([:spop, key])
+    end
+  end
+
+  # Get one or more random members from a set.
+  #
+  # @param [String] key
+  # @param [Fixnum] count
+  # @return [String]
+  def srandmember(key, count = nil)
+    synchronize do |client|
+      if count.nil?
+        client.call([:srandmember, key])
+      else
+        client.call([:srandmember, key, count])
+      end
+    end
+  end
+
+  # Move a member from one set to another.
+  #
+  # @param [String] source source key
+  # @param [String] destination destination key
+  # @param [String] member member to move from `source` to `destination`
+  # @return [Boolean]
+  def smove(source, destination, member)
+    synchronize do |client|
+      client.call([:smove, source, destination, member], &Boolify)
+    end
+  end
+
+  # Determine if a given value is a member of a set.
+  #
+  # @param [String] key
+  # @param [String] member
+  # @return [Boolean]
+  def sismember(key, member)
+    synchronize do |client|
+      client.call([:sismember, key, member], &Boolify)
+    end
+  end
+
+  # Get all the members in a set.
+  #
+  # @param [String] key
+  # @return [Array<String>]
+  def smembers(key)
+    synchronize do |client|
+      client.call([:smembers, key])
+    end
+  end
+
+  # Subtract multiple sets.
+  #
+  # @param [String, Array<String>] keys keys pointing to sets to subtract
+  # @return [Array<String>] members in the difference
+  def sdiff(*keys)
+    synchronize do |client|
+      client.call([:sdiff] + keys)
+    end
+  end
+
+  # Subtract multiple sets and store the resulting set in a key.
+  #
+  # @param [String] destination destination key
+  # @param [String, Array<String>] keys keys pointing to sets to subtract
+  # @return [Fixnum] number of elements in the resulting set
+  def sdiffstore(destination, *keys)
+    synchronize do |client|
+      client.call([:sdiffstore, destination] + keys)
+    end
+  end
+
+  # Intersect multiple sets.
+  #
+  # @param [String, Array<String>] keys keys pointing to sets to intersect
+  # @return [Array<String>] members in the intersection
+  def sinter(*keys)
+    synchronize do |client|
+      client.call([:sinter] + keys)
+    end
+  end
+
+  # Intersect multiple sets and store the resulting set in a key.
+  #
+  # @param [String] destination destination key
+  # @param [String, Array<String>] keys keys pointing to sets to intersect
+  # @return [Fixnum] number of elements in the resulting set
+  def sinterstore(destination, *keys)
+    synchronize do |client|
+      client.call([:sinterstore, destination] + keys)
+    end
+  end
+
+  # Add multiple sets.
+  #
+  # @param [String, Array<String>] keys keys pointing to sets to unify
+  # @return [Array<String>] members in the union
+  def sunion(*keys)
+    synchronize do |client|
+      client.call([:sunion] + keys)
+    end
+  end
+
+  # Add multiple sets and store the resulting set in a key.
+  #
+  # @param [String] destination destination key
+  # @param [String, Array<String>] keys keys pointing to sets to unify
+  # @return [Fixnum] number of elements in the resulting set
+  def sunionstore(destination, *keys)
+    synchronize do |client|
+      client.call([:sunionstore, destination] + keys)
+    end
+  end
+
+  # Get the number of members in a sorted set.
+  #
+  # @example
+  #   redis.zcard("zset")
+  #     # => 4
+  #
+  # @param [String] key
+  # @return [Fixnum]
+  def zcard(key)
+    synchronize do |client|
+      client.call([:zcard, key])
+    end
+  end
+
+  # Add one or more members to a sorted set, or update the score for members
+  # that already exist.
+  #
+  # @example Add a single `[score, member]` pair to a sorted set
+  #   redis.zadd("zset", 32.0, "member")
+  # @example Add an array of `[score, member]` pairs to a sorted set
+  #   redis.zadd("zset", [[32.0, "a"], [64.0, "b"]])
+  #
+  # @param [String] key
+  # @param [[Float, String], Array<[Float, String]>] args
+  #   - a single `[score, member]` pair
+  #   - an array of `[score, member]` pairs
+  # @param [Hash] options
+  #   - `:xx => true`: Only update elements that already exist (never
+  #   add elements)
+  #   - `:nx => true`: Don't update already existing elements (always
+  #   add new elements)
+  #   - `:ch => true`: Modify the return value from the number of new
+  #   elements added, to the total number of elements changed (CH is an
+  #   abbreviation of changed); changed elements are new elements added
+  #   and elements already existing for which the score was updated
+  #   - `:incr => true`: When this option is specified ZADD acts like
+  #   ZINCRBY; only one score-element pair can be specified in this mode
+  #
+  # @return [Boolean, Fixnum, Float]
+  #   - `Boolean` when a single pair is specified, holding whether or not it was
+  #   **added** to the sorted set.
+  #   - `Fixnum` when an array of pairs is specified, holding the number of
+  #   pairs that were **added** to the sorted set.
+  #   - `Float` when option :incr is specified, holding the score of the member
+  #   after incrementing it.
+  def zadd(key, *args) #, options
+    zadd_options = []
+    if args.last.is_a?(Hash)
+      options = args.pop
+
+      nx = options[:nx]
+      zadd_options << "NX" if nx
+
+      xx = options[:xx]
+      zadd_options << "XX" if xx
+
+      ch = options[:ch]
+      zadd_options << "CH" if ch
+
+      incr = options[:incr]
+      zadd_options << "INCR" if incr
+    end
+
+    synchronize do |client|
+      if args.size == 1 && args[0].is_a?(Array)
+        # Variadic: return float if INCR, integer if !INCR
+        client.call([:zadd, key] + zadd_options + args[0], &(incr ? Floatify : nil))
+      elsif args.size == 2
+        # Single pair: return float if INCR, boolean if !INCR
+        client.call([:zadd, key] + zadd_options + args, &(incr ? Floatify : Boolify))
+      else
+        raise ArgumentError, "wrong number of arguments"
+      end
+    end
+  end
+
+  # Increment the score of a member in a sorted set.
+  #
+  # @example
+  #   redis.zincrby("zset", 32.0, "a")
+  #     # => 64.0
+  #
+  # @param [String] key
+  # @param [Float] increment
+  # @param [String] member
+  # @return [Float] score of the member after incrementing it
+  def zincrby(key, increment, member)
+    synchronize do |client|
+      client.call([:zincrby, key, increment, member], &Floatify)
+    end
+  end
+
+  # Remove one or more members from a sorted set.
+  #
+  # @example Remove a single member from a sorted set
+  #   redis.zrem("zset", "a")
+  # @example Remove an array of members from a sorted set
+  #   redis.zrem("zset", ["a", "b"])
+  #
+  # @param [String] key
+  # @param [String, Array<String>] member
+  #   - a single member
+  #   - an array of members
+  #
+  # @return [Boolean, Fixnum]
+  #   - `Boolean` when a single member is specified, holding whether or not it
+  #   was removed from the sorted set
+  #   - `Fixnum` when an array of pairs is specified, holding the number of
+  #   members that were removed to the sorted set
+  def zrem(key, member)
+    synchronize do |client|
+      client.call([:zrem, key, member]) do |reply|
+        if member.is_a? Array
+          # Variadic: return integer
+          reply
+        else
+          # Single argument: return boolean
+          Boolify.call(reply)
+        end
+      end
+    end
+  end
+
+  # Get the score associated with the given member in a sorted set.
+  #
+  # @example Get the score for member "a"
+  #   redis.zscore("zset", "a")
+  #     # => 32.0
+  #
+  # @param [String] key
+  # @param [String] member
+  # @return [Float] score of the member
+  def zscore(key, member)
+    synchronize do |client|
+      client.call([:zscore, key, member], &Floatify)
+    end
+  end
+
+  # Return a range of members in a sorted set, by index.
+  #
+  # @example Retrieve all members from a sorted set
+  #   redis.zrange("zset", 0, -1)
+  #     # => ["a", "b"]
+  # @example Retrieve all members and their scores from a sorted set
+  #   redis.zrange("zset", 0, -1, :with_scores => true)
+  #     # => [["a", 32.0], ["b", 64.0]]
+  #
+  # @param [String] key
+  # @param [Fixnum] start start index
+  # @param [Fixnum] stop stop index
+  # @param [Hash] options
+  #   - `:with_scores => true`: include scores in output
+  #
+  # @return [Array<String>, Array<[String, Float]>]
+  #   - when `:with_scores` is not specified, an array of members
+  #   - when `:with_scores` is specified, an array with `[member, score]` pairs
+  def zrange(key, start, stop, options = {})
+    args = []
+
+    with_scores = options[:with_scores] || options[:withscores]
+
+    if with_scores
+      args << "WITHSCORES"
+      block = FloatifyPairs
+    end
+
+    synchronize do |client|
+      client.call([:zrange, key, start, stop] + args, &block)
+    end
+  end
+
+  # Return a range of members in a sorted set, by index, with scores ordered
+  # from high to low.
+  #
+  # @example Retrieve all members from a sorted set
+  #   redis.zrevrange("zset", 0, -1)
+  #     # => ["b", "a"]
+  # @example Retrieve all members and their scores from a sorted set
+  #   redis.zrevrange("zset", 0, -1, :with_scores => true)
+  #     # => [["b", 64.0], ["a", 32.0]]
+  #
+  # @see #zrange
+  def zrevrange(key, start, stop, options = {})
+    args = []
+
+    with_scores = options[:with_scores] || options[:withscores]
+
+    if with_scores
+      args << "WITHSCORES"
+      block = FloatifyPairs
+    end
+
+    synchronize do |client|
+      client.call([:zrevrange, key, start, stop] + args, &block)
+    end
+  end
+
+  # Determine the index of a member in a sorted set.
+  #
+  # @param [String] key
+  # @param [String] member
+  # @return [Fixnum]
+  def zrank(key, member)
+    synchronize do |client|
+      client.call([:zrank, key, member])
+    end
+  end
+
+  # Determine the index of a member in a sorted set, with scores ordered from
+  # high to low.
+  #
+  # @param [String] key
+  # @param [String] member
+  # @return [Fixnum]
+  def zrevrank(key, member)
+    synchronize do |client|
+      client.call([:zrevrank, key, member])
+    end
+  end
+
+  # Remove all members in a sorted set within the given indexes.
+  #
+  # @example Remove first 5 members
+  #   redis.zremrangebyrank("zset", 0, 4)
+  #     # => 5
+  # @example Remove last 5 members
+  #   redis.zremrangebyrank("zset", -5, -1)
+  #     # => 5
+  #
+  # @param [String] key
+  # @param [Fixnum] start start index
+  # @param [Fixnum] stop stop index
+  # @return [Fixnum] number of members that were removed
+  def zremrangebyrank(key, start, stop)
+    synchronize do |client|
+      client.call([:zremrangebyrank, key, start, stop])
+    end
+  end
+
+  # Return a range of members with the same score in a sorted set, by lexicographical ordering
+  #
+  # @example Retrieve members matching a
+  #   redis.zrangebylex("zset", "[a", "[a\xff")
+  #     # => ["aaren", "aarika", "abagael", "abby"]
+  # @example Retrieve the first 2 members matching a
+  #   redis.zrangebylex("zset", "[a", "[a\xff", :limit => [0, 2])
+  #     # => ["aaren", "aarika"]
+  #
+  # @param [String] key
+  # @param [String] min
+  #   - inclusive minimum is specified by prefixing `(`
+  #   - exclusive minimum is specified by prefixing `[`
+  # @param [String] max
+  #   - inclusive maximum is specified by prefixing `(`
+  #   - exclusive maximum is specified by prefixing `[`
+  # @param [Hash] options
+  #   - `:limit => [offset, count]`: skip `offset` members, return a maximum of
+  #   `count` members
+  #
+  # @return [Array<String>, Array<[String, Float]>]
+  def zrangebylex(key, min, max, options = {})
+    args = []
+
+    limit = options[:limit]
+    args.concat(["LIMIT"] + limit) if limit
+
+    synchronize do |client|
+      client.call([:zrangebylex, key, min, max] + args)
+    end
+  end
+
+  # Return a range of members with the same score in a sorted set, by reversed lexicographical ordering.
+  # Apart from the reversed ordering, #zrevrangebylex is similar to #zrangebylex.
+  #
+  # @example Retrieve members matching a
+  #   redis.zrevrangebylex("zset", "[a", "[a\xff")
+  #     # => ["abbygail", "abby", "abagael", "aaren"]
+  # @example Retrieve the last 2 members matching a
+  #   redis.zrevrangebylex("zset", "[a", "[a\xff", :limit => [0, 2])
+  #     # => ["abbygail", "abby"]
+  #
+  # @see #zrangebylex
+  def zrevrangebylex(key, max, min, options = {})
+    args = []
+
+    limit = options[:limit]
+    args.concat(["LIMIT"] + limit) if limit
+
+    synchronize do |client|
+      client.call([:zrevrangebylex, key, max, min] + args)
+    end
+  end
+
+  # Return a range of members in a sorted set, by score.
+  #
+  # @example Retrieve members with score `>= 5` and `< 100`
+  #   redis.zrangebyscore("zset", "5", "(100")
+  #     # => ["a", "b"]
+  # @example Retrieve the first 2 members with score `>= 0`
+  #   redis.zrangebyscore("zset", "0", "+inf", :limit => [0, 2])
+  #     # => ["a", "b"]
+  # @example Retrieve members and their scores with scores `> 5`
+  #   redis.zrangebyscore("zset", "(5", "+inf", :with_scores => true)
+  #     # => [["a", 32.0], ["b", 64.0]]
+  #
+  # @param [String] key
+  # @param [String] min
+  #   - inclusive minimum score is specified verbatim
+  #   - exclusive minimum score is specified by prefixing `(`
+  # @param [String] max
+  #   - inclusive maximum score is specified verbatim
+  #   - exclusive maximum score is specified by prefixing `(`
+  # @param [Hash] options
+  #   - `:with_scores => true`: include scores in output
+  #   - `:limit => [offset, count]`: skip `offset` members, return a maximum of
+  #   `count` members
+  #
+  # @return [Array<String>, Array<[String, Float]>]
+  #   - when `:with_scores` is not specified, an array of members
+  #   - when `:with_scores` is specified, an array with `[member, score]` pairs
+  def zrangebyscore(key, min, max, options = {})
+    args = []
+
+    with_scores = options[:with_scores] || options[:withscores]
+
+    if with_scores
+      args << "WITHSCORES"
+      block = FloatifyPairs
+    end
+
+    limit = options[:limit]
+    args.concat(["LIMIT"] + limit) if limit
+
+    synchronize do |client|
+      client.call([:zrangebyscore, key, min, max] + args, &block)
+    end
+  end
+
+  # Return a range of members in a sorted set, by score, with scores ordered
+  # from high to low.
+  #
+  # @example Retrieve members with score `< 100` and `>= 5`
+  #   redis.zrevrangebyscore("zset", "(100", "5")
+  #     # => ["b", "a"]
+  # @example Retrieve the first 2 members with score `<= 0`
+  #   redis.zrevrangebyscore("zset", "0", "-inf", :limit => [0, 2])
+  #     # => ["b", "a"]
+  # @example Retrieve members and their scores with scores `> 5`
+  #   redis.zrevrangebyscore("zset", "+inf", "(5", :with_scores => true)
+  #     # => [["b", 64.0], ["a", 32.0]]
+  #
+  # @see #zrangebyscore
+  def zrevrangebyscore(key, max, min, options = {})
+    args = []
+
+    with_scores = options[:with_scores] || options[:withscores]
+
+    if with_scores
+      args << ["WITHSCORES"]
+      block = FloatifyPairs
+    end
+
+    limit = options[:limit]
+    args.concat(["LIMIT"] + limit) if limit
+
+    synchronize do |client|
+      client.call([:zrevrangebyscore, key, max, min] + args, &block)
+    end
+  end
+
+  # Remove all members in a sorted set within the given scores.
+  #
+  # @example Remove members with score `>= 5` and `< 100`
+  #   redis.zremrangebyscore("zset", "5", "(100")
+  #     # => 2
+  # @example Remove members with scores `> 5`
+  #   redis.zremrangebyscore("zset", "(5", "+inf")
+  #     # => 2
+  #
+  # @param [String] key
+  # @param [String] min
+  #   - inclusive minimum score is specified verbatim
+  #   - exclusive minimum score is specified by prefixing `(`
+  # @param [String] max
+  #   - inclusive maximum score is specified verbatim
+  #   - exclusive maximum score is specified by prefixing `(`
+  # @return [Fixnum] number of members that were removed
+  def zremrangebyscore(key, min, max)
+    synchronize do |client|
+      client.call([:zremrangebyscore, key, min, max])
+    end
+  end
+
+  # Count the members in a sorted set with scores within the given values.
+  #
+  # @example Count members with score `>= 5` and `< 100`
+  #   redis.zcount("zset", "5", "(100")
+  #     # => 2
+  # @example Count members with scores `> 5`
+  #   redis.zcount("zset", "(5", "+inf")
+  #     # => 2
+  #
+  # @param [String] key
+  # @param [String] min
+  #   - inclusive minimum score is specified verbatim
+  #   - exclusive minimum score is specified by prefixing `(`
+  # @param [String] max
+  #   - inclusive maximum score is specified verbatim
+  #   - exclusive maximum score is specified by prefixing `(`
+  # @return [Fixnum] number of members in within the specified range
+  def zcount(key, min, max)
+    synchronize do |client|
+      client.call([:zcount, key, min, max])
+    end
+  end
+
+  # Intersect multiple sorted sets and store the resulting sorted set in a new
+  # key.
+  #
+  # @example Compute the intersection of `2*zsetA` with `1*zsetB`, summing their scores
+  #   redis.zinterstore("zsetC", ["zsetA", "zsetB"], :weights => [2.0, 1.0], :aggregate => "sum")
+  #     # => 4
+  #
+  # @param [String] destination destination key
+  # @param [Array<String>] keys source keys
+  # @param [Hash] options
+  #   - `:weights => [Float, Float, ...]`: weights to associate with source
+  #   sorted sets
+  #   - `:aggregate => String`: aggregate function to use (sum, min, max, ...)
+  # @return [Fixnum] number of elements in the resulting sorted set
+  def zinterstore(destination, keys, options = {})
+    args = []
+
+    weights = options[:weights]
+    args.concat(["WEIGHTS"] + weights) if weights
+
+    aggregate = options[:aggregate]
+    args.concat(["AGGREGATE", aggregate]) if aggregate
+
+    synchronize do |client|
+      client.call([:zinterstore, destination, keys.size] + keys + args)
+    end
+  end
+
+  # Add multiple sorted sets and store the resulting sorted set in a new key.
+  #
+  # @example Compute the union of `2*zsetA` with `1*zsetB`, summing their scores
+  #   redis.zunionstore("zsetC", ["zsetA", "zsetB"], :weights => [2.0, 1.0], :aggregate => "sum")
+  #     # => 8
+  #
+  # @param [String] destination destination key
+  # @param [Array<String>] keys source keys
+  # @param [Hash] options
+  #   - `:weights => [Float, Float, ...]`: weights to associate with source
+  #   sorted sets
+  #   - `:aggregate => String`: aggregate function to use (sum, min, max, ...)
+  # @return [Fixnum] number of elements in the resulting sorted set
+  def zunionstore(destination, keys, options = {})
+    args = []
+
+    weights = options[:weights]
+    args.concat(["WEIGHTS"] + weights) if weights
+
+    aggregate = options[:aggregate]
+    args.concat(["AGGREGATE", aggregate]) if aggregate
+
+    synchronize do |client|
+      client.call([:zunionstore, destination, keys.size] + keys + args)
+    end
+  end
+
+  # Get the number of fields in a hash.
+  #
+  # @param [String] key
+  # @return [Fixnum] number of fields in the hash
+  def hlen(key)
+    synchronize do |client|
+      client.call([:hlen, key])
+    end
+  end
+
+  # Set the string value of a hash field.
+  #
+  # @param [String] key
+  # @param [String] field
+  # @param [String] value
+  # @return [Boolean] whether or not the field was **added** to the hash
+  def hset(key, field, value)
+    synchronize do |client|
+      client.call([:hset, key, field, value], &Boolify)
+    end
+  end
+
+  # Set the value of a hash field, only if the field does not exist.
+  #
+  # @param [String] key
+  # @param [String] field
+  # @param [String] value
+  # @return [Boolean] whether or not the field was **added** to the hash
+  def hsetnx(key, field, value)
+    synchronize do |client|
+      client.call([:hsetnx, key, field, value], &Boolify)
+    end
+  end
+
+  # Set one or more hash values.
+  #
+  # @example
+  #   redis.hmset("hash", "f1", "v1", "f2", "v2")
+  #     # => "OK"
+  #
+  # @param [String] key
+  # @param [Array<String>] attrs array of fields and values
+  # @return [String] `"OK"`
+  #
+  # @see #mapped_hmset
+  def hmset(key, *attrs)
+    synchronize do |client|
+      client.call([:hmset, key] + attrs)
+    end
+  end
+
+  # Set one or more hash values.
+  #
+  # @example
+  #   redis.mapped_hmset("hash", { "f1" => "v1", "f2" => "v2" })
+  #     # => "OK"
+  #
+  # @param [String] key
+  # @param [Hash] hash a non-empty hash with fields mapping to values
+  # @return [String] `"OK"`
+  #
+  # @see #hmset
+  def mapped_hmset(key, hash)
+    hmset(key, hash.to_a.flatten)
+  end
+
+  # Get the value of a hash field.
+  #
+  # @param [String] key
+  # @param [String] field
+  # @return [String]
+  def hget(key, field)
+    synchronize do |client|
+      client.call([:hget, key, field])
+    end
+  end
+
+  # Get the values of all the given hash fields.
+  #
+  # @example
+  #   redis.hmget("hash", "f1", "f2")
+  #     # => ["v1", "v2"]
+  #
+  # @param [String] key
+  # @param [Array<String>] fields array of fields
+  # @return [Array<String>] an array of values for the specified fields
+  #
+  # @see #mapped_hmget
+  def hmget(key, *fields, &blk)
+    synchronize do |client|
+      client.call([:hmget, key] + fields, &blk)
+    end
+  end
+
+  # Get the values of all the given hash fields.
+  #
+  # @example
+  #   redis.mapped_hmget("hash", "f1", "f2")
+  #     # => { "f1" => "v1", "f2" => "v2" }
+  #
+  # @param [String] key
+  # @param [Array<String>] fields array of fields
+  # @return [Hash] a hash mapping the specified fields to their values
+  #
+  # @see #hmget
+  def mapped_hmget(key, *fields)
+    hmget(key, *fields) do |reply|
+      if reply.kind_of?(Array)
+        Hash[fields.zip(reply)]
+      else
+        reply
+      end
+    end
+  end
+
+  # Delete one or more hash fields.
+  #
+  # @param [String] key
+  # @param [String, Array<String>] field
+  # @return [Fixnum] the number of fields that were removed from the hash
+  def hdel(key, field)
+    synchronize do |client|
+      client.call([:hdel, key, field])
+    end
+  end
+
+  # Determine if a hash field exists.
+  #
+  # @param [String] key
+  # @param [String] field
+  # @return [Boolean] whether or not the field exists in the hash
+  def hexists(key, field)
+    synchronize do |client|
+      client.call([:hexists, key, field], &Boolify)
+    end
+  end
+
+  # Increment the integer value of a hash field by the given integer number.
+  #
+  # @param [String] key
+  # @param [String] field
+  # @param [Fixnum] increment
+  # @return [Fixnum] value of the field after incrementing it
+  def hincrby(key, field, increment)
+    synchronize do |client|
+      client.call([:hincrby, key, field, increment])
+    end
+  end
+
+  # Increment the numeric value of a hash field by the given float number.
+  #
+  # @param [String] key
+  # @param [String] field
+  # @param [Float] increment
+  # @return [Float] value of the field after incrementing it
+  def hincrbyfloat(key, field, increment)
+    synchronize do |client|
+      client.call([:hincrbyfloat, key, field, increment], &Floatify)
+    end
+  end
+
+  # Get all the fields in a hash.
+  #
+  # @param [String] key
+  # @return [Array<String>]
+  def hkeys(key)
+    synchronize do |client|
+      client.call([:hkeys, key])
+    end
+  end
+
+  # Get all the values in a hash.
+  #
+  # @param [String] key
+  # @return [Array<String>]
+  def hvals(key)
+    synchronize do |client|
+      client.call([:hvals, key])
+    end
+  end
+
+  # Get all the fields and values in a hash.
+  #
+  # @param [String] key
+  # @return [Hash<String, String>]
+  def hgetall(key)
+    synchronize do |client|
+      client.call([:hgetall, key], &Hashify)
+    end
+  end
+
+  # Post a message to a channel.
+  def publish(channel, message)
+    synchronize do |client|
+      client.call([:publish, channel, message])
+    end
+  end
+
+  def subscribed?
+    synchronize do |client|
+      client.kind_of? SubscribedClient
+    end
+  end
+
+  # Listen for messages published to the given channels.
+  def subscribe(*channels, &block)
+    synchronize do |client|
+      _subscription(:subscribe, 0, channels, block)
+    end
+  end
+
+  # Listen for messages published to the given channels. Throw a timeout error if there is no messages for a timeout period.
+  def subscribe_with_timeout(timeout, *channels, &block)
+    synchronize do |client|
+      _subscription(:subscribe_with_timeout, timeout, channels, block)
+    end
+  end
+
+  # Stop listening for messages posted to the given channels.
+  def unsubscribe(*channels)
+    synchronize do |client|
+      raise RuntimeError, "Can't unsubscribe if not subscribed." unless subscribed?
+      client.unsubscribe(*channels)
+    end
+  end
+
+  # Listen for messages published to channels matching the given patterns.
+  def psubscribe(*channels, &block)
+    synchronize do |client|
+      _subscription(:psubscribe, 0, channels, block)
+    end
+  end
+
+  # Listen for messages published to channels matching the given patterns. Throw a timeout error if there is no messages for a timeout period.
+  def psubscribe_with_timeout(timeout, *channels, &block)
+    synchronize do |client|
+      _subscription(:psubscribe_with_timeout, timeout, channels, block)
+    end
+  end
+
+  # Stop listening for messages posted to channels matching the given patterns.
+  def punsubscribe(*channels)
+    synchronize do |client|
+      raise RuntimeError, "Can't unsubscribe if not subscribed." unless subscribed?
+      client.punsubscribe(*channels)
+    end
+  end
+
+  # Inspect the state of the Pub/Sub subsystem.
+  # Possible subcommands: channels, numsub, numpat.
+  def pubsub(subcommand, *args)
+    synchronize do |client|
+      client.call([:pubsub, subcommand] + args)
+    end
+  end
+
+  # Watch the given keys to determine execution of the MULTI/EXEC block.
+  #
+  # Using a block is optional, but is necessary for thread-safety.
+  #
+  # An `#unwatch` is automatically issued if an exception is raised within the
+  # block that is a subclass of StandardError and is not a ConnectionError.
+  #
+  # @example With a block
+  #   redis.watch("key") do
+  #     if redis.get("key") == "some value"
+  #       redis.multi do |multi|
+  #         multi.set("key", "other value")
+  #         multi.incr("counter")
+  #       end
+  #     else
+  #       redis.unwatch
+  #     end
+  #   end
+  #     # => ["OK", 6]
+  #
+  # @example Without a block
+  #   redis.watch("key")
+  #     # => "OK"
+  #
+  # @param [String, Array<String>] keys one or more keys to watch
+  # @return [Object] if using a block, returns the return value of the block
+  # @return [String] if not using a block, returns `OK`
+  #
+  # @see #unwatch
+  # @see #multi
+  def watch(*keys)
+    synchronize do |client|
+      res = client.call([:watch] + keys)
+
+      if block_given?
+        begin
+          yield(self)
+        rescue ConnectionError
+          raise
+        rescue StandardError
+          unwatch
+          raise
+        end
+      else
+        res
+      end
+    end
+  end
+
+  # Forget about all watched keys.
+  #
+  # @return [String] `OK`
+  #
+  # @see #watch
+  # @see #multi
+  def unwatch
+    synchronize do |client|
+      client.call([:unwatch])
+    end
+  end
+
+  def pipelined
+    synchronize do |client|
+      begin
+        original, @client = @client, Pipeline.new
+        yield(self)
+        original.call_pipeline(@client)
+      ensure
+        @client = original
+      end
+    end
+  end
+
+  # Mark the start of a transaction block.
+  #
+  # Passing a block is optional.
+  #
+  # @example With a block
+  #   redis.multi do |multi|
+  #     multi.set("key", "value")
+  #     multi.incr("counter")
+  #   end # => ["OK", 6]
+  #
+  # @example Without a block
+  #   redis.multi
+  #     # => "OK"
+  #   redis.set("key", "value")
+  #     # => "QUEUED"
+  #   redis.incr("counter")
+  #     # => "QUEUED"
+  #   redis.exec
+  #     # => ["OK", 6]
+  #
+  # @yield [multi] the commands that are called inside this block are cached
+  #   and written to the server upon returning from it
+  # @yieldparam [Redis] multi `self`
+  #
+  # @return [String, Array<...>]
+  #   - when a block is not given, `OK`
+  #   - when a block is given, an array with replies
+  #
+  # @see #watch
+  # @see #unwatch
+  def multi
+    synchronize do |client|
+      if !block_given?
+        client.call([:multi])
+      else
+        begin
+          pipeline = Pipeline::Multi.new
+          original, @client = @client, pipeline
+          yield(self)
+          original.call_pipeline(pipeline)
+        ensure
+          @client = original
+        end
+      end
+    end
+  end
+
+  # Execute all commands issued after MULTI.
+  #
+  # Only call this method when `#multi` was called **without** a block.
+  #
+  # @return [nil, Array<...>]
+  #   - when commands were not executed, `nil`
+  #   - when commands were executed, an array with their replies
+  #
+  # @see #multi
+  # @see #discard
+  def exec
+    synchronize do |client|
+      client.call([:exec])
+    end
+  end
+
+  # Discard all commands issued after MULTI.
+  #
+  # Only call this method when `#multi` was called **without** a block.
+  #
+  # @return [String] `"OK"`
+  #
+  # @see #multi
+  # @see #exec
+  def discard
+    synchronize do |client|
+      client.call([:discard])
+    end
+  end
+
+  # Control remote script registry.
+  #
+  # @example Load a script
+  #   sha = redis.script(:load, "return 1")
+  #     # => <sha of this script>
+  # @example Check if a script exists
+  #   redis.script(:exists, sha)
+  #     # => true
+  # @example Check if multiple scripts exist
+  #   redis.script(:exists, [sha, other_sha])
+  #     # => [true, false]
+  # @example Flush the script registry
+  #   redis.script(:flush)
+  #     # => "OK"
+  # @example Kill a running script
+  #   redis.script(:kill)
+  #     # => "OK"
+  #
+  # @param [String] subcommand e.g. `exists`, `flush`, `load`, `kill`
+  # @param [Array<String>] args depends on subcommand
+  # @return [String, Boolean, Array<Boolean>, ...] depends on subcommand
+  #
+  # @see #eval
+  # @see #evalsha
+  def script(subcommand, *args)
+    subcommand = subcommand.to_s.downcase
+
+    if subcommand == "exists"
+      synchronize do |client|
+        arg = args.first
+
+        client.call([:script, :exists, arg]) do |reply|
+          reply = reply.map { |r| Boolify.call(r) }
+
+          if arg.is_a?(Array)
+            reply
+          else
+            reply.first
+          end
+        end
+      end
+    else
+      synchronize do |client|
+        client.call([:script, subcommand] + args)
+      end
+    end
+  end
+
+  def _eval(cmd, args)
+    script = args.shift
+    options = args.pop if args.last.is_a?(Hash)
+    options ||= {}
+
+    keys = args.shift || options[:keys] || []
+    argv = args.shift || options[:argv] || []
+
+    synchronize do |client|
+      client.call([cmd, script, keys.length] + keys + argv)
+    end
+  end
+
+  # Evaluate Lua script.
+  #
+  # @example EVAL without KEYS nor ARGV
+  #   redis.eval("return 1")
+  #     # => 1
+  # @example EVAL with KEYS and ARGV as array arguments
+  #   redis.eval("return { KEYS, ARGV }", ["k1", "k2"], ["a1", "a2"])
+  #     # => [["k1", "k2"], ["a1", "a2"]]
+  # @example EVAL with KEYS and ARGV in a hash argument
+  #   redis.eval("return { KEYS, ARGV }", :keys => ["k1", "k2"], :argv => ["a1", "a2"])
+  #     # => [["k1", "k2"], ["a1", "a2"]]
+  #
+  # @param [Array<String>] keys optional array with keys to pass to the script
+  # @param [Array<String>] argv optional array with arguments to pass to the script
+  # @param [Hash] options
+  #   - `:keys => Array<String>`: optional array with keys to pass to the script
+  #   - `:argv => Array<String>`: optional array with arguments to pass to the script
+  # @return depends on the script
+  #
+  # @see #script
+  # @see #evalsha
+  def eval(*args)
+    _eval(:eval, args)
+  end
+
+  # Evaluate Lua script by its SHA.
+  #
+  # @example EVALSHA without KEYS nor ARGV
+  #   redis.evalsha(sha)
+  #     # => <depends on script>
+  # @example EVALSHA with KEYS and ARGV as array arguments
+  #   redis.evalsha(sha, ["k1", "k2"], ["a1", "a2"])
+  #     # => <depends on script>
+  # @example EVALSHA with KEYS and ARGV in a hash argument
+  #   redis.evalsha(sha, :keys => ["k1", "k2"], :argv => ["a1", "a2"])
+  #     # => <depends on script>
+  #
+  # @param [Array<String>] keys optional array with keys to pass to the script
+  # @param [Array<String>] argv optional array with arguments to pass to the script
+  # @param [Hash] options
+  #   - `:keys => Array<String>`: optional array with keys to pass to the script
+  #   - `:argv => Array<String>`: optional array with arguments to pass to the script
+  # @return depends on the script
+  #
+  # @see #script
+  # @see #eval
+  def evalsha(*args)
+    _eval(:evalsha, args)
+  end
+
+  def _scan(command, cursor, args, options = {}, &block)
+    # SSCAN/ZSCAN/HSCAN already prepend the key to +args+.
+
+    args << cursor
+
+    if match = options[:match]
+      args.concat(["MATCH", match])
+    end
+
+    if count = options[:count]
+      args.concat(["COUNT", count])
+    end
+
+    synchronize do |client|
+      client.call([command] + args, &block)
+    end
+  end
+
+  # Scan the keyspace
+  #
+  # @example Retrieve the first batch of keys
+  #   redis.scan(0)
+  #     # => ["4", ["key:21", "key:47", "key:42"]]
+  # @example Retrieve a batch of keys matching a pattern
+  #   redis.scan(4, :match => "key:1?")
+  #     # => ["92", ["key:13", "key:18"]]
+  #
+  # @param [String, Integer] cursor the cursor of the iteration
+  # @param [Hash] options
+  #   - `:match => String`: only return keys matching the pattern
+  #   - `:count => Integer`: return count keys at most per iteration
+  #
+  # @return [String, Array<String>] the next cursor and all found keys
+  def scan(cursor, options={})
+    _scan(:scan, cursor, [], options)
+  end
+
+  # Scan the keyspace
+  #
+  # @example Retrieve all of the keys (with possible duplicates)
+  #   redis.scan_each.to_a
+  #     # => ["key:21", "key:47", "key:42"]
+  # @example Execute block for each key matching a pattern
+  #   redis.scan_each(:match => "key:1?") {|key| puts key}
+  #     # => key:13
+  #     # => key:18
+  #
+  # @param [Hash] options
+  #   - `:match => String`: only return keys matching the pattern
+  #   - `:count => Integer`: return count keys at most per iteration
+  #
+  # @return [Enumerator] an enumerator for all found keys
+  def scan_each(options={}, &block)
+    return to_enum(:scan_each, options) unless block_given?
+    cursor = 0
+    loop do
+      cursor, keys = scan(cursor, options)
+      keys.each(&block)
+      break if cursor == "0"
+    end
+  end
+
+  # Scan a hash
+  #
+  # @example Retrieve the first batch of key/value pairs in a hash
+  #   redis.hscan("hash", 0)
+  #
+  # @param [String, Integer] cursor the cursor of the iteration
+  # @param [Hash] options
+  #   - `:match => String`: only return keys matching the pattern
+  #   - `:count => Integer`: return count keys at most per iteration
+  #
+  # @return [String, Array<[String, String]>] the next cursor and all found keys
+  def hscan(key, cursor, options={})
+    _scan(:hscan, cursor, [key], options) do |reply|
+      [reply[0], reply[1].each_slice(2).to_a]
+    end
+  end
+
+  # Scan a hash
+  #
+  # @example Retrieve all of the key/value pairs in a hash
+  #   redis.hscan_each("hash").to_a
+  #   # => [["key70", "70"], ["key80", "80"]]
+  #
+  # @param [Hash] options
+  #   - `:match => String`: only return keys matching the pattern
+  #   - `:count => Integer`: return count keys at most per iteration
+  #
+  # @return [Enumerator] an enumerator for all found keys
+  def hscan_each(key, options={}, &block)
+    return to_enum(:hscan_each, key, options) unless block_given?
+    cursor = 0
+    loop do
+      cursor, values = hscan(key, cursor, options)
+      values.each(&block)
+      break if cursor == "0"
+    end
+  end
+
+  # Scan a sorted set
+  #
+  # @example Retrieve the first batch of key/value pairs in a hash
+  #   redis.zscan("zset", 0)
+  #
+  # @param [String, Integer] cursor the cursor of the iteration
+  # @param [Hash] options
+  #   - `:match => String`: only return keys matching the pattern
+  #   - `:count => Integer`: return count keys at most per iteration
+  #
+  # @return [String, Array<[String, Float]>] the next cursor and all found
+  #   members and scores
+  def zscan(key, cursor, options={})
+    _scan(:zscan, cursor, [key], options) do |reply|
+      [reply[0], FloatifyPairs.call(reply[1])]
+    end
+  end
+
+  # Scan a sorted set
+  #
+  # @example Retrieve all of the members/scores in a sorted set
+  #   redis.zscan_each("zset").to_a
+  #   # => [["key70", "70"], ["key80", "80"]]
+  #
+  # @param [Hash] options
+  #   - `:match => String`: only return keys matching the pattern
+  #   - `:count => Integer`: return count keys at most per iteration
+  #
+  # @return [Enumerator] an enumerator for all found scores and members
+  def zscan_each(key, options={}, &block)
+    return to_enum(:zscan_each, key, options) unless block_given?
+    cursor = 0
+    loop do
+      cursor, values = zscan(key, cursor, options)
+      values.each(&block)
+      break if cursor == "0"
+    end
+  end
+
+  # Scan a set
+  #
+  # @example Retrieve the first batch of keys in a set
+  #   redis.sscan("set", 0)
+  #
+  # @param [String, Integer] cursor the cursor of the iteration
+  # @param [Hash] options
+  #   - `:match => String`: only return keys matching the pattern
+  #   - `:count => Integer`: return count keys at most per iteration
+  #
+  # @return [String, Array<String>] the next cursor and all found members
+  def sscan(key, cursor, options={})
+    _scan(:sscan, cursor, [key], options)
+  end
+
+  # Scan a set
+  #
+  # @example Retrieve all of the keys in a set
+  #   redis.sscan_each("set").to_a
+  #   # => ["key1", "key2", "key3"]
+  #
+  # @param [Hash] options
+  #   - `:match => String`: only return keys matching the pattern
+  #   - `:count => Integer`: return count keys at most per iteration
+  #
+  # @return [Enumerator] an enumerator for all keys in the set
+  def sscan_each(key, options={}, &block)
+    return to_enum(:sscan_each, key, options) unless block_given?
+    cursor = 0
+    loop do
+      cursor, keys = sscan(key, cursor, options)
+      keys.each(&block)
+      break if cursor == "0"
+    end
+  end
+
+  # Add one or more members to a HyperLogLog structure.
+  #
+  # @param [String] key
+  # @param [String, Array<String>] member one member, or array of members
+  # @return [Boolean] true if at least 1 HyperLogLog internal register was altered. false otherwise.
+  def pfadd(key, member)
+    synchronize do |client|
+      client.call([:pfadd, key, member], &Boolify)
+    end
+  end
+
+  # Get the approximate cardinality of members added to HyperLogLog structure.
+  #
+  # If called with multiple keys, returns the approximate cardinality of the
+  # union of the HyperLogLogs contained in the keys.
+  #
+  # @param [String, Array<String>] keys
+  # @return [Fixnum]
+  def pfcount(*keys)
+    synchronize do |client|
+      client.call([:pfcount] + keys)
+    end
+  end
+
+  # Merge multiple HyperLogLog values into an unique value that will approximate the cardinality of the union of
+  # the observed Sets of the source HyperLogLog structures.
+  #
+  # @param [String] dest_key destination key
+  # @param [String, Array<String>] source_key source key, or array of keys
+  # @return [Boolean]
+  def pfmerge(dest_key, *source_key)
+    synchronize do |client|
+      client.call([:pfmerge, dest_key, *source_key], &BoolifySet)
+    end
+  end
+
+  # Interact with the sentinel command (masters, master, slaves, failover)
+  #
+  # @param [String] subcommand e.g. `masters`, `master`, `slaves`
+  # @param [Array<String>] args depends on subcommand
+  # @return [Array<String>, Hash<String, String>, String] depends on subcommand
+  def sentinel(subcommand, *args)
+    subcommand = subcommand.to_s.downcase
+    synchronize do |client|
+      client.call([:sentinel, subcommand] + args) do |reply|
+        case subcommand
+        when "get-master-addr-by-name"
+          reply
+        else
+          if reply.kind_of?(Array)
+            if reply[0].kind_of?(Array)
+              reply.map(&Hashify)
+            else
+              Hashify.call(reply)
+            end
+          else
+            reply
+          end
+        end
+      end
+    end
+  end
+
+  def id
+    @original_client.id
+  end
+
+  def inspect
+    "#<Redis client v#{Redis::VERSION} for #{id}>"
+  end
+
+  def dup
+    self.class.new(@options)
+  end
+
+  def method_missing(command, *args)
+    synchronize do |client|
+      client.call([command] + args)
+    end
+  end
+
+private
+
+  # Commands returning 1 for true and 0 for false may be executed in a pipeline
+  # where the method call will return nil. Propagate the nil instead of falsely
+  # returning false.
+  Boolify =
+    lambda { |value|
+      value == 1 if value
+    }
+
+  BoolifySet =
+    lambda { |value|
+      if value && "OK" == value
+        true
+      else
+        false
+      end
+    }
+
+  Hashify =
+    lambda { |array|
+      hash = Hash.new
+      array.each_slice(2) do |field, value|
+        hash[field] = value
+      end
+      hash
+    }
+
+  Floatify =
+    lambda { |str|
+      if str
+        if (inf = str.match(/^(-)?inf/i))
+          (inf[1] ? -1.0 : 1.0) / 0.0
+        else
+          Float(str)
+        end
+      end
+    }
+
+  FloatifyPairs =
+    lambda { |array|
+      if array
+        array.each_slice(2).map do |member, score|
+          [member, Floatify.call(score)]
+        end
+      end
+    }
+
+  def _subscription(method, timeout, channels, block)
+    return @client.call([method] + channels) if subscribed?
+
+    begin
+      original, @client = @client, SubscribedClient.new(@client)
+      if timeout > 0
+        @client.send(method, timeout, *channels, &block)
+      else
+        @client.send(method, *channels, &block)
+      end
+    ensure
+      @client = original
+    end
+  end
+
+end
+
+require "redis/version"
+require "redis/connection"
+require "redis/client"
+require "redis/pipeline"
+require "redis/subscribe"
diff --git a/lib/vendor/redis/client.rb b/lib/vendor/redis/lib/redis/client.rb
index 4a5691d..c867f63 100644
--- a/lib/vendor/redis/client.rb
+++ b/lib/vendor/redis/lib/redis/client.rb
@@ -1,4 +1,4 @@
-require_relative "errors"
+require "redis/errors"
 require "socket"
 require "cgi"
 
@@ -478,7 +478,7 @@ class Redis
 
       if driver.kind_of?(String)
         begin
-          require_relative "connection/#{driver}"
+          require "redis/connection/#{driver}"
           driver = Connection.const_get(driver.capitalize)
         rescue LoadError, NameError
           raise RuntimeError, "Cannot load driver #{driver.inspect}"
diff --git a/lib/vendor/redis/connection.rb b/lib/vendor/redis/lib/redis/connection.rb
index d8a51b3..badff22 100644
--- a/lib/vendor/redis/connection.rb
+++ b/lib/vendor/redis/lib/redis/connection.rb
@@ -1,4 +1,4 @@
-require_relative "connection/registry"
+require "redis/connection/registry"
 
 # If a connection driver was required before this file, the array
 # Redis::Connection.drivers will contain one or more classes. The last driver
@@ -6,4 +6,4 @@ require_relative "connection/registry"
 # the plain Ruby driver as our default. Another driver can be required at a
 # later point in time, causing it to be the last element of the #drivers array
 # and therefore be chosen by default.
-require_relative "connection/ruby" if Redis::Connection.drivers.empty?
+require "redis/connection/ruby" if Redis::Connection.drivers.empty?
\ No newline at end of file
diff --git a/lib/vendor/redis/connection/command_helper.rb b/lib/vendor/redis/lib/redis/connection/command_helper.rb
index 74e89dc..74e89dc 100644
--- a/lib/vendor/redis/connection/command_helper.rb
+++ b/lib/vendor/redis/lib/redis/connection/command_helper.rb
diff --git a/lib/vendor/redis/connection/hiredis.rb b/lib/vendor/redis/lib/redis/connection/hiredis.rb
index f7baf31..f4056d3 100644
--- a/lib/vendor/redis/connection/hiredis.rb
+++ b/lib/vendor/redis/lib/redis/connection/hiredis.rb
@@ -1,5 +1,5 @@
-require_relative "registry"
-require_relative "../errors"
+require "redis/connection/registry"
+require "redis/errors"
 require "hiredis/connection"
 require "timeout"
 
diff --git a/lib/vendor/redis/connection/registry.rb b/lib/vendor/redis/lib/redis/connection/registry.rb
index 69ca63d..69ca63d 100644
--- a/lib/vendor/redis/connection/registry.rb
+++ b/lib/vendor/redis/lib/redis/connection/registry.rb
diff --git a/lib/vendor/redis/connection/ruby.rb b/lib/vendor/redis/lib/redis/connection/ruby.rb
index 7aa2808..e3cf002 100644
--- a/lib/vendor/redis/connection/ruby.rb
+++ b/lib/vendor/redis/lib/redis/connection/ruby.rb
@@ -1,6 +1,6 @@
-require_relative "registry"
-require_relative "command_helper"
-require_relative "../errors"
+require "redis/connection/registry"
+require "redis/connection/command_helper"
+require "redis/errors"
 require "socket"
 require "timeout"
 
diff --git a/lib/vendor/redis/connection/synchrony.rb b/lib/vendor/redis/lib/redis/connection/synchrony.rb
index c8b3dab..9f0b67c 100644
--- a/lib/vendor/redis/connection/synchrony.rb
+++ b/lib/vendor/redis/lib/redis/connection/synchrony.rb
@@ -1,6 +1,6 @@
-require_relative "command_helper"
-require_relative "registry"
-require_relative "../errors"
+require "redis/connection/command_helper"
+require "redis/connection/registry"
+require "redis/errors"
 require "em-synchrony"
 require "hiredis/reader"
 
diff --git a/lib/vendor/redis/distributed.rb b/lib/vendor/redis/lib/redis/distributed.rb
index 774c754..4bda232 100644
--- a/lib/vendor/redis/distributed.rb
+++ b/lib/vendor/redis/lib/redis/distributed.rb
@@ -1,4 +1,4 @@
-require_relative "hash_ring"
+require "redis/hash_ring"
 
 class Redis
   class Distributed
diff --git a/lib/vendor/redis/errors.rb b/lib/vendor/redis/lib/redis/errors.rb
index 85b222e..85b222e 100644
--- a/lib/vendor/redis/errors.rb
+++ b/lib/vendor/redis/lib/redis/errors.rb
diff --git a/lib/vendor/redis/hash_ring.rb b/lib/vendor/redis/lib/redis/hash_ring.rb
index 2a199bd..2a199bd 100644
--- a/lib/vendor/redis/hash_ring.rb
+++ b/lib/vendor/redis/lib/redis/hash_ring.rb
diff --git a/lib/vendor/redis/pipeline.rb b/lib/vendor/redis/lib/redis/pipeline.rb
index a77f86d..a77f86d 100644
--- a/lib/vendor/redis/pipeline.rb
+++ b/lib/vendor/redis/lib/redis/pipeline.rb
diff --git a/lib/vendor/redis/subscribe.rb b/lib/vendor/redis/lib/redis/subscribe.rb
index 3029d04..3029d04 100644
--- a/lib/vendor/redis/subscribe.rb
+++ b/lib/vendor/redis/lib/redis/subscribe.rb
diff --git a/lib/vendor/redis/version.rb b/lib/vendor/redis/lib/redis/version.rb
index 3f1fbc0..3f1fbc0 100644
--- a/lib/vendor/redis/version.rb
+++ b/lib/vendor/redis/lib/redis/version.rb