Add redis-rb as a vendored library

`make update-redis` will clone the library and adjust the paths properly

20 files changed, 5306 insertions, 6 deletions

diff --git a/.gitignore b/.gitignore
index 62e2cd1..277c4b4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,3 +8,4 @@ coverage/
 .bundle
 tags
 .bundle/
+*.orig
diff --git a/Gemfile b/Gemfile
index 4fed1a1..7c5ce9d 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,7 +1,5 @@
 source "http://rubygems.org"
 
-gem 'redis', '~> 3.3'
-
 group :development, :test do
   gem 'coveralls', require: false
   gem 'rspec', '~> 2.14.0'
diff --git a/Gemfile.lock b/Gemfile.lock
index cd07c9b..0fbade8 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -37,7 +37,6 @@ GEM
       method_source (~> 0.8)
       slop (~> 3.3.1)
     rainbow (2.0.0)
-    redis (3.3.0)
     rest-client (1.7.2)
       mime-types (>= 1.16, < 3.0)
       netrc (~> 0.7)
@@ -78,7 +77,6 @@ DEPENDENCIES
   coveralls
   guard
   guard-rspec
-  redis (~> 3.3)
   rspec (~> 2.14.0)
   rubocop (= 0.28.0)
   vcr
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..c1dde95
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,21 @@
+REDIS_RB_VERSION=v3.3.0
+REDIS_RB_TMP_DIR := $(shell mktemp -d)
+REDIS_RB_VENDOR_DIR=lib/vendor
+PWD=`pwd`
+
+all:
+
+update-redis:
+	cd lib
+	git clone https://github.com/redis/redis-rb.git $(REDIS_RB_TMP_DIR)
+	cd $(REDIS_RB_TMP_DIR); git checkout $(REDIS_RB_VERSION)
+	cd $(PWD)
+	mkdir -p $(REDIS_RB_VENDOR_DIR)
+	cp -r $(REDIS_RB_TMP_DIR)/lib/* $(REDIS_RB_VENDOR_DIR)
+	# Adjust all 'require redis/' paths to relative paths
+	sed -i.orig -e 's/require "redis/require_relative "redis/g' $(REDIS_RB_VENDOR_DIR)/redis.rb
+	find $(REDIS_RB_VENDOR_DIR)/redis -name \*.rb -maxdepth 1 -exec sed -i.orig -e "s/require \"redis\//require_relative \"/g" {} \;
+	find $(REDIS_RB_VENDOR_DIR)/redis/connection -name \*.rb -maxdepth 1 -exec sed -i.orig -e 's/require "redis\/connection\//require_relative "/g' *.rb {} \;
+	find $(REDIS_RB_VENDOR_DIR)/redis/connection -name \*.rb -maxdepth 1 -exec sed -i.orig -e 's/require "redis\//require_relative "..\//g' *.rb {} \;
+
+.PHONY=update-redis
diff --git a/lib/gitlab_net.rb b/lib/gitlab_net.rb
index 8e1fe39..e9f8ffd 100644
--- a/lib/gitlab_net.rb
+++ b/lib/gitlab_net.rb
@@ -1,12 +1,12 @@
 require 'net/http'
 require 'openssl'
 require 'json'
-require 'redis'
 
 require_relative 'gitlab_config'
 require_relative 'gitlab_logger'
 require_relative 'gitlab_access'
 require_relative 'httpunix'
+require_relative 'vendor/redis'
 
 class GitlabNet
   class ApiUnreachableError < StandardError; end
diff --git a/lib/gitlab_post_receive.rb b/lib/gitlab_post_receive.rb
index 8632432..9f75433 100644
--- a/lib/gitlab_post_receive.rb
+++ b/lib/gitlab_post_receive.rb
@@ -2,7 +2,6 @@ require_relative 'gitlab_init'
 require_relative 'gitlab_net'
 require 'json'
 require 'base64'
-require 'redis'
 require 'securerandom'
 
 class GitlabPostReceive
diff --git a/lib/vendor/redis.rb b/lib/vendor/redis.rb
new file mode 100644
index 0000000..c4fae37
--- /dev/null
+++ b/lib/vendor/redis.rb
@@ -0,0 +1,2773 @@
+require "monitor"
+require_relative "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_relative "redis/version"
+require_relative "redis/connection"
+require_relative "redis/client"
+require_relative "redis/pipeline"
+require_relative "redis/subscribe"
diff --git a/lib/vendor/redis/client.rb b/lib/vendor/redis/client.rb
new file mode 100644
index 0000000..4a5691d
--- /dev/null
+++ b/lib/vendor/redis/client.rb
@@ -0,0 +1,590 @@
+require_relative "errors"
+require "socket"
+require "cgi"
+
+class Redis
+  class Client
+
+    DEFAULTS = {
+      :url => lambda { ENV["REDIS_URL"] },
+      :scheme => "redis",
+      :host => "127.0.0.1",
+      :port => 6379,
+      :path => nil,
+      :timeout => 5.0,
+      :password => nil,
+      :db => 0,
+      :driver => nil,
+      :id => nil,
+      :tcp_keepalive => 0,
+      :reconnect_attempts => 1,
+      :inherit_socket => false
+    }
+
+    def options
+      Marshal.load(Marshal.dump(@options))
+    end
+
+    def scheme
+      @options[:scheme]
+    end
+
+    def host
+      @options[:host]
+    end
+
+    def port
+      @options[:port]
+    end
+
+    def path
+      @options[:path]
+    end
+
+    def read_timeout
+      @options[:read_timeout]
+    end
+
+    def connect_timeout
+      @options[:connect_timeout]
+    end
+
+    def timeout
+      @options[:read_timeout]
+    end
+
+    def password
+      @options[:password]
+    end
+
+    def db
+      @options[:db]
+    end
+
+    def db=(db)
+      @options[:db] = db.to_i
+    end
+
+    def driver
+      @options[:driver]
+    end
+
+    def inherit_socket?
+      @options[:inherit_socket]
+    end
+
+    attr_accessor :logger
+    attr_reader :connection
+    attr_reader :command_map
+
+    def initialize(options = {})
+      @options = _parse_options(options)
+      @reconnect = true
+      @logger = @options[:logger]
+      @connection = nil
+      @command_map = {}
+
+      @pending_reads = 0
+
+      if options.include?(:sentinels)
+        @connector = Connector::Sentinel.new(@options)
+      else
+        @connector = Connector.new(@options)
+      end
+    end
+
+    def connect
+      @pid = Process.pid
+
+      # Don't try to reconnect when the connection is fresh
+      with_reconnect(false) do
+        establish_connection
+        call [:auth, password] if password
+        call [:select, db] if db != 0
+        call [:client, :setname, @options[:id]] if @options[:id]
+        @connector.check(self)
+      end
+
+      self
+    end
+
+    def id
+      @options[:id] || "redis://#{location}/#{db}"
+    end
+
+    def location
+      path || "#{host}:#{port}"
+    end
+
+    def call(command)
+      reply = process([command]) { read }
+      raise reply if reply.is_a?(CommandError)
+
+      if block_given?
+        yield reply
+      else
+        reply
+      end
+    end
+
+    def call_loop(command, timeout = 0)
+      error = nil
+
+      result = with_socket_timeout(timeout) do
+        process([command]) do
+          loop do
+            reply = read
+            if reply.is_a?(CommandError)
+              error = reply
+              break
+            else
+              yield reply
+            end
+          end
+        end
+      end
+
+      # Raise error when previous block broke out of the loop.
+      raise error if error
+
+      # Result is set to the value that the provided block used to break.
+      result
+    end
+
+    def call_pipeline(pipeline)
+      with_reconnect pipeline.with_reconnect? do
+        begin
+          pipeline.finish(call_pipelined(pipeline.commands)).tap do
+            self.db = pipeline.db if pipeline.db
+          end
+        rescue ConnectionError => e
+          return nil if pipeline.shutdown?
+          # Assume the pipeline was sent in one piece, but execution of
+          # SHUTDOWN caused none of the replies for commands that were executed
+          # prior to it from coming back around.
+          raise e
+        end
+      end
+    end
+
+    def call_pipelined(commands)
+      return [] if commands.empty?
+
+      # The method #ensure_connected (called from #process) reconnects once on
+      # I/O errors. To make an effort in making sure that commands are not
+      # executed more than once, only allow reconnection before the first reply
+      # has been read. When an error occurs after the first reply has been
+      # read, retrying would re-execute the entire pipeline, thus re-issuing
+      # already successfully executed commands. To circumvent this, don't retry
+      # after the first reply has been read successfully.
+
+      result = Array.new(commands.size)
+      reconnect = @reconnect
+
+      begin
+        exception = nil
+
+        process(commands) do
+          result[0] = read
+
+          @reconnect = false
+
+          (commands.size - 1).times do |i|
+            reply = read
+            result[i + 1] = reply
+            exception = reply if exception.nil? && reply.is_a?(CommandError)
+          end
+        end
+
+        raise exception if exception
+      ensure
+        @reconnect = reconnect
+      end
+
+      result
+    end
+
+    def call_with_timeout(command, timeout, &blk)
+      with_socket_timeout(timeout) do
+        call(command, &blk)
+      end
+    rescue ConnectionError
+      retry
+    end
+
+    def call_without_timeout(command, &blk)
+      call_with_timeout(command, 0, &blk)
+    end
+
+    def process(commands)
+      logging(commands) do
+        ensure_connected do
+          commands.each do |command|
+            if command_map[command.first]
+              command = command.dup
+              command[0] = command_map[command.first]
+            end
+
+            write(command)
+          end
+
+          yield if block_given?
+        end
+      end
+    end
+
+    def connected?
+      !! (connection && connection.connected?)
+    end
+
+    def disconnect
+      connection.disconnect if connected?
+    end
+
+    def reconnect
+      disconnect
+      connect
+    end
+
+    def io
+      yield
+    rescue TimeoutError => e1
+      # Add a message to the exception without destroying the original stack
+      e2 = TimeoutError.new("Connection timed out")
+      e2.set_backtrace(e1.backtrace)
+      raise e2
+    rescue Errno::ECONNRESET, Errno::EPIPE, Errno::ECONNABORTED, Errno::EBADF, Errno::EINVAL => e
+      raise ConnectionError, "Connection lost (%s)" % [e.class.name.split("::").last]
+    end
+
+    def read
+      io do
+        value = connection.read
+        @pending_reads -= 1
+        value
+      end
+    end
+
+    def write(command)
+      io do
+        @pending_reads += 1
+        connection.write(command)
+      end
+    end
+
+    def with_socket_timeout(timeout)
+      connect unless connected?
+
+      begin
+        connection.timeout = timeout
+        yield
+      ensure
+        connection.timeout = self.timeout if connected?
+      end
+    end
+
+    def without_socket_timeout(&blk)
+      with_socket_timeout(0, &blk)
+    end
+
+    def with_reconnect(val=true)
+      begin
+        original, @reconnect = @reconnect, val
+        yield
+      ensure
+        @reconnect = original
+      end
+    end
+
+    def without_reconnect(&blk)
+      with_reconnect(false, &blk)
+    end
+
+  protected
+
+    def logging(commands)
+      return yield unless @logger && @logger.debug?
+
+      begin
+        commands.each do |name, *args|
+          logged_args = args.map do |a|
+            case
+            when a.respond_to?(:inspect) then a.inspect
+            when a.respond_to?(:to_s)    then a.to_s
+            else
+              # handle poorly-behaved descendants of BasicObject
+              klass = a.instance_exec { (class << self; self end).superclass }
+              "\#<#{klass}:#{a.__id__}>"
+            end
+          end
+          @logger.debug("[Redis] command=#{name.to_s.upcase} args=#{logged_args.join(' ')}")
+        end
+
+        t1 = Time.now
+        yield
+      ensure
+        @logger.debug("[Redis] call_time=%0.2f ms" % ((Time.now - t1) * 1000)) if t1
+      end
+    end
+
+    def establish_connection
+      server = @connector.resolve.dup
+
+      @options[:host] = server[:host]
+      @options[:port] = Integer(server[:port]) if server.include?(:port)
+
+      @connection = @options[:driver].connect(@options)
+      @pending_reads = 0
+    rescue TimeoutError,
+           Errno::ECONNREFUSED,
+           Errno::EHOSTDOWN,
+           Errno::EHOSTUNREACH,
+           Errno::ENETUNREACH,
+           Errno::ETIMEDOUT
+
+      raise CannotConnectError, "Error connecting to Redis on #{location} (#{$!.class})"
+    end
+
+    def ensure_connected
+      disconnect if @pending_reads > 0
+
+      attempts = 0
+
+      begin
+        attempts += 1
+
+        if connected?
+          unless inherit_socket? || Process.pid == @pid
+            raise InheritedError,
+              "Tried to use a connection from a child process without reconnecting. " +
+              "You need to reconnect to Redis after forking " +
+              "or set :inherit_socket to true."
+          end
+        else
+          connect
+        end
+
+        yield
+      rescue BaseConnectionError
+        disconnect
+
+        if attempts <= @options[:reconnect_attempts] && @reconnect
+          retry
+        else
+          raise
+        end
+      rescue Exception
+        disconnect
+        raise
+      end
+    end
+
+    def _parse_options(options)
+      return options if options[:_parsed]
+
+      defaults = DEFAULTS.dup
+      options = options.dup
+
+      defaults.keys.each do |key|
+        # Fill in defaults if needed
+        if defaults[key].respond_to?(:call)
+          defaults[key] = defaults[key].call
+        end
+
+        # Symbolize only keys that are needed
+        options[key] = options[key.to_s] if options.has_key?(key.to_s)
+      end
+
+      url = options[:url] || defaults[:url]
+
+      # Override defaults from URL if given
+      if url
+        require "uri"
+
+        uri = URI(url)
+
+        if uri.scheme == "unix"
+          defaults[:path]   = uri.path
+        elsif uri.scheme == "redis" || uri.scheme == "rediss"
+          defaults[:scheme]   = uri.scheme
+          defaults[:host]     = uri.host if uri.host
+          defaults[:port]     = uri.port if uri.port
+          defaults[:password] = CGI.unescape(uri.password) if uri.password
+          defaults[:db]       = uri.path[1..-1].to_i if uri.path
+          defaults[:role] = :master
+        else
+          raise ArgumentError, "invalid uri scheme '#{uri.scheme}'"
+        end
+
+        defaults[:ssl] = true if uri.scheme == "rediss"
+      end
+
+      # Use default when option is not specified or nil
+      defaults.keys.each do |key|
+        options[key] = defaults[key] if options[key].nil?
+      end
+
+      if options[:path]
+        # Unix socket
+        options[:scheme] = "unix"
+        options.delete(:host)
+        options.delete(:port)
+      else
+        # TCP socket
+        options[:host] = options[:host].to_s
+        options[:port] = options[:port].to_i
+      end
+
+      if options.has_key?(:timeout)
+        options[:connect_timeout] ||= options[:timeout]
+        options[:read_timeout]    ||= options[:timeout]
+        options[:write_timeout]   ||= options[:timeout]
+      end
+
+      options[:connect_timeout] = Float(options[:connect_timeout])
+      options[:read_timeout]    = Float(options[:read_timeout])
+      options[:write_timeout]   = Float(options[:write_timeout])
+
+      options[:db] = options[:db].to_i
+      options[:driver] = _parse_driver(options[:driver]) || Connection.drivers.last
+
+      case options[:tcp_keepalive]
+      when Hash
+        [:time, :intvl, :probes].each do |key|
+          unless options[:tcp_keepalive][key].is_a?(Fixnum)
+            raise "Expected the #{key.inspect} key in :tcp_keepalive to be a Fixnum"
+          end
+        end
+
+      when Fixnum
+        if options[:tcp_keepalive] >= 60
+          options[:tcp_keepalive] = {:time => options[:tcp_keepalive] - 20, :intvl => 10, :probes => 2}
+
+        elsif options[:tcp_keepalive] >= 30
+          options[:tcp_keepalive] = {:time => options[:tcp_keepalive] - 10, :intvl => 5, :probes => 2}
+
+        elsif options[:tcp_keepalive] >= 5
+          options[:tcp_keepalive] = {:time => options[:tcp_keepalive] - 2, :intvl => 2, :probes => 1}
+        end
+      end
+
+      options[:_parsed] = true
+
+      options
+    end
+
+    def _parse_driver(driver)
+      driver = driver.to_s if driver.is_a?(Symbol)
+
+      if driver.kind_of?(String)
+        begin
+          require_relative "connection/#{driver}"
+          driver = Connection.const_get(driver.capitalize)
+        rescue LoadError, NameError
+          raise RuntimeError, "Cannot load driver #{driver.inspect}"
+        end
+      end
+
+      driver
+    end
+
+    class Connector
+      def initialize(options)
+        @options = options.dup
+      end
+
+      def resolve
+        @options
+      end
+
+      def check(client)
+      end
+
+      class Sentinel < Connector
+        def initialize(options)
+          super(options)
+
+          @options[:password] = DEFAULTS.fetch(:password)
+          @options[:db] = DEFAULTS.fetch(:db)
+
+          @sentinels = @options.delete(:sentinels).dup
+          @role = @options.fetch(:role, "master").to_s
+          @master = @options[:host]
+        end
+
+        def check(client)
+          # Check the instance is really of the role we are looking for.
+          # We can't assume the command is supported since it was introduced
+          # recently and this client should work with old stuff.
+          begin
+            role = client.call([:role])[0]
+          rescue Redis::CommandError
+            # Assume the test is passed if we can't get a reply from ROLE...
+            role = @role
+          end
+
+          if role != @role
+            client.disconnect
+            raise ConnectionError, "Instance role mismatch. Expected #{@role}, got #{role}."
+          end
+        end
+
+        def resolve
+          result = case @role
+                   when "master"
+                     resolve_master
+                   when "slave"
+                     resolve_slave
+                   else
+                     raise ArgumentError, "Unknown instance role #{@role}"
+                   end
+
+          result || (raise ConnectionError, "Unable to fetch #{@role} via Sentinel.")
+        end
+
+        def sentinel_detect
+          @sentinels.each do |sentinel|
+            client = Client.new(@options.merge({
+              :host => sentinel[:host],
+              :port => sentinel[:port],
+              :reconnect_attempts => 0,
+            }))
+
+            begin
+              if result = yield(client)
+                # This sentinel responded. Make sure we ask it first next time.
+                @sentinels.delete(sentinel)
+                @sentinels.unshift(sentinel)
+
+                return result
+              end
+            rescue BaseConnectionError
+            ensure
+              client.disconnect
+            end
+          end
+
+          raise CannotConnectError, "No sentinels available."
+        end
+
+        def resolve_master
+          sentinel_detect do |client|
+            if reply = client.call(["sentinel", "get-master-addr-by-name", @master])
+              {:host => reply[0], :port => reply[1]}
+            end
+          end
+        end
+
+        def resolve_slave
+          sentinel_detect do |client|
+            if reply = client.call(["sentinel", "slaves", @master])
+              slave = Hash[*reply.sample]
+
+              {:host => slave.fetch("ip"), :port => slave.fetch("port")}
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/vendor/redis/connection.rb b/lib/vendor/redis/connection.rb
new file mode 100644
index 0000000..d8a51b3
--- /dev/null
+++ b/lib/vendor/redis/connection.rb
@@ -0,0 +1,9 @@
+require_relative "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
+# in this array will be used as default driver. If this array is empty, we load
+# 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?
diff --git a/lib/vendor/redis/connection/command_helper.rb b/lib/vendor/redis/connection/command_helper.rb
new file mode 100644
index 0000000..74e89dc
--- /dev/null
+++ b/lib/vendor/redis/connection/command_helper.rb
@@ -0,0 +1,44 @@
+class Redis
+  module Connection
+    module CommandHelper
+
+      COMMAND_DELIMITER = "\r\n"
+
+      def build_command(args)
+        command = [nil]
+
+        args.each do |i|
+          if i.is_a? Array
+            i.each do |j|
+              j = j.to_s
+              command << "$#{j.bytesize}"
+              command << j
+            end
+          else
+            i = i.to_s
+            command << "$#{i.bytesize}"
+            command << i
+          end
+        end
+
+        command[0] = "*#{(command.length - 1) / 2}"
+
+        # Trailing delimiter
+        command << ""
+        command.join(COMMAND_DELIMITER)
+      end
+
+    protected
+
+      if defined?(Encoding::default_external)
+        def encode(string)
+          string.force_encoding(Encoding::default_external)
+        end
+      else
+        def encode(string)
+          string
+        end
+      end
+    end
+  end
+end
diff --git a/lib/vendor/redis/connection/hiredis.rb b/lib/vendor/redis/connection/hiredis.rb
new file mode 100644
index 0000000..f7baf31
--- /dev/null
+++ b/lib/vendor/redis/connection/hiredis.rb
@@ -0,0 +1,66 @@
+require_relative "registry"
+require_relative "../errors"
+require "hiredis/connection"
+require "timeout"
+
+class Redis
+  module Connection
+    class Hiredis
+
+      def self.connect(config)
+        connection = ::Hiredis::Connection.new
+        connect_timeout = (config.fetch(:connect_timeout, 0) * 1_000_000).to_i
+
+        if config[:scheme] == "unix"
+          connection.connect_unix(config[:path], connect_timeout)
+        elsif config[:scheme] == "rediss" || config[:ssl]
+          raise NotImplementedError, "SSL not supported by hiredis driver"
+        else
+          connection.connect(config[:host], config[:port], connect_timeout)
+        end
+
+        instance = new(connection)
+        instance.timeout = config[:read_timeout]
+        instance
+      rescue Errno::ETIMEDOUT
+        raise TimeoutError
+      end
+
+      def initialize(connection)
+        @connection = connection
+      end
+
+      def connected?
+        @connection && @connection.connected?
+      end
+
+      def timeout=(timeout)
+        # Hiredis works with microsecond timeouts
+        @connection.timeout = Integer(timeout * 1_000_000)
+      end
+
+      def disconnect
+        @connection.disconnect
+        @connection = nil
+      end
+
+      def write(command)
+        @connection.write(command.flatten(1))
+      rescue Errno::EAGAIN
+        raise TimeoutError
+      end
+
+      def read
+        reply = @connection.read
+        reply = CommandError.new(reply.message) if reply.is_a?(RuntimeError)
+        reply
+      rescue Errno::EAGAIN
+        raise TimeoutError
+      rescue RuntimeError => err
+        raise ProtocolError.new(err.message)
+      end
+    end
+  end
+end
+
+Redis::Connection.drivers << Redis::Connection::Hiredis
diff --git a/lib/vendor/redis/connection/registry.rb b/lib/vendor/redis/connection/registry.rb
new file mode 100644
index 0000000..69ca63d
--- /dev/null
+++ b/lib/vendor/redis/connection/registry.rb
@@ -0,0 +1,12 @@
+class Redis
+  module Connection
+
+    # Store a list of loaded connection drivers in the Connection module.
+    # Redis::Client uses the last required driver by default, and will be aware
+    # of the loaded connection drivers if the user chooses to override the
+    # default connection driver.
+    def self.drivers
+      @drivers ||= []
+    end
+  end
+end
diff --git a/lib/vendor/redis/connection/ruby.rb b/lib/vendor/redis/connection/ruby.rb
new file mode 100644
index 0000000..7aa2808
--- /dev/null
+++ b/lib/vendor/redis/connection/ruby.rb
@@ -0,0 +1,376 @@
+require_relative "registry"
+require_relative "command_helper"
+require_relative "../errors"
+require "socket"
+require "timeout"
+
+begin
+  require "openssl"
+rescue LoadError
+  # Not all systems have OpenSSL support
+end
+
+class Redis
+  module Connection
+    module SocketMixin
+
+      CRLF = "\r\n".freeze
+
+      # Exceptions raised during non-blocking I/O ops that require retrying the op
+      NBIO_EXCEPTIONS = [Errno::EWOULDBLOCK, Errno::EAGAIN]
+      NBIO_EXCEPTIONS << IO::WaitReadable if RUBY_VERSION >= "1.9.3"
+
+      def initialize(*args)
+        super(*args)
+
+        @timeout = @write_timeout = nil
+        @buffer = ""
+      end
+
+      def timeout=(timeout)
+        if timeout && timeout > 0
+          @timeout = timeout
+        else
+          @timeout = nil
+        end
+      end
+
+      def write_timeout=(timeout)
+        if timeout && timeout > 0
+          @write_timeout = timeout
+        else
+          @write_timeout = nil
+        end
+      end
+
+      def read(nbytes)
+        result = @buffer.slice!(0, nbytes)
+
+        while result.bytesize < nbytes
+          result << _read_from_socket(nbytes - result.bytesize)
+        end
+
+        result
+      end
+
+      def gets
+        crlf = nil
+
+        while (crlf = @buffer.index(CRLF)) == nil
+          @buffer << _read_from_socket(1024)
+        end
+
+        @buffer.slice!(0, crlf + CRLF.bytesize)
+      end
+
+      def _read_from_socket(nbytes)
+
+        begin
+          read_nonblock(nbytes)
+
+        rescue *NBIO_EXCEPTIONS
+          if IO.select([self], nil, nil, @timeout)
+            retry
+          else
+            raise Redis::TimeoutError
+          end
+        end
+
+      rescue EOFError
+        raise Errno::ECONNRESET
+      end
+
+      # UNIXSocket and TCPSocket don't support write timeouts
+      def write(*args)
+        Timeout.timeout(@write_timeout, TimeoutError) { super }
+      end
+    end
+
+    if defined?(RUBY_ENGINE) && RUBY_ENGINE == "jruby"
+
+      require "timeout"
+
+      class TCPSocket < ::TCPSocket
+
+        include SocketMixin
+
+        def self.connect(host, port, timeout)
+          Timeout.timeout(timeout) do
+            sock = new(host, port)
+            sock
+          end
+        rescue Timeout::Error
+          raise TimeoutError
+        end
+      end
+
+      if defined?(::UNIXSocket)
+
+        class UNIXSocket < ::UNIXSocket
+
+          include SocketMixin
+
+          def self.connect(path, timeout)
+            Timeout.timeout(timeout) do
+              sock = new(path)
+              sock
+            end
+          rescue Timeout::Error
+            raise TimeoutError
+          end
+
+          # JRuby raises Errno::EAGAIN on #read_nonblock even when IO.select
+          # says it is readable (1.6.6, in both 1.8 and 1.9 mode).
+          # Use the blocking #readpartial method instead.
+
+          def _read_from_socket(nbytes)
+            readpartial(nbytes)
+
+          rescue EOFError
+            raise Errno::ECONNRESET
+          end
+        end
+
+      end
+
+    else
+
+      class TCPSocket < ::Socket
+
+        include SocketMixin
+
+        def self.connect_addrinfo(ai, port, timeout)
+          sock = new(::Socket.const_get(ai[0]), Socket::SOCK_STREAM, 0)
+          sockaddr = ::Socket.pack_sockaddr_in(port, ai[3])
+
+          begin
+            sock.connect_nonblock(sockaddr)
+          rescue Errno::EINPROGRESS
+            if IO.select(nil, [sock], nil, timeout) == nil
+              raise TimeoutError
+            end
+
+            begin
+              sock.connect_nonblock(sockaddr)
+            rescue Errno::EISCONN
+            end
+          end
+
+          sock
+        end
+
+        def self.connect(host, port, timeout)
+          # Don't pass AI_ADDRCONFIG as flag to getaddrinfo(3)
+          #
+          # From the man page for getaddrinfo(3):
+          #
+          #   If hints.ai_flags includes the AI_ADDRCONFIG flag, then IPv4
+          #   addresses are returned in the list pointed to by res only if the
+          #   local system has at least one IPv4 address configured, and IPv6
+          #   addresses are returned only if the local system has at least one
+          #   IPv6 address configured. The loopback address is not considered
+          #   for this case as valid as a configured address.
+          #
+          # We do want the IPv6 loopback address to be returned if applicable,
+          # even if it is the only configured IPv6 address on the machine.
+          # Also see: https://github.com/redis/redis-rb/pull/394.
+          addrinfo = ::Socket.getaddrinfo(host, nil, Socket::AF_UNSPEC, Socket::SOCK_STREAM)
+
+          # From the man page for getaddrinfo(3):
+          #
+          #   Normally, the application should try using the addresses in the
+          #   order in which they are returned. The sorting function used
+          #   within getaddrinfo() is defined in RFC 3484 [...].
+          #
+          addrinfo.each_with_index do |ai, i|
+            begin
+              return connect_addrinfo(ai, port, timeout)
+            rescue SystemCallError
+              # Raise if this was our last attempt.
+              raise if addrinfo.length == i+1
+            end
+          end
+        end
+      end
+
+      class UNIXSocket < ::Socket
+
+        include SocketMixin
+
+        def self.connect(path, timeout)
+          sock = new(::Socket::AF_UNIX, Socket::SOCK_STREAM, 0)
+          sockaddr = ::Socket.pack_sockaddr_un(path)
+
+          begin
+            sock.connect_nonblock(sockaddr)
+          rescue Errno::EINPROGRESS
+            if IO.select(nil, [sock], nil, timeout) == nil
+              raise TimeoutError
+            end
+
+            begin
+              sock.connect_nonblock(sockaddr)
+            rescue Errno::EISCONN
+            end
+          end
+
+          sock
+        end
+      end
+
+    end
+
+    if defined?(OpenSSL)
+      class SSLSocket < ::OpenSSL::SSL::SSLSocket
+        include SocketMixin
+
+        def self.connect(host, port, timeout, ssl_params)
+          # Note: this is using Redis::Connection::TCPSocket
+          tcp_sock = TCPSocket.connect(host, port, timeout)
+
+          ctx = OpenSSL::SSL::SSLContext.new
+          ctx.set_params(ssl_params) if ssl_params && !ssl_params.empty?
+
+          ssl_sock = new(tcp_sock, ctx)
+          ssl_sock.hostname = host
+          ssl_sock.connect
+          ssl_sock.post_connection_check(host)
+
+          ssl_sock
+        end
+      end
+    end
+
+    class Ruby
+      include Redis::Connection::CommandHelper
+
+      MINUS    = "-".freeze
+      PLUS     = "+".freeze
+      COLON    = ":".freeze
+      DOLLAR   = "$".freeze
+      ASTERISK = "*".freeze
+
+      def self.connect(config)
+        if config[:scheme] == "unix"
+          raise ArgumentError, "SSL incompatible with unix sockets" if config[:ssl]
+          sock = UNIXSocket.connect(config[:path], config[:connect_timeout])
+        elsif config[:scheme] == "rediss" || config[:ssl]
+          sock = SSLSocket.connect(config[:host], config[:port], config[:connect_timeout], config[:ssl_params])
+        else
+          sock = TCPSocket.connect(config[:host], config[:port], config[:connect_timeout])
+        end
+
+        instance = new(sock)
+        instance.timeout = config[:timeout]
+        instance.write_timeout = config[:write_timeout]
+        instance.set_tcp_keepalive config[:tcp_keepalive]
+        instance
+      end
+
+      if [:SOL_SOCKET, :SO_KEEPALIVE, :SOL_TCP, :TCP_KEEPIDLE, :TCP_KEEPINTVL, :TCP_KEEPCNT].all?{|c| Socket.const_defined? c}
+        def set_tcp_keepalive(keepalive)
+          return unless keepalive.is_a?(Hash)
+
+          @sock.setsockopt(Socket::SOL_SOCKET, Socket::SO_KEEPALIVE,  true)
+          @sock.setsockopt(Socket::SOL_TCP,    Socket::TCP_KEEPIDLE,  keepalive[:time])
+          @sock.setsockopt(Socket::SOL_TCP,    Socket::TCP_KEEPINTVL, keepalive[:intvl])
+          @sock.setsockopt(Socket::SOL_TCP,    Socket::TCP_KEEPCNT,   keepalive[:probes])
+        end
+
+        def get_tcp_keepalive
+          {
+            :time   => @sock.getsockopt(Socket::SOL_TCP, Socket::TCP_KEEPIDLE).int,
+            :intvl  => @sock.getsockopt(Socket::SOL_TCP, Socket::TCP_KEEPINTVL).int,
+            :probes => @sock.getsockopt(Socket::SOL_TCP, Socket::TCP_KEEPCNT).int,
+          }
+        end
+      else
+        def set_tcp_keepalive(keepalive)
+        end
+
+        def get_tcp_keepalive
+          {
+          }
+        end
+      end
+
+      def initialize(sock)
+        @sock = sock
+      end
+
+      def connected?
+        !! @sock
+      end
+
+      def disconnect
+        @sock.close
+      rescue
+      ensure
+        @sock = nil
+      end
+
+      def timeout=(timeout)
+        if @sock.respond_to?(:timeout=)
+          @sock.timeout = timeout
+        end
+      end
+
+      def write_timeout=(timeout)
+        @sock.write_timeout = timeout
+      end
+
+      def write(command)
+        @sock.write(build_command(command))
+      end
+
+      def read
+        line = @sock.gets
+        reply_type = line.slice!(0, 1)
+        format_reply(reply_type, line)
+
+      rescue Errno::EAGAIN
+        raise TimeoutError
+      end
+
+      def format_reply(reply_type, line)
+        case reply_type
+        when MINUS    then format_error_reply(line)
+        when PLUS     then format_status_reply(line)
+        when COLON    then format_integer_reply(line)
+        when DOLLAR   then format_bulk_reply(line)
+        when ASTERISK then format_multi_bulk_reply(line)
+        else raise ProtocolError.new(reply_type)
+        end
+      end
+
+      def format_error_reply(line)
+        CommandError.new(line.strip)
+      end
+
+      def format_status_reply(line)
+        line.strip
+      end
+
+      def format_integer_reply(line)
+        line.to_i
+      end
+
+      def format_bulk_reply(line)
+        bulklen = line.to_i
+        return if bulklen == -1
+        reply = encode(@sock.read(bulklen))
+        @sock.read(2) # Discard CRLF.
+        reply
+      end
+
+      def format_multi_bulk_reply(line)
+        n = line.to_i
+        return if n == -1
+
+        Array.new(n) { read }
+      end
+    end
+  end
+end
+
+Redis::Connection.drivers << Redis::Connection::Ruby
diff --git a/lib/vendor/redis/connection/synchrony.rb b/lib/vendor/redis/connection/synchrony.rb
new file mode 100644
index 0000000..c8b3dab
--- /dev/null
+++ b/lib/vendor/redis/connection/synchrony.rb
@@ -0,0 +1,133 @@
+require_relative "command_helper"
+require_relative "registry"
+require_relative "../errors"
+require "em-synchrony"
+require "hiredis/reader"
+
+class Redis
+  module Connection
+    class RedisClient < EventMachine::Connection
+      include EventMachine::Deferrable
+
+      attr_accessor :timeout
+
+      def post_init
+        @req = nil
+        @connected = false
+        @reader = ::Hiredis::Reader.new
+      end
+
+      def connection_completed
+        @connected = true
+        succeed
+      end
+
+      def connected?
+        @connected
+      end
+
+      def receive_data(data)
+        @reader.feed(data)
+
+        loop do
+          begin
+            reply = @reader.gets
+          rescue RuntimeError => err
+            @req.fail [:error, ProtocolError.new(err.message)]
+            break
+          end
+
+          break if reply == false
+
+          reply = CommandError.new(reply.message) if reply.is_a?(RuntimeError)
+          @req.succeed [:reply, reply]
+        end
+      end
+
+      def read
+        @req = EventMachine::DefaultDeferrable.new
+        if @timeout > 0
+          @req.timeout(@timeout, :timeout)
+        end
+        EventMachine::Synchrony.sync @req
+      end
+
+      def send(data)
+        callback { send_data data }
+      end
+
+      def unbind
+        @connected = false
+        if @req
+          @req.fail [:error, Errno::ECONNRESET]
+          @req = nil
+        else
+          fail
+        end
+      end
+    end
+
+    class Synchrony
+      include Redis::Connection::CommandHelper
+
+      def self.connect(config)
+        if config[:scheme] == "unix"
+          conn = EventMachine.connect_unix_domain(config[:path], RedisClient)
+        elsif config[:scheme] == "rediss" || config[:ssl]
+          raise NotImplementedError, "SSL not supported by synchrony driver"
+        else
+          conn = EventMachine.connect(config[:host], config[:port], RedisClient) do |c|
+            c.pending_connect_timeout = [config[:connect_timeout], 0.1].max
+          end
+        end
+
+        fiber = Fiber.current
+        conn.callback { fiber.resume }
+        conn.errback { fiber.resume :refused }
+
+        raise Errno::ECONNREFUSED if Fiber.yield == :refused
+
+        instance = new(conn)
+        instance.timeout = config[:read_timeout]
+        instance
+      end
+
+      def initialize(connection)
+        @connection = connection
+      end
+
+      def connected?
+        @connection && @connection.connected?
+      end
+
+      def timeout=(timeout)
+        @connection.timeout = timeout
+      end
+
+      def disconnect
+        @connection.close_connection
+        @connection = nil
+      end
+
+      def write(command)
+        @connection.send(build_command(command))
+      end
+
+      def read
+        type, payload = @connection.read
+
+        if type == :reply
+          payload
+        elsif type == :error
+          raise payload
+        elsif type == :timeout
+          raise TimeoutError
+        else
+          raise "Unknown type #{type.inspect}"
+        end
+      end
+    end
+  end
+end
+
+Redis::Connection.drivers << Redis::Connection::Synchrony
diff --git a/lib/vendor/redis/distributed.rb b/lib/vendor/redis/distributed.rb
new file mode 100644
index 0000000..774c754
--- /dev/null
+++ b/lib/vendor/redis/distributed.rb
@@ -0,0 +1,873 @@
+require_relative "hash_ring"
+
+class Redis
+  class Distributed
+
+    class CannotDistribute < RuntimeError
+      def initialize(command)
+        @command = command
+      end
+
+      def message
+        "#{@command.to_s.upcase} cannot be used in Redis::Distributed because the keys involved need to be on the same server or because we cannot guarantee that the operation will be atomic."
+      end
+    end
+
+    attr_reader :ring
+
+    def initialize(node_configs, options = {})
+      @tag = options[:tag] || /^\{(.+?)\}/
+      @ring = options[:ring] || HashRing.new
+      @node_configs = node_configs.dup
+      @default_options = options.dup
+      node_configs.each { |node_config| add_node(node_config) }
+      @subscribed_node = nil
+    end
+
+    def node_for(key)
+      @ring.get_node(key_tag(key.to_s) || key.to_s)
+    end
+
+    def nodes
+      @ring.nodes
+    end
+
+    def add_node(options)
+      options = { :url => options } if options.is_a?(String)
+      options = @default_options.merge(options)
+      @ring.add_node Redis.new( options )
+    end
+
+    # Change the selected database for the current connection.
+    def select(db)
+      on_each_node :select, db
+    end
+
+    # Ping the server.
+    def ping
+      on_each_node :ping
+    end
+
+    # Echo the given string.
+    def echo(value)
+      on_each_node :echo, value
+    end
+
+    # Close the connection.
+    def quit
+      on_each_node :quit
+    end
+
+    # Asynchronously save the dataset to disk.
+    def bgsave
+      on_each_node :bgsave
+    end
+
+    # Return the number of keys in the selected database.
+    def dbsize
+      on_each_node :dbsize
+    end
+
+    # Remove all keys from all databases.
+    def flushall
+      on_each_node :flushall
+    end
+
+    # Remove all keys from the current database.
+    def flushdb
+      on_each_node :flushdb
+    end
+
+    # Get information and statistics about the server.
+    def info(cmd = nil)
+      on_each_node :info, cmd
+    end
+
+    # Get the UNIX time stamp of the last successful save to disk.
+    def lastsave
+      on_each_node :lastsave
+    end
+
+    # Listen for all requests received by the server in real time.
+    def monitor
+      raise NotImplementedError
+    end
+
+    # Synchronously save the dataset to disk.
+    def save
+      on_each_node :save
+    end
+
+    # Get server time: an UNIX timestamp and the elapsed microseconds in the current second.
+    def time
+      on_each_node :time
+    end
+
+    # Remove the expiration from a key.
+    def persist(key)
+      node_for(key).persist(key)
+    end
+
+    # Set a key's time to live in seconds.
+    def expire(key, seconds)
+      node_for(key).expire(key, seconds)
+    end
+
+    # Set the expiration for a key as a UNIX timestamp.
+    def expireat(key, unix_time)
+      node_for(key).expireat(key, unix_time)
+    end
+
+    # Get the time to live (in seconds) for a key.
+    def ttl(key)
+      node_for(key).ttl(key)
+    end
+
+    # Set a key's time to live in milliseconds.
+    def pexpire(key, milliseconds)
+      node_for(key).pexpire(key, milliseconds)
+    end
+
+    # Set the expiration for a key as number of milliseconds from UNIX Epoch.
+    def pexpireat(key, ms_unix_time)
+      node_for(key).pexpireat(key, ms_unix_time)
+    end
+
+    # Get the time to live (in milliseconds) for a key.
+    def pttl(key)
+      node_for(key).pttl(key)
+    end
+
+    # Return a serialized version of the value stored at a key.
+    def dump(key)
+      node_for(key).dump(key)
+    end
+
+    # Create a key using the serialized value, previously obtained using DUMP.
+    def restore(key, ttl, serialized_value)
+      node_for(key).restore(key, ttl, serialized_value)
+    end
+
+    # Transfer a key from the connected instance to another instance.
+    def migrate(key, options)
+      raise CannotDistribute, :migrate
+    end
+
+    # Delete a key.
+    def del(*args)
+      keys_per_node = args.group_by { |key| node_for(key) }
+      keys_per_node.inject(0) do |sum, (node, keys)|
+        sum + node.del(*keys)
+      end
+    end
+
+    # Determine if a key exists.
+    def exists(key)
+      node_for(key).exists(key)
+    end
+
+    # Find all keys matching the given pattern.
+    def keys(glob = "*")
+      on_each_node(:keys, glob).flatten
+    end
+
+    # Move a key to another database.
+    def move(key, db)
+      node_for(key).move(key, db)
+    end
+
+    # Return a random key from the keyspace.
+    def randomkey
+      raise CannotDistribute, :randomkey
+    end
+
+    # Rename a key.
+    def rename(old_name, new_name)
+      ensure_same_node(:rename, [old_name, new_name]) do |node|
+        node.rename(old_name, new_name)
+      end
+    end
+
+    # Rename a key, only if the new key does not exist.
+    def renamenx(old_name, new_name)
+      ensure_same_node(:renamenx, [old_name, new_name]) do |node|
+        node.renamenx(old_name, new_name)
+      end
+    end
+
+    # Sort the elements in a list, set or sorted set.
+    def sort(key, options = {})
+      keys = [key, options[:by], options[:store], *Array(options[:get])].compact
+
+      ensure_same_node(:sort, keys) do |node|
+        node.sort(key, options)
+      end
+    end
+
+    # Determine the type stored at key.
+    def type(key)
+      node_for(key).type(key)
+    end
+
+    # Decrement the integer value of a key by one.
+    def decr(key)
+      node_for(key).decr(key)
+    end
+
+    # Decrement the integer value of a key by the given number.
+    def decrby(key, decrement)
+      node_for(key).decrby(key, decrement)
+    end
+
+    # Increment the integer value of a key by one.
+    def incr(key)
+      node_for(key).incr(key)
+    end
+
+    # Increment the integer value of a key by the given integer number.
+    def incrby(key, increment)
+      node_for(key).incrby(key, increment)
+    end
+
+    # Increment the numeric value of a key by the given float number.
+    def incrbyfloat(key, increment)
+      node_for(key).incrbyfloat(key, increment)
+    end
+
+    # Set the string value of a key.
+    def set(key, value, options = {})
+      node_for(key).set(key, value, options)
+    end
+
+    # Set the time to live in seconds of a key.
+    def setex(key, ttl, value)
+      node_for(key).setex(key, ttl, value)
+    end
+
+    # Set the time to live in milliseconds of a key.
+    def psetex(key, ttl, value)
+      node_for(key).psetex(key, ttl, value)
+    end
+
+    # Set the value of a key, only if the key does not exist.
+    def setnx(key, value)
+      node_for(key).setnx(key, value)
+    end
+
+    # Set multiple keys to multiple values.
+    def mset(*args)
+      raise CannotDistribute, :mset
+    end
+
+    def mapped_mset(hash)
+      raise CannotDistribute, :mapped_mset
+    end
+
+    # Set multiple keys to multiple values, only if none of the keys exist.
+    def msetnx(*args)
+      raise CannotDistribute, :msetnx
+    end
+
+    def mapped_msetnx(hash)
+      raise CannotDistribute, :mapped_msetnx
+    end
+
+    # Get the value of a key.
+    def get(key)
+      node_for(key).get(key)
+    end
+
+    # Get the values of all the given keys.
+    def mget(*keys)
+      raise CannotDistribute, :mget
+    end
+
+    def mapped_mget(*keys)
+      raise CannotDistribute, :mapped_mget
+    end
+
+    # Overwrite part of a string at key starting at the specified offset.
+    def setrange(key, offset, value)
+      node_for(key).setrange(key, offset, value)
+    end
+
+    # Get a substring of the string stored at a key.
+    def getrange(key, start, stop)
+      node_for(key).getrange(key, start, stop)
+    end
+
+    # Sets or clears the bit at offset in the string value stored at key.
+    def setbit(key, offset, value)
+      node_for(key).setbit(key, offset, value)
+    end
+
+    # Returns the bit value at offset in the string value stored at key.
+    def getbit(key, offset)
+      node_for(key).getbit(key, offset)
+    end
+
+    # Append a value to a key.
+    def append(key, value)
+      node_for(key).append(key, value)
+    end
+
+    # Count the number of set bits in a range of the string value stored at key.
+    def bitcount(key, start = 0, stop = -1)
+      node_for(key).bitcount(key, start, stop)
+    end
+
+    # Perform a bitwise operation between strings and store the resulting string in a key.
+    def bitop(operation, destkey, *keys)
+      ensure_same_node(:bitop, [destkey] + keys) do |node|
+        node.bitop(operation, destkey, *keys)
+      end
+    end
+
+    # Return the position of the first bit set to 1 or 0 in a string.
+    def bitpos(key, bit, start=nil, stop=nil)
+      node_for(key).bitpos(key, bit, start, stop)
+    end
+
+    # Set the string value of a key and return its old value.
+    def getset(key, value)
+      node_for(key).getset(key, value)
+    end
+
+    # Get the length of the value stored in a key.
+    def strlen(key)
+      node_for(key).strlen(key)
+    end
+
+    def [](key)
+      get(key)
+    end
+
+    def []=(key,value)
+      set(key, value)
+    end
+
+    # Get the length of a list.
+    def llen(key)
+      node_for(key).llen(key)
+    end
+
+    # Prepend one or more values to a list.
+    def lpush(key, value)
+      node_for(key).lpush(key, value)
+    end
+
+    # Prepend a value to a list, only if the list exists.
+    def lpushx(key, value)
+      node_for(key).lpushx(key, value)
+    end
+
+    # Append one or more values to a list.
+    def rpush(key, value)
+      node_for(key).rpush(key, value)
+    end
+
+    # Append a value to a list, only if the list exists.
+    def rpushx(key, value)
+      node_for(key).rpushx(key, value)
+    end
+
+    # Remove and get the first element in a list.
+    def lpop(key)
+      node_for(key).lpop(key)
+    end
+
+    # Remove and get the last element in a list.
+    def rpop(key)
+      node_for(key).rpop(key)
+    end
+
+    # Remove the last element in a list, append it to another list and return
+    # it.
+    def rpoplpush(source, destination)
+      ensure_same_node(:rpoplpush, [source, destination]) do |node|
+        node.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
+
+      ensure_same_node(cmd, keys) do |node|
+        node.__send__(cmd, keys, options)
+      end
+    end
+
+    # Remove and get the first element in a list, or block until one is
+    # available.
+    def blpop(*args)
+      _bpop(:blpop, args)
+    end
+
+    # Remove and get the last element in a list, or block until one is
+    # available.
+    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.
+    def brpoplpush(source, destination, options = {})
+      case options
+      when Integer
+        # Issue deprecation notice in obnoxious mode...
+        options = { :timeout => options }
+      end
+
+      ensure_same_node(:brpoplpush, [source, destination]) do |node|
+        node.brpoplpush(source, destination, options)
+      end
+    end
+
+    # Get an element from a list by its index.
+    def lindex(key, index)
+      node_for(key).lindex(key, index)
+    end
+
+    # Insert an element before or after another element in a list.
+    def linsert(key, where, pivot, value)
+      node_for(key).linsert(key, where, pivot, value)
+    end
+
+    # Get a range of elements from a list.
+    def lrange(key, start, stop)
+      node_for(key).lrange(key, start, stop)
+    end
+
+    # Remove elements from a list.
+    def lrem(key, count, value)
+      node_for(key).lrem(key, count, value)
+    end
+
+    # Set the value of an element in a list by its index.
+    def lset(key, index, value)
+      node_for(key).lset(key, index, value)
+    end
+
+    # Trim a list to the specified range.
+    def ltrim(key, start, stop)
+      node_for(key).ltrim(key, start, stop)
+    end
+
+    # Get the number of members in a set.
+    def scard(key)
+      node_for(key).scard(key)
+    end
+
+    # Add one or more members to a set.
+    def sadd(key, member)
+      node_for(key).sadd(key, member)
+    end
+
+    # Remove one or more members from a set.
+    def srem(key, member)
+      node_for(key).srem(key, member)
+    end
+
+    # Remove and return a random member from a set.
+    def spop(key)
+      node_for(key).spop(key)
+    end
+
+    # Get a random member from a set.
+    def srandmember(key, count = nil)
+      node_for(key).srandmember(key, count)
+    end
+
+    # Move a member from one set to another.
+    def smove(source, destination, member)
+      ensure_same_node(:smove, [source, destination]) do |node|
+        node.smove(source, destination, member)
+      end
+    end
+
+    # Determine if a given value is a member of a set.
+    def sismember(key, member)
+      node_for(key).sismember(key, member)
+    end
+
+    # Get all the members in a set.
+    def smembers(key)
+      node_for(key).smembers(key)
+    end
+
+    # Subtract multiple sets.
+    def sdiff(*keys)
+      ensure_same_node(:sdiff, keys) do |node|
+        node.sdiff(*keys)
+      end
+    end
+
+    # Subtract multiple sets and store the resulting set in a key.
+    def sdiffstore(destination, *keys)
+      ensure_same_node(:sdiffstore, [destination] + keys) do |node|
+        node.sdiffstore(destination, *keys)
+      end
+    end
+
+    # Intersect multiple sets.
+    def sinter(*keys)
+      ensure_same_node(:sinter, keys) do |node|
+        node.sinter(*keys)
+      end
+    end
+
+    # Intersect multiple sets and store the resulting set in a key.
+    def sinterstore(destination, *keys)
+      ensure_same_node(:sinterstore, [destination] + keys) do |node|
+        node.sinterstore(destination, *keys)
+      end
+    end
+
+    # Add multiple sets.
+    def sunion(*keys)
+      ensure_same_node(:sunion, keys) do |node|
+        node.sunion(*keys)
+      end
+    end
+
+    # Add multiple sets and store the resulting set in a key.
+    def sunionstore(destination, *keys)
+      ensure_same_node(:sunionstore, [destination] + keys) do |node|
+        node.sunionstore(destination, *keys)
+      end
+    end
+
+    # Get the number of members in a sorted set.
+    def zcard(key)
+      node_for(key).zcard(key)
+    end
+
+    # Add one or more members to a sorted set, or update the score for members
+    # that already exist.
+    def zadd(key, *args)
+      node_for(key).zadd(key, *args)
+    end
+
+    # Increment the score of a member in a sorted set.
+    def zincrby(key, increment, member)
+      node_for(key).zincrby(key, increment, member)
+    end
+
+    # Remove one or more members from a sorted set.
+    def zrem(key, member)
+      node_for(key).zrem(key, member)
+    end
+
+    # Get the score associated with the given member in a sorted set.
+    def zscore(key, member)
+      node_for(key).zscore(key, member)
+    end
+
+    # Return a range of members in a sorted set, by index.
+    def zrange(key, start, stop, options = {})
+      node_for(key).zrange(key, start, stop, options)
+    end
+
+    # Return a range of members in a sorted set, by index, with scores ordered
+    # from high to low.
+    def zrevrange(key, start, stop, options = {})
+      node_for(key).zrevrange(key, start, stop, options)
+    end
+
+    # Determine the index of a member in a sorted set.
+    def zrank(key, member)
+      node_for(key).zrank(key, member)
+    end
+
+    # Determine the index of a member in a sorted set, with scores ordered from
+    # high to low.
+    def zrevrank(key, member)
+      node_for(key).zrevrank(key, member)
+    end
+
+    # Remove all members in a sorted set within the given indexes.
+    def zremrangebyrank(key, start, stop)
+      node_for(key).zremrangebyrank(key, start, stop)
+    end
+
+    # Return a range of members in a sorted set, by score.
+    def zrangebyscore(key, min, max, options = {})
+      node_for(key).zrangebyscore(key, min, max, options)
+    end
+
+    # Return a range of members in a sorted set, by score, with scores ordered
+    # from high to low.
+    def zrevrangebyscore(key, max, min, options = {})
+      node_for(key).zrevrangebyscore(key, max, min, options)
+    end
+
+    # Remove all members in a sorted set within the given scores.
+    def zremrangebyscore(key, min, max)
+      node_for(key).zremrangebyscore(key, min, max)
+    end
+
+    # Get the number of members in a particular score range.
+    def zcount(key, min, max)
+      node_for(key).zcount(key, min, max)
+    end
+
+    # Intersect multiple sorted sets and store the resulting sorted set in a new
+    # key.
+    def zinterstore(destination, keys, options = {})
+      ensure_same_node(:zinterstore, [destination] + keys) do |node|
+        node.zinterstore(destination, keys, options)
+      end
+    end
+
+    # Add multiple sorted sets and store the resulting sorted set in a new key.
+    def zunionstore(destination, keys, options = {})
+      ensure_same_node(:zunionstore, [destination] + keys) do |node|
+        node.zunionstore(destination, keys, options)
+      end
+    end
+
+    # Get the number of fields in a hash.
+    def hlen(key)
+      node_for(key).hlen(key)
+    end
+
+    # Set the string value of a hash field.
+    def hset(key, field, value)
+      node_for(key).hset(key, field, value)
+    end
+
+    # Set the value of a hash field, only if the field does not exist.
+    def hsetnx(key, field, value)
+      node_for(key).hsetnx(key, field, value)
+    end
+
+    # Set multiple hash fields to multiple values.
+    def hmset(key, *attrs)
+      node_for(key).hmset(key, *attrs)
+    end
+
+    def mapped_hmset(key, hash)
+      node_for(key).hmset(key, *hash.to_a.flatten)
+    end
+
+    # Get the value of a hash field.
+    def hget(key, field)
+      node_for(key).hget(key, field)
+    end
+
+    # Get the values of all the given hash fields.
+    def hmget(key, *fields)
+      node_for(key).hmget(key, *fields)
+    end
+
+    def mapped_hmget(key, *fields)
+      Hash[*fields.zip(hmget(key, *fields)).flatten]
+    end
+
+    # Delete one or more hash fields.
+    def hdel(key, field)
+      node_for(key).hdel(key, field)
+    end
+
+    # Determine if a hash field exists.
+    def hexists(key, field)
+      node_for(key).hexists(key, field)
+    end
+
+    # Increment the integer value of a hash field by the given integer number.
+    def hincrby(key, field, increment)
+      node_for(key).hincrby(key, field, increment)
+    end
+
+    # Increment the numeric value of a hash field by the given float number.
+    def hincrbyfloat(key, field, increment)
+      node_for(key).hincrbyfloat(key, field, increment)
+    end
+
+    # Get all the fields in a hash.
+    def hkeys(key)
+      node_for(key).hkeys(key)
+    end
+
+    # Get all the values in a hash.
+    def hvals(key)
+      node_for(key).hvals(key)
+    end
+
+    # Get all the fields and values in a hash.
+    def hgetall(key)
+      node_for(key).hgetall(key)
+    end
+
+    # Post a message to a channel.
+    def publish(channel, message)
+      node_for(channel).publish(channel, message)
+    end
+
+    def subscribed?
+      !! @subscribed_node
+    end
+
+    # Listen for messages published to the given channels.
+    def subscribe(channel, *channels, &block)
+      if channels.empty?
+        @subscribed_node = node_for(channel)
+        @subscribed_node.subscribe(channel, &block)
+      else
+        ensure_same_node(:subscribe, [channel] + channels) do |node|
+          @subscribed_node = node
+          node.subscribe(channel, *channels, &block)
+        end
+      end
+    end
+
+    # Stop listening for messages posted to the given channels.
+    def unsubscribe(*channels)
+      raise RuntimeError, "Can't unsubscribe if not subscribed." unless subscribed?
+      @subscribed_node.unsubscribe(*channels)
+    end
+
+    # Listen for messages published to channels matching the given patterns.
+    def psubscribe(*channels, &block)
+      raise NotImplementedError
+    end
+
+    # Stop listening for messages posted to channels matching the given
+    # patterns.
+    def punsubscribe(*channels)
+      raise NotImplementedError
+    end
+
+    # Watch the given keys to determine execution of the MULTI/EXEC block.
+    def watch(*keys)
+      raise CannotDistribute, :watch
+    end
+
+    # Forget about all watched keys.
+    def unwatch
+      raise CannotDistribute, :unwatch
+    end
+
+    def pipelined
+      raise CannotDistribute, :pipelined
+    end
+
+    # Mark the start of a transaction block.
+    def multi
+      raise CannotDistribute, :multi
+    end
+
+    # Execute all commands issued after MULTI.
+    def exec
+      raise CannotDistribute, :exec
+    end
+
+    # Discard all commands issued after MULTI.
+    def discard
+      raise CannotDistribute, :discard
+    end
+
+    # Control remote script registry.
+    def script(subcommand, *args)
+      on_each_node(:script, subcommand, *args)
+    end
+
+    # Add one or more members to a HyperLogLog structure.
+    def pfadd(key, member)
+      node_for(key).pfadd(key, member)
+    end
+
+    # Get the approximate cardinality of members added to HyperLogLog structure.
+    def pfcount(*keys)
+      ensure_same_node(:pfcount, keys.flatten(1)) do |node|
+        node.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.
+    def pfmerge(dest_key, *source_key)
+      ensure_same_node(:pfmerge, [dest_key, *source_key]) do |node|
+        node.pfmerge(dest_key, *source_key)
+      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] || []
+
+      ensure_same_node(cmd, keys) do |node|
+        node.send(cmd, script, keys, argv)
+      end
+    end
+
+    # Evaluate Lua script.
+    def eval(*args)
+      _eval(:eval, args)
+    end
+
+    # Evaluate Lua script by its SHA.
+    def evalsha(*args)
+      _eval(:evalsha, args)
+    end
+
+    def inspect
+      "#<Redis client v#{Redis::VERSION} for #{nodes.map(&:id).join(', ')}>"
+    end
+
+    def dup
+      self.class.new(@node_configs, @default_options)
+    end
+
+  protected
+
+    def on_each_node(command, *args)
+      nodes.map do |node|
+        node.send(command, *args)
+      end
+    end
+
+    def node_index_for(key)
+      nodes.index(node_for(key))
+    end
+
+    def key_tag(key)
+      key.to_s[@tag, 1] if @tag
+    end
+
+    def ensure_same_node(command, keys)
+      all = true
+
+      tags = keys.map do |key|
+        tag = key_tag(key)
+        all = false unless tag
+        tag
+      end
+
+      if (all && tags.uniq.size != 1) || (!all && keys.uniq.size != 1)
+        # Not 1 unique tag or not 1 unique key
+        raise CannotDistribute, command
+      end
+
+      yield(node_for(keys.first))
+    end
+  end
+end
diff --git a/lib/vendor/redis/errors.rb b/lib/vendor/redis/errors.rb
new file mode 100644
index 0000000..85b222e
--- /dev/null
+++ b/lib/vendor/redis/errors.rb
@@ -0,0 +1,40 @@
+class Redis
+  # Base error for all redis-rb errors.
+  class BaseError < RuntimeError
+  end
+
+  # Raised by the connection when a protocol error occurs.
+  class ProtocolError < BaseError
+    def initialize(reply_type)
+      super(<<-EOS.gsub(/(?:^|\n)\s*/, " "))
+        Got '#{reply_type}' as initial reply byte.
+        If you're in a forking environment, such as Unicorn, you need to
+        connect to Redis after forking.
+      EOS
+    end
+  end
+
+  # Raised by the client when command execution returns an error reply.
+  class CommandError < BaseError
+  end
+
+  # Base error for connection related errors.
+  class BaseConnectionError < BaseError
+  end
+
+  # Raised when connection to a Redis server cannot be made.
+  class CannotConnectError < BaseConnectionError
+  end
+
+  # Raised when connection to a Redis server is lost.
+  class ConnectionError < BaseConnectionError
+  end
+
+  # Raised when performing I/O times out.
+  class TimeoutError < BaseConnectionError
+  end
+
+  # Raised when the connection was inherited by a child process.
+  class InheritedError < BaseConnectionError
+  end
+end
diff --git a/lib/vendor/redis/hash_ring.rb b/lib/vendor/redis/hash_ring.rb
new file mode 100644
index 0000000..2a199bd
--- /dev/null
+++ b/lib/vendor/redis/hash_ring.rb
@@ -0,0 +1,132 @@
+require 'zlib'
+
+class Redis
+  class HashRing
+
+    POINTS_PER_SERVER = 160 # this is the default in libmemcached
+
+    attr_reader :ring, :sorted_keys, :replicas, :nodes
+
+    # nodes is a list of objects that have a proper to_s representation.
+    # replicas indicates how many virtual points should be used pr. node,
+    # replicas are required to improve the distribution.
+    def initialize(nodes=[], replicas=POINTS_PER_SERVER)
+      @replicas = replicas
+      @ring = {}
+      @nodes = []
+      @sorted_keys = []
+      nodes.each do |node|
+        add_node(node)
+      end
+    end
+
+    # Adds a `node` to the hash ring (including a number of replicas).
+    def add_node(node)
+      @nodes << node
+      @replicas.times do |i|
+        key = Zlib.crc32("#{node.id}:#{i}")
+        raise "Node ID collision" if @ring.has_key?(key)
+        @ring[key] = node
+        @sorted_keys << key
+      end
+      @sorted_keys.sort!
+    end
+
+    def remove_node(node)
+      @nodes.reject!{|n| n.id == node.id}
+      @replicas.times do |i|
+        key = Zlib.crc32("#{node.id}:#{i}")
+        @ring.delete(key)
+        @sorted_keys.reject! {|k| k == key}
+      end
+    end
+
+    # get the node in the hash ring for this key
+    def get_node(key)
+      get_node_pos(key)[0]
+    end
+
+    def get_node_pos(key)
+      return [nil,nil] if @ring.size == 0
+      crc = Zlib.crc32(key)
+      idx = HashRing.binary_search(@sorted_keys, crc)
+      return [@ring[@sorted_keys[idx]], idx]
+    end
+
+    def iter_nodes(key)
+      return [nil,nil] if @ring.size == 0
+      _, pos = get_node_pos(key)
+      @ring.size.times do |n|
+        yield @ring[@sorted_keys[(pos+n) % @ring.size]]
+      end
+    end
+
+    class << self
+
+      # gem install RubyInline to use this code
+      # Native extension to perform the binary search within the hashring.
+      # There's a pure ruby version below so this is purely optional
+      # for performance.  In testing 20k gets and sets, the native
+      # binary search shaved about 12% off the runtime (9sec -> 8sec).
+      begin
+        require 'inline'
+        inline do |builder|
+          builder.c <<-EOM
+          int binary_search(VALUE ary, unsigned int r) {
+              int upper = RARRAY_LEN(ary) - 1;
+              int lower = 0;
+              int idx = 0;
+
+              while (lower <= upper) {
+                  idx = (lower + upper) / 2;
+
+                  VALUE continuumValue = RARRAY_PTR(ary)[idx];
+                  unsigned int l = NUM2UINT(continuumValue);
+                  if (l == r) {
+                      return idx;
+                  }
+                  else if (l > r) {
+                      upper = idx - 1;
+                  }
+                  else {
+                      lower = idx + 1;
+                  }
+              }
+              if (upper < 0) {
+                upper = RARRAY_LEN(ary) - 1;
+              }
+              return upper;
+          }
+          EOM
+        end
+      rescue Exception
+        # Find the closest index in HashRing with value <= the given value
+        def binary_search(ary, value, &block)
+          upper = ary.size - 1
+          lower = 0
+          idx = 0
+
+          while(lower <= upper) do
+            idx = (lower + upper) / 2
+            comp = ary[idx] <=> value
+
+            if comp == 0
+              return idx
+            elsif comp > 0
+              upper = idx - 1
+            else
+              lower = idx + 1
+            end
+          end
+
+          if upper < 0
+            upper = ary.size - 1
+          end
+          return upper
+        end
+
+      end
+    end
+
+  end
+end
diff --git a/lib/vendor/redis/pipeline.rb b/lib/vendor/redis/pipeline.rb
new file mode 100644
index 0000000..a77f86d
--- /dev/null
+++ b/lib/vendor/redis/pipeline.rb
@@ -0,0 +1,141 @@
+class Redis
+  unless defined?(::BasicObject)
+    class BasicObject
+      instance_methods.each { |meth| undef_method(meth) unless meth =~ /\A(__|instance_eval)/ }
+    end
+  end
+
+  class Pipeline
+    attr_accessor :db
+
+    attr :futures
+
+    def initialize
+      @with_reconnect = true
+      @shutdown = false
+      @futures = []
+    end
+
+    def with_reconnect?
+      @with_reconnect
+    end
+
+    def without_reconnect?
+      !@with_reconnect
+    end
+
+    def shutdown?
+      @shutdown
+    end
+
+    def call(command, &block)
+      # A pipeline that contains a shutdown should not raise ECONNRESET when
+      # the connection is gone.
+      @shutdown = true if command.first == :shutdown
+      future = Future.new(command, block)
+      @futures << future
+      future
+    end
+
+    def call_pipeline(pipeline)
+      @shutdown = true if pipeline.shutdown?
+      @futures.concat(pipeline.futures)
+      @db = pipeline.db
+      nil
+    end
+
+    def commands
+      @futures.map { |f| f._command }
+    end
+
+    def with_reconnect(val=true)
+      @with_reconnect = false unless val
+      yield
+    end
+
+    def without_reconnect(&blk)
+      with_reconnect(false, &blk)
+    end
+
+    def finish(replies, &blk)
+      if blk
+        futures.each_with_index.map do |future, i|
+          future._set(blk.call(replies[i]))
+        end
+      else
+        futures.each_with_index.map do |future, i|
+          future._set(replies[i])
+        end
+      end
+    end
+
+    class Multi < self
+      def finish(replies)
+        exec = replies.last
+
+        return if exec.nil? # The transaction failed because of WATCH.
+
+        # EXEC command failed.
+        raise exec if exec.is_a?(CommandError)
+
+        if exec.size < futures.size
+          # Some command wasn't recognized by Redis.
+          raise replies.detect { |r| r.is_a?(CommandError) }
+        end
+
+        super(exec) do |reply|
+          # Because an EXEC returns nested replies, hiredis won't be able to
+          # convert an error reply to a CommandError instance itself. This is
+          # specific to MULTI/EXEC, so we solve this here.
+          reply.is_a?(::RuntimeError) ? CommandError.new(reply.message) : reply
+        end
+      end
+
+      def commands
+        [[:multi]] + super + [[:exec]]
+      end
+    end
+  end
+
+  class FutureNotReady < RuntimeError
+    def initialize
+      super("Value will be available once the pipeline executes.")
+    end
+  end
+
+  class Future < BasicObject
+    FutureNotReady = ::Redis::FutureNotReady.new
+
+    def initialize(command, transformation)
+      @command = command
+      @transformation = transformation
+      @object = FutureNotReady
+    end
+
+    def inspect
+      "<Redis::Future #{@command.inspect}>"
+    end
+
+    def _set(object)
+      @object = @transformation ? @transformation.call(object) : object
+      value
+    end
+
+    def _command
+      @command
+    end
+
+    def value
+      ::Kernel.raise(@object) if @object.kind_of?(::RuntimeError)
+      @object
+    end
+
+    def is_a?(other)
+      self.class.ancestors.include?(other)
+    end
+
+    def class
+      Future
+    end
+  end
+end
diff --git a/lib/vendor/redis/subscribe.rb b/lib/vendor/redis/subscribe.rb
new file mode 100644
index 0000000..3029d04
--- /dev/null
+++ b/lib/vendor/redis/subscribe.rb
@@ -0,0 +1,91 @@
+class Redis
+  class SubscribedClient
+    def initialize(client)
+      @client = client
+    end
+
+    def call(command)
+      @client.process([command])
+    end
+
+    def subscribe(*channels, &block)
+      subscription("subscribe", "unsubscribe", channels, block)
+    end
+
+    def subscribe_with_timeout(timeout, *channels, &block)
+      subscription("subscribe", "unsubscribe", channels, block, timeout)
+    end
+
+    def psubscribe(*channels, &block)
+      subscription("psubscribe", "punsubscribe", channels, block)
+    end
+
+    def psubscribe_with_timeout(timeout, *channels, &block)
+      subscription("psubscribe", "punsubscribe", channels, block, timeout)
+    end
+
+    def unsubscribe(*channels)
+      call([:unsubscribe, *channels])
+    end
+
+    def punsubscribe(*channels)
+      call([:punsubscribe, *channels])
+    end
+
+  protected
+
+    def subscription(start, stop, channels, block, timeout = 0)
+      sub = Subscription.new(&block)
+
+      unsubscribed = false
+
+      begin
+        @client.call_loop([start, *channels], timeout) do |line|
+          type, *rest = line
+          sub.callbacks[type].call(*rest)
+          unsubscribed = type == stop && rest.last == 0
+          break if unsubscribed
+        end
+      ensure
+        # No need to unsubscribe here. The real client closes the connection
+        # whenever an exception is raised (see #ensure_connected).
+      end
+    end
+  end
+
+  class Subscription
+    attr :callbacks
+
+    def initialize
+      @callbacks = Hash.new do |hash, key|
+        hash[key] = lambda { |*_| }
+      end
+
+      yield(self)
+    end
+
+    def subscribe(&block)
+      @callbacks["subscribe"] = block
+    end
+
+    def unsubscribe(&block)
+      @callbacks["unsubscribe"] = block
+    end
+
+    def message(&block)
+      @callbacks["message"] = block
+    end
+
+    def psubscribe(&block)
+      @callbacks["psubscribe"] = block
+    end
+
+    def punsubscribe(&block)
+      @callbacks["punsubscribe"] = block
+    end
+
+    def pmessage(&block)
+      @callbacks["pmessage"] = block
+    end
+  end
+end
diff --git a/lib/vendor/redis/version.rb b/lib/vendor/redis/version.rb
new file mode 100644
index 0000000..3f1fbc0
--- /dev/null
+++ b/lib/vendor/redis/version.rb
@@ -0,0 +1,3 @@
+class Redis
+  VERSION = "3.3.0"
+end