class Redis

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 [Integer] :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] :username Username to authenticate against server @option options [String] :password Password to authenticate against server @option options [Integer] :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, Integer] :tcp_keepalive Keepalive values, if Integer `intvl` and `probe` are calculated

based on the value, if Hash `time`, `intvl` and `probes` can be specified as a Integer

@option options [Integer] :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` @option options [Array<String, Hash{Symbol => String, Integer}>] :cluster List of cluster nodes to contact @option options [Boolean] :replica Whether to use readonly replica nodes in Redis Cluster or not @option options [Class] :connector Class of custom connector

@return [Redis] a new client instance

# File lib/redis.rb, line 59
def initialize(options = {})
  @options = options.dup
  @cluster_mode = options.key?(:cluster)
  client = @cluster_mode ? Cluster : Client
  @original_client = @client = client.new(options)
  @queue = Hash.new { |h, k| h[k] = [] }

  super() # Monitor#initialize
end

Append a value to a key.

@param [String] key @param [String] value value to append @return [Integer] length of the string after appending

# File lib/redis.rb, line 1049
def append(key, value)
  synchronize do |client|
    client.call([:append, key, value])
  end
end

Sends `ASKING` command to random node and returns its reply.

@see redis.io/topics/cluster-spec#ask-redirection ASK redirection

@return [String] `'OK'`

# File lib/redis.rb, line 3336
def asking
  synchronize { |client| client.call(%i[asking]) }
end

Authenticate to the server.

@param [Array<String>] args includes both username and password

or only password

@return [String] `OK` @see redis.io/commands/auth AUTH command

# File lib/redis.rb, line 151
def auth(*args)
  synchronize do |client|
    client.call([:auth, *args])
  end
end

Asynchronously rewrite the append-only file.

@return [String] `OK`

# File lib/redis.rb, line 205
def bgrewriteaof
  synchronize do |client|
    client.call([:bgrewriteaof])
  end
end

Asynchronously save the dataset to disk.

@return [String] `OK`

# File lib/redis.rb, line 214
def bgsave
  synchronize do |client|
    client.call([:bgsave])
  end
end

Count the number of set bits in a range of the string value stored at key.

@param [String] key @param [Integer] start start index @param [Integer] stop stop index @return [Integer] the number of bits set to 1

# File lib/redis.rb, line 1061
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 [Integer] the length of the string stored in `destkey`

# File lib/redis.rb, line 1073
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 [Integer] bit whether to look for the first 1 or 0 bit @param [Integer] start start index @param [Integer] stop stop index @return [Integer] the position of the first 1/0 bit.

-1 if looking for 1 and it is not found or start and stop are given.

# File lib/redis.rb, line 1087
def bitpos(key, bit, start = nil, stop = nil)
  raise(ArgumentError, 'stop parameter specified without start parameter') if stop && !start

  synchronize do |client|
    command = [:bitpos, key, bit]
    command << start if start
    command << stop if stop
    client.call(command)
  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 => Integer`: 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

# File lib/redis.rb, line 1257
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 => Integer`: 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

# File lib/redis.rb, line 1273
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 => Integer`: timeout in seconds, defaults to no timeout

@return [nil, String]

- `nil` when the operation timed out
- the element was popped and pushed otherwise

# File lib/redis.rb, line 1288
def brpoplpush(source, destination, deprecated_timeout = 0, timeout: deprecated_timeout)
  synchronize do |client|
    command = [:brpoplpush, source, destination, timeout]
    timeout += client.timeout if timeout > 0
    client.call_with_timeout(command, timeout)
  end
end

Removes and returns up to count members with the highest scores in the sorted set stored at keys,

or block until one is available.

@example Popping a member from a sorted set

redis.bzpopmax('zset', 1)
#=> ['zset', 'b', 2.0]

@example Popping a member from multiple sorted sets

redis.bzpopmax('zset1', 'zset2', 1)
#=> ['zset1', 'b', 2.0]

@params keys [Array<String>] one or multiple keys of the sorted sets @params timeout [Integer] the maximum number of seconds to block

@return [Array<String, String, Float>] a touple of key, member and score @return [nil] when no element could be popped and the timeout expired

# File lib/redis.rb, line 1721
def bzpopmax(*args)
  _bpop(:bzpopmax, args) do |reply|
    reply.is_a?(Array) ? [reply[0], reply[1], Floatify.call(reply[2])] : reply
  end
end

Removes and returns up to count members with the lowest scores in the sorted set stored at keys,

or block until one is available.

@example Popping a member from a sorted set

redis.bzpopmin('zset', 1)
#=> ['zset', 'a', 1.0]

@example Popping a member from multiple sorted sets

redis.bzpopmin('zset1', 'zset2', 1)
#=> ['zset1', 'a', 1.0]

@params keys [Array<String>] one or multiple keys of the sorted sets @params timeout [Integer] the maximum number of seconds to block

@return [Array<String, String, Float>] a touple of key, member and score @return [nil] when no element could be popped and the timeout expired

# File lib/redis.rb, line 1742
def bzpopmin(*args)
  _bpop(:bzpopmin, args) do |reply|
    reply.is_a?(Array) ? [reply[0], reply[1], Floatify.call(reply[2])] : reply
  end
end

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.

# File lib/redis.rb, line 104
def call(*command)
  synchronize do |client|
    client.call(command)
  end
end

Manage client connections.

@param [String, Symbol] subcommand e.g. `kill`, `list`, `getname`, `setname` @return [String, Hash] depends on subcommand

# File lib/redis.rb, line 241
def client(subcommand = nil, *args)
  synchronize do |client|
    client.call([:client, subcommand] + args) do |reply|
      if subcommand.to_s == "list"
        reply.lines.map do |line|
          entries = line.chomp.split(/[ =]/)
          Hash[entries.each_slice(2).to_a]
        end
      else
        reply
      end
    end
  end
end

Disconnect the client as quickly and silently as possible.

# File lib/redis.rb, line 91
def close
  @original_client.disconnect
end

Sends `CLUSTER *` command to random node and returns its reply.

@see redis.io/commands#cluster Reference of cluster command

@param subcommand [String, Symbol] the subcommand of cluster command

e.g. `:slots`, `:nodes`, `:slaves`, `:info`

@return [Object] depends on the subcommand

# File lib/redis.rb, line 3308
def cluster(subcommand, *args)
  subcommand = subcommand.to_s.downcase
  block = case subcommand
  when 'slots'
    HashifyClusterSlots
  when 'nodes'
    HashifyClusterNodes
  when 'slaves'
    HashifyClusterSlaves
  when 'info'
    HashifyInfo
  else
    Noop
  end

  # @see https://github.com/antirez/redis/blob/unstable/src/redis-trib.rb#L127 raw reply expected
  block = Noop unless @cluster_mode

  synchronize do |client|
    client.call([:cluster, subcommand] + args, &block)
  end
end

Sends all commands in the queue.

See redis.io/topics/pipelining for more details.

# File lib/redis.rb, line 126
def commit
  synchronize do |client|
    begin
      pipeline = Pipeline.new(client)
      @queue[Thread.current.object_id].each do |command|
        pipeline.call(command)
      end

      client.call_pipelined(pipeline)
    ensure
      @queue.delete(Thread.current.object_id)
    end
  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`

# File lib/redis.rb, line 225
def config(action, *args)
  synchronize do |client|
    client.call([:config, action] + args) do |reply|
      if reply.is_a?(Array) && action == :get
        Hashify.call(reply)
      else
        reply
      end
    end
  end
end

Test whether or not the client is connected

# File lib/redis.rb, line 86
def connected?
  @original_client.connected?
end

Return the number of keys in the selected database.

@return [Integer]

# File lib/redis.rb, line 259
def dbsize
  synchronize do |client|
    client.call([:dbsize])
  end
end

Decrement the integer value of a key by one.

@example

redis.decr("value")
  # => 4

@param [String] key @return [Integer] value after decrementing it

# File lib/redis.rb, line 762
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 [Integer] decrement @return [Integer] value after decrementing it

# File lib/redis.rb, line 777
def decrby(key, decrement)
  synchronize do |client|
    client.call([:decrby, key, decrement])
  end
end

Delete one or more keys.

@param [String, Array<String>] keys @return [Integer] number of keys that were deleted

# File lib/redis.rb, line 557
def del(*keys)
  synchronize do |client|
    client.call([:del] + keys)
  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

# File lib/redis.rb, line 2530
def discard
  synchronize do |client|
    client.call([:discard])
  end
end

Return a serialized version of the value stored at a key.

@param [String] key @return [String] serialized_value

# File lib/redis.rb, line 504
def dump(key)
  synchronize do |client|
    client.call([:dump, key])
  end
end

Echo the given string.

@param [String] value @return [String]

# File lib/redis.rb, line 182
def echo(value)
  synchronize do |client|
    client.call([:echo, value])
  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

# File lib/redis.rb, line 2618
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

# File lib/redis.rb, line 2643
def evalsha(*args)
  _eval(:evalsha, args)
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

# File lib/redis.rb, line 2516
def exec
  synchronize do |client|
    client.call([:exec])
  end
end

Determine how many of the keys exists.

@param [String, Array<String>] keys @return [Integer]

# File lib/redis.rb, line 577
def exists(*keys)
  if !Redis.exists_returns_integer && keys.size == 1
    if Redis.exists_returns_integer.nil?
      message = "`Redis#exists(key)` will return an Integer in redis-rb 4.3. `exists?` returns a boolean, you " \
        "should use it instead. To opt-in to the new behavior now you can set Redis.exists_returns_integer =  " \
        "true. To disable this message and keep the current (boolean) behaviour of 'exists' you can set " \
        "`Redis.exists_returns_integer = false`, but this option will be removed in 5.0. " \
        "(#{::Kernel.caller(1, 1).first})\n"

      ::Kernel.warn(message)
    end

    exists?(*keys)
  else
    _exists(*keys)
  end
end

Determine if any of the keys exists.

@param [String, Array<String>] keys @return [Boolean]

# File lib/redis.rb, line 605
def exists?(*keys)
  synchronize do |client|
    client.call([:exists, *keys]) do |value|
      value > 0
    end
  end
end

Set a key's time to live in seconds.

@param [String] key @param [Integer] seconds time to live @return [Boolean] whether the timeout was set or not

# File lib/redis.rb, line 426
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 [Integer] unix_time expiry time specified as a UNIX timestamp @return [Boolean] whether the timeout was set or not

# File lib/redis.rb, line 437
def expireat(key, unix_time)
  synchronize do |client|
    client.call([:expireat, key, unix_time], &Boolify)
  end
end

Remove all keys from all databases.

@param [Hash] options

- `:async => Boolean`: async flush (default: false)

@return [String] `OK`

# File lib/redis.rb, line 276
def flushall(options = nil)
  synchronize do |client|
    if options && options[:async]
      client.call(%i[flushall async])
    else
      client.call([:flushall])
    end
  end
end

Remove all keys from the current database.

@param [Hash] options

- `:async => Boolean`: async flush (default: false)

@return [String] `OK`

# File lib/redis.rb, line 291
def flushdb(options = nil)
  synchronize do |client|
    if options && options[:async]
      client.call(%i[flushdb async])
    else
      client.call([:flushdb])
    end
  end
end

Adds the specified geospatial items (latitude, longitude, name) to the specified key

@param [String] key @param [Array] member arguemnts for member or members: longitude, latitude, name @return [Integer] number of elements added to the sorted set

# File lib/redis.rb, line 2871
def geoadd(key, *member)
  synchronize do |client|
    client.call([:geoadd, key, *member])
  end
end

Returns the distance between two members of a geospatial index

@param [String ]key @param [Array<String>] members @param ['m', 'km', 'mi', 'ft'] unit @return [String, nil] returns distance in spefied unit if both members present, nil otherwise.

# File lib/redis.rb, line 2942
def geodist(key, member1, member2, unit = 'm')
  synchronize do |client|
    client.call([:geodist, key, member1, member2, unit])
  end
end

Returns geohash string representing position for specified members of the specified key.

@param [String] key @param [String, Array<String>] member one member or array of members @return [Array<String, nil>] returns array containg geohash string if member is present, nil otherwise

# File lib/redis.rb, line 2882
def geohash(key, member)
  synchronize do |client|
    client.call([:geohash, key, member])
  end
end

Returns longitude and latitude of members of a geospatial index

@param [String] key @param [String, Array<String>] member one member or array of members @return [Array<Array<String>, nil>] returns array of elements, where each

element is either array of longitude and latitude or nil

# File lib/redis.rb, line 2930
def geopos(key, member)
  synchronize do |client|
    client.call([:geopos, key, member])
  end
end

Query a sorted set representing a geospatial index to fetch members matching a given maximum distance from a point

@param [Array] args key, longitude, latitude, radius, unit(m|km|ft|mi) @param ['asc', 'desc'] sort sort returned items from the nearest to the farthest

or the farthest to the nearest relative to the center

@param [Integer] count limit the results to the first N matching items @param ['WITHDIST', 'WITHCOORD', 'WITHHASH'] options to return additional information @return [Array<String>] may be changed with `options`

# File lib/redis.rb, line 2898
def georadius(*args, **geoptions)
  geoarguments = _geoarguments(*args, **geoptions)

  synchronize do |client|
    client.call([:georadius, *geoarguments])
  end
end

Query a sorted set representing a geospatial index to fetch members matching a given maximum distance from an already existing member

@param [Array] args key, member, radius, unit(m|km|ft|mi) @param ['asc', 'desc'] sort sort returned items from the nearest to the farthest or the farthest

to the nearest relative to the center

@param [Integer] count limit the results to the first N matching items @param ['WITHDIST', 'WITHCOORD', 'WITHHASH'] options to return additional information @return [Array<String>] may be changed with `options`

# File lib/redis.rb, line 2916
def georadiusbymember(*args, **geoptions)
  geoarguments = _geoarguments(*args, **geoptions)

  synchronize do |client|
    client.call([:georadiusbymember, *geoarguments])
  end
end

Get the value of a key.

@param [String] key @return [String]

# File lib/redis.rb, line 954
def get(key)
  synchronize do |client|
    client.call([:get, key])
  end
end

Returns the bit value at offset in the string value stored at key.

@param [String] key @param [Integer] offset bit offset @return [Integer] `0` or `1`

# File lib/redis.rb, line 1038
def getbit(key, offset)
  synchronize do |client|
    client.call([:getbit, key, offset])
  end
end

Get a substring of the string stored at a key.

@param [String] key @param [Integer] start zero-based start offset @param [Integer] stop zero-based end offset. Use -1 for representing

the end of the string

@return [Integer] `0` or `1`

# File lib/redis.rb, line 1015
def getrange(key, start, stop)
  synchronize do |client|
    client.call([:getrange, key, start, stop])
  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

# File lib/redis.rb, line 1104
def getset(key, value)
  synchronize do |client|
    client.call([:getset, key, value.to_s])
  end
end

Delete one or more hash fields.

@param [String] key @param [String, Array<String>] field @return [Integer] the number of fields that were removed from the hash

# File lib/redis.rb, line 2247
def hdel(key, *fields)
  synchronize do |client|
    client.call([:hdel, key, *fields])
  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

# File lib/redis.rb, line 2258
def hexists(key, field)
  synchronize do |client|
    client.call([:hexists, key, field], &Boolify)
  end
end

Get the value of a hash field.

@param [String] key @param [String] field @return [String]

# File lib/redis.rb, line 2198
def hget(key, field)
  synchronize do |client|
    client.call([:hget, key, field])
  end
end

Get all the fields and values in a hash.

@param [String] key @return [Hash<String, String>]

# File lib/redis.rb, line 2312
def hgetall(key)
  synchronize do |client|
    client.call([:hgetall, key], &Hashify)
  end
end

Increment the integer value of a hash field by the given integer number.

@param [String] key @param [String] field @param [Integer] increment @return [Integer] value of the field after incrementing it

# File lib/redis.rb, line 2270
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

# File lib/redis.rb, line 2282
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>]

# File lib/redis.rb, line 2292
def hkeys(key)
  synchronize do |client|
    client.call([:hkeys, key])
  end
end

Get the number of fields in a hash.

@param [String] key @return [Integer] number of fields in the hash

# File lib/redis.rb, line 2126
def hlen(key)
  synchronize do |client|
    client.call([:hlen, key])
  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

# File lib/redis.rb, line 2215
def hmget(key, *fields, &blk)
  synchronize do |client|
    client.call([:hmget, key] + fields, &blk)
  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

# File lib/redis.rb, line 2172
def hmset(key, *attrs)
  synchronize do |client|
    client.call([:hmset, key] + attrs)
  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

# File lib/redis.rb, line 2725
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

# File lib/redis.rb, line 2742
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

Set one or more hash values.

@example

redis.hset("hash", "f1", "v1", "f2", "v2") # => 2
redis.hset("hash", { "f1" => "v1", "f2" => "v2" }) # => 2

@param [String] key @param [Array<String> | Hash<String, String>] attrs array or hash of fields and values @return [Integer] The number of fields that were added to the hash

# File lib/redis.rb, line 2141
def hset(key, *attrs)
  attrs = attrs.first.flatten if attrs.size == 1 && attrs.first.is_a?(Hash)

  synchronize do |client|
    client.call([:hset, key, *attrs])
  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

# File lib/redis.rb, line 2155
def hsetnx(key, field, value)
  synchronize do |client|
    client.call([:hsetnx, key, field, value], &Boolify)
  end
end

Get all the values in a hash.

@param [String] key @return [Array<String>]

# File lib/redis.rb, line 2302
def hvals(key)
  synchronize do |client|
    client.call([:hvals, key])
  end
end

Increment the integer value of a key by one.

@example

redis.incr("value")
  # => 6

@param [String] key @return [Integer] value after incrementing it

# File lib/redis.rb, line 791
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 [Integer] increment @return [Integer] value after incrementing it

# File lib/redis.rb, line 806
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

# File lib/redis.rb, line 821
def incrbyfloat(key, increment)
  synchronize do |client|
    client.call([:incrbyfloat, key, increment], &Floatify)
  end
end

Get information and statistics about the server.

@param [String, Symbol] cmd e.g. “commandstats” @return [Hash<String, String>]

# File lib/redis.rb, line 305
def info(cmd = nil)
  synchronize do |client|
    client.call([:info, cmd].compact) do |reply|
      if reply.is_a?(String)
        reply = HashifyInfo.call(reply)

        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

Find all keys matching the given pattern.

@param [String] pattern @return [Array<String>]

# File lib/redis.rb, line 617
def keys(pattern = "*")
  synchronize do |client|
    client.call([:keys, pattern]) do |reply|
      if reply.is_a?(String)
        reply.split(" ")
      else
        reply
      end
    end
  end
end

Get the UNIX time stamp of the last successful save to disk.

@return [Integer]

# File lib/redis.rb, line 328
def lastsave
  synchronize do |client|
    client.call([:lastsave])
  end
end

Get an element from a list by its index.

@param [String] key @param [Integer] index @return [String]

# File lib/redis.rb, line 1301
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 [Integer] length of the list after the insert operation, or `-1`

when the element `pivot` was not found

# File lib/redis.rb, line 1315
def linsert(key, where, pivot, value)
  synchronize do |client|
    client.call([:linsert, key, where, pivot, value])
  end
end

Get the length of a list.

@param [String] key @return [Integer]

# File lib/redis.rb, line 1125
def llen(key)
  synchronize do |client|
    client.call([:llen, key])
  end
end

Remove and get the first elements in a list.

@param [String] key @param [Integer] count number of elements to remove @return [String, Array<String>] the values of the first elements

# File lib/redis.rb, line 1180
def lpop(key, count = nil)
  synchronize do |client|
    command = [:lpop, key]
    command << count if count
    client.call(command)
  end
end

Prepend one or more values to a list, creating the list if it doesn't exist

@param [String] key @param [String, Array<String>] value string value, or array of string values to push @return [Integer] the length of the list after the push operation

# File lib/redis.rb, line 1136
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 [Integer] the length of the list after the push operation

# File lib/redis.rb, line 1147
def lpushx(key, value)
  synchronize do |client|
    client.call([:lpushx, key, value])
  end
end

Get a range of elements from a list.

@param [String] key @param [Integer] start start index @param [Integer] stop stop index @return [Array<String>]

# File lib/redis.rb, line 1327
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 [Integer] 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 [Integer] the number of removed elements

# File lib/redis.rb, line 1342
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 [Integer] index @param [String] value @return [String] `OK`

# File lib/redis.rb, line 1354
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 [Integer] start start index @param [Integer] stop stop index @return [String] `OK`

# File lib/redis.rb, line 1366
def ltrim(key, start, stop)
  synchronize do |client|
    client.call([:ltrim, key, start, stop])
  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

# File lib/redis.rb, line 2232
def mapped_hmget(key, *fields)
  hmget(key, *fields) do |reply|
    if reply.is_a?(Array)
      Hash[fields.zip(reply)]
    else
      reply
    end
  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

# File lib/redis.rb, line 2189
def mapped_hmset(key, hash)
  hmset(key, hash.to_a.flatten)
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

# File lib/redis.rb, line 986
def mapped_mget(*keys)
  mget(*keys) do |reply|
    if reply.is_a?(Array)
      Hash[keys.zip(reply)]
    else
      reply
    end
  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

# File lib/redis.rb, line 916
def mapped_mset(hash)
  mset(hash.to_a.flatten)
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

# File lib/redis.rb, line 946
def mapped_msetnx(hash)
  msetnx(hash.to_a.flatten)
end

Get the values of all the given keys.

@example

redis.mget("key1", "key2")
  # => ["v1", "v2"]

@param [Array<String>] keys @return [Array<String>] an array of values for the specified keys

@see mapped_mget

# File lib/redis.rb, line 970
def mget(*keys, &blk)
  synchronize do |client|
    client.call([:mget, *keys], &blk)
  end
end

Transfer a key from the connected instance to another instance.

@param [String, Array<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)
- `:copy => Boolean`: Do not remove the key from the local instance.
- `:replace => Boolean`: Replace existing key on the remote instance.

@return [String] `“OK”`

# File lib/redis.rb, line 539
def migrate(key, options)
  args = [:migrate]
  args << (options[:host] || raise(':host not specified'))
  args << (options[:port] || raise(':port not specified'))
  args << (key.is_a?(String) ? key : '')
  args << (options[:db] || @client.db).to_i
  args << (options[:timeout] || @client.timeout).to_i
  args << 'COPY' if options[:copy]
  args << 'REPLACE' if options[:replace]
  args += ['KEYS', *key] if key.is_a?(Array)

  synchronize { |client| client.call(args) }
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

# File lib/redis.rb, line 340
def monitor(&block)
  synchronize do |client|
    client.call_loop([:monitor], &block)
  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 [Integer] db @return [Boolean] whether the key was moved or not

# File lib/redis.rb, line 648
def move(key, db)
  synchronize do |client|
    client.call([:move, key, db], &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

# File lib/redis.rb, line 900
def mset(*args)
  synchronize do |client|
    client.call([:mset] + args)
  end
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

# File lib/redis.rb, line 930
def msetnx(*args)
  synchronize do |client|
    client.call([:msetnx, *args], &Boolify)
  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

# File lib/redis.rb, line 2490
def multi
  synchronize do |prior_client|
    if !block_given?
      prior_client.call([:multi])
    else
      begin
        @client = Pipeline::Multi.new(prior_client)
        yield(self)
        prior_client.call_pipeline(@client)
      ensure
        @client = prior_client
      end
    end
  end
end

Remove the expiration from a key.

@param [String] key @return [Boolean] whether the timeout was removed or not

# File lib/redis.rb, line 415
def persist(key)
  synchronize do |client|
    client.call([:persist, key], &Boolify)
  end
end

Set a key's time to live in milliseconds.

@param [String] key @param [Integer] milliseconds time to live @return [Boolean] whether the timeout was set or not

# File lib/redis.rb, line 466
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 [Integer] ms_unix_time expiry time specified as number of milliseconds from UNIX Epoch. @return [Boolean] whether the timeout was set or not

# File lib/redis.rb, line 477
def pexpireat(key, ms_unix_time)
  synchronize do |client|
    client.call([:pexpireat, key, ms_unix_time], &Boolify)
  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.

# File lib/redis.rb, line 2835
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 [Integer]

# File lib/redis.rb, line 2848
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]

# File lib/redis.rb, line 2860
def pfmerge(dest_key, *source_key)
  synchronize do |client|
    client.call([:pfmerge, dest_key, *source_key], &BoolifySet)
  end
end

Ping the server.

@param [optional, String] message @return [String] `PONG`

# File lib/redis.rb, line 172
def ping(message = nil)
  synchronize do |client|
    client.call([:ping, message].compact)
  end
end

Set the time to live in milliseconds of a key.

@param [String] key @param [Integer] ttl @param [String] value @return [String] `“OK”`

# File lib/redis.rb, line 873
def psetex(key, ttl, value)
  synchronize do |client|
    client.call([:psetex, key, ttl, value.to_s])
  end
end

Listen for messages published to channels matching the given patterns.

# File lib/redis.rb, line 2356
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.

# File lib/redis.rb, line 2364
def psubscribe_with_timeout(timeout, *channels, &block)
  synchronize do |_client|
    _subscription(:psubscribe_with_timeout, timeout, channels, block)
  end
end

Get the time to live (in milliseconds) for a key.

@param [String] key @return [Integer] 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.

# File lib/redis.rb, line 494
def pttl(key)
  synchronize do |client|
    client.call([:pttl, key])
  end
end

Post a message to a channel.

# File lib/redis.rb, line 2319
def publish(channel, message)
  synchronize do |client|
    client.call([:publish, channel, message])
  end
end

Inspect the state of the Pub/Sub subsystem. Possible subcommands: channels, numsub, numpat.

# File lib/redis.rb, line 2381
def pubsub(subcommand, *args)
  synchronize do |client|
    client.call([:pubsub, subcommand] + args)
  end
end

Stop listening for messages posted to channels matching the given patterns.

# File lib/redis.rb, line 2371
def punsubscribe(*channels)
  synchronize do |client|
    raise "Can't unsubscribe if not subscribed." unless subscribed?

    client.punsubscribe(*channels)
  end
end

Queues a command for pipelining.

Commands in the queue are executed with the Redis#commit method.

See redis.io/topics/pipelining for more details.

# File lib/redis.rb, line 116
def queue(*command)
  synchronize do
    @queue[Thread.current.object_id] << command
  end
end

Close the connection.

@return [String] `OK`

# File lib/redis.rb, line 191
def quit
  synchronize do |client|
    begin
      client.call([:quit])
    rescue ConnectionError
    ensure
      client.disconnect
    end
  end
end

Return a random key from the keyspace.

@return [String]

# File lib/redis.rb, line 663
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`

# File lib/redis.rb, line 674
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

# File lib/redis.rb, line 685
def renamenx(old_name, new_name)
  synchronize do |client|
    client.call([:renamenx, old_name, new_name], &Boolify)
  end
end

Create a key using the serialized value, previously obtained using DUMP.

@param [String] key @param [String] ttl @param [String] serialized_value @param [Hash] options

- `:replace => Boolean`: if false, raises an error if key already exists

@raise [Redis::CommandError] @return [String] `“OK”`

# File lib/redis.rb, line 519
def restore(key, ttl, serialized_value, replace: nil)
  args = [:restore, key, ttl, serialized_value]
  args << 'REPLACE' if replace

  synchronize do |client|
    client.call(args)
  end
end

Remove and get the last elements in a list.

@param [String] key @param [Integer] count number of elements to remove @return [String, Array<String>] the values of the last elements

# File lib/redis.rb, line 1193
def rpop(key, count = nil)
  synchronize do |client|
    command = [:rpop, key]
    command << count if count
    client.call(command)
  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

# File lib/redis.rb, line 1206
def rpoplpush(source, destination)
  synchronize do |client|
    client.call([:rpoplpush, source, destination])
  end
end

Append one or more values to a list, creating the list if it doesn't exist

@param [String] key @param [String, Array<String>] value string value, or array of string values to push @return [Integer] the length of the list after the push operation

# File lib/redis.rb, line 1158
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 [Integer] the length of the list after the push operation

# File lib/redis.rb, line 1169
def rpushx(key, value)
  synchronize do |client|
    client.call([:rpushx, key, value])
  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, Integer] `Boolean` when a single member is specified,

holding whether or not adding the member succeeded, or `Integer` when an
array of members is specified, holding the number of members that were
successfully added

# File lib/redis.rb, line 1390
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

Synchronously save the dataset to disk.

@return [String]

# File lib/redis.rb, line 349
def save
  synchronize do |client|
    client.call([:save])
  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"]]

@example Retrieve a batch of keys of a certain type

redis.scan(92, :type => "zset")
  # => ["173", ["sortedset:14", "sortedset:78"]]

@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
- `:type => String`: return keys only of the given type

@return [String, Array<String>] the next cursor and all found keys

# File lib/redis.rb, line 2679
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

@example Execute block for each key of a type

redis.scan_each(:type => "hash") {|key| puts redis.type(key)}
  # => "hash"
  # => "hash"

@param [Hash] options

- `:match => String`: only return keys matching the pattern
- `:count => Integer`: return count keys at most per iteration
- `:type => String`: return keys only of the given type

@return [Enumerator] an enumerator for all found keys

# File lib/redis.rb, line 2703
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

Get the number of members in a set.

@param [String] key @return [Integer]

# File lib/redis.rb, line 1376
def scard(key)
  synchronize do |client|
    client.call([:scard, key])
  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

# File lib/redis.rb, line 2560
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

Subtract multiple sets.

@param [String, Array<String>] keys keys pointing to sets to subtract @return [Array<String>] members in the difference

# File lib/redis.rb, line 1493
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 [Integer] number of elements in the resulting set

# File lib/redis.rb, line 1504
def sdiffstore(destination, *keys)
  synchronize do |client|
    client.call([:sdiffstore, destination, *keys])
  end
end

Change the selected database for the current connection.

@param [Integer] db zero-based index of the DB to use (0 to 15) @return [String] `OK`

# File lib/redis.rb, line 161
def select(db)
  synchronize do |client|
    client.db = db
    client.call([:select, db])
  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

# File lib/redis.rb, line 3278
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.is_a?(Array)
          if reply[0].is_a?(Array)
            reply.map(&Hashify)
          else
            Hashify.call(reply)
          end
        else
          reply
        end
      end
    end
  end
end

Set the string value of a key.

@param [String] key @param [String] value @param [Hash] options

- `:ex => Integer`: Set the specified expire time, in seconds.
- `:px => Integer`: 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.
- `:keepttl => true`: Retain the time to live associated with the key.

@return [String, Boolean] `“OK”` or true, false if `:nx => true` or `:xx => true`

# File lib/redis.rb, line 838
def set(key, value, ex: nil, px: nil, nx: nil, xx: nil, keepttl: nil)
  args = [:set, key, value.to_s]
  args << "EX" << ex if ex
  args << "PX" << px if px
  args << "NX" if nx
  args << "XX" if xx
  args << "KEEPTTL" if keepttl

  synchronize do |client|
    if nx || xx
      client.call(args, &BoolifySet)
    else
      client.call(args)
    end
  end
end

Sets or clears the bit at offset in the string value stored at key.

@param [String] key @param [Integer] offset bit offset @param [Integer] value bit value `0` or `1` @return [Integer] the original bit value stored at `offset`

# File lib/redis.rb, line 1027
def setbit(key, offset, value)
  synchronize do |client|
    client.call([:setbit, key, offset, value])
  end
end

Set the time to live in seconds of a key.

@param [String] key @param [Integer] ttl @param [String] value @return [String] `“OK”`

# File lib/redis.rb, line 861
def setex(key, ttl, value)
  synchronize do |client|
    client.call([:setex, 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

# File lib/redis.rb, line 884
def setnx(key, value)
  synchronize do |client|
    client.call([:setnx, key, value.to_s], &Boolify)
  end
end

Overwrite part of a string at key starting at the specified offset.

@param [String] key @param [Integer] offset byte offset @param [String] value @return [Integer] length of the string after it was modified

# File lib/redis.rb, line 1002
def setrange(key, offset, value)
  synchronize do |client|
    client.call([:setrange, key, offset, value.to_s])
  end
end

Synchronously save the dataset to disk and then shut down the server.

# File lib/redis.rb, line 356
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

Intersect multiple sets.

@param [String, Array<String>] keys keys pointing to sets to intersect @return [Array<String>] members in the intersection

# File lib/redis.rb, line 1514
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 [Integer] number of elements in the resulting set

# File lib/redis.rb, line 1525
def sinterstore(destination, *keys)
  synchronize do |client|
    client.call([:sinterstore, destination, *keys])
  end
end

Determine if a given value is a member of a set.

@param [String] key @param [String] member @return [Boolean]

# File lib/redis.rb, line 1473
def sismember(key, member)
  synchronize do |client|
    client.call([:sismember, key, member], &Boolify)
  end
end

Make the server a slave of another instance, or promote it as master.

# File lib/redis.rb, line 370
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 [Integer] length maximum number of entries to return @return [Array<String>, Integer, String] depends on subcommand

# File lib/redis.rb, line 381
def slowlog(subcommand, length = nil)
  synchronize do |client|
    args = [:slowlog, subcommand]
    args << length if length
    client.call args
  end
end

Get all the members in a set.

@param [String] key @return [Array<String>]

# File lib/redis.rb, line 1483
def smembers(key)
  synchronize do |client|
    client.call([:smembers, key])
  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]

# File lib/redis.rb, line 1462
def smove(source, destination, member)
  synchronize do |client|
    client.call([:smove, source, destination, member], &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>>, Integer]

- 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

# File lib/redis.rb, line 716
def sort(key, by: nil, limit: nil, get: nil, order: nil, store: nil)
  args = [:sort, key]
  args << "BY" << by if by

  if limit
    args << "LIMIT"
    args.concat(limit)
  end

  get = Array(get)
  get.each do |item|
    args << "GET" << item
  end

  args.concat(order.split(" ")) if order
  args << "STORE" << store if store

  synchronize do |client|
    client.call(args) do |reply|
      if get.size > 1 && !store
        reply.each_slice(get.size).to_a if reply
      else
        reply
      end
    end
  end
end

Remove and return one or more random member from a set.

@param [String] key @return [String] @param [Integer] count

# File lib/redis.rb, line 1431
def spop(key, count = nil)
  synchronize do |client|
    if count.nil?
      client.call([:spop, key])
    else
      client.call([:spop, key, count])
    end
  end
end

Get one or more random members from a set.

@param [String] key @param [Integer] count @return [String]

# File lib/redis.rb, line 1446
def srandmember(key, count = nil)
  synchronize do |client|
    if count.nil?
      client.call([:srandmember, key])
    else
      client.call([:srandmember, key, count])
    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, Integer] `Boolean` when a single member is specified,

holding whether or not removing the member succeeded, or `Integer` when an
array of members is specified, holding the number of members that were
successfully removed

# File lib/redis.rb, line 1412
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

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

# File lib/redis.rb, line 2804
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

# File lib/redis.rb, line 2819
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

Get the length of the value stored in a key.

@param [String] key @return [Integer] the length of the value stored in the key, or 0

if the key does not exist

# File lib/redis.rb, line 1115
def strlen(key)
  synchronize do |client|
    client.call([:strlen, key])
  end
end

Listen for messages published to the given channels.

# File lib/redis.rb, line 2332
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.

# File lib/redis.rb, line 2340
def subscribe_with_timeout(timeout, *channels, &block)
  synchronize do |_client|
    _subscription(:subscribe_with_timeout, timeout, channels, block)
  end
end

Add multiple sets.

@param [String, Array<String>] keys keys pointing to sets to unify @return [Array<String>] members in the union

# File lib/redis.rb, line 1535
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 [Integer] number of elements in the resulting set

# File lib/redis.rb, line 1546
def sunionstore(destination, *keys)
  synchronize do |client|
    client.call([:sunionstore, destination, *keys])
  end
end

Internal command used for replication.

# File lib/redis.rb, line 390
def sync
  synchronize do |client|
    client.call([:sync])
  end
end

Return the server time.

@example

r.time # => [ 1333093196, 606806 ]

@return [Array<Integer>] tuple of seconds since UNIX epoch and

microseconds in the current second

# File lib/redis.rb, line 403
def time
  synchronize do |client|
    client.call([:time]) do |reply|
      reply&.map(&:to_i)
    end
  end
end

Get the time to live (in seconds) for a key.

@param [String] key @return [Integer] 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.

# File lib/redis.rb, line 455
def ttl(key)
  synchronize do |client|
    client.call([:ttl, key])
  end
end

Determine the type stored at key.

@param [String] key @return [String] `string`, `list`, `set`, `zset`, `hash` or `none`

# File lib/redis.rb, line 748
def type(key)
  synchronize do |client|
    client.call([:type, key])
  end
end

Unlink one or more keys.

@param [String, Array<String>] keys @return [Integer] number of keys that were unlinked

# File lib/redis.rb, line 567
def unlink(*keys)
  synchronize do |client|
    client.call([:unlink] + keys)
  end
end

Stop listening for messages posted to the given channels.

# File lib/redis.rb, line 2347
def unsubscribe(*channels)
  synchronize do |client|
    raise "Can't unsubscribe if not subscribed." unless subscribed?

    client.unsubscribe(*channels)
  end
end

Forget about all watched keys.

@return [String] `OK`

@see watch @see multi

# File lib/redis.rb, line 2442
def unwatch
  synchronize do |client|
    client.call([:unwatch])
  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

# File lib/redis.rb, line 2417
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

Run code with the client reconnecting

# File lib/redis.rb, line 74
def with_reconnect(val = true, &blk)
  synchronize do |client|
    client.with_reconnect(val, &blk)
  end
end

Run code without the client reconnecting

# File lib/redis.rb, line 81
def without_reconnect(&blk)
  with_reconnect(false, &blk)
end

Removes one or multiple entries from the pending entries list of a stream consumer group.

@example With a entry id

redis.xack('mystream', 'mygroup', '1526569495631-0')

@example With splatted entry ids

redis.xack('mystream', 'mygroup', '0-1', '0-2')

@example With arrayed entry ids

redis.xack('mystream', 'mygroup', %w[0-1 0-2])

@param key [String] the stream key @param group [String] the consumer group name @param ids [Array<String>] one or multiple entry ids

@return [Integer] the number of entries successfully acknowledged

# File lib/redis.rb, line 3193
def xack(key, group, *ids)
  args = [:xack, key, group].concat(ids.flatten)
  synchronize { |client| client.call(args) }
end

Add new entry to the stream.

@example Without options

redis.xadd('mystream', f1: 'v1', f2: 'v2')

@example With options

redis.xadd('mystream', { f1: 'v1', f2: 'v2' }, id: '0-0', maxlen: 1000, approximate: true)

@param key [String] the stream key @param entry [Hash] one or multiple field-value pairs @param opts [Hash] several options for `XADD` command

@option opts [String] :id the entry id, default value is `*`, it means auto generation @option opts [Integer] :maxlen max length of entries @option opts [Boolean] :approximate whether to add `~` modifier of maxlen or not

@return [String] the entry id

# File lib/redis.rb, line 2993
def xadd(key, entry, approximate: nil, maxlen: nil, id: '*')
  args = [:xadd, key]
  if maxlen
    args << "MAXLEN"
    args << "~" if approximate
    args << maxlen
  end
  args << id
  args.concat(entry.to_a.flatten)
  synchronize { |client| client.call(args) }
end

Changes the ownership of a pending entry

@example With splatted entry ids

redis.xclaim('mystream', 'mygroup', 'consumer1', 3600000, '0-1', '0-2')

@example With arrayed entry ids

redis.xclaim('mystream', 'mygroup', 'consumer1', 3600000, %w[0-1 0-2])

@example With idle option

redis.xclaim('mystream', 'mygroup', 'consumer1', 3600000, %w[0-1 0-2], idle: 1000)

@example With time option

redis.xclaim('mystream', 'mygroup', 'consumer1', 3600000, %w[0-1 0-2], time: 1542866959000)

@example With retrycount option

redis.xclaim('mystream', 'mygroup', 'consumer1', 3600000, %w[0-1 0-2], retrycount: 10)

@example With force option

redis.xclaim('mystream', 'mygroup', 'consumer1', 3600000, %w[0-1 0-2], force: true)

@example With justid option

redis.xclaim('mystream', 'mygroup', 'consumer1', 3600000, %w[0-1 0-2], justid: true)

@param key [String] the stream key @param group [String] the consumer group name @param consumer [String] the consumer name @param min_idle_time [Integer] the number of milliseconds @param ids [Array<String>] one or multiple entry ids @param opts [Hash] several options for `XCLAIM` command

@option opts [Integer] :idle the number of milliseconds as last time it was delivered of the entry @option opts [Integer] :time the number of milliseconds as a specific Unix Epoch time @option opts [Integer] :retrycount the number of retry counter @option opts [Boolean] :force whether to create the pending entry to the pending entries list or not @option opts [Boolean] :justid whether to fetch just an array of entry ids or not

@return [Hash{String => Hash}] the entries successfully claimed @return [Array<String>] the entry ids successfully claimed if justid option is `true`

# File lib/redis.rb, line 3230
def xclaim(key, group, consumer, min_idle_time, *ids, **opts)
  args = [:xclaim, key, group, consumer, min_idle_time].concat(ids.flatten)
  args.concat(['IDLE',       opts[:idle].to_i])  if opts[:idle]
  args.concat(['TIME',       opts[:time].to_i])  if opts[:time]
  args.concat(['RETRYCOUNT', opts[:retrycount]]) if opts[:retrycount]
  args << 'FORCE'                                if opts[:force]
  args << 'JUSTID'                               if opts[:justid]
  blk = opts[:justid] ? Noop : HashifyStreamEntries
  synchronize { |client| client.call(args, &blk) }
end

Delete entries by entry ids.

@example With splatted entry ids

redis.xdel('mystream', '0-1', '0-2')

@example With arrayed entry ids

redis.xdel('mystream', ['0-1', '0-2'])

@param key [String] the stream key @param ids [Array<String>] one or multiple entry ids

@return [Integer] the number of entries actually deleted

# File lib/redis.rb, line 3033
def xdel(key, *ids)
  args = [:xdel, key].concat(ids.flatten)
  synchronize { |client| client.call(args) }
end

Manages the consumer group of the stream.

@example With `create` subcommand

redis.xgroup(:create, 'mystream', 'mygroup', '$')

@example With `setid` subcommand

redis.xgroup(:setid, 'mystream', 'mygroup', '$')

@example With `destroy` subcommand

redis.xgroup(:destroy, 'mystream', 'mygroup')

@example With `delconsumer` subcommand

redis.xgroup(:delconsumer, 'mystream', 'mygroup', 'consumer1')

@param subcommand [String] `create` `setid` `destroy` `delconsumer` @param key [String] the stream key @param group [String] the consumer group name @param id_or_consumer [String]

* the entry id or `$`, required if subcommand is `create` or `setid`
* the consumer name, required if subcommand is `delconsumer`

@param mkstream [Boolean] whether to create an empty stream automatically or not

@return [String] `OK` if subcommand is `create` or `setid` @return [Integer] effected count if subcommand is `destroy` or `delconsumer`

# File lib/redis.rb, line 3141
def xgroup(subcommand, key, group, id_or_consumer = nil, mkstream: false)
  args = [:xgroup, subcommand, key, group, id_or_consumer, (mkstream ? 'MKSTREAM' : nil)].compact
  synchronize { |client| client.call(args) }
end

Returns the stream information each subcommand.

@example stream

redis.xinfo(:stream, 'mystream')

@example groups

redis.xinfo(:groups, 'mystream')

@example consumers

redis.xinfo(:consumers, 'mystream', 'mygroup')

@param subcommand [String] e.g. `stream` `groups` `consumers` @param key [String] the stream key @param group [String] the consumer group name, required if subcommand is `consumers`

@return [Hash] information of the stream if subcommand is `stream` @return [Array<Hash>] information of the consumer groups if subcommand is `groups` @return [Array<Hash>] information of the consumers if subcommand is `consumers`

# File lib/redis.rb, line 2964
def xinfo(subcommand, key, group = nil)
  args = [:xinfo, subcommand, key, group].compact
  synchronize do |client|
    client.call(args) do |reply|
      case subcommand.to_s.downcase
      when 'stream'              then Hashify.call(reply)
      when 'groups', 'consumers' then reply.map { |arr| Hashify.call(arr) }
      else reply
      end
    end
  end
end

Returns the number of entries inside a stream.

@example With key

redis.xlen('mystream')

@param key [String] the stream key

@return [Integer] the number of entries

# File lib/redis.rb, line 3092
def xlen(key)
  synchronize { |client| client.call([:xlen, key]) }
end

Fetches not acknowledging pending entries

@example With key and group

redis.xpending('mystream', 'mygroup')

@example With range options

redis.xpending('mystream', 'mygroup', '-', '+', 10)

@example With range and consumer options

redis.xpending('mystream', 'mygroup', '-', '+', 10, 'consumer1')

@param key [String] the stream key @param group [String] the consumer group name @param start [String] start first entry id of range @param end [String] end last entry id of range @param count [Integer] count the number of entries as limit @param consumer [String] the consumer name

@return [Hash] the summary of pending entries @return [Array<Hash>] the pending entries details if options were specified

# File lib/redis.rb, line 3259
def xpending(key, group, *args)
  command_args = [:xpending, key, group]
  case args.size
  when 0, 3, 4
    command_args.concat(args)
  else
    raise ArgumentError, "wrong number of arguments (given #{args.size + 2}, expected 2, 5 or 6)"
  end

  summary_needed = args.empty?
  blk = summary_needed ? HashifyStreamPendings : HashifyStreamPendingDetails
  synchronize { |client| client.call(command_args, &blk) }
end

Fetches entries of the stream in ascending order.

@example Without options

redis.xrange('mystream')

@example With a specific start

redis.xrange('mystream', '0-1')

@example With a specific start and end

redis.xrange('mystream', '0-1', '0-3')

@example With count options

redis.xrange('mystream', count: 10)

@param key [String] the stream key @param start [String] first entry id of range, default value is `-` @param end [String] last entry id of range, default value is `+` @param count [Integer] the number of entries as limit

@return [Array<Array<String, Hash>>] the ids and entries pairs

# File lib/redis.rb, line 3055
def xrange(key, start = '-', range_end = '+', count: nil)
  args = [:xrange, key, start, range_end]
  args.concat(['COUNT', count]) if count
  synchronize { |client| client.call(args, &HashifyStreamEntries) }
end

Fetches entries from one or multiple streams. Optionally blocking.

@example With a key

redis.xread('mystream', '0-0')

@example With multiple keys

redis.xread(%w[mystream1 mystream2], %w[0-0 0-0])

@example With count option

redis.xread('mystream', '0-0', count: 2)

@example With block option

redis.xread('mystream', '$', block: 1000)

@param keys [Array<String>] one or multiple stream keys @param ids [Array<String>] one or multiple entry ids @param count [Integer] the number of entries as limit per stream @param block [Integer] the number of milliseconds as blocking timeout

@return [Hash{String => Hash{String => Hash}}] the entries

# File lib/redis.rb, line 3113
def xread(keys, ids, count: nil, block: nil)
  args = [:xread]
  args << 'COUNT' << count if count
  args << 'BLOCK' << block.to_i if block
  _xread(args, keys, ids, block)
end

Fetches a subset of the entries from one or multiple streams related with the consumer group. Optionally blocking.

@example With a key

redis.xreadgroup('mygroup', 'consumer1', 'mystream', '>')

@example With multiple keys

redis.xreadgroup('mygroup', 'consumer1', %w[mystream1 mystream2], %w[> >])

@example With count option

redis.xreadgroup('mygroup', 'consumer1', 'mystream', '>', count: 2)

@example With block option

redis.xreadgroup('mygroup', 'consumer1', 'mystream', '>', block: 1000)

@example With noack option

redis.xreadgroup('mygroup', 'consumer1', 'mystream', '>', noack: true)

@param group [String] the consumer group name @param consumer [String] the consumer name @param keys [Array<String>] one or multiple stream keys @param ids [Array<String>] one or multiple entry ids @param opts [Hash] several options for `XREADGROUP` command

@option opts [Integer] :count the number of entries as limit @option opts [Integer] :block the number of milliseconds as blocking timeout @option opts [Boolean] :noack whether message loss is acceptable or not

@return [Hash{String => Hash{String => Hash}}] the entries

# File lib/redis.rb, line 3171
def xreadgroup(group, consumer, keys, ids, count: nil, block: nil, noack: nil)
  args = [:xreadgroup, 'GROUP', group, consumer]
  args << 'COUNT' << count if count
  args << 'BLOCK' << block.to_i if block
  args << 'NOACK' if noack
  _xread(args, keys, ids, block)
end

Fetches entries of the stream in descending order.

@example Without options

redis.xrevrange('mystream')

@example With a specific end

redis.xrevrange('mystream', '0-3')

@example With a specific end and start

redis.xrevrange('mystream', '0-3', '0-1')

@example With count options

redis.xrevrange('mystream', count: 10)

@param key [String] the stream key @param end [String] first entry id of range, default value is `+` @param start [String] last entry id of range, default value is `-` @params count [Integer] the number of entries as limit

@return [Array<Array<String, Hash>>] the ids and entries pairs

# File lib/redis.rb, line 3078
def xrevrange(key, range_end = '+', start = '-', count: nil)
  args = [:xrevrange, key, range_end, start]
  args.concat(['COUNT', count]) if count
  synchronize { |client| client.call(args, &HashifyStreamEntries) }
end

Trims older entries of the stream if needed.

@example Without options

redis.xtrim('mystream', 1000)

@example With options

redis.xtrim('mystream', 1000, approximate: true)

@param key [String] the stream key @param mexlen [Integer] max length of entries @param approximate [Boolean] whether to add `~` modifier of maxlen or not

@return [Integer] the number of entries actually deleted

# File lib/redis.rb, line 3017
def xtrim(key, maxlen, approximate: false)
  args = [:xtrim, key, 'MAXLEN', (approximate ? '~' : nil), maxlen].compact
  synchronize { |client| client.call(args) }
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, Integer, Float]

- `Boolean` when a single pair is specified, holding whether or not it was
**added** to the sorted set.
- `Integer` 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.

# File lib/redis.rb, line 1597
def zadd(key, *args, nx: nil, xx: nil, ch: nil, incr: nil)
  command = [:zadd, key]
  command << "NX" if nx
  command << "XX" if xx
  command << "CH" if ch
  command << "INCR" if incr

  synchronize do |client|
    if args.size == 1 && args[0].is_a?(Array)
      # Variadic: return float if INCR, integer if !INCR
      client.call(command + args[0], &(incr ? Floatify : nil))
    elsif args.size == 2
      # Single pair: return float if INCR, boolean if !INCR
      client.call(command + args, &(incr ? Floatify : Boolify))
    else
      raise ArgumentError, "wrong number of arguments"
    end
  end
end

Get the number of members in a sorted set.

@example

redis.zcard("zset")
  # => 4

@param [String] key @return [Integer]

# File lib/redis.rb, line 1560
def zcard(key)
  synchronize do |client|
    client.call([:zcard, key])
  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 [Integer] number of members in within the specified range

# File lib/redis.rb, line 2059
def zcount(key, min, max)
  synchronize do |client|
    client.call([:zcount, key, min, max])
  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

# File lib/redis.rb, line 1627
def zincrby(key, increment, member)
  synchronize do |client|
    client.call([:zincrby, key, increment, member], &Floatify)
  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 [Integer] number of elements in the resulting sorted set

# File lib/redis.rb, line 2079
def zinterstore(destination, keys, weights: nil, aggregate: nil)
  args = [:zinterstore, destination, keys.size, *keys]

  if weights
    args << "WEIGHTS"
    args.concat(weights)
  end

  args << "AGGREGATE" << aggregate if aggregate

  synchronize do |client|
    client.call(args)
  end
end

Count the members, with the same score in a sorted set, within the given lexicographical range.

@example Count members matching a

redis.zlexcount("zset", "[a", "[a\xff")
  # => 1

@example Count members matching a-z

redis.zlexcount("zset", "[a", "[z\xff")
  # => 26

@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 `[`

@return [Integer] number of members within the specified lexicographical range

# File lib/redis.rb, line 1878
def zlexcount(key, min, max)
  synchronize do |client|
    client.call([:zlexcount, key, min, max])
  end
end

Removes and returns up to count members with the highest scores in the sorted set stored at key.

@example Popping a member

redis.zpopmax('zset')
#=> ['b', 2.0]

@example With count option

redis.zpopmax('zset', 2)
#=> [['b', 2.0], ['a', 1.0]]

@params key [String] a key of the sorted set @params count [Integer] a number of members

@return [Array<String, Float>] element and score pair if count is not specified @return [Array<Array<String, Float>>] list of popped elements and scores

# File lib/redis.rb, line 1678
def zpopmax(key, count = nil)
  synchronize do |client|
    members = client.call([:zpopmax, key, count].compact, &FloatifyPairs)
    count.to_i > 1 ? members : members.first
  end
end

Removes and returns up to count members with the lowest scores in the sorted set stored at key.

@example Popping a member

redis.zpopmin('zset')
#=> ['a', 1.0]

@example With count option

redis.zpopmin('zset', 2)
#=> [['a', 1.0], ['b', 2.0]]

@params key [String] a key of the sorted set @params count [Integer] a number of members

@return [Array<String, Float>] element and score pair if count is not specified @return [Array<Array<String, Float>>] list of popped elements and scores

# File lib/redis.rb, line 1699
def zpopmin(key, count = nil)
  synchronize do |client|
    members = client.call([:zpopmin, key, count].compact, &FloatifyPairs)
    count.to_i > 1 ? members : members.first
  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 [Integer] start start index @param [Integer] 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

# File lib/redis.rb, line 1781
def zrange(key, start, stop, withscores: false, with_scores: withscores)
  args = [:zrange, key, start, stop]

  if with_scores
    args << "WITHSCORES"
    block = FloatifyPairs
  end

  synchronize do |client|
    client.call(args, &block)
  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]>]

# File lib/redis.rb, line 1905
def zrangebylex(key, min, max, limit: nil)
  args = [:zrangebylex, key, min, max]

  if limit
    args << "LIMIT"
    args.concat(limit)
  end

  synchronize do |client|
    client.call(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

# File lib/redis.rb, line 1969
def zrangebyscore(key, min, max, withscores: false, with_scores: withscores, limit: nil)
  args = [:zrangebyscore, key, min, max]

  if with_scores
    args << "WITHSCORES"
    block = FloatifyPairs
  end

  if limit
    args << "LIMIT"
    args.concat(limit)
  end

  synchronize do |client|
    client.call(args, &block)
  end
end