class UUIDTools::UUID

UUIDTools was designed to be a simple library for generating any of the various types of UUIDs. It conforms to RFC 4122 whenever possible.

@example

UUID.md5_create(UUID_DNS_NAMESPACE, "www.widgets.com")
# => #<UUID:0x287576 UUID:3d813cbb-47fb-32ba-91df-831e1593ac29>
UUID.sha1_create(UUID_DNS_NAMESPACE, "www.widgets.com")
# => #<UUID:0x2a0116 UUID:21f7f8de-8051-5b89-8680-0195ef798b6a>
UUID.timestamp_create
# => #<UUID:0x2adfdc UUID:64a5189c-25b3-11da-a97b-00c04fd430c8>
UUID.random_create
# => #<UUID:0x19013a UUID:984265dc-4200-4f02-ae70-fe4f48964159>

Attributes

ifconfig_command[RW]
ifconfig_path_default[RW]
ip_command[RW]
ip_path_default[RW]
clock_seq_hi_and_reserved[RW]

Returns the value of attribute `clock_seq_hi_and_reserved`

clock_seq_low[RW]

Returns the value of attribute `clock_seq_low`

nodes[RW]

Returns the value of attribute `nodes`

time_hi_and_version[RW]

Returns the value of attribute `time_hi_and_version`

time_low[RW]

Returns the value of attribute `time_low`

time_mid[RW]

Returns the value of attribute `time_mid`

Public Class Methods

convert_byte_string_to_int(byte_string) click to toggle source

@api private

# File lib/uuidtools.rb, line 709
def self.convert_byte_string_to_int(byte_string)
  if byte_string.respond_to?(:force_encoding)
    byte_string.force_encoding(Encoding::ASCII_8BIT)
  end
  integer = 0
  size = byte_string.size
  for i in 0..(size - 1)
    ordinal = (byte_string[i].respond_to?(:ord) ?
      byte_string[i].ord : byte_string[i])
    integer += (ordinal << (((size - 1) - i) * 8))
  end
  return integer
end
convert_int_to_byte_string(integer, size) click to toggle source

@api private

# File lib/uuidtools.rb, line 696
def self.convert_int_to_byte_string(integer, size)
  byte_string = ""
  if byte_string.respond_to?(:force_encoding)
    byte_string.force_encoding(Encoding::ASCII_8BIT)
  end
  for i in 0..(size - 1)
    byte_string << ((integer >> (((size - 1) - i) * 8)) & 0xFF)
  end
  return byte_string
end
create_from_hash(hash_class, namespace, name) click to toggle source

Creates a new UUID from a SHA1 or MD5 hash

@api private

# File lib/uuidtools.rb, line 671
def self.create_from_hash(hash_class, namespace, name)
  if hash_class == Digest::MD5
    version = 3
  elsif hash_class == Digest::SHA1
    version = 5
  else
    raise ArgumentError,
      "Expected Digest::SHA1 or Digest::MD5, got #{hash_class.name}."
  end
  hash = hash_class.new
  hash.update(namespace.raw)
  hash.update(name)
  hash_string = hash.to_s[0..31]
  new_uuid = self.parse("#{hash_string[0..7]}-#{hash_string[8..11]}-" +
    "#{hash_string[12..15]}-#{hash_string[16..19]}-#{hash_string[20..31]}")

  new_uuid.time_hi_and_version &= 0x0FFF
  new_uuid.time_hi_and_version |= (version << 12)
  new_uuid.clock_seq_hi_and_reserved &= 0x3F
  new_uuid.clock_seq_hi_and_reserved |= 0x80
  return new_uuid
end
first_mac(instring) click to toggle source

Match and return the first Mac address found

# File lib/uuidtools.rb, line 590
def self.first_mac(instring)
  mac_regexps = [
    Regexp.new("address:? (#{(["[0-9a-fA-F]{2}"] * 6).join(":")})"),
    Regexp.new("addr:? (#{(["[0-9a-fA-F]{2}"] * 6).join(":")})"),
    Regexp.new("ether:? (#{(["[0-9a-fA-F]{1,2}"] * 6).join(":")})"),
    Regexp.new("HWaddr:? (#{(["[0-9a-fA-F]{2}"] * 6).join(":")})"),
    Regexp.new("link/ether? (#{(["[0-9a-fA-F]{2}"] * 6).join(":")})"),
    Regexp.new("(#{(["[0-9a-fA-F]{2}"] * 6).join(":")})"),
    Regexp.new("(#{(["[0-9a-fA-F]{2}"] * 6).join("-")})")
  ]
  parse_mac = lambda do |output|
    (mac_regexps.map do |regexp|
       result = output[regexp, 1]
       result.downcase.gsub(/-/, ":") if result != nil
    end).compact.first
  end

  mac = parse_mac.call(instring)
  if mac
    # expand octets that were compressed (solaris)
    return (mac.split(':').map do |octet|
      (octet.length == 1 ? "0#{octet}" : octet)
    end).join(':')
  else
    return nil
  end
end
ifconfig(all=nil) click to toggle source

Call the ifconfig or ip command that is found

# File lib/uuidtools.rb, line 574
def self.ifconfig(all=nil)
  # find the path of the ifconfig command
  ifconfig_path = UUID.ifconfig_path

  # if it does not exist, try the ip command
  if ifconfig_path == nil
    ifconfig_path = "#{UUID.ip_path} addr list"
    # all makes no sense when using ip(1)
    all = nil
  end

  all_switch = all == nil ? "" : "-a"
  return %x`#{ifconfig_path} #{all_switch}` if not ifconfig_path == nil
end
ifconfig_path() click to toggle source

Find the path of the ifconfig(8) command if it is present

# File lib/uuidtools.rb, line 556
def self.ifconfig_path
  path = %x`which #{UUID.ifconfig_command} 2>/dev/null`.strip
  path = UUID.ifconfig_path_default if (path == "" && File.exist?(UUID.ifconfig_path_default))
  return (path === "" ? nil : path)
end
ip_path() click to toggle source

Find the path of the ip(8) command if it is present

# File lib/uuidtools.rb, line 565
def self.ip_path
  path = %x`which #{UUID.ip_command} 2>/dev/null`.strip
  path = UUID.ip_path_default if (path == "" && File.exist?(UUID.ip_path_default))
  return (path === "" ? nil : path)
end
mac_address() click to toggle source

Returns the MAC address of the current computer's network card. Returns nil if a MAC address could not be found.

# File lib/uuidtools.rb, line 621
def self.mac_address
  if !defined?(@@mac_address)
    require 'rbconfig'

    os_class = UUID.os_class

    if os_class == :windows
      begin
        @@mac_address = UUID.first_mac %x`ipconfig /all`
      rescue
      end
    else # linux, bsd, macos, solaris
      @@mac_address = UUID.first_mac(UUID.ifconfig(:all))
    end

    if @@mac_address != nil
      if @@mac_address.respond_to?(:to_str)
        @@mac_address = @@mac_address.to_str
      else
        @@mac_address = @@mac_address.to_s
      end
      @@mac_address.downcase!
      @@mac_address.strip!
    end

    # Verify that the MAC address is in the right format.
    # Nil it out if it isn't.
    unless @@mac_address.respond_to?(:scan) &&
        @@mac_address.scan(/#{(["[0-9a-f]{2}"] * 6).join(":")}/)
      @@mac_address = nil
    end
  end
  return @@mac_address
end
mac_address=(new_mac_address) click to toggle source

Allows users to set the MAC address manually in cases where the MAC address cannot be obtained programatically.

# File lib/uuidtools.rb, line 659
def self.mac_address=(new_mac_address)
  @@mac_address = new_mac_address
end
md5_create(namespace, name) click to toggle source

Creates a UUID using the MD5 hash. (Version 3)

# File lib/uuidtools.rb, line 288
def self.md5_create(namespace, name)
  return self.create_from_hash(Digest::MD5, namespace, name)
end
new(time_low, time_mid, time_hi_and_version, clock_seq_hi_and_reserved, clock_seq_low, nodes) click to toggle source

Creates a new UUID structure from its component values. @see ::md5_create @see ::sha1_create @see ::timestamp_create @see ::random_create @api private

# File lib/uuidtools.rb, line 79
def initialize(time_low, time_mid, time_hi_and_version,
    clock_seq_hi_and_reserved, clock_seq_low, nodes)
  unless time_low >= 0 && time_low < 4294967296
    raise ArgumentError,
      "Expected unsigned 32-bit number for time_low, got #{time_low}."
  end
  unless time_mid >= 0 && time_mid < 65536
    raise ArgumentError,
      "Expected unsigned 16-bit number for time_mid, got #{time_mid}."
  end
  unless time_hi_and_version >= 0 && time_hi_and_version < 65536
    raise ArgumentError,
      "Expected unsigned 16-bit number for time_hi_and_version, " +
      "got #{time_hi_and_version}."
  end
  unless clock_seq_hi_and_reserved >= 0 && clock_seq_hi_and_reserved < 256
    raise ArgumentError,
      "Expected unsigned 8-bit number for clock_seq_hi_and_reserved, " +
      "got #{clock_seq_hi_and_reserved}."
  end
  unless clock_seq_low >= 0 && clock_seq_low < 256
    raise ArgumentError,
      "Expected unsigned 8-bit number for clock_seq_low, " +
      "got #{clock_seq_low}."
  end
  unless nodes.kind_of?(Enumerable)
    raise TypeError,
      "Expected Enumerable, got #{nodes.class.name}."
  end
  unless nodes.size == 6
    raise ArgumentError,
      "Expected nodes to have size of 6."
  end
  for node in nodes
    unless node >= 0 && node < 256
      raise ArgumentError,
        "Expected unsigned 8-bit number for each node, " +
        "got #{node}."
    end
  end
  @time_low = time_low
  @time_mid = time_mid
  @time_hi_and_version = time_hi_and_version
  @clock_seq_hi_and_reserved = clock_seq_hi_and_reserved
  @clock_seq_low = clock_seq_low
  @nodes = nodes
end
os_class() click to toggle source

Determine what OS we're running on. Helps decide how to find the MAC

# File lib/uuidtools.rb, line 526
def self.os_class
  require 'rbconfig'
  os_platform = RbConfig::CONFIG['target_os']
  os_class = nil
  if (os_platform =~ /win/i && !(os_platform =~ /darwin/i)) ||
      os_platform =~ /w32/i
    os_class = :windows
  elsif os_platform =~ /solaris/i
    os_class = :solaris
  elsif os_platform =~ /netbsd/i
    os_class = :netbsd
  elsif os_platform =~ /openbsd/i
    os_class = :openbsd
  end
end
parse(uuid_string) click to toggle source

Parses a UUID from a string.

# File lib/uuidtools.rb, line 153
def self.parse(uuid_string)
  unless uuid_string.kind_of? String
    raise TypeError,
      "Expected String, got #{uuid_string.class.name} instead."
  end
  uuid_components = uuid_string.downcase.scan(UUIDTools::UUID_REGEXP).first
  raise ArgumentError, "Invalid UUID format." if uuid_components.nil?
  time_low = uuid_components[0].to_i(16)
  time_mid = uuid_components[1].to_i(16)
  time_hi_and_version = uuid_components[2].to_i(16)
  clock_seq_hi_and_reserved = uuid_components[3].to_i(16)
  clock_seq_low = uuid_components[4].to_i(16)
  nodes = []
  for i in 0..5
    nodes << uuid_components[5][(i * 2)..(i * 2) + 1].to_i(16)
  end
  return self.new(time_low, time_mid, time_hi_and_version,
    clock_seq_hi_and_reserved, clock_seq_low, nodes)
end
parse_hexdigest(uuid_hexdigest) click to toggle source

Parse a UUID from a hexdigest String.

# File lib/uuidtools.rb, line 207
def self.parse_hexdigest(uuid_hexdigest)
  unless uuid_hexdigest.kind_of?(String)
    raise ArgumentError,
      "Expected String, got #{uuid_hexdigest.class.name} instead."
  end
  return self.parse_int(uuid_hexdigest.to_i(16))
end
parse_int(uuid_int) click to toggle source

Parses a UUID from an Integer.

# File lib/uuidtools.rb, line 197
def self.parse_int(uuid_int)
  unless uuid_int.kind_of?(Integer)
    raise ArgumentError,
      "Expected Integer, got #{uuid_int.class.name} instead."
  end
  return self.parse_raw(self.convert_int_to_byte_string(uuid_int, 16))
end
parse_raw(raw_string) click to toggle source

Parses a UUID from a raw byte string.

# File lib/uuidtools.rb, line 175
def self.parse_raw(raw_string)
  unless raw_string.kind_of? String
    raise TypeError,
      "Expected String, got #{raw_string.class.name} instead."
  end
  integer = self.convert_byte_string_to_int(raw_string)

  time_low = (integer >> 96) & 0xFFFFFFFF
  time_mid = (integer >> 80) & 0xFFFF
  time_hi_and_version = (integer >> 64) & 0xFFFF
  clock_seq_hi_and_reserved = (integer >> 56) & 0xFF
  clock_seq_low = (integer >> 48) & 0xFF
  nodes = []
  for i in 0..5
    nodes << ((integer >> (40 - (i * 8))) & 0xFF)
  end
  return self.new(time_low, time_mid, time_hi_and_version,
    clock_seq_hi_and_reserved, clock_seq_low, nodes)
end
random_create() click to toggle source

Creates a UUID from a random value.

# File lib/uuidtools.rb, line 217
def self.random_create()
  new_uuid = self.parse_raw(SecureRandom.random_bytes(16))
  new_uuid.time_hi_and_version &= 0x0FFF
  new_uuid.time_hi_and_version |= (4 << 12)
  new_uuid.clock_seq_hi_and_reserved &= 0x3F
  new_uuid.clock_seq_hi_and_reserved |= 0x80
  return new_uuid
end
sha1_create(namespace, name) click to toggle source

Creates a UUID using the SHA1 hash. (Version 5)

# File lib/uuidtools.rb, line 294
def self.sha1_create(namespace, name)
  return self.create_from_hash(Digest::SHA1, namespace, name)
end
timestamp_create(timestamp=nil) click to toggle source

Creates a UUID from a timestamp.

# File lib/uuidtools.rb, line 228
def self.timestamp_create(timestamp=nil)
  # We need a lock here to prevent two threads from ever
  # getting the same timestamp.
  @@mutex.synchronize do
    # Always use GMT to generate UUIDs.
    if timestamp.nil?
      gmt_timestamp = Time.now.gmtime
    else
      gmt_timestamp = timestamp.gmtime
    end
    # Convert to 100 nanosecond blocks
    gmt_timestamp_100_nanoseconds = (gmt_timestamp.tv_sec * 10000000) +
      (gmt_timestamp.tv_usec * 10) + 0x01B21DD213814000
    mac_address = self.mac_address
    node_id = 0
    if mac_address != nil
      nodes = mac_address.split(":").collect do |octet|
        octet.to_i(16)
      end
    else
      nodes = SecureRandom.random_bytes(6).unpack("C*")
      nodes[0] |= 0b00000001
    end
    for i in 0..5
      node_id += (nodes[i] << (40 - (i * 8)))
    end
    clock_sequence = @@last_clock_sequence
    if clock_sequence.nil?
      clock_sequence = self.convert_byte_string_to_int(
        SecureRandom.random_bytes(16)
      )
    end
    if @@last_node_id != nil && @@last_node_id != node_id
      # The node id has changed.  Change the clock id.
      clock_sequence = self.convert_byte_string_to_int(
        SecureRandom.random_bytes(16)
      )
    elsif @@last_timestamp != nil &&
        gmt_timestamp_100_nanoseconds <= @@last_timestamp
      clock_sequence = clock_sequence + 1
    end
    @@last_timestamp = gmt_timestamp_100_nanoseconds
    @@last_node_id = node_id
    @@last_clock_sequence = clock_sequence

    time_low = gmt_timestamp_100_nanoseconds & 0xFFFFFFFF
    time_mid = ((gmt_timestamp_100_nanoseconds >> 32) & 0xFFFF)
    time_hi_and_version = ((gmt_timestamp_100_nanoseconds >> 48) & 0x0FFF)
    time_hi_and_version |= (1 << 12)
    clock_seq_low = clock_sequence & 0xFF;
    clock_seq_hi_and_reserved = (clock_sequence & 0x3F00) >> 8
    clock_seq_hi_and_reserved |= 0x80

    return self.new(time_low, time_mid, time_hi_and_version,
      clock_seq_hi_and_reserved, clock_seq_low, nodes)
  end
end

Public Instance Methods

<=>(other_uuid) click to toggle source

Compares two UUIDs lexically

# File lib/uuidtools.rb, line 394
def <=>(other_uuid)
  return nil unless other_uuid.is_a?(UUIDTools::UUID)
  check = self.time_low <=> other_uuid.time_low
  return check if check != 0
  check = self.time_mid <=> other_uuid.time_mid
  return check if check != 0
  check = self.time_hi_and_version <=> other_uuid.time_hi_and_version
  return check if check != 0
  check = self.clock_seq_hi_and_reserved <=>
    other_uuid.clock_seq_hi_and_reserved
  return check if check != 0
  check = self.clock_seq_low <=> other_uuid.clock_seq_low
  return check if check != 0
  for i in 0..5
    if (self.nodes[i] < other_uuid.nodes[i])
      return -1
    end
    if (self.nodes[i] > other_uuid.nodes[i])
      return 1
    end
  end
  return 0
end
eql?(other) click to toggle source

Returns true if this UUID is exactly equal to the other UUID.

# File lib/uuidtools.rb, line 519
def eql?(other)
  return self == other
end
hash() click to toggle source

Returns an integer hash value.

# File lib/uuidtools.rb, line 459
def hash
  self.frozen? ? generate_hash : (@hash ||= generate_hash)
end
hexdigest() click to toggle source

Returns the hex digest of the UUID object.

# File lib/uuidtools.rb, line 426
def hexdigest
  (self.frozen? ?
    generate_hexdigest : (@hexdigest ||= generate_hexdigest)
  ).dup
end
inspect() click to toggle source

Returns a representation of the object's state

# File lib/uuidtools.rb, line 420
def inspect
  return "#<UUID:0x#{self.object_id.to_s(16)} UUID:#{self.to_s}>"
end
mac_address() click to toggle source

Returns the IEEE 802 address used to generate this UUID or nil if a MAC address was not used.

# File lib/uuidtools.rb, line 371
def mac_address
  return nil if self.version != 1
  return nil if self.random_node_id?
  return (self.nodes.collect do |node|
    sprintf("%2.2x", node)
  end).join(":")
end
nil_uuid?() click to toggle source

Returns true if this UUID is the nil UUID (00000000-0000-0000-0000-000000000000).

# File lib/uuidtools.rb, line 313
def nil_uuid?
  return false if self.time_low != 0
  return false if self.time_mid != 0
  return false if self.time_hi_and_version != 0
  return false if self.clock_seq_hi_and_reserved != 0
  return false if self.clock_seq_low != 0
  self.nodes.each do |node|
    return false if node != 0
  end
  return true
end
random_node_id?() click to toggle source

This method applies only to version 1 UUIDs. Checks if the node ID was generated from a random number or from an IEEE 802 address (MAC address). Always returns false for UUIDs that aren't version 1. This should not be confused with version 4 UUIDs where more than just the node id is random.

# File lib/uuidtools.rb, line 305
def random_node_id?
  return false if self.version != 1
  return ((self.nodes.first & 0x01) == 1)
end
raw() click to toggle source

Returns the raw bytes that represent this UUID.

# File lib/uuidtools.rb, line 434
def raw
  (self.frozen? ? generate_raw : (@raw ||= generate_raw)).dup
end
timestamp() click to toggle source

Returns the timestamp used to generate this UUID

# File lib/uuidtools.rb, line 381
def timestamp
  return nil if self.version != 1
  gmt_timestamp_100_nanoseconds = 0
  gmt_timestamp_100_nanoseconds +=
    ((self.time_hi_and_version  & 0x0FFF) << 48)
  gmt_timestamp_100_nanoseconds += (self.time_mid << 32)
  gmt_timestamp_100_nanoseconds += self.time_low
  return Time.at(
    (gmt_timestamp_100_nanoseconds - 0x01B21DD213814000) / 10000000.0)
end
to_i() click to toggle source

Returns an integer representation for this UUID.

# File lib/uuidtools.rb, line 447
def to_i
  self.frozen? ? generate_i : (@integer ||= generate_i)
end
to_s() click to toggle source

Returns a string representation for this UUID.

# File lib/uuidtools.rb, line 440
def to_s
  (self.frozen? ? generate_s : (@string ||= generate_s)).dup
end
Also aliased as: to_str
to_str()
Alias for: to_s
to_uri() click to toggle source

Returns a URI string for this UUID.

# File lib/uuidtools.rb, line 453
def to_uri
  return "urn:uuid:#{self.to_s}"
end
valid?() click to toggle source

Returns true if this UUID is valid.

# File lib/uuidtools.rb, line 359
def valid?
  if [0b000, 0b100, 0b110, 0b111].include?(self.variant) &&
    (1..5).include?(self.version)
    return true
  else
    return false
  end
end
variant() click to toggle source

Returns the UUID variant. Possible values: 0b000 - Reserved, NCS backward compatibility. 0b100 - The variant specified in this document. 0b110 - Reserved, Microsoft Corporation backward compatibility. 0b111 - Reserved for future definition.

# File lib/uuidtools.rb, line 344
def variant
  variant_raw = (clock_seq_hi_and_reserved >> 5)
  result = nil
  if (variant_raw >> 2) == 0
    result = 0x000
  elsif (variant_raw >> 1) == 2
    result = 0x100
  else
    result = variant_raw
  end
  return (result >> 6)
end
version() click to toggle source

Returns the UUID version type. Possible values: 1 - Time-based with unique or random host identifier 2 - DCE Security version (with POSIX UIDs) 3 - Name-based (MD5 hash) 4 - Random 5 - Name-based (SHA-1 hash)

# File lib/uuidtools.rb, line 333
def version
  return (time_hi_and_version >> 12)
end

Protected Instance Methods

generate_hash() click to toggle source

Generates an integer hash value.

@api private

# File lib/uuidtools.rb, line 475
def generate_hash
  return self.to_i % 0x3fffffff
end
generate_hexdigest() click to toggle source

Generates the hex digest of the UUID object.

@api private

# File lib/uuidtools.rb, line 468
def generate_hexdigest
  return self.to_i.to_s(16).rjust(32, "0")
end
generate_i() click to toggle source

Generates an integer representation for this UUID.

@api private

# File lib/uuidtools.rb, line 483
def generate_i
  return (begin
    bytes = (time_low << 96) + (time_mid << 80) +
      (time_hi_and_version << 64) + (clock_seq_hi_and_reserved << 56) +
      (clock_seq_low << 48)
    for i in 0..5
      bytes += (nodes[i] << (40 - (i * 8)))
    end
    bytes
  end)
end
generate_raw() click to toggle source

Generates the raw bytes that represent this UUID.

@api private

# File lib/uuidtools.rb, line 512
def generate_raw
  return self.class.convert_int_to_byte_string(self.to_i, 16)
end
generate_s() click to toggle source

Generates a string representation for this UUID.

@api private

# File lib/uuidtools.rb, line 499
def generate_s
  result = sprintf("%8.8x-%4.4x-%4.4x-%2.2x%2.2x-", @time_low, @time_mid,
    @time_hi_and_version, @clock_seq_hi_and_reserved, @clock_seq_low);
  for i in 0..5
    result << sprintf("%2.2x", @nodes[i])
  end
  return result.downcase
end