Method: FFaker::UUID#uuidv6

Defined in:
lib/ffaker/uuid.rb

#uuidv6 ⇒ Object

> UUID version 6 is a field-compatible version of UUIDv1 Section 5.1, > reordered for improved DB locality. It is expected that UUIDv6 will > primarily be used in contexts where UUIDv1 is used. Systems that do not > involve legacy UUIDv1 SHOULD use UUIDv7 instead.



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# File 'lib/ffaker/uuid.rb', line 51

def uuidv6
  timestamp = rand((2**60) - 1)

  uuid = 0
  # time_high
  # > The most significant 32 bits of the 60 bit starting timestamp.
  # > Occupies bits 0 through 31 (octets 0-3).
  # @note Shifts 28 bits to remove `time_mid` and `time_low`.
  uuid |= (timestamp >> 28) << 96
  # time_mid
  # > The middle 16 bits of the 60 bit starting timestamp. Occupies bits 32
  # > through 47 (octets 4-5).
  # @note Shifts 12 bits to remove `time_low`.
  uuid |= ((timestamp >> 12) & ((2**16) - 1)) << 80
  # ver
  # > The 4 bit version field as defined by Section 4.2, set to 0b0110 (6).
  # > Occupies bits 48 through 51 of octet 6.
  uuid |= 0b0110 << 76
  # time_low
  # > 12 bits that will contain the least significant 12 bits from the 60
  # > bit starting timestamp. Occupies bits 52 through 63 (octets 6-7).
  uuid |= (timestamp & ((2**12) - 1)) << 64
  # var
  # > The 2 bit variant field as defined by Section 4.1, set to 0b10.
  # > Occupies bits 64 and 65 of octet 8.
  uuid |= 0b10 << 62
  # clk_seq
  # > The 14 bits containing the clock sequence. Occupies bits 66 through
  # > 79 (octets 8-9).
  #
  # (earlier in the document)
  # > The clock sequence and node bits SHOULD be reset to a pseudo-random
  # > value for each new UUIDv6 generated; however, implementations MAY
  # > choose to retain the old clock sequence and MAC address behavior from
  # > Section 5.1.
  uuid |= rand((2**14) - 1) << 48
  # node
  # > 48 bit spatially unique identifier. Occupies bits 80 through 127
  # > (octets 10-15).
  uuid |= rand((2**48) - 1)

  as_string(uuid)
end