Module: FFaker::UUID

Extended by:
ModuleUtils, UUID
Included in:
UUID
Defined in:
lib/ffaker/uuid.rb

Overview

Note:

This generates lowercase strings, but UUIDs are case-insensitive.

UUIDs are a 128-bit value (16 bytes), often represented as a 32-character hexadecimal string in the format ‘xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx`.

See Also:

Instance Method Summary collapse

Methods included from ModuleUtils

const_missing, k, luhn_check, underscore, unique

Methods included from RandomUtils

#fetch_sample, #rand, #shuffle

Instance Method Details

#uuidv4 ⇒ Object

> UUID version 4 is meant for generating UUIDs from truly-random or > pseudo-random numbers.



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# File 'lib/ffaker/uuid.rb', line 20

def uuidv4
  uuid = 0
  # random_a
  # > The first 48 bits of the layout that can be filled with random data
  # > as specified in Section 6.9. Occupies bits 0 through 47 (octets 0-5).
  uuid |= rand((2**48) - 1) << 80
  # ver
  # > The 4 bit version field as defined by Section 4.2, set to 0b0100 (4).
  # > Occupies bits 48 through 51 of octet 6.
  uuid |= 0b0100 << 76
  # random_b
  # > 12 more bits of the layout that can be filled random data as per
  # > Section 6.9. Occupies bits 52 through 63 (octets 6-7).
  uuid |= rand((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
  # random_c
  # > The final 62 bits of the layout immediately following the var field
  # > field to be filled with random data as per Section 6.9. Occupies bits
  # > 66 through 127 (octets 8-15).
  uuid |= rand((2**62) - 1)

  as_string(uuid)
end

#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

#uuidv7 ⇒ Object

> UUID version 7 features a time-ordered value field derived from the > widely implemented and well known Unix Epoch timestamp source, the > number of milliseconds since midnight 1 Jan 1970 UTC, leap seconds > excluded. UUIDv7 generally has improved entropy characteristics over > UUIDv1 Section 5.1 or UUIDv6 Section 5.6.



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# File 'lib/ffaker/uuid.rb', line 100

def uuidv7
  timestamp = rand((2**48) - 1)

  uuid = 0
  # unix_ts_ms
  # > 48 bit big-endian unsigned number of Unix epoch timestamp in
  # > milliseconds as per Section 6.1. Occupies bits 0 through 47 (octets
  # > 0-5).
  uuid |= timestamp << 80
  # ver
  # > The 4 bit version field as defined by Section 4.2, set to 0b0111 (7).
  # > Occupies bits 48 through 51 of octet 6.
  uuid |= 0b0111 << 76
  # rand_a
  # > 12 bits pseudo-random data to provide uniqueness as per Section 6.9
  # > and/or optional constructs to guarantee additional monotonicity as
  # > per Section 6.2. Occupies bits 52 through 63 (octets 6-7).
  uuid |= rand((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
  # rand_b
  # > The final 62 bits of pseudo-random data to provide uniqueness as per
  # > Section 6.9 and/or an optional counter to guarantee additional
  # > monotonicity as per Section 6.2. Occupies bits 66 through 127 (octets
  # > 8-15).
  uuid |= rand((2**62) - 1)

  as_string(uuid)
end

#uuidv8 ⇒ Object

> UUID version 8 provides an RFC-compatible format for experimental or > vendor-specific use cases. The only requirement is that the variant and > version bits MUST be set as defined in Section 4.1 and Section 4.2. > UUIDv8’s uniqueness will be implementation-specific and MUST NOT be > assumed. > > […] To be clear: UUIDv8 is not a replacement for UUIDv4 Section 5.4 > where all 122 extra bits are filled with random data.



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# File 'lib/ffaker/uuid.rb', line 140

def uuidv8
  uuid = 0
  # custom_a
  # > The first 48 bits of the layout that can be filled as an
  # > implementation sees fit. Occupies bits 0 through 47 (octets 0-5).
  uuid |= rand((2**48) - 1) << 80
  # ver
  # > The 4 bit version field as defined by Section 4.2, set to 0b1000 (8).
  # > Occupies bits 48 through 51 of octet 6.
  uuid |= 0b1000 << 76
  # custom_b
  # > 12 more bits of the layout that can be filled as an implementation
  # > sees fit. Occupies bits 52 through 63 (octets 6-7).
  uuid |= rand((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
  # custom_c
  # > The final 62 bits of the layout immediately following the var field
  # > to be filled as an implementation sees fit. Occupies bits 66 through
  # > 127 (octets 8-15).
  uuid |= rand((2**62) - 1)

  as_string(uuid)
end