module Digest::UUID - activesupport-4.2.4 Documentation

# module Digest::UUID

### Public Class Methods

uuid_from_hash(hash_class, uuid_namespace, name) click to toggle source

Generates a v5 non-random UUID (Universally Unique IDentifier).

Using Digest::MD5 generates version 3 UUIDs; Digest::SHA1 generates version 5 UUIDs. ::uuid_from_hash always generates the same UUID for a given name and namespace combination.

See RFC 4122 for details of UUID at: www.ietf.org/rfc/rfc4122.txt

    # File lib/active_support/core_ext/digest/uuid.rb, line 16
    def self.uuid_from_hash(hash_class, uuid_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(uuid_namespace)
      hash.update(name)

      ary = hash.digest.unpack('NnnnnN')
      ary[2] = (ary[2] & 0x0FFF) | (version << 12)
      ary[3] = (ary[3] & 0x3FFF) | 0x8000

      "%08x-%04x-%04x-%04x-%04x%08x" % ary
    end

uuid_v3(uuid_namespace, name) click to toggle source

Convenience method for ::uuid_from_hash using Digest::MD5.

    # File lib/active_support/core_ext/digest/uuid.rb, line 37
    def self.uuid_v3(uuid_namespace, name)
      self.uuid_from_hash(Digest::MD5, uuid_namespace, name)
    end

uuid_v4() click to toggle source

Convenience method for SecureRandom.uuid.

    # File lib/active_support/core_ext/digest/uuid.rb, line 47
    def self.uuid_v4
      SecureRandom.uuid
    end

uuid_v5(uuid_namespace, name) click to toggle source

Convenience method for ::uuid_from_hash using Digest::SHA1.

    # File lib/active_support/core_ext/digest/uuid.rb, line 42
    def self.uuid_v5(uuid_namespace, name)
      self.uuid_from_hash(Digest::SHA1, uuid_namespace, name)
    end