generate_uuid.coffee

generate_uuid = () ->
  "aaaaaaaa-aaaa-4aaa-baaa-aaaaaaaaaaaa".replace /[ab]/g, (ch) ->
    rnd = Math.random() * 16 | 0
    out = (if ch is "a" then rnd else (rnd & 0x3 | 0x8))
    out.toString 16

#
# Conforms to: http://tools.ietf.org/html/rfc4122
#
# 4.4.  Algorithms for Creating a UUID from Truly Random or
#       Pseudo-Random Numbers
#
#    The version 4 UUID is meant for generating UUIDs from truly-random or
#    pseudo-random numbers.
#
#    The algorithm is as follows:
#    o  Set the two most significant bits (bits 6 and 7) of the
#       clock_seq_hi_and_reserved to zero and one, respectively.
#    o  Set the four most significant bits (bits 12 through 15) of the
#       time_hi_and_version field to the 4-bit version number from
#       Section 4.1.3.
#    o  Set all the other bits to randomly (or pseudo-randomly) chosen
#       values.
#
# typedef struct {
#     unsigned32  time_low;
#     unsigned16  time_mid;
#     unsigned16  time_hi_and_version;
#     unsigned8   clock_seq_hi_and_reserved;
#     unsigned8   clock_seq_low;
#     byte        node[6];
# } uuid_t;