On 03/19/2014 11:58 AM, Przemyslaw Marczak wrote:
This patch adds support to generate UUID (Universally Unique Identifier) in version 4 based on RFC4122, which is randomly.
Some nits in the comments below, but otherwise: Acked-by: Stephen Warren swarren@nvidia.com
diff --git a/include/uuid.h b/include/uuid.h
+/* This is structure is in big-endian */ +struct uuid {
Not any more; with the introduction of enum uuid_str_t, some of the fields could be either LE or BE. I would say "See the comment near the top of lib/uuid.c for details of the endianness of fields in this struct".
diff --git a/lib/uuid.c b/lib/uuid.c
/*
- UUID - Universally Unique IDentifier - 128 bits unique number.
There are 5 versions and one variant of UUID defined by RFC4122
specification. Depends on version uuid number base on a time,
host name, MAC address or random data.
specification. Depends on version uuid number base on:
I still have no idea what "Depends on version uuid number base on" means.
- time, MAC address(v1),
- user ID(v2),
- MD5 of name or URL(v3),
- random data(v4),
- SHA-1 of name or URL(v5),
- This library implements UUID v4.
I think that should say "gen_rand_uuid()" not "This library", since the source of the data in the UUID fields only matters when creating the UUID, not when performing str<->bin conversion.
- Layout of UUID Version 4:
- timestamp - 60-bit: time_low, time_mid, time_hi_and_version
- version - 4 bit (bit 4 through 7 of the time_hi_and_version)
- clock seq - 14 bit: clock_seq_hi_and_reserved, clock_seq_low
- variant: - bit 6 and 7 of clock_seq_hi_and_reserved
- node - 48 bit
- In this version all fields beside 4 bit version are randomly generated.
gen_rand_uuid() doesn't actually honor that format; it creates pure random data rather than filling in any timestamps, clock sequence data, etc.