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| author | Peter Eisentraut <peter@eisentraut.org> | 2019-07-14 14:30:27 +0200 |
|---|---|---|
| committer | Peter Eisentraut <peter@eisentraut.org> | 2019-07-14 14:30:27 +0200 |
| commit | 5925e5549890416bcf588334d9d0bc99f8ad6c7f (patch) | |
| tree | 0b9d6556f5e4dcaa389d2f35cf60804645d2c5f8 /src/backend | |
| parent | 565f3390005318ea4c982b8d054d56e9fe5a6454 (diff) | |
| download | postgresql-5925e5549890416bcf588334d9d0bc99f8ad6c7f.tar.gz postgresql-5925e5549890416bcf588334d9d0bc99f8ad6c7f.zip | |
Add gen_random_uuid function
This adds a built-in function to generate UUIDs.
PostgreSQL hasn't had a built-in function to generate a UUID yet,
relying on external modules such as uuid-ossp and pgcrypto to provide
one. Now that we have a strong random number generator built-in, we
can easily provide a version 4 (random) UUID generation function.
This patch takes the existing function gen_random_uuid() from pgcrypto
and makes it a built-in function. The pgcrypto implementation now
internally redirects to the built-in one.
Reviewed-by: Fabien COELHO <coelho@cri.ensmp.fr>
Discussion: https://www.postgresql.org/message-id/6a65610c-46fc-2323-6b78-e8086340a325@2ndquadrant.com
Diffstat (limited to 'src/backend')
| -rw-r--r-- | src/backend/utils/adt/uuid.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/src/backend/utils/adt/uuid.c b/src/backend/utils/adt/uuid.c index 09aa6b6daab..589c2d51dde 100644 --- a/src/backend/utils/adt/uuid.c +++ b/src/backend/utils/adt/uuid.c @@ -416,3 +416,23 @@ uuid_hash_extended(PG_FUNCTION_ARGS) return hash_any_extended(key->data, UUID_LEN, PG_GETARG_INT64(1)); } + +Datum +gen_random_uuid(PG_FUNCTION_ARGS) +{ + pg_uuid_t *uuid = palloc(UUID_LEN); + + if (!pg_strong_random(uuid, UUID_LEN)) + ereport(ERROR, + (errcode(ERRCODE_INTERNAL_ERROR), + errmsg("could not generate random values"))); + + /* + * Set magic numbers for a "version 4" (pseudorandom) UUID, see + * http://tools.ietf.org/html/rfc4122#section-4.4 + */ + uuid->data[6] = (uuid->data[6] & 0x0f) | 0x40; /* time_hi_and_version */ + uuid->data[8] = (uuid->data[8] & 0x3f) | 0x80; /* clock_seq_hi_and_reserved */ + + PG_RETURN_UUID_P(uuid); +} |