Use hex_decode_safe() to speed up UUID input. Previously, string_to_uuid() decoded one byte at a time, calling isxdigit() twice and strtoul() once for every pair of hexadecimal digits. Commit ec8719ccbfcd made hex_decode_safe() decode a run of hexadecimal digits in bulk, so add a fast path for the two common shapes: 32 contiguous hexadecimal digits, and the canonical 8x-4x-4x-4x-12x form, each optionally wrapped in braces.
Anything else, and any decoding error, falls back to the byte-at-a-time parser, so the accepted grammar and the error messages don't change. hex_decode_safe() also skips whitespace, which the UUID grammar forbids, so we treat a short decode as an error too. Rejecting an input that has a fast-path shape therefore costs a second parse. But this only happens for syntax-error cases, so it's not a problem in practice. Reviewed-by: Bharath Rupireddy <[email protected]> Reviewed-by: Haibo Yan <[email protected]> Reviewed-by: Chao Li <[email protected]> Reviewed-by: John Naylor <[email protected]> Discussion: https://postgr.es/m/cad21aocqer4uqu77q_yomnnzj7aveio5qzt+4hnzpm4wm-e...@mail.gmail.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/72af14bccd2127bf20ddeaf198b78de46e9e892b Modified Files -------------- src/backend/utils/adt/uuid.c | 101 +++++++++++++++++++++++++++++++++++-- src/test/regress/expected/uuid.out | 74 +++++++++++++++++++++++++++ src/test/regress/sql/uuid.sql | 24 +++++++++ 3 files changed, 194 insertions(+), 5 deletions(-)
