Document and check that PgStat_HashKey has no padding This change is a tighter rework of 7d85d87f4d5c, which tried to improve the code so as it would work should PgStat_HashKey gain new fields that create padding bytes. However, the previous change is proving to not be enough as some code paths of pgstats do not pass PgStat_HashKey by reference (valgrind would warn when padding is added to the structure, through a new field).
Per discussion, let's document and check that PgStat_HashKey has no padding rather than try to complicate the code of pgstats so as it is able to work around that. This removes a couple of memset(0) calls that should not be required. While on it, this commit adds a static assertion checking that no padding is introduced in the structure, by checking that the size of PgStat_HashKey matches with the sum of the size of all its fields. The object ID part of the hash key is already 8 bytes, which should be plenty enough already. A comment is added to discourage the addition of new fields. Author: Michael Paquier <mich...@paquier.xyz> Reviewed-by: Sami Imseih <samims...@gmail.com> Discussion: https://postgr.es/m/caa5rz0t9omat+hvsakjxwtmwvhpyfcazb41rpwkwrkfugma...@mail.gmail.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/3cd3a039da7f36b827455a8b9a7068c16b85e15d Modified Files -------------- src/backend/utils/activity/pgstat.c | 5 +---- src/backend/utils/activity/pgstat_shmem.c | 10 ++-------- src/include/utils/pgstat_internal.h | 17 ++++++++++++++++- 3 files changed, 19 insertions(+), 13 deletions(-)
