missing PG_FREE_IF_COPY in textlike() and textnlike() ?
Hi Hackers,
I see in the texteq() function calls to DatumGetTextPP() are followed
by conditional calls to PG_FREE_IF_COPY. e.g.
https://github.com/postgres/postgres/blob/master/src/backend/utils/adt/varlena.c#L1792
text *targ1 = DatumGetTextPP(arg1);
text *targ2 = DatumGetTextPP(arg2);
result = (memcmp(VARDATA_ANY(targ1), VARDATA_ANY(targ2), len1 -
VARHDRSZ) == 0);
PG_FREE_IF_COPY(targ1, 0);
PG_FREE_IF_COPY(targ2, 1);
However, in textlike(), PG_FREE_IF_COPY calls are missing.
https://github.com/postgres/postgres/blob/master/src/backend/utils/adt/like.c#L283
Is this a memory leak bug?
Regards,
-cktan
CK Tan <cktan@vitessedata.com> writes:
I see in the texteq() function calls to DatumGetTextPP() are followed
by conditional calls to PG_FREE_IF_COPY. e.g.
That's because texteq() is potentially usable as a btree index
function, and btree isn't too forgiving about leaks.
However, in textlike(), PG_FREE_IF_COPY calls are missing.
https://github.com/postgres/postgres/blob/master/src/backend/utils/adt/like.c#L283
textlike() isn't a member of any btree opclass.
Is this a memory leak bug?
Not unless you can demonstrate a case where it causes problems.
For the most part, such functions run in short-lived contexts.
regards, tom lane
Got it. It is a leak-by-design for efficiency.
Thanks,
-cktan
Show quoted text
On Fri, Sep 16, 2022 at 12:03 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
CK Tan <cktan@vitessedata.com> writes:
I see in the texteq() function calls to DatumGetTextPP() are followed
by conditional calls to PG_FREE_IF_COPY. e.g.That's because texteq() is potentially usable as a btree index
function, and btree isn't too forgiving about leaks.However, in textlike(), PG_FREE_IF_COPY calls are missing.
https://github.com/postgres/postgres/blob/master/src/backend/utils/adt/like.c#L283textlike() isn't a member of any btree opclass.
Is this a memory leak bug?
Not unless you can demonstrate a case where it causes problems.
For the most part, such functions run in short-lived contexts.regards, tom lane