Corey Huinker писал(а) 2025-07-22 22:42:
On Sun, Jul 20, 2025 at 6:21 PM Dmitry Mityugov
<d.mityu...@postgrespro.ru> wrote:
Code in src/port/pgmkdirp.c uses strstr() to find a single character
in
a string, but strstr() seems to be too generic for this job. Another
function, strchr(), might be better suited for this purpose, because
it
is optimized to search for exactly one character in a string. In
addition, if strchr() is used, the compiler doesn't have to generate
a
terminating \0 byte for the substring, producing slightly smaller
code.
I'm attaching the patch.
Regards,
Dmitry
Seems like a simple-enough change, not a huge win but probably worth
doing.
Using ripgrep to search for 'strstr(.*".")' turns up two similar
situations in contrib/fuzzystrmatch/dmetaphone.c, so perhaps we
include those.
There's also a match in src/bin/pg_rewind/filemap.c, but that one is a
false positive.
Thank you for your attention to this problem. The code in
contrib/fuzzystrmatch/dmetaphone.c indeed uses several calls to strstr()
to search for a single character, but it also uses strstr() to search
for strings that consist of more than a single character on adjacent
lines, and replacing half of those strstr()s with strchr()s would make
the code less consistent in my opinion.
What's more important, it seems that this code in
contrib/fuzzystrmatch/dmetaphone.c contains a bug. Statement `else if
(strstr(s->str, "WITZ"))` at line 317 will never be executed, because if
the string contains substring “W”, it will be handled at line 311, `if
(strstr(s->str, "W"))`. Probably this bug should be fixed in a separate
commit.
