Re: small pg_dump code cleanup - Mailing list pgsql-hackers

From Tom Lane
Subject Re: small pg_dump code cleanup
Date
Msg-id 892531.1717610334@sss.pgh.pa.us
Whole thread Raw
In response to Re: small pg_dump code cleanup  (Nathan Bossart <nathandbossart@gmail.com>)
Responses Re: small pg_dump code cleanup
List pgsql-hackers
Nathan Bossart <nathandbossart@gmail.com> writes:
> On Wed, Jun 05, 2024 at 12:22:03PM -0400, Neil Conway wrote:
>> (1) Names like `getXXX` for these functions suggest to me that they return
>> a value, rather than side-effecting. I realize some variants continue to
>> return a value, but the majority no longer do. Perhaps a name like
>> lookupXXX() or readXXX() would be clearer?

> What about collectXXX() to match similar functions in pg_dump.c (e.g.,
> collectRoleNames(), collectComments(), collectSecLabels())?

Personally I see nothing much wrong with leaving them as getXXX.

>> (2) These functions malloc() a single ntups * sizeof(struct) allocation and
>> then index into it to fill-in each struct before entering it into the hash
>> table. It might be more straightforward to just malloc each individual
>> struct.

> That'd increase the number of allocations quite significantly, but I'd be
> surprised if that was noticeable outside of extreme scenarios.  At the
> moment, I'm inclined to leave these as-is for this reason and because I
> doubt it'd result in much cleanup, but I'll yield to the majority opinion
> here.

I think that would be quite an invasive change; it would require
many hundreds of edits like

-        finfo[i].dobj.objType = DO_FUNC;
+        finfo->dobj.objType = DO_FUNC;

which aside from being tedious would create a back-patching hazard.
So I'm kind of -0.1 or so.

Another angle to this is that Coverity and possibly other tools tend
to report that these functions leak these allocations, apparently
because they don't notice that pointers into the allocations get
stored in hash tables by a subroutine.  I'm not sure if making this
change would make that worse or better.  If we really want to change
it, that might be worth checking somehow before we jump.

            regards, tom lane



pgsql-hackers by date:

Previous
From: Jeff Davis
Date:
Subject: Re: Extension security improvement: Add support for extensions with an owned schema
Next
From: Joe Conway
Date:
Subject: question regarding policy for patches to out-of-support branches