Обсуждение: Use correct macro for accessing offset numbers.

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Use correct macro for accessing offset numbers.

От
Kirill Reshke
Дата:
Hi hackers!

While working on pageinspect support for GIN and SpGiST (welcome to
review them [0] & [1]), I spotted $subi.

PFA trivial patch that uses UInt16GetDatum for OffsetNumber rather
than Int16GetDatum


[0]https://www.postgresql.org/message-id/CALdSSPiN13n7feQcY0WCmq8jzxjwqhNrt1E%3Dg%3Dg6aZANyE_OoQ%40mail.gmail.com
[1] https://www.postgresql.org/message-id/CALdSSPhbAQbFtjK0nT8_G5GsXmsSEVx8J735Ga%2BZxLp9osHcRA%40mail.gmail.com

-- 
Best regards,
Kirill Reshke

Вложения

Re: Use correct macro for accessing offset numbers.

От
Roman Khapov
Дата:
> On 11 Jan 2026, at 16:21, Kirill Reshke <reshkekirill@gmail.com> wrote:
> 
> Hi hackers!
> 
> PFA trivial patch that uses UInt16GetDatum for OffsetNumber rather
> than Int16GetDatum

Hi!

LGTM, should we check another places of offset number conversations to Datum
as part of this thread?

--
Best regards,
Roman Khapov



Re: Use correct macro for accessing offset numbers.

От
Kirill Reshke
Дата:
On Sun, 11 Jan 2026 at 16:41, Roman Khapov <rkhapov@yandex-team.ru> wrote:
>
> should we check another places of offset number conversations to Datum
> as part of this thread?

Maybe, I have stopped some more cases, in v2-0001


-- 
Best regards,
Kirill Reshke

Вложения

Re: Use correct macro for accessing offset numbers.

От
Michael Paquier
Дата:
On Sun, Jan 11, 2026 at 04:58:39PM +0500, Kirill Reshke wrote:
> Maybe, I have stopped some more cases, in v2-0001

Right.  It's true that we could be more consistent for all these based
on their base type, some of them, particularly in the GIN code now,
caring about using the correct macro.  It may be a good occasion to
double-check the whole tree for similar holes based on unsigned types.
--
Michael

Вложения

RE: Use correct macro for accessing offset numbers.

От
li carol
Дата:
>
> On Sun, Jan 11, 2026 at 04:58:39PM +0500, Kirill Reshke wrote:
> > Maybe, I have stopped some more cases, in v2-0001
>
> Right.  It's true that we could be more consistent for all these based on their
> base type, some of them, particularly in the GIN code now, caring about using
> the correct macro.  It may be a good occasion to double-check the whole tree
> for similar holes based on unsigned types.
> --
> Michael

Hi Kirill, Roman, and Michael,
While double-checking the tree for similar holes as Michael suggested, I noticed a couple more inconsistencies in
contrib/pageinspect/ginfuncs.cwhere we are using signed macros for unsigned types. 
Specifically, in gin_page_opaque_info, we use Int32GetDatum for maxoff:

values[1] = Int32GetDatum(opaq->maxoff);

Since maxoff is of type OffsetNumber (uint16), this seems to be the exact same pattern Kirill is addressing in other
partsof the GIN code. Although it is widened to int32 here, for the sake of consistency, it should probably be using a
16-bitor unsigned macro. 

Similarly, in gin_metapage_info, tailFreeSize (which is defined as uint32 in GinMetaPageData) is also converted using
Int32GetDatum:

values[2] = Int32GetDatum(metadata->tailFreeSize);

It might be better to include these cleanups in the next version of the patch to ensure all pageinspect GIN functions
followthe same standard. 

Best regards,
Yuan Li(carol)




Re: Use correct macro for accessing offset numbers.

От
"zengman"
Дата:
Hi,

I’ve also seen such cases in the kernel code, and I’m wondering if this should be added to the patch here?
```
postgres@zxm-VMware-Virtual-Platform:~/code/postgres$ git diff
diff --git a/src/backend/utils/adt/lockfuncs.c b/src/backend/utils/adt/lockfuncs.c
index bcbc226125c..9dadd6da672 100644
--- a/src/backend/utils/adt/lockfuncs.c
+++ b/src/backend/utils/adt/lockfuncs.c
@@ -329,7 +329,7 @@ pg_lock_status(PG_FUNCTION_ARGS)
                                values[1] = ObjectIdGetDatum(instance->locktag.locktag_field1);
                                values[8] = ObjectIdGetDatum(instance->locktag.locktag_field2);
                                values[6] = ObjectIdGetDatum(instance->locktag.locktag_field3);
-                               values[9] = Int16GetDatum(instance->locktag.locktag_field4);
+                               values[9] = UInt16GetDatum(instance->locktag.locktag_field4);
                                nulls[2] = true;
                                nulls[3] = true;
                                nulls[4] = true;
@@ -343,7 +343,7 @@ pg_lock_status(PG_FUNCTION_ARGS)
                                values[1] = ObjectIdGetDatum(instance->locktag.locktag_field1);
                                values[7] = ObjectIdGetDatum(instance->locktag.locktag_field2);
                                values[8] = ObjectIdGetDatum(instance->locktag.locktag_field3);
-                               values[9] = Int16GetDatum(instance->locktag.locktag_field4);
+                               values[9] = UInt16GetDatum(instance->locktag.locktag_field4);
                                nulls[2] = true;
                                nulls[3] = true;
                                nulls[4] = true;
```

--
Regards,
Man Zeng
www.openhalo.org

Re: Use correct macro for accessing offset numbers.

От
Kirill Reshke
Дата:
On Mon, 12 Jan 2026 at 04:23, Michael Paquier <michael@paquier.xyz> wrote:
>
> On Sun, Jan 11, 2026 at 04:58:39PM +0500, Kirill Reshke wrote:
> > Maybe, I have stopped some more cases, in v2-0001
>
> Right.  It's true that we could be more consistent for all these based
> on their base type, some of them, particularly in the GIN code now,
> caring about using the correct macro.  It may be a good occasion to
> double-check the whole tree for similar holes based on unsigned types.
> --
> Michael

Ok

> Hi Kirill, Roman, and Michael,
> While double-checking the tree for similar holes as Michael suggested, I noticed a couple more inconsistencies in
contrib/pageinspect/ginfuncs.cwhere we are using signed macros for unsigned types. 
> Specifically, in gin_page_opaque_info, we use Int32GetDatum for maxoff:
>
> values[1] = Int32GetDatum(opaq->maxoff);
>
> Since maxoff is of type OffsetNumber (uint16), this seems to be the exact same pattern Kirill is addressing in other
partsof the GIN code. Although it is widened to int32 here, for the sake of consistency, it should probably be using a
16-bitor unsigned macro. 
>
> Similarly, in gin_metapage_info, tailFreeSize (which is defined as uint32 in GinMetaPageData) is also converted using
Int32GetDatum:
>
> values[2] = Int32GetDatum(metadata->tailFreeSize);
>
> It might be better to include these cleanups in the next version of the patch to ensure all pageinspect GIN functions
followthe same standard. 

Thank you, I have included your findings in v3.

On Mon, 12 Jan 2026 at 11:53, zengman <zengman@halodbtech.com> wrote:
>
> Hi,
>
> I’ve also seen such cases in the kernel code, and I’m wondering if this should be added to the patch here?
> ```
> postgres@zxm-VMware-Virtual-Platform:~/code/postgres$ git diff
> diff --git a/src/backend/utils/adt/lockfuncs.c b/src/backend/utils/adt/lockfuncs.c
> index bcbc226125c..9dadd6da672 100644
> --- a/src/backend/utils/adt/lockfuncs.c
> +++ b/src/backend/utils/adt/lockfuncs.c
> @@ -329,7 +329,7 @@ pg_lock_status(PG_FUNCTION_ARGS)
>                                 values[1] = ObjectIdGetDatum(instance->locktag.locktag_field1);
>                                 values[8] = ObjectIdGetDatum(instance->locktag.locktag_field2);
>                                 values[6] = ObjectIdGetDatum(instance->locktag.locktag_field3);
> -                               values[9] = Int16GetDatum(instance->locktag.locktag_field4);
> +                               values[9] = UInt16GetDatum(instance->locktag.locktag_field4);
>                                 nulls[2] = true;
>                                 nulls[3] = true;
>                                 nulls[4] = true;
> @@ -343,7 +343,7 @@ pg_lock_status(PG_FUNCTION_ARGS)
>                                 values[1] = ObjectIdGetDatum(instance->locktag.locktag_field1);
>                                 values[7] = ObjectIdGetDatum(instance->locktag.locktag_field2);
>                                 values[8] = ObjectIdGetDatum(instance->locktag.locktag_field3);
> -                               values[9] = Int16GetDatum(instance->locktag.locktag_field4);
> +                               values[9] = UInt16GetDatum(instance->locktag.locktag_field4);
>                                 nulls[2] = true;
>                                 nulls[3] = true;
>                                 nulls[4] = true;

Thank you, I have included your findings in v3.


PFA v3 with fixes for signed usage across the tree, with my new
findings and suggestions from thread

--
Best regards,
Kirill Reshke

Вложения

Re: Use correct macro for accessing offset numbers.

От
Michael Paquier
Дата:
On Mon, Jan 12, 2026 at 01:51:10PM +0500, Kirill Reshke wrote:
> PFA v3 with fixes for signed usage across the tree, with my new
> findings and suggestions from thread

Note that the change in get_opfamily_member() is not right based on
the type of "strategy".  The rest was OK, so done.
--
Michael

Вложения