Re: some Page/PageData const stuff - Mailing list pgsql-hackers

From Peter Eisentraut
Subject Re: some Page/PageData const stuff
Date
Msg-id 56a6e40d-52d4-4ecb-a37e-0b2c86fb7d72@eisentraut.org
Whole thread Raw
In response to Re: some Page/PageData const stuff  (Andres Freund <andres@anarazel.de>)
List pgsql-hackers
On 03.01.26 18:23, Andres Freund wrote:
> On 2026-01-03 18:05:19 +0100, Peter Eisentraut wrote:
>> On 02.01.26 20:17, Andres Freund wrote:
>>> On 2025-01-20 15:01:08 +0100, Peter Eisentraut wrote:
>>>> This has been committed.
>>>
>>> I don't like the const markings in PageGetItem():
>>>
>>>
>>> /*
>>>    * PageGetItem
>>>    *        Retrieves an item on the given page.
>>>    *
>>>    * Note:
>>>    *        This does not change the status of any of the resources passed.
>>>    *        The semantics may change in the future.
>>>    */
>>> static inline void *
>>> PageGetItem(const PageData *page, const ItemIdData *itemId)
>>> {
>>>     Assert(page);
>>>     Assert(ItemIdHasStorage(itemId));
>>>
>>>     return (void *) (((const char *) page) + ItemIdGetOffset(itemId));
>>> }
>>>
>>> The const for PageData seems like a lie to me, because we cast it away. And
>>> indeed, we often then use the returned value to set hint bits etc.
>>
>> I agree this is incorrect.  Since no callers appear to rely on the const
>> qualification of the argument, the easiest solution would be to just remove
>> it.  See attached patch.
> 
> LGTM

committed




pgsql-hackers by date:

Previous
From: Tatsuo Ishii
Date:
Subject: Re: Row pattern recognition
Next
From: Andrew Dunstan
Date:
Subject: Re: Non-text mode for pg_dumpall