Re: [PATCH v3 5/9] midx: refactor permutation logic and pack sorting

From: Derrick Stolee <stolee@gmail.com>
Date: Jan 24, 2019, 19:17 UTC
Message-ID: <295eb5fb-5497-0517-a5ed-af96aafb3133@gmail.com>
In-Reply-To: <14fe05d0-75e5-0975-d490-550539dbb34a@gmail.com>

On 1/24/2019 12:34 PM, Derrick Stolee wrote:

Show 14 quoted lines

> On 1/23/2019 4:00 PM, Jonathan Tan wrote:
>> Indeed, the sorting of pack_info is moved to after get_sorted_entries().
>> Also, pack_perm[old number] = new number, as expected.
>
> Thanks for chiming in with all the detail on the use of 'perm'. This 
> is the most confusing part of this code path.
>
>> I think a comment explaining why the perm is needed would be helpful -
>> something explaining that the entries were generated using the old pack
>> numbers, so we need this mapping to be able to write them using the new
>> numbers.
>
> I can put this comment in the struct definition. Is that the right 
> place for it?

I mistakenly thought the pack_perm array was placed into the pack_list struct. I'll put the comment right before we populate the contents of the array.

Thanks, -Stolee