Re: [PATCH v3 2/6] pack-bitmap-write.c: write lookup table extension

From: Martin Ågren <martin.agren@gmail.com>
Date: Jul 18, 2022, 08:59 UTC
Message-ID: <CAN0heSoBca4BcBgR01cwE567NHQyjO+gRkY1V_6Z0nEd-_tW4g@mail.gmail.com>
In-Reply-To: <5e9b985e39b0b9edee7af55dd8b0698a20062cf7.1656924376.git.gitgitgadget@gmail.com>

On Mon, 4 Jul 2022 at 10:48, Abhradeep Chakraborty via GitGitGadget <gitgitgadget@gmail.com> wrote:

Show 6 quoted lines

>
> +static int table_cmp(const void *_va, const void *_vb, void *_data)
> +{
> +       uint32_t *commit_positions = _data;
> +       uint32_t a = commit_positions[*(uint32_t *)_va];
> +       uint32_t b = commit_positions[*(uint32_t *)_vb];

This casting and dereferencing are ok because ...

Show 11 quoted lines

> +static void write_lookup_table(struct hashfile *f,
> +                              struct pack_idx_entry **index,
> +                              uint32_t index_nr,
> +                              off_t *offsets)
> +{
> +       uint32_t i;
> +       uint32_t *table, *table_inv, *commit_positions;
> +
> +       ALLOC_ARRAY(table, writer.selected_nr);
> +       ALLOC_ARRAY(table_inv, writer.selected_nr);
> +       ALLOC_ARRAY(commit_positions, writer.selected_nr);

... `table` is where `_va` and `_vb` will be pointing into.

> +       QSORT_S(table, writer.selected_nr, table_cmp, commit_positions);

I started looking at this casting because of something similar in "pack-bitmap: prepare to read lookup table extension". I'm pointing out this instance just to say that it looks ok to me.

Martin