Subject: Re: [PATCH 09/10] t-reftable-block: add tests for obj blocks

From: Patrick Steinhardt <[email-masked]>
Date: Fri, 16 Aug 2024 09:44:56 +0200

On Fri, Aug 16, 2024 at 12:41:34AM +0530, Chandra Pratap wrote:
> On Thu, 15 Aug 2024 at 15:11, Patrick Steinhardt <[email-masked]> wrote:
> >
> > On Wed, Aug 14, 2024 at 05:33:17PM +0530, Chandra Pratap wrote:
> > > In the current testing setup, block operations are left unexercised
> > > for obj blocks. Add a test that exercises these operations for obj
> > > blocks.
> >
> > Same remarks here as for the preceding commit.
> >
> > > @@ -186,9 +186,88 @@ static void t_log_block_read_write(void)
> > >               reftable_record_release(&recs[i]);
> > >  }
> > >
> > > +static void t_obj_block_read_write(void)
> > > +{
> > > +     const int header_off = 21;
> > > +     struct reftable_record recs[30];
> > > +     const size_t N = ARRAY_SIZE(recs);
> > > +     const size_t block_size = 1024;
> > > +     struct reftable_block block = { 0 };
> > > +     struct block_writer bw = {
> > > +             .last_key = STRBUF_INIT,
> > > +     };
> > > +     struct reftable_record rec = {
> > > +             .type = BLOCK_TYPE_OBJ,
> > > +     };
> > > +     size_t i = 0;
> > > +     int n;
> > > +     struct block_reader br = { 0 };
> > > +     struct block_iter it = BLOCK_ITER_INIT;
> > > +     struct strbuf want = STRBUF_INIT;
> > > +
> > > +     REFTABLE_CALLOC_ARRAY(block.data, block_size);
> > > +     block.len = block_size;
> > > +     block.source = malloc_block_source();
> > > +     block_writer_init(&bw, BLOCK_TYPE_OBJ, block.data, block_size,
> > > +                       header_off, hash_size(GIT_SHA1_FORMAT_ID));
> > > +
> > > +     for (i = 0; i < N; i++) {
> > > +             uint8_t *bytes = reftable_malloc(sizeof(uint8_t[5]));
> > > +             memcpy(bytes, (uint8_t[]){i, i+1, i+2, i+3, i+5}, sizeof(uint8_t[5]));
> >
> > From the top of my head I'm not sure whether we use inline-array
> > declarations like this anywhere. I'd rather just make it a separate
> > variable, which also allows us to get rid of the magic 5 via
> > `ARRAY_SIZE()`.
> 
> We _do_ use inline array declarations like this, here's an example from
> t/unit-tests/t-prio-queue.c:
> TEST(TEST_INPUT(((int []){ STACK, 1, 2, 3, 4, 5, 6, REVERSE, DUMP }),
>           ((int []){ 1, 2, 3, 4, 5, 6 })), "prio-queue works when LIFO
> stack is reversed");
> 
> I did implement bytes[] as a local variable array when I first worked
> on this patch but that turned out to be tricky due to variable scoping
> and pointer semantics, so I ultimately settled on this approach.

Oh, I didn't mean to say that you should _only_ use the local array.
Rather something like this:

        uint8_t[] bytes = { i, i + 1, i + 2, i + 3, i + 5 }, *allocated;
        DUP_ARRAY(allocated, bytes, ARRAY_SIZE(bytes));

Patrick