Re: [PATCH 5/6] reftable/reader: make table iterator reseekable

> diff --git a/t/unit-tests/t-reftable-merged.c b/t/unit-tests/t-reftable-merged.c
> index b8c92fdb365..19e54bdfb8b 100644
> --- a/t/unit-tests/t-reftable-merged.c
> +++ b/t/unit-tests/t-reftable-merged.c
> @@ -194,6 +194,81 @@ static void t_merged_refs(void)
>  	reftable_free(bs);
>  }
>
> +static void t_merged_seek_multiple_times(void)
> +{
> +	struct reftable_ref_record r1[] = {
> +		{
> +			.refname = (char *) "a",
> +			.update_index = 1,
> +			.value_type = REFTABLE_REF_VAL1,
> +			.value.val1 = { 1 },
> +		},
> +		{
> +			.refname = (char *) "c",
> +			.update_index = 1,
> +			.value_type = REFTABLE_REF_VAL1,
> +			.value.val1 = { 2 },
> +		}
> +	};
> +	struct reftable_ref_record r2[] = {
> +		{
> +			.refname = (char *) "b",
> +			.update_index = 2,
> +			.value_type = REFTABLE_REF_VAL1,
> +			.value.val1 = { 3 },
> +		},
> +		{
> +			.refname = (char *) "d",
> +			.update_index = 2,
> +			.value_type = REFTABLE_REF_VAL1,
> +			.value.val1 = { 4 },
> +		},
> +	};
> +	struct reftable_ref_record *refs[] = {
> +		r1, r2,
> +	};
> +	size_t sizes[] = {
> +		ARRAY_SIZE(r1), ARRAY_SIZE(r2),
> +	};
> +	struct strbuf bufs[] = {
> +		STRBUF_INIT, STRBUF_INIT,
> +	};
> +	struct reftable_block_source *sources = NULL;
> +	struct reftable_reader **readers = NULL;
> +	struct reftable_ref_record rec = { 0 };
> +	struct reftable_iterator it = { 0 };
> +	struct reftable_merged_table *mt;
> +
> +	mt = merged_table_from_records(refs, &sources, &readers, sizes, bufs, 2);
> +	merged_table_init_iter(mt, &it, BLOCK_TYPE_REF);
> +
> +	for (size_t i = 0; i < 5; i++) {
> +		int err = reftable_iterator_seek_ref(&it, "c");
> +		check(!err);
> +
> +		err = reftable_iterator_next_ref(&it, &rec);
> +		check(!err);
> +		err = reftable_ref_record_equal(&rec, &r1[1], GIT_SHA1_RAWSZ);
> +		check(err == 1);
> +
> +		err = reftable_iterator_next_ref(&it, &rec);
> +		check(!err);
> +		err = reftable_ref_record_equal(&rec, &r2[1], GIT_SHA1_RAWSZ);
> +		check(err == 1);
> +

> diff --git a/t/unit-tests/t-reftable-reader.c b/t/unit-tests/t-reftable-reader.c
> new file mode 100644
> index 00000000000..7a46580b6f1
> --- /dev/null
> +++ b/t/unit-tests/t-reftable-reader.c
> @@ -0,0 +1,96 @@
> +#include "test-lib.h"
> +#include "lib-reftable.h"
> +#include "reftable/blocksource.h"
> +#include "reftable/reader.h"
> +
> +static int t_reader_seek_once(void)
> +{
> +	struct reftable_ref_record records[] = {
> +		{
> +			.refname = (char *) "refs/heads/main",
> +			.value_type = REFTABLE_REF_VAL1,
> +			.value.val1 = { 42 },
> +		},
> +	};
> +	struct reftable_block_source source = { 0 };
> +	struct reftable_ref_record ref = { 0 };
> +	struct reftable_iterator it = { 0 };
> +	struct reftable_reader *reader;
> +	struct strbuf buf = STRBUF_INIT;
> +	int ret;
> +
> +	t_reftable_write_to_buf(&buf, records, ARRAY_SIZE(records), NULL, 0, NULL);
> +	block_source_from_strbuf(&source, &buf);
> +
> +	ret = reftable_reader_new(&reader, &source, "name");
> +	check_int(ret, ==, 0);
> +
> +	reftable_reader_init_ref_iterator(reader, &it);
> +	ret = reftable_iterator_seek_ref(&it, "");
> +	check_int(ret, ==, 0);
> +	ret = reftable_iterator_next_ref(&it, &ref);
> +	check_int(ret, ==, 0);
> +
> +	ret = reftable_ref_record_equal(&ref, &records[0], 20);