On 26/08/19 03:19PM, Karthik Nayak wrote:
> In 80e7342ea8 (reftable/stack: allow locking of outdated stacks,
> 2024年09月24日), the `REFTABLE_STACK_NEW_ADDITION_RELOAD` was introduced so
> that callers of `reftable_stack_init_addition()` can also reload the
> stack if there was a concurrent update made before the lock was
> obtained.
>
> Then 16684b6fae (refs/reftable: always reload stacks when creating
> lock, 2025年08月12日) updated all of the remaining call-sites to propagate
> this flag to ensure that we always reload the stack whenever there was a
> concurrent update.
Ok, if all call sites already wire this flag, then we probably don't
need if anymore.
> As all calls to `reftable_stack_init_addition()` inevitably propagate
> the flag, it is safe to remove the flag and its associated code and make
> the reloading of the stack the default flow. This makes it easier to
> follow the flow and simplifies the logic.
Makes sense.
> The only exceptions are:
>
> 1. Unit tests, where we explicitly do not propagate the flag. These
> tests are now modified with the new status quo.
I assume this means we no longer need to test for the case where we
don't reload.
> 2. `reftable_stack_clean_locked()`, which was propagating 0 to
Did you mean `reftable_stack_clean()`?
> `reftable_stack_new_addition()` but was then manually reloading the
> stack after. Here the new flow will achieve the same, while also
> allowing us to remove the manual reload.
Out of curiousity, was this call site just forgotten previously? Or was
there any reason a manual reload was useful?
> This also makes two checks for 'REFTABLE_OUTDATED_ERROR' redundant, so
> remove them also.
>
> Signed-off-by: Karthik Nayak <karthik.188@xxxxxxxxx>
> ---
[snip]
> diff --git a/reftable/reftable-stack.h b/reftable/reftable-stack.h
> index 5d22d84e80..5d224f8079 100644
> --- a/reftable/reftable-stack.h
> +++ b/reftable/reftable-stack.h
> @@ -58,22 +58,13 @@ uint64_t reftable_stack_next_update_index(struct reftable_stack *st);
> /* holds a transaction to add tables at the top of a stack. */
> struct reftable_addition;
>
> -enum {
> - /*
> - * Reload the stack when the stack is out-of-date after locking it.
> - */
> - REFTABLE_STACK_NEW_ADDITION_RELOAD = (1 << 0),
> -};
The flag is dropped now that it is the only behavior.
> /*
> * returns a new transaction to add reftables to the given stack. As a side
> - * effect, the ref database is locked. Accepts REFTABLE_STACK_NEW_ADDITION_*
> - * flags.
> + * effect, the ref database is locked.
> */
> int reftable_stack_new_addition(struct reftable_addition **dest,
> struct reftable_stack *st,
> - const struct reftable_write_options *opts,
> - unsigned int flags);
> + const struct reftable_write_options *opts);
Signatures updated. Ok.
[snip]
> diff --git a/reftable/stack.c b/reftable/stack.c
> index 308f9578f0..540f5e77ac 100644
> --- a/reftable/stack.c
> +++ b/reftable/stack.c
> @@ -659,8 +659,7 @@ static void reftable_addition_close(struct reftable_addition *add)
>
> static int reftable_stack_init_addition(struct reftable_addition *add,
> struct reftable_stack *st,
> - const struct reftable_write_options *opts,
> - unsigned int flags)
> + const struct reftable_write_options *opts)
> {
> struct reftable_buf lock_file_name = REFTABLE_BUF_INIT;
> int err;
> @@ -686,15 +685,11 @@ static int reftable_stack_init_addition(struct reftable_addition *add,
> err = stack_uptodate(st);
> if (err < 0)
> goto done;
> - if (err > 0 && flags & REFTABLE_STACK_NEW_ADDITION_RELOAD) {
> + if (err > 0) {
> err = reftable_stack_reload_maybe_reuse(add->stack, 1);
> if (err)
> goto done;
> }
> - if (err > 0) {
> - err = REFTABLE_OUTDATED_ERROR;
> - goto done;
> - }
`reftable_stack_init_addition()` now reload unconditionally. Looks good.
> add->next_update_index = reftable_stack_next_update_index(st);
> done:
> @@ -708,13 +703,12 @@ static int stack_try_add(struct reftable_stack *st,
> int (*write_table)(struct reftable_writer *wr,
> void *arg),
> void *arg,
> - const struct reftable_write_options *opts,
> - unsigned flags)
> + const struct reftable_write_options *opts)
> {
> struct reftable_addition add;
> int err;
>
> - err = reftable_stack_init_addition(&add, st, opts, flags);
> + err = reftable_stack_init_addition(&add, st, opts);
> if (err < 0)
> goto done;
>
> @@ -731,17 +725,10 @@ static int stack_try_add(struct reftable_stack *st,
> int reftable_stack_add(struct reftable_stack *st,
> int (*write)(struct reftable_writer *wr, void *arg),
> void *arg,
> - const struct reftable_write_options *opts,
> - unsigned flags)
> + const struct reftable_write_options *opts)
> {
> - int err = stack_try_add(st, write, arg, opts, flags);
> + int err = stack_try_add(st, write, arg, opts);
> if (err < 0) {
> - if (err == REFTABLE_OUTDATED_ERROR) {
> - /* Ignore error return, we want to propagate
> - REFTABLE_OUTDATED_ERROR.
> - */
> - reftable_stack_reload(st);
> - }
Since we always reload now, the REFTABLE_OUTDATED_ERROR is no longer a
possibility and doesn't need to be handled anymore.
[snip]
> diff --git a/t/unit-tests/u-reftable-stack.c b/t/unit-tests/u-reftable-stack.c
> index e6c1635940..c6254190e6 100644
> --- a/t/unit-tests/u-reftable-stack.c
> +++ b/t/unit-tests/u-reftable-stack.c
> @@ -127,7 +127,7 @@ static void write_n_ref_tables(struct reftable_stack *st,
> cl_reftable_set_hash(ref.value.val1, i, REFTABLE_HASH_SHA1);
>
> cl_assert_equal_i(reftable_stack_add(st,
> - &write_test_ref, &ref, &opts, 0), 0);
> + &write_test_ref, &ref, &opts), 0);
> }
> }
>
> @@ -168,7 +168,7 @@ void test_reftable_stack__add_one(void)
> err = reftable_new_stack(&st, dir, NULL);
> cl_assert(!err);
>
> - err = reftable_stack_add(st, write_test_ref, &ref, &opts, 0);
> + err = reftable_stack_add(st, write_test_ref, &ref, &opts);
> cl_assert(!err);
>
> err = reftable_stack_read_ref(st, ref.refname, &dest);
> @@ -231,12 +231,9 @@ void test_reftable_stack__uptodate(void)
> cl_assert_equal_i(reftable_new_stack(&st1, dir, NULL), 0);
> cl_assert_equal_i(reftable_new_stack(&st2, dir, NULL), 0);
> cl_assert_equal_i(reftable_stack_add(st1, write_test_ref,
> - &ref1, NULL, 0), 0);
> + &ref1, NULL), 0);
> cl_assert_equal_i(reftable_stack_add(st2, write_test_ref,
> - &ref2, NULL, 0), REFTABLE_OUTDATED_ERROR);
> - cl_assert_equal_i(reftable_stack_reload(st2), 0);
> - cl_assert_equal_i(reftable_stack_add(st2, write_test_ref,
> - &ref2, NULL, 0), 0);
> + &ref2, NULL), 0);
We no longer need to check for REFTABLE_OUTDATED_ERROR since the stack
is always reloaded now. Makes sense.
> reftable_stack_destroy(st1);
> reftable_stack_destroy(st2);
> clear_dir(dir);
> @@ -260,7 +257,7 @@ void test_reftable_stack__transaction_api(void)
>
> reftable_addition_destroy(add);
>
> - cl_assert_equal_i(reftable_stack_new_addition(&add, st, NULL, 0), 0);
> + cl_assert_equal_i(reftable_stack_new_addition(&add, st, NULL), 0);
> cl_assert_equal_i(reftable_addition_add(add, write_test_ref,
> &ref), 0);
> cl_assert_equal_i(reftable_addition_commit(add), 0);
> @@ -301,21 +298,17 @@ void test_reftable_stack__transaction_with_reload(void)
>
> cl_assert_equal_i(reftable_new_stack(&st1, dir, NULL), 0);
> cl_assert_equal_i(reftable_new_stack(&st2, dir, NULL), 0);
> - cl_assert_equal_i(reftable_stack_new_addition(&add, st1, NULL, 0), 0);
> + cl_assert_equal_i(reftable_stack_new_addition(&add, st1, NULL), 0);
> cl_assert_equal_i(reftable_addition_add(add, write_test_ref,
> &refs[0]), 0);
> cl_assert_equal_i(reftable_addition_commit(add), 0);
> reftable_addition_destroy(add);
>
> /*
> - * The second stack is now outdated, which we should notice. We do not
> - * create the addition and lock the stack by default, but allow the
> - * reload to happen when REFTABLE_STACK_NEW_ADDITION_RELOAD is set.
> + * The second stack is now outdated, but it should automatically reload it
> + * with the newer updates.
> */
> - cl_assert_equal_i(reftable_stack_new_addition(&add, st2, NULL, 0),
> - REFTABLE_OUTDATED_ERROR);
> - cl_assert_equal_i(reftable_stack_new_addition(&add, st2, NULL,
> - REFTABLE_STACK_NEW_ADDITION_RELOAD), 0);
> + cl_assert_equal_i(reftable_stack_new_addition(&add, st2, NULL), 0);
Same here.
The rest of this patch is just updating call sites and looks good.
-Justin