"Victoria Dye via GitGitGadget" <gitgitgadget@xxxxxxxxx> writes:
> -int convert_to_sparse(struct index_state *istate, int flags)
> +static int can_convert_to_sparse(struct index_state *istate, int flags)
> {
> int test_env;
May not be a problem with this patch, but this variable does not
need to be in this large a scope.
> - if (istate->sparse_index || !istate->cache_nr ||
> - !core_apply_sparse_checkout || !core_sparse_checkout_cone)
> + if (!core_apply_sparse_checkout || !core_sparse_checkout_cone)
> return 0;
>
> if (!istate->repo)
> @@ -187,6 +186,30 @@ int convert_to_sparse(struct index_state *istate, int flags)
> if (cache_tree_update(istate, WRITE_TREE_MISSING_OK))
> return 0;
>
> + return 1;
> +}
> +
> +int convert_to_sparse(struct index_state *istate, int flags)
> +{
> + int verify = flags & SPARSE_INDEX_VERIFY_ALLOWED;
> +
> + /*
> + * If validating with strict checks against whether the sparse index is
> + * allowed, we want to check `can_convert_to_sparse` *before* exiting
> + * early due to an already sparse or empty index.
> + *
> + * If not performing strict validation, the order is reversed to avoid
> + * the more expensive checks in `can_convert_to_sparse` whenver possible.
> + */
> + if (verify) {
> + if (!can_convert_to_sparse(istate, flags))
> + return -1;
> + else if (istate->sparse_index || !istate->cache_nr)
> + return 0;
> + } else if (istate->sparse_index || !istate->cache_nr ||
> + !can_convert_to_sparse(istate, flags))
> + return 0;
> +
> remove_fsmonitor(istate);
>
> trace2_region_enter("index", "convert_to_sparse", istate->repo);
> @@ -313,6 +336,19 @@ void ensure_full_index(struct index_state *istate)
> trace2_region_leave("index", "ensure_full_index", istate->repo);
> }
>
> +void ensure_correct_sparsity(struct index_state *istate)
> +{
> + /*
> + * First check whether the index can be converted to sparse by attempting
> + * to convert it with the SPARSE_INDEX_VERIFY_ALLOWED flag. If the
> + * SPARSE_INDEX_VERIFY_ALLOWED checks indicate that the index cannot
> + * be converted because repository settings and/or index properties
> + * do not allow it, expand the index to full.
> + */
The logic may be OK, but the need to give this long description is a
sign that the meaning of the value returned from the function is not
clear from the name of the function.
> + if (convert_to_sparse(istate, SPARSE_INDEX_VERIFY_ALLOWED))
> + ensure_full_index(istate);
It might make it more straight-forward to
(1) drop the "if (verify)" part in convert_to_sparse(), which would
mean that for all callers convert_to_sparse() will retain the
same behaviour as before;
(2) make a call to can_convert_to_sparse() here, and if that
returns true, make a call to ensure_full_index(); this would
behave identically to what this patch does when can_convert is
false; and
(3) correct the can_convert_to_sparse() function to not blow away
the cache_tree unconditionally and recompute, so that calling
it twice in a row will not be costly.
