Shuqi Liang wrote:
> Update 'git write-tree' to allow using the sparse-index in memory
> without expanding to a full one.
>
> The recursive algorithm for update_one() was already updated in 2de37c5
> (cache-tree: integrate with sparse directory entries, 2021-03-03) to
> handle sparse directory entries in the index. Hence we can just set the
> requires-full-index to false for "write-tree".
>
> The `p2000` tests demonstrate a ~96% execution time reduction for 'git
> write-tree' using a sparse index:
>
> Test before after
> -----------------------------------------------------------------
> 2000.78: git write-tree (full-v3) 0.34 0.33 -2.9%
> 2000.79: git write-tree (full-v4) 0.32 0.30 -6.3%
> 2000.80: git write-tree (sparse-v3) 0.47 0.02 -95.8%
> 2000.81: git write-tree (sparse-v4) 0.45 0.02 -95.6%
Please update your commit message to explain only the incremental updates on
top of 1a65b41b38a (write-tree: integrate with sparse index, 2023-04-03);
that patch's message (what you have here) does not accurately describe what
_this_ patch is doing.
> diff --git a/builtin/write-tree.c b/builtin/write-tree.c
> index 32e302a813..a9d5c20cde 100644
> --- a/builtin/write-tree.c
> +++ b/builtin/write-tree.c
> @@ -38,12 +38,15 @@ int cmd_write_tree(int argc, const char **argv, const char *cmd_prefix)
> };
>
> git_config(git_default_config, NULL);
> +
> + if (the_repository->gitdir) {
> + prepare_repo_settings(the_repository);
> + the_repository->settings.command_requires_full_index = 0;
> + }
> +
> argc = parse_options(argc, argv, cmd_prefix, write_tree_options,
> write_tree_usage, 0);
>
> - prepare_repo_settings(the_repository);
> - the_repository->settings.command_requires_full_index = 0;
> -
What is the functional benefit of this change? AFAICT, we don't need
'command_requires_full_index' to be set before 'parse_options' in this case,
so this won't have any effect on the behavior of 'write-tree'.
> diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
> index 9bbc0d646b..d3eb31326b 100755
> --- a/t/t1092-sparse-checkout-compatibility.sh
> +++ b/t/t1092-sparse-checkout-compatibility.sh
> @@ -2055,22 +2055,32 @@ test_expect_success 'grep sparse directory within submodules' '
> test_cmp actual expect
> '
>
> -test_expect_success 'write-tree on all' '
> +test_expect_success 'write-tree' '
> init_repos &&
>
> + test_all_match git write-tree &&
> +
> write_script edit-contents <<-\EOF &&
> echo text >>"$1"
> EOF
>
> + # make a change inside the sparse cone
> run_on_all ../edit-contents deep/a &&
> - run_on_all git update-index deep/a &&
> + test_all_match git update-index deep/a &&
> test_all_match git write-tree &&
> + test_all_match git status --porcelain=v2 &&
>
> + # make a change outside the sparse cone
> run_on_all mkdir -p folder1 &&
> run_on_all cp a folder1/a &&
> run_on_all ../edit-contents folder1/a &&
> - run_on_all git update-index folder1/a &&
> - test_all_match git write-tree
> + test_all_match git update-index folder1/a &&
> + test_all_match git write-tree &&
> + test_all_match git status --porcelain=v2 &&
> +
> + # check that SKIP_WORKTREE files are not materialized
> + test_path_is_missing sparse-checkout/folder2/a &&
> + test_path_is_missing sparse-index/folder2/a
Test updates look good!
> '
>
> test_expect_success 'sparse-index is not expanded: write-tree' '
> @@ -2080,7 +2090,7 @@ test_expect_success 'sparse-index is not expanded: write-tree' '
>
> echo "test1" >>sparse-index/a &&
> git -C sparse-index update-index a &&
> - ensure_not_expanded write-tree
> + ensure_not_expanded write-tree
nit: trailing whitespace should be removed
> '
>
> test_done
