diff mbox series

[v5,15/17] sparse-checkout: update working directory in-process

Message ID d7af75672ba20ed208d51a35243b96ce10202a54.1571666187.git.gitgitgadget@gmail.com (mailing list archive)
State New, archived
Headers show
Series New sparse-checkout builtin and "cone" mode | expand

Commit Message

Johannes Schindelin via GitGitGadget Oct. 21, 2019, 1:56 p.m. UTC 
From: Derrick Stolee <dstolee@microsoft.com>

The sparse-checkout builtin used 'git read-tree -mu HEAD' to update the
skip-worktree bits in the index and to update the working directory.
This extra process is overly complex, and prone to failure. It also
requires that we write our changes to the sparse-checkout file before
trying to update the index.

Remove this extra process call by creating a direct call to
unpack_trees() in the same way 'git read-tree -mu HEAD' does. In
addition, provide an in-memory list of patterns so we can avoid
reading from the sparse-checkout file. This allows us to test a
proposed change to the file before writing to it.

An earlier version of this patch included a bug when the 'set' command
failed due to the "Sparse checkout leaves no entry on working directory"
error. It would not rollback the index.lock file, so the replay of the
old sparse-checkout specification would fail. A test in t1091 now
covers that scenario.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
---
 builtin/read-tree.c                |  2 +-
 builtin/sparse-checkout.c          | 83 +++++++++++++++++++++++++-----
 t/t1091-sparse-checkout-builtin.sh | 28 ++++++++++
 unpack-trees.c                     |  5 +-
 unpack-trees.h                     |  3 +-
 5 files changed, 105 insertions(+), 16 deletions(-)

Comments

SZEDER Gábor Nov. 19, 2019, 5:07 p.m. UTC | #1 
On Mon, Oct 21, 2019 at 01:56:24PM +0000, Derrick Stolee via GitGitGadget wrote:
> From: Derrick Stolee <dstolee@microsoft.com>
> 
> The sparse-checkout builtin used 'git read-tree -mu HEAD' to update the
> skip-worktree bits in the index and to update the working directory.
> This extra process is overly complex, and prone to failure. It also
> requires that we write our changes to the sparse-checkout file before
> trying to update the index.
> 
> Remove this extra process call by creating a direct call to
> unpack_trees() in the same way 'git read-tree -mu HEAD' does. In
> addition, provide an in-memory list of patterns so we can avoid
> reading from the sparse-checkout file.

OK, the way I understand the above two paragraphs is that after this
patch it won't be necessary to write the updated patterns to the
'sparse-checkout' file before calling unpack_trees(), and to me it
implies that it won't be necessary to write the "include everything"
pattern to that file during disabling sparse checkout.

> @@ -378,7 +436,8 @@ static int sparse_checkout_disable(int argc, const char **argv)
>  	fprintf(fp, "/*\n");
>  	fclose(fp);

However, as the patch context here shows we still write that "include
everything" pattern to the 'sparse-checkout' file during disabling.

FWIW, deleting those lines updating the 'sparse-checkout' file make
the 'sparse-checkout disable' test fail.

Did I misunderstand what the commit message is trying to say?

> -	if (update_working_directory())
> +	core_apply_sparse_checkout = 1;
> +	if (update_working_directory(NULL))
>  		die(_("error while refreshing working directory"));
>  
>  	unlink(sparse_filename);
diff mbox series

Patch

diff --git a/builtin/read-tree.c b/builtin/read-tree.c
index 69963d83dc..d7eeaa26ec 100644
--- a/builtin/read-tree.c
+++ b/builtin/read-tree.c
@@ -186,7 +186,7 @@  int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
 
 	if (opts.reset || opts.merge || opts.prefix) {
 		if (read_cache_unmerged() && (opts.prefix || opts.merge))
-			die("You need to resolve your current index first");
+			die(_("You need to resolve your current index first"));
 		stage = opts.merge = 1;
 	}
 	resolve_undo_clear();
diff --git a/builtin/sparse-checkout.c b/builtin/sparse-checkout.c
index b02e085495..ea2e7ee51b 100644
--- a/builtin/sparse-checkout.c
+++ b/builtin/sparse-checkout.c
@@ -7,6 +7,11 @@ 
 #include "run-command.h"
 #include "strbuf.h"
 #include "string-list.h"
+#include "cache.h"
+#include "cache-tree.h"
+#include "lockfile.h"
+#include "resolve-undo.h"
+#include "unpack-trees.h"
 
 static char const * const builtin_sparse_checkout_usage[] = {
 	N_("git sparse-checkout (init|list|set|disable) <options>"),
@@ -60,18 +65,54 @@  static int sparse_checkout_list(int argc, const char **argv)
 	return 0;
 }
 
-static int update_working_directory(void)
+static int update_working_directory(struct pattern_list *pl)
 {
-	struct argv_array argv = ARGV_ARRAY_INIT;
 	int result = 0;
-	argv_array_pushl(&argv, "read-tree", "-m", "-u", "HEAD", NULL);
+	struct unpack_trees_options o;
+	struct lock_file lock_file = LOCK_INIT;
+	struct object_id oid;
+	struct tree *tree;
+	struct tree_desc t;
+	struct repository *r = the_repository;
 
-	if (run_command_v_opt(argv.argv, RUN_GIT_CMD)) {
-		error(_("failed to update index with new sparse-checkout paths"));
-		result = 1;
-	}
+	if (repo_read_index_unmerged(r))
+		die(_("You need to resolve your current index first"));
+
+	if (get_oid("HEAD", &oid))
+		return 0;
+
+	tree = parse_tree_indirect(&oid);
+	parse_tree(tree);
+	init_tree_desc(&t, tree->buffer, tree->size);
+
+	memset(&o, 0, sizeof(o));
+	o.verbose_update = isatty(2);
+	o.merge = 1;
+	o.update = 1;
+	o.fn = oneway_merge;
+	o.head_idx = -1;
+	o.src_index = r->index;
+	o.dst_index = r->index;
+	o.skip_sparse_checkout = 0;
+	o.pl = pl;
+	o.keep_pattern_list = !!pl;
+
+	resolve_undo_clear_index(r->index);
+	setup_work_tree();
+
+	cache_tree_free(&r->index->cache_tree);
+
+	repo_hold_locked_index(r, &lock_file, LOCK_DIE_ON_ERROR);
+
+	core_apply_sparse_checkout = 1;
+	result = unpack_trees(1, &t, &o);
+
+	if (!result) {
+		prime_cache_tree(r, r->index, tree);
+		write_locked_index(r->index, &lock_file, COMMIT_LOCK);
+	} else
+		rollback_lock_file(&lock_file);
 
-	argv_array_clear(&argv);
 	return result;
 }
 
@@ -147,7 +188,11 @@  static int sparse_checkout_init(int argc, const char **argv)
 			     builtin_sparse_checkout_init_options,
 			     builtin_sparse_checkout_init_usage, 0);
 
-	mode = init_opts.cone_mode ? MODE_CONE_PATTERNS : MODE_ALL_PATTERNS;
+	if (init_opts.cone_mode) {
+		mode = MODE_CONE_PATTERNS;
+		core_sparse_checkout_cone = 1;
+	} else
+		mode = MODE_ALL_PATTERNS;
 
 	if (sc_set_config(mode))
 		return 1;
@@ -175,7 +220,8 @@  static int sparse_checkout_init(int argc, const char **argv)
 	}
 
 reset_dir:
-	return update_working_directory();
+	core_apply_sparse_checkout = 1;
+	return update_working_directory(NULL);
 }
 
 static void insert_recursive_pattern(struct pattern_list *pl, struct strbuf *path)
@@ -260,6 +306,15 @@  static int write_patterns_and_update(struct pattern_list *pl)
 {
 	char *sparse_filename;
 	FILE *fp;
+	int result;
+
+	result = update_working_directory(pl);
+
+	if (result) {
+		clear_pattern_list(pl);
+		update_working_directory(NULL);
+		return result;
+	}
 
 	sparse_filename = get_sparse_checkout_filename();
 	fp = fopen(sparse_filename, "w");
@@ -270,9 +325,11 @@  static int write_patterns_and_update(struct pattern_list *pl)
 		write_patterns_to_file(fp, pl);
 
 	fclose(fp);
+
 	free(sparse_filename);
+	clear_pattern_list(pl);
 
-	return update_working_directory();
+	return 0;
 }
 
 static void strbuf_to_cone_pattern(struct strbuf *line, struct pattern_list *pl)
@@ -324,6 +381,7 @@  static int sparse_checkout_set(int argc, const char **argv, const char *prefix)
 		struct strbuf line = STRBUF_INIT;
 		hashmap_init(&pl.recursive_hashmap, pl_hashmap_cmp, NULL, 0);
 		hashmap_init(&pl.parent_hashmap, pl_hashmap_cmp, NULL, 0);
+		pl.use_cone_patterns = 1;
 
 		if (set_opts.use_stdin) {
 			while (!strbuf_getline(&line, stdin))
@@ -378,7 +436,8 @@  static int sparse_checkout_disable(int argc, const char **argv)
 	fprintf(fp, "/*\n");
 	fclose(fp);
 
-	if (update_working_directory())
+	core_apply_sparse_checkout = 1;
+	if (update_working_directory(NULL))
 		die(_("error while refreshing working directory"));
 
 	unlink(sparse_filename);
diff --git a/t/t1091-sparse-checkout-builtin.sh b/t/t1091-sparse-checkout-builtin.sh
index 0792caeb7e..a580b79595 100755
--- a/t/t1091-sparse-checkout-builtin.sh
+++ b/t/t1091-sparse-checkout-builtin.sh
@@ -248,4 +248,32 @@  test_expect_success 'cone mode: set with nested folders' '
 	test_cmp repo/.git/info/sparse-checkout expect
 '
 
+test_expect_success 'revert to old sparse-checkout on bad update' '
+	echo update >repo/deep/deeper2/a &&
+	cp repo/.git/info/sparse-checkout expect &&
+	test_must_fail git -C repo sparse-checkout set deep/deeper1 2>err &&
+	test_i18ngrep "Cannot update sparse checkout" err &&
+	test_cmp repo/.git/info/sparse-checkout expect &&
+	ls repo/deep >dir &&
+	cat >expect <<-EOF &&
+		a
+		deeper1
+		deeper2
+	EOF
+	test_cmp dir expect
+'
+
+test_expect_success 'revert to old sparse-checkout on empty update' '
+	git init empty-test &&
+	(
+		echo >file &&
+		git add file &&
+		git commit -m "test" &&
+		test_must_fail git sparse-checkout set nothing 2>err &&
+		test_i18ngrep "Sparse checkout leaves no entry on working directory" err &&
+		test_i18ngrep ! ".git/index.lock" err &&
+		git sparse-checkout set file
+	)
+'
+
 test_done
diff --git a/unpack-trees.c b/unpack-trees.c
index 8bb684ad62..3789a22cf0 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -1511,7 +1511,7 @@  int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 	memset(&pl, 0, sizeof(pl));
 	if (!core_apply_sparse_checkout || !o->update)
 		o->skip_sparse_checkout = 1;
-	if (!o->skip_sparse_checkout) {
+	if (!o->skip_sparse_checkout && !o->pl) {
 		char *sparse = git_pathdup("info/sparse-checkout");
 		pl.use_cone_patterns = core_sparse_checkout_cone;
 		if (add_patterns_from_file_to_list(sparse, "", 0, &pl, NULL) < 0)
@@ -1684,7 +1684,8 @@  int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 
 done:
 	trace_performance_leave("unpack_trees");
-	clear_pattern_list(&pl);
+	if (!o->keep_pattern_list)
+		clear_pattern_list(&pl);
 	return ret;
 
 return_failed:
diff --git a/unpack-trees.h b/unpack-trees.h
index f2eee0c7c5..ca94a421a5 100644
--- a/unpack-trees.h
+++ b/unpack-trees.h
@@ -59,7 +59,8 @@  struct unpack_trees_options {
 		     quiet,
 		     exiting_early,
 		     show_all_errors,
-		     dry_run;
+		     dry_run,
+		     keep_pattern_list;
 	const char *prefix;
 	int cache_bottom;
 	struct dir_struct *dir;