git/list[1] front-page[2] threads[3] people[4] search[5] about
 

[PATCH v2 3/3] builtin/commit-graph.c: support '--input=none'

From
Taylor Blau <me@ttaylorr.com>
Date
Feb 5, 2020, 00:28 UTC
Message-ID
<4c6425f0da9a6e5ae86530a12f18959ada07404b.1580862307.git.me@ttaylorr.com>
In-Reply-To
<cover.1580862307.git.me@ttaylorr.com>

In the previous commit, we introduced '--split=<no-merge|merge-all>', and alluded to the fact that '--split=merge-all' would be useful for callers who wish to always trigger a merge of an incremental chain.

There is a problem with the above approach, which is that there is no way to specify to the commit-graph builtin that a caller only wants to include commits already in the graph. One can specify '--input=append' to include all commits in the existing graphs, but the absence of '--input=stdin-{commits,packs}' causes the builtin to call 'fill_oids_from_all_packs()'.

Passing '--input=reachable' (as in 'git commit-graph write --split=merge-all --input=reachable --input=append') works around this issue by making '--input=reachable' effectively a no-op, but this can be prohibitively expensive in large repositories, making it an undesirable choice for some users.

Teach '--input=none' as an option to behave as if '--input=append' were given, but to consider no other sources in addition.

This, in conjunction with the option introduced in the previous patch offers the convenient way to force the commit-graph machinery to condense a chain of incrementals without requiring any new commits:

  $ git commit-graph write --split=merge-all --input=none
Signed-off-by: Taylor Blau <me@ttaylorr.com>
---
 Documentation/git-commit-graph.txt |  8 +++++++-
 builtin/commit-graph.c             | 11 ++++++++---
 commit-graph.c                     |  6 ++++--
 commit-graph.h                     |  3 ++-
 t/t5324-split-commit-graph.sh      | 26 ++++++++++++++++++++++++++
 5 files changed, 47 insertions(+), 7 deletions(-)
diff --git a/Documentation/git-commit-graph.txt b/Documentation/git-commit-graph.txt
index 2ae9de679a..633cfbe023 100644
--- a/Documentation/git-commit-graph.txt
+++ b/Documentation/git-commit-graph.txt
@@ -39,7 +39,7 @@ COMMANDS
 --------
 'write'::
 
-Write a commit-graph file based on the commits found in packfiles.
+Write a commit-graph file based on the specified sources of input:
 +
 With the `--input=stdin-packs` option, generate the new commit graph by
 walking objects only in the specified pack-indexes. (Cannot be combined
@@ -57,6 +57,12 @@ walking commits starting at all refs. (Cannot be combined with
 With the `--input=append` option, include all commits that are present
 in the existing commit-graph file.
 +
+With the `--input=none` option, behave as if `--input=append` were
+given, but do not walk other packs to find additional commits.
+
+If none of the above options are given, then generate the new
+commit-graph by walking over all pack-indexes.
++
 With the `--split[=<strategy>]` option, write the commit-graph as a
 chain of multiple commit-graph files stored in
 `<dir>/info/commit-graphs`. Commit-graph layers are merged based on the
diff --git a/builtin/commit-graph.c b/builtin/commit-graph.c
index 0ff25896d0..a71af88815 100644
--- a/builtin/commit-graph.c
+++ b/builtin/commit-graph.c
@@ -11,7 +11,7 @@ static char const * const builtin_commit_graph_usage[] = {
 	N_("git commit-graph verify [--object-dir <objdir>] [--shallow] [--[no-]progress]"),
 	N_("git commit-graph write [--object-dir <objdir>] "
 	   "[--split[=<strategy>]] "
-	   "[--input=<reachable|stdin-packs|stdin-commits|append>] "
+	   "[--input=<reachable|stdin-packs|stdin-commits|append|none>] "
 	   "[--[no-]progress] <split options>"),
 	NULL
 };
@@ -24,7 +24,7 @@ static const char * const builtin_commit_graph_verify_usage[] = {
 static const char * const builtin_commit_graph_write_usage[] = {
 	N_("git commit-graph write [--object-dir <objdir>] "
 	   "[--split[=<strategy>]] "
-	   "[--input=<reachable|stdin-packs|stdin-commits|append>] "
+	   "[--input=<reachable|stdin-packs|stdin-commits|append|none>] "
 	   "[--[no-]progress] <split options>"),
 	NULL
 };
@@ -33,7 +33,8 @@ enum commit_graph_input {
 	COMMIT_GRAPH_INPUT_REACHABLE     = (1 << 1),
 	COMMIT_GRAPH_INPUT_STDIN_PACKS   = (1 << 2),
 	COMMIT_GRAPH_INPUT_STDIN_COMMITS = (1 << 3),
-	COMMIT_GRAPH_INPUT_APPEND        = (1 << 4)
+	COMMIT_GRAPH_INPUT_APPEND        = (1 << 4),
+	COMMIT_GRAPH_INPUT_NONE          = (1 << 5)
 };
 
 static struct opts_commit_graph {
@@ -80,6 +81,8 @@ static int option_parse_input(const struct option *opt, const char *arg,
 		*to |= COMMIT_GRAPH_INPUT_STDIN_COMMITS;
 	else if (!strcmp(arg, "append"))
 		*to |= COMMIT_GRAPH_INPUT_APPEND;
+	else if (!strcmp(arg, "none"))
+		*to |= (COMMIT_GRAPH_INPUT_APPEND | COMMIT_GRAPH_INPUT_NONE);
 	else
 		die(_("unrecognized --input source, %s"), arg);
 	return 0;
@@ -225,6 +228,8 @@ static int graph_write(int argc, const char **argv)
 		opts.obj_dir = get_object_directory();
 	if (opts.input & COMMIT_GRAPH_INPUT_APPEND)
 		flags |= COMMIT_GRAPH_WRITE_APPEND;
+	if (opts.input & COMMIT_GRAPH_INPUT_NONE)
+		flags |= COMMIT_GRAPH_WRITE_NO_INPUT;
 	if (opts.split)
 		flags |= COMMIT_GRAPH_WRITE_SPLIT;
 	if (opts.progress)
diff --git a/commit-graph.c b/commit-graph.c
index 3a5cb23cd7..417b7eac9c 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -788,7 +788,8 @@ struct write_commit_graph_context {
 	unsigned append:1,
 		 report_progress:1,
 		 split:1,
-		 check_oids:1;
+		 check_oids:1,
+		 no_input:1;
 
 	const struct split_commit_graph_opts *split_opts;
 };
@@ -1785,6 +1786,7 @@ int write_commit_graph(struct object_directory *odb,
 	ctx->split = flags & COMMIT_GRAPH_WRITE_SPLIT ? 1 : 0;
 	ctx->check_oids = flags & COMMIT_GRAPH_WRITE_CHECK_OIDS ? 1 : 0;
 	ctx->split_opts = split_opts;
+	ctx->no_input = flags & COMMIT_GRAPH_WRITE_NO_INPUT ? 1 : 0;
 
 	if (ctx->split) {
 		struct commit_graph *g;
@@ -1843,7 +1845,7 @@ int write_commit_graph(struct object_directory *odb,
 			goto cleanup;
 	}
 
-	if (!pack_indexes && !commit_hex)
+	if (!ctx->no_input && !pack_indexes && !commit_hex)
 		fill_oids_from_all_packs(ctx);
 
 	close_reachable(ctx);
diff --git a/commit-graph.h b/commit-graph.h
index 65a7d2edae..df7f3f5961 100644
--- a/commit-graph.h
+++ b/commit-graph.h
@@ -79,7 +79,8 @@ enum commit_graph_write_flags {
 	COMMIT_GRAPH_WRITE_PROGRESS   = (1 << 1),
 	COMMIT_GRAPH_WRITE_SPLIT      = (1 << 2),
 	/* Make sure that each OID in the input is a valid commit OID. */
-	COMMIT_GRAPH_WRITE_CHECK_OIDS = (1 << 3)
+	COMMIT_GRAPH_WRITE_CHECK_OIDS = (1 << 3),
+	COMMIT_GRAPH_WRITE_NO_INPUT   = (1 << 4)
 };
 
 enum commit_graph_split_flags {
diff --git a/t/t5324-split-commit-graph.sh b/t/t5324-split-commit-graph.sh
index 353523eca4..e3f317a1f4 100755
--- a/t/t5324-split-commit-graph.sh
+++ b/t/t5324-split-commit-graph.sh
@@ -369,4 +369,30 @@ test_expect_success '--split=no-merge always writes an incremental' '
 	test_line_count = 2 $graphdir/commit-graph-chain
 '
 
+test_expect_success '--split=no-merge, --input=none writes nothing' '
+	test_when_finished rm -rf a graphs.before graphs.after &&
+	rm -rf $graphdir &&
+	git reset --hard commits/2 &&
+	git rev-list -1 HEAD~1 >a &&
+	git commit-graph write --split=no-merge --input=stdin-commits <a &&
+	ls $graphdir/graph-*.graph >graphs.before &&
+	test_line_count = 1 $graphdir/commit-graph-chain &&
+	git commit-graph write --split --input=none &&
+	ls $graphdir/graph-*.graph >graphs.after &&
+	test_cmp graphs.before graphs.after
+'
+
+test_expect_success '--split=merge-all, --input=none merges the chain' '
+	test_when_finished rm -rf a b &&
+	rm -rf $graphdir &&
+	git reset --hard commits/2 &&
+	git rev-list -1 HEAD~1 >a &&
+	git rev-list -1 HEAD >b &&
+	git commit-graph write --split=no-merge --input=stdin-commits <a &&
+	git commit-graph write --split=no-merge --input=stdin-commits <b &&
+	test_line_count = 2 $graphdir/commit-graph-chain &&
+	git commit-graph write --split=merge-all --input=none &&
+	test_line_count = 1 $graphdir/commit-graph-chain
+'
+
 test_done

-- 
2.25.0.119.gaa12b7378b
Previous: Taylor BlauNext: Martin Ågren
Message 43 of 58 in “builtin/commit-graph.c: new split/merge options”
  1. 0/3 builtin/commit-graph.c: new split/merge optionsTaylor Blau, Jan 31, 2020
  2. 1/3 builtin/commit-graph.c: support '--split[=<strategy>]'Taylor Blau, Jan 31, 2020
  3. Derrick StoleeJan 31, 2020
  4. Taylor BlauFeb 4, 2020
  5. Martin ÅgrenJan 31, 2020
  6. Taylor BlauFeb 4, 2020
  7. Martin ÅgrenFeb 6, 2020
  8. Taylor BlauFeb 9, 2020
  9. SZEDER GáborJan 31, 2020
  10. Johannes SchindelinFeb 1, 2020
  11. SZEDER GáborFeb 3, 2020
  12. Jeff KingFeb 3, 2020
  13. Taylor BlauFeb 4, 2020
  14. Jeff KingFeb 4, 2020
  15. Taylor BlauFeb 4, 2020
  16. Taylor BlauFeb 4, 2020
  17. 2/3 builtin/commit-graph.c: introduce '--input=<source>'Taylor Blau, Jan 31, 2020
  18. Derrick StoleeJan 31, 2020
  19. Taylor BlauFeb 4, 2020
  20. Martin ÅgrenJan 31, 2020
  21. Taylor BlauFeb 4, 2020
  22. SZEDER GáborFeb 13, 2020
  23. SZEDER GáborFeb 13, 2020
  24. Taylor BlauFeb 13, 2020
  25. 3/3 builtin/commit-graph.c: support '--input=none'Taylor Blau, Jan 31, 2020
  26. Derrick StoleeJan 31, 2020
  27. Martin ÅgrenJan 31, 2020
  28. Taylor BlauFeb 4, 2020
  29. Taylor BlauJan 31, 2020
  30. Derrick StoleeJan 31, 2020
  31. Derrick StoleeJan 31, 2020
  32. Junio C HamanoFeb 4, 2020
  33. Taylor BlauFeb 5, 2020
  34. 0/3 builtin/commit-graph.c: new split/merge optionsTaylor Blau, Feb 5, 2020
  35. 1/3 builtin/commit-graph.c: support '--split[=<strategy>]'Taylor Blau, Feb 5, 2020
  36. Martin ÅgrenFeb 6, 2020
  37. Derrick StoleeFeb 7, 2020
  38. Taylor BlauFeb 9, 2020
  39. Martin ÅgrenFeb 12, 2020
  40. Taylor BlauFeb 12, 2020
  41. Taylor BlauFeb 9, 2020
  42. 2/3 builtin/commit-graph.c: introduce '--input=<source>'Taylor Blau, Feb 5, 2020
  43. 3/3 builtin/commit-graph.c: support '--input=none'Taylor Blau, Feb 5, 2020
  44. Martin ÅgrenFeb 6, 2020
  45. Taylor BlauFeb 9, 2020
  46. Junio C HamanoFeb 5, 2020
  47. 0/3 builtin/commit-graph.c: new split/merge optionsTaylor Blau, Feb 12, 2020
  48. 1/3 builtin/commit-graph.c: support '--split[=<strategy>]'Taylor Blau, Feb 12, 2020
  49. 2/3 builtin/commit-graph.c: introduce '--input=<source>'Taylor Blau, Feb 12, 2020
  50. 3/3 builtin/commit-graph.c: support '--input=none'Taylor Blau, Feb 12, 2020
  51. SZEDER GáborFeb 13, 2020
  52. SZEDER GáborFeb 13, 2020
  53. Junio C HamanoFeb 13, 2020
  54. Taylor BlauFeb 13, 2020
  55. Taylor BlauFeb 13, 2020
  56. Junio C HamanoFeb 12, 2020
  57. Taylor BlauFeb 13, 2020
  58. Martin ÅgrenFeb 17, 2020

Read the whole thread, see it on lore, or plain text.

$ cat FOOTERMessages come from the public archive at lore.kernel.org/git, fetched every hour. The front page is chosen and written each morning by an AI editor and can be wrong; the threads themselves are the record. About and API. For agents: an MCP server at https://gitlist.dev/mcp, and any thread, story or person page as Markdown by adding .md to its URL (or sending Accept: text/markdown). Details in /llms.txt.