git notes merge: Initial implementation handling trivial merges only
This initial implementation of 'git notes merge' only handles the trivial merge cases (i.e. where the merge is either a no-op, or a fast-forward). The patch includes testcases for these trivial merge cases. Future patches will extend the functionality of 'git notes merge'. This patch has been improved by the following contributions: - Stephen Boyd: Simplify argc logic - Stephen Boyd: Use test_commit - Ævar Arnfjörð Bjarmason: Don't use C99 comments. - Jonathan Nieder: Add constants for common verbosity values - Jonathan Nieder: Use trace_printf(...) instead of OUTPUT(o, 5, ...) - Jonathan Nieder: Remove extraneous show() function - Jonathan Nieder: Clarify handling of empty/missing notes ref in notes_merge() - Junio C Hamano: fixup minor style issues Thanks-to: Stephen Boyd <bebarino@gmail.com> Thanks-to: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Thanks-to: Jonathan Nieder <jrnieder@gmail.com> Thanks-to: Junio C Hamano <gitster@pobox.com> Signed-off-by: Johan Herland <johan@herland.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Johan Herland committed
Nov 9, 2010 at 22:49 UTC
75ef3f4a5cc69b21bc825ed0e739030d77a4f077
5 files changed
+392
Makefile
+2
@@ -503,6 +503,7 @@ LIB_H += mailmap.h
503
LIB_H += merge-recursive.h
504
LIB_H += notes.h
505
LIB_H += notes-cache.h
506
+LIB_H += notes-merge.h
507
LIB_H += object.h
508
LIB_H += pack.h
509
LIB_H += pack-refs.h
@@ -593,6 +594,7 @@ LIB_OBJS += merge-recursive.o
594
LIB_OBJS += name-hash.o
595
LIB_OBJS += notes.o
596
LIB_OBJS += notes-cache.o
597
+LIB_OBJS += notes-merge.o
598
LIB_OBJS += object.o
599
LIB_OBJS += pack-check.o
600
LIB_OBJS += pack-refs.o
builtin/notes.c
+54
@@ -17,6 +17,7 @@
17
#include "run-command.h"
18
#include "parse-options.h"
19
#include "string-list.h"
20
+#include "notes-merge.h"
21
22
static const char * const git_notes_usage[] = {
23
"git notes [--ref <notes_ref>] [list [<object>]]",
@@ -25,6 +26,7 @@ static const char * const git_notes_usage[] = {
26
"git notes [--ref <notes_ref>] append [-m <msg> | -F <file> | (-c | -C) <object>] [<object>]",
27
"git notes [--ref <notes_ref>] edit [<object>]",
28
"git notes [--ref <notes_ref>] show [<object>]",
29
+ "git notes [--ref <notes_ref>] merge [-v | -q] <notes_ref>",
30
"git notes [--ref <notes_ref>] remove [<object>]",
31
"git notes [--ref <notes_ref>] prune [-n | -v]",
32
NULL
@@ -61,6 +63,11 @@ static const char * const git_notes_show_usage[] = {
63
NULL
64
};
65
66
+static const char * const git_notes_merge_usage[] = {
67
+ "git notes merge [<options>] <notes_ref>",
68
+ NULL
69
+};
70
+
71
static const char * const git_notes_remove_usage[] = {
72
"git notes remove [<object>]",
73
NULL
@@ -772,6 +779,51 @@ static int show(int argc, const char **argv, const char *prefix)
779
return retval;
780
}
781
782
+static int merge(int argc, const char **argv, const char *prefix)
783
+{
784
+ struct strbuf remote_ref = STRBUF_INIT, msg = STRBUF_INIT;
785
+ unsigned char result_sha1[20];
786
+ struct notes_merge_options o;
787
+ int verbosity = 0, result;
788
+ struct option options[] = {
789
+ OPT__VERBOSITY(&verbosity),
790
+ OPT_END()
791
+ };
792
+
793
+ argc = parse_options(argc, argv, prefix, options,
794
+ git_notes_merge_usage, 0);
795
+
796
+ if (argc != 1) {
797
+ error("Must specify a notes ref to merge");
798
+ usage_with_options(git_notes_merge_usage, options);
799
+ }
800
+
801
+ init_notes_merge_options(&o);
802
+ o.verbosity = verbosity + NOTES_MERGE_VERBOSITY_DEFAULT;
803
+
804
+ o.local_ref = default_notes_ref();
805
+ strbuf_addstr(&remote_ref, argv[0]);
806
+ expand_notes_ref(&remote_ref);
807
+ o.remote_ref = remote_ref.buf;
808
+
809
+ result = notes_merge(&o, result_sha1);
810
+
811
+ strbuf_addf(&msg, "notes: Merged notes from %s into %s",
812
+ remote_ref.buf, default_notes_ref());
813
+ if (result == 0) { /* Merge resulted (trivially) in result_sha1 */
814
+ /* Update default notes ref with new commit */
815
+ update_ref(msg.buf, default_notes_ref(), result_sha1, NULL,
816
+ 0, DIE_ON_ERR);
817
+ } else {
818
+ /* TODO: */
819
+ die("'git notes merge' cannot yet handle non-trivial merges!");
820
+ }
821
+
822
+ strbuf_release(&remote_ref);
823
+ strbuf_release(&msg);
824
+ return 0;
825
+}
826
+
827
static int remove_cmd(int argc, const char **argv, const char *prefix)
828
{
829
struct option options[] = {
@@ -865,6 +917,8 @@ int cmd_notes(int argc, const char **argv, const char *prefix)
917
result = append_edit(argc, argv, prefix);
918
else if (!strcmp(argv[0], "show"))
919
result = show(argc, argv, prefix);
920
+ else if (!strcmp(argv[0], "merge"))
921
+ result = merge(argc, argv, prefix);
922
else if (!strcmp(argv[0], "remove"))
923
result = remove_cmd(argc, argv, prefix);
924
else if (!strcmp(argv[0], "prune"))
notes-merge.c
new
+120
@@ -0,0 +1,120 @@
1
+#include "cache.h"
2
+#include "commit.h"
3
+#include "refs.h"
4
+#include "notes-merge.h"
5
+
6
+void init_notes_merge_options(struct notes_merge_options *o)
7
+{
8
+ memset(o, 0, sizeof(struct notes_merge_options));
9
+ o->verbosity = NOTES_MERGE_VERBOSITY_DEFAULT;
10
+}
11
+
12
+#define OUTPUT(o, v, ...) \
13
+ do { \
14
+ if ((o)->verbosity >= (v)) { \
15
+ printf(__VA_ARGS__); \
16
+ puts(""); \
17
+ } \
18
+ } while (0)
19
+
20
+int notes_merge(struct notes_merge_options *o,
21
+ unsigned char *result_sha1)
22
+{
23
+ unsigned char local_sha1[20], remote_sha1[20];
24
+ struct commit *local, *remote;
25
+ struct commit_list *bases = NULL;
26
+ const unsigned char *base_sha1;
27
+ int result = 0;
28
+
29
+ assert(o->local_ref && o->remote_ref);
30
+ hashclr(result_sha1);
31
+
32
+ trace_printf("notes_merge(o->local_ref = %s, o->remote_ref = %s)\n",
33
+ o->local_ref, o->remote_ref);
34
+
35
+ /* Dereference o->local_ref into local_sha1 */
36
+ if (!resolve_ref(o->local_ref, local_sha1, 0, NULL))
37
+ die("Failed to resolve local notes ref '%s'", o->local_ref);
38
+ else if (!check_ref_format(o->local_ref) && is_null_sha1(local_sha1))
39
+ local = NULL; /* local_sha1 == null_sha1 indicates unborn ref */
40
+ else if (!(local = lookup_commit_reference(local_sha1)))
41
+ die("Could not parse local commit %s (%s)",
42
+ sha1_to_hex(local_sha1), o->local_ref);
43
+ trace_printf("\tlocal commit: %.7s\n", sha1_to_hex(local_sha1));
44
+
45
+ /* Dereference o->remote_ref into remote_sha1 */
46
+ if (get_sha1(o->remote_ref, remote_sha1)) {
47
+ /*
48
+ * Failed to get remote_sha1. If o->remote_ref looks like an
49
+ * unborn ref, perform the merge using an empty notes tree.
50
+ */
51
+ if (!check_ref_format(o->remote_ref)) {
52
+ hashclr(remote_sha1);
53
+ remote = NULL;
54
+ } else {
55
+ die("Failed to resolve remote notes ref '%s'",
56
+ o->remote_ref);
57
+ }
58
+ } else if (!(remote = lookup_commit_reference(remote_sha1))) {
59
+ die("Could not parse remote commit %s (%s)",
60
+ sha1_to_hex(remote_sha1), o->remote_ref);
61
+ }
62
+ trace_printf("\tremote commit: %.7s\n", sha1_to_hex(remote_sha1));
63
+
64
+ if (!local && !remote)
65
+ die("Cannot merge empty notes ref (%s) into empty notes ref "
66
+ "(%s)", o->remote_ref, o->local_ref);
67
+ if (!local) {
68
+ /* result == remote commit */
69
+ hashcpy(result_sha1, remote_sha1);
70
+ goto found_result;
71
+ }
72
+ if (!remote) {
73
+ /* result == local commit */
74
+ hashcpy(result_sha1, local_sha1);
75
+ goto found_result;
76
+ }
77
+ assert(local && remote);
78
+
79
+ /* Find merge bases */
80
+ bases = get_merge_bases(local, remote, 1);
81
+ if (!bases) {
82
+ base_sha1 = null_sha1;
83
+ OUTPUT(o, 4, "No merge base found; doing history-less merge");
84
+ } else if (!bases->next) {
85
+ base_sha1 = bases->item->object.sha1;
86
+ OUTPUT(o, 4, "One merge base found (%.7s)",
87
+ sha1_to_hex(base_sha1));
88
+ } else {
89
+ /* TODO: How to handle multiple merge-bases? */
90
+ base_sha1 = bases->item->object.sha1;
91
+ OUTPUT(o, 3, "Multiple merge bases found. Using the first "
92
+ "(%.7s)", sha1_to_hex(base_sha1));
93
+ }
94
+
95
+ OUTPUT(o, 4, "Merging remote commit %.7s into local commit %.7s with "
96
+ "merge-base %.7s", sha1_to_hex(remote->object.sha1),
97
+ sha1_to_hex(local->object.sha1), sha1_to_hex(base_sha1));
98
+
99
+ if (!hashcmp(remote->object.sha1, base_sha1)) {
100
+ /* Already merged; result == local commit */
101
+ OUTPUT(o, 2, "Already up-to-date!");
102
+ hashcpy(result_sha1, local->object.sha1);
103
+ goto found_result;
104
+ }
105
+ if (!hashcmp(local->object.sha1, base_sha1)) {
106
+ /* Fast-forward; result == remote commit */
107
+ OUTPUT(o, 2, "Fast-forward");
108
+ hashcpy(result_sha1, remote->object.sha1);
109
+ goto found_result;
110
+ }
111
+
112
+ /* TODO: */
113
+ result = error("notes_merge() cannot yet handle real merges.");
114
+
115
+found_result:
116
+ free_commit_list(bases);
117
+ trace_printf("notes_merge(): result = %i, result_sha1 = %.7s\n",
118
+ result, sha1_to_hex(result_sha1));
119
+ return result;
120
+}
notes-merge.h
new
+36
@@ -0,0 +1,36 @@
1
+#ifndef NOTES_MERGE_H
2
+#define NOTES_MERGE_H
3
+
4
+enum notes_merge_verbosity {
5
+ NOTES_MERGE_VERBOSITY_DEFAULT = 2,
6
+ NOTES_MERGE_VERBOSITY_MAX = 5
7
+};
8
+
9
+struct notes_merge_options {
10
+ const char *local_ref;
11
+ const char *remote_ref;
12
+ int verbosity;
13
+};
14
+
15
+void init_notes_merge_options(struct notes_merge_options *o);
16
+
17
+/*
18
+ * Merge notes from o->remote_ref into o->local_ref
19
+ *
20
+ * The commits given by the two refs are merged, producing one of the following
21
+ * outcomes:
22
+ *
23
+ * 1. The merge trivially results in an existing commit (e.g. fast-forward or
24
+ * already-up-to-date). The SHA1 of the result is written into 'result_sha1'
25
+ * and 0 is returned.
26
+ * 2. The merge fails. result_sha1 is set to null_sha1, and non-zero returned.
27
+ *
28
+ * Both o->local_ref and o->remote_ref must be given (non-NULL), but either ref
29
+ * (although not both) may refer to a non-existing notes ref, in which case
30
+ * that notes ref is interpreted as an empty notes tree, and the merge
31
+ * trivially results in what the other ref points to.
32
+ */
33
+int notes_merge(struct notes_merge_options *o,
34
+ unsigned char *result_sha1);
35
+
36
+#endif
t/t3308-notes-merge.sh
new
+180
@@ -0,0 +1,180 @@
1
+#!/bin/sh
2
+#
3
+# Copyright (c) 2010 Johan Herland
4
+#
5
+
6
+test_description='Test merging of notes trees'
7
+
8
+. ./test-lib.sh
9
+
10
+test_expect_success setup '
11
+ test_commit 1st &&
12
+ test_commit 2nd &&
13
+ test_commit 3rd &&
14
+ test_commit 4th &&
15
+ test_commit 5th &&
16
+ # Create notes on 4 first commits
17
+ git config core.notesRef refs/notes/x &&
18
+ git notes add -m "Notes on 1st commit" 1st &&
19
+ git notes add -m "Notes on 2nd commit" 2nd &&
20
+ git notes add -m "Notes on 3rd commit" 3rd &&
21
+ git notes add -m "Notes on 4th commit" 4th
22
+'
23
+
24
+commit_sha1=$(git rev-parse 1st^{commit})
25
+commit_sha2=$(git rev-parse 2nd^{commit})
26
+commit_sha3=$(git rev-parse 3rd^{commit})
27
+commit_sha4=$(git rev-parse 4th^{commit})
28
+commit_sha5=$(git rev-parse 5th^{commit})
29
+
30
+verify_notes () {
31
+ notes_ref="$1"
32
+ git -c core.notesRef="refs/notes/$notes_ref" notes |
33
+ sort >"output_notes_$notes_ref" &&
34
+ test_cmp "expect_notes_$notes_ref" "output_notes_$notes_ref" &&
35
+ git -c core.notesRef="refs/notes/$notes_ref" log --format="%H %s%n%N" \
36
+ >"output_log_$notes_ref" &&
37
+ test_cmp "expect_log_$notes_ref" "output_log_$notes_ref"
38
+}
39
+
40
+cat <<EOF | sort >expect_notes_x
41
+5e93d24084d32e1cb61f7070505b9d2530cca987 $commit_sha4
42
+8366731eeee53787d2bdf8fc1eff7d94757e8da0 $commit_sha3
43
+eede89064cd42441590d6afec6c37b321ada3389 $commit_sha2
44
+daa55ffad6cb99bf64226532147ffcaf5ce8bdd1 $commit_sha1
45
+EOF
46
+
47
+cat >expect_log_x <<EOF
48
+$commit_sha5 5th
49
+
50
+$commit_sha4 4th
51
+Notes on 4th commit
52
+
53
+$commit_sha3 3rd
54
+Notes on 3rd commit
55
+
56
+$commit_sha2 2nd
57
+Notes on 2nd commit
58
+
59
+$commit_sha1 1st
60
+Notes on 1st commit
61
+
62
+EOF
63
+
64
+test_expect_success 'verify initial notes (x)' '
65
+ verify_notes x
66
+'
67
+
68
+cp expect_notes_x expect_notes_y
69
+cp expect_log_x expect_log_y
70
+
71
+test_expect_success 'fail to merge empty notes ref into empty notes ref (z => y)' '
72
+ test_must_fail git -c "core.notesRef=refs/notes/y" notes merge z
73
+'
74
+
75
+test_expect_success 'fail to merge into various non-notes refs' '
76
+ test_must_fail git -c "core.notesRef=refs/notes" notes merge x &&
77
+ test_must_fail git -c "core.notesRef=refs/notes/" notes merge x &&
78
+ mkdir -p .git/refs/notes/dir &&
79
+ test_must_fail git -c "core.notesRef=refs/notes/dir" notes merge x &&
80
+ test_must_fail git -c "core.notesRef=refs/notes/dir/" notes merge x &&
81
+ test_must_fail git -c "core.notesRef=refs/heads/master" notes merge x &&
82
+ test_must_fail git -c "core.notesRef=refs/notes/y:" notes merge x &&
83
+ test_must_fail git -c "core.notesRef=refs/notes/y:foo" notes merge x &&
84
+ test_must_fail git -c "core.notesRef=refs/notes/foo^{bar" notes merge x
85
+'
86
+
87
+test_expect_success 'fail to merge various non-note-trees' '
88
+ git config core.notesRef refs/notes/y &&
89
+ test_must_fail git notes merge refs/notes &&
90
+ test_must_fail git notes merge refs/notes/ &&
91
+ test_must_fail git notes merge refs/notes/dir &&
92
+ test_must_fail git notes merge refs/notes/dir/ &&
93
+ test_must_fail git notes merge refs/heads/master &&
94
+ test_must_fail git notes merge x: &&
95
+ test_must_fail git notes merge x:foo &&
96
+ test_must_fail git notes merge foo^{bar
97
+'
98
+
99
+test_expect_success 'merge notes into empty notes ref (x => y)' '
100
+ git config core.notesRef refs/notes/y &&
101
+ git notes merge x &&
102
+ verify_notes y &&
103
+ # x and y should point to the same notes commit
104
+ test "$(git rev-parse refs/notes/x)" = "$(git rev-parse refs/notes/y)"
105
+'
106
+
107
+test_expect_success 'merge empty notes ref (z => y)' '
108
+ git notes merge z &&
109
+ # y should not change (still == x)
110
+ test "$(git rev-parse refs/notes/x)" = "$(git rev-parse refs/notes/y)"
111
+'
112
+
113
+test_expect_success 'change notes on other notes ref (y)' '
114
+ # Not touching notes to 1st commit
115
+ git notes remove 2nd &&
116
+ git notes append -m "More notes on 3rd commit" 3rd &&
117
+ git notes add -f -m "New notes on 4th commit" 4th &&
118
+ git notes add -m "Notes on 5th commit" 5th
119
+'
120
+
121
+test_expect_success 'merge previous notes commit (y^ => y) => No-op' '
122
+ pre_state="$(git rev-parse refs/notes/y)" &&
123
+ git notes merge y^ &&
124
+ # y should not move
125
+ test "$pre_state" = "$(git rev-parse refs/notes/y)"
126
+'
127
+
128
+cat <<EOF | sort >expect_notes_y
129
+0f2efbd00262f2fd41dfae33df8765618eeacd99 $commit_sha5
130
+dec2502dac3ea161543f71930044deff93fa945c $commit_sha4
131
+4069cdb399fd45463ec6eef8e051a16a03592d91 $commit_sha3
132
+daa55ffad6cb99bf64226532147ffcaf5ce8bdd1 $commit_sha1
133
+EOF
134
+
135
+cat >expect_log_y <<EOF
136
+$commit_sha5 5th
137
+Notes on 5th commit
138
+
139
+$commit_sha4 4th
140
+New notes on 4th commit
141
+
142
+$commit_sha3 3rd
143
+Notes on 3rd commit
144
+
145
+More notes on 3rd commit
146
+
147
+$commit_sha2 2nd
148
+
149
+$commit_sha1 1st
150
+Notes on 1st commit
151
+
152
+EOF
153
+
154
+test_expect_success 'verify changed notes on other notes ref (y)' '
155
+ verify_notes y
156
+'
157
+
158
+test_expect_success 'verify unchanged notes on original notes ref (x)' '
159
+ verify_notes x
160
+'
161
+
162
+test_expect_success 'merge original notes (x) into changed notes (y) => No-op' '
163
+ git notes merge -vvv x &&
164
+ verify_notes y &&
165
+ verify_notes x
166
+'
167
+
168
+cp expect_notes_y expect_notes_x
169
+cp expect_log_y expect_log_x
170
+
171
+test_expect_success 'merge changed (y) into original (x) => Fast-forward' '
172
+ git config core.notesRef refs/notes/x &&
173
+ git notes merge y &&
174
+ verify_notes x &&
175
+ verify_notes y &&
176
+ # x and y should point to same the notes commit
177
+ test "$(git rev-parse refs/notes/x)" = "$(git rev-parse refs/notes/y)"
178
+'
179
+
180
+test_done