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[PATCHv3 19/21] git notes merge: Add another auto-resolving strategy: "cat_sort_uniq"

From
Johan Herland <johan@herland.net>
Date
Oct 9, 2010, 01:15 UTC
Message-ID
<1286586956-3714-20-git-send-email-johan@herland.net>
In-Reply-To
<1286586528-3473-1-git-send-email-johan@herland.net>

This new strategy is similar to "concatenate", but in addition to concatenating the two note candidates, this strategy sorts the resulting lines, and removes duplicate lines from the result. This is equivalent to applying the "cat | sort | uniq" shell pipeline to the two note candidates.

This strategy is useful if the notes follow a line-based format where one wants to avoid duplicate lines in the merge result.

Note that if either of the note candidates contain duplicate lines _prior_ to the merge, these will also be removed by this merge strategy.

The patch also contains tests and documentation for the new strategy.
Signed-off-by: Johan Herland <johan@herland.net>
---
 Documentation/git-notes.txt         |   12 +++-
 builtin/notes.c                     |    8 ++-
 notes-merge.c                       |    6 ++
 notes-merge.h                       |    3 +-
 notes.c                             |   76 ++++++++++++++++++
 notes.h                             |    1 +
 t/t3309-notes-merge-auto-resolve.sh |  145 +++++++++++++++++++++++++++++++++++
 7 files changed, 247 insertions(+), 4 deletions(-)
diff --git a/Documentation/git-notes.txt b/Documentation/git-notes.txt
index 5bb9784..466885a 100644
--- a/Documentation/git-notes.txt
+++ b/Documentation/git-notes.txt
@@ -155,7 +155,7 @@ OPTIONS
 --strategy=<strategy>::
 	When merging notes, resolve notes conflicts using the given
 	strategy. The following strategies are recognized: "manual"
-	(default), "ours", "theirs" and "union".
+	(default), "ours", "theirs", "union" and "cat_sort_uniq".
 	See the "NOTES MERGE STRATEGIES" section below for more
 	information on each notes merge strategy.
 
@@ -230,6 +230,16 @@ ref).
 "union" automatically resolves notes conflicts by concatenating the
 local and remote versions.
 
+"cat_sort_uniq" is similar to "union", but in addition to concatenating
+the local and remote versions, this strategy also sorts the resulting
+lines, and removes duplicate lines from the result. This is equivalent
+to applying the "cat | sort | uniq" shell pipeline to the local and
+remote versions. This strategy is useful if the notes follow a line-based
+format where one wants to avoid duplicated lines in the merge result.
+Note that if either the local or remote version contain duplicate lines
+prior to the merge, these will also be removed by this notes merge
+strategy.
+
 
 EXAMPLES
 --------
diff --git a/builtin/notes.c b/builtin/notes.c
index d3754ab..abf26e5 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c
@@ -324,6 +324,8 @@ combine_notes_fn parse_combine_notes_fn(const char *v)
 		return combine_notes_ignore;
 	else if (!strcasecmp(v, "concatenate"))
 		return combine_notes_concatenate;
+	else if (!strcasecmp(v, "cat_sort_uniq"))
+		return combine_notes_cat_sort_uniq;
 	else
 		return NULL;
 }
@@ -846,8 +848,8 @@ static int merge(int argc, const char **argv, const char *prefix)
 		OPT__VERBOSITY(&verbosity),
 		OPT_GROUP("Merge options"),
 		OPT_STRING('s', "strategy", &strategy, "strategy",
-			   "resolve notes conflicts using the given "
-			   "strategy (manual/ours/theirs/union)"),
+			   "resolve notes conflicts using the given strategy "
+			   "(manual/ours/theirs/union/cat_sort_uniq)"),
 		OPT_GROUP("Committing unmerged notes"),
 		{ OPTION_BOOLEAN, 0, "commit", &do_commit, NULL,
 			"finalize notes merge by committing unmerged notes",
@@ -899,6 +901,8 @@ static int merge(int argc, const char **argv, const char *prefix)
 			o.strategy = NOTES_MERGE_RESOLVE_THEIRS;
 		else if (!strcmp(strategy, "union"))
 			o.strategy = NOTES_MERGE_RESOLVE_UNION;
+		else if (!strcmp(strategy, "cat_sort_uniq"))
+			o.strategy = NOTES_MERGE_RESOLVE_CAT_SORT_UNIQ;
 		else {
 			error("Unknown -s/--strategy: %s", strategy);
 			usage_with_options(git_notes_merge_usage, options);
diff --git a/notes-merge.c b/notes-merge.c
index a66c60b..9b6b9d1 100644
--- a/notes-merge.c
+++ b/notes-merge.c
@@ -451,6 +451,12 @@ static int merge_one_change(struct notes_merge_options *o,
 		if (add_note(t, p->obj, p->remote, combine_notes_concatenate))
 			die("confused: combine_notes_concatenate failed");
 		return 0;
+	case NOTES_MERGE_RESOLVE_CAT_SORT_UNIQ:
+		OUTPUT(o, 2, "Concatenating unique lines in local and remote "
+		       "notes for %s", sha1_to_hex(p->obj));
+		if (add_note(t, p->obj, p->remote, combine_notes_cat_sort_uniq))
+			die("confused: combine_notes_cat_sort_uniq failed");
+		return 0;
 	}
 	die("Unknown strategy (%i).", o->strategy);
 }
diff --git a/notes-merge.h b/notes-merge.h
index 5669836..f7cccb0 100644
--- a/notes-merge.h
+++ b/notes-merge.h
@@ -17,7 +17,8 @@ struct notes_merge_options {
 		NOTES_MERGE_RESOLVE_MANUAL = 0,
 		NOTES_MERGE_RESOLVE_OURS,
 		NOTES_MERGE_RESOLVE_THEIRS,
-		NOTES_MERGE_RESOLVE_UNION
+		NOTES_MERGE_RESOLVE_UNION,
+		NOTES_MERGE_RESOLVE_CAT_SORT_UNIQ
 	} strategy;
 	unsigned has_worktree:1;
 };
diff --git a/notes.c b/notes.c
index a7a901a..521f5d0 100644
--- a/notes.c
+++ b/notes.c
@@ -847,6 +847,82 @@ int combine_notes_ignore(unsigned char *cur_sha1,
 	return 0;
 }
 
+static int string_list_add_note_lines(struct string_list *sort_uniq_list,
+				      const unsigned char *sha1)
+{
+	char *data;
+	unsigned long len;
+	enum object_type t;
+	struct strbuf buf = STRBUF_INIT;
+	struct strbuf **lines = NULL;
+	int i, list_index;
+
+	if (is_null_sha1(sha1))
+		return 0;
+
+	/* read_sha1_file NUL-terminates */
+	data = read_sha1_file(sha1, &t, &len);
+	if (t != OBJ_BLOB || !data || !len) {
+		free(data);
+		return t != OBJ_BLOB || !data;
+	}
+
+	strbuf_attach(&buf, data, len, len + 1);
+	lines = strbuf_split(&buf, '\n');
+
+	for (i = 0; lines[i]; i++) {
+		if (lines[i]->buf[lines[i]->len - 1] == '\n')
+			strbuf_setlen(lines[i], lines[i]->len - 1);
+		if (!lines[i]->len)
+			continue; /* skip empty lines */
+		list_index = string_list_find_insert_index(sort_uniq_list,
+							   lines[i]->buf, 0);
+		if (list_index < 0)
+			continue; /* skip duplicate lines */
+		string_list_insert_at_index(sort_uniq_list, list_index,
+					    lines[i]->buf);
+	}
+
+	strbuf_list_free(lines);
+	strbuf_release(&buf);
+	return 0;
+}
+
+static int string_list_join_lines_helper(struct string_list_item *item,
+					 void *cb_data)
+{
+	struct strbuf *buf = cb_data;
+	strbuf_addstr(buf, item->string);
+	strbuf_addch(buf, '\n');
+	return 0;
+}
+
+int combine_notes_cat_sort_uniq(unsigned char *cur_sha1,
+		const unsigned char *new_sha1)
+{
+	struct string_list sort_uniq_list = { NULL, 0, 0, 1 };
+	struct strbuf buf = STRBUF_INIT;
+	int ret = 1;
+
+	/* read both note blob objects into unique_lines */
+	if (string_list_add_note_lines(&sort_uniq_list, cur_sha1))
+		goto out;
+	if (string_list_add_note_lines(&sort_uniq_list, new_sha1))
+		goto out;
+
+	/* create a new blob object from sort_uniq_list */
+	if (for_each_string_list(&sort_uniq_list,
+				 string_list_join_lines_helper, &buf))
+		goto out;
+
+	ret = write_sha1_file(buf.buf, buf.len, blob_type, cur_sha1);
+
+out:
+	strbuf_release(&buf);
+	string_list_clear(&sort_uniq_list, 0);
+	return ret;
+}
+
 static int string_list_add_one_ref(const char *path, const unsigned char *sha1,
 				   int flag, void *cb)
 {
diff --git a/notes.h b/notes.h
index b372575..93a7365 100644
--- a/notes.h
+++ b/notes.h
@@ -27,6 +27,7 @@ typedef int (*combine_notes_fn)(unsigned char *cur_sha1, const unsigned char *ne
 int combine_notes_concatenate(unsigned char *cur_sha1, const unsigned char *new_sha1);
 int combine_notes_overwrite(unsigned char *cur_sha1, const unsigned char *new_sha1);
 int combine_notes_ignore(unsigned char *cur_sha1, const unsigned char *new_sha1);
+int combine_notes_cat_sort_uniq(unsigned char *cur_sha1, const unsigned char *new_sha1);
 
 /*
  * Notes tree object
diff --git a/t/t3309-notes-merge-auto-resolve.sh b/t/t3309-notes-merge-auto-resolve.sh
index 1a1fc7e..461fd84 100755
--- a/t/t3309-notes-merge-auto-resolve.sh
+++ b/t/t3309-notes-merge-auto-resolve.sh
@@ -499,4 +499,149 @@ test_expect_success 'merge z into y with "union" strategy => Non-conflicting 3-w
 	verify_notes y union
 '
 
+test_expect_success 'reset to pre-merge state (y)' '
+	git update-ref refs/notes/y refs/notes/y^1 &&
+	# Verify pre-merge state
+	verify_notes y y
+'
+
+cat <<EOF | sort >expect_notes_union2
+d682107b8bf7a7aea1e537a8d5cb6a12b60135f1 $commit_sha15
+5de7ea7ad4f47e7ff91989fb82234634730f75df $commit_sha14
+3a631fdb6f41b05b55d8f4baf20728ba8f6fccbc $commit_sha13
+a66055fa82f7a03fe0c02a6aba3287a85abf7c62 $commit_sha12
+7e3c53503a3db8dd996cb62e37c66e070b44b54d $commit_sha11
+b8d03e173f67f6505a76f6e00cf93440200dd9be $commit_sha10
+851e1638784a884c7dd26c5d41f3340f6387413a $commit_sha8
+357b6ca14c7afd59b7f8b8aaaa6b8b723771135b $commit_sha5
+e2bfd06a37dd2031684a59a6e2b033e212239c78 $commit_sha4
+5772f42408c0dd6f097a7ca2d24de0e78d1c46b1 $commit_sha3
+283b48219aee9a4105f6cab337e789065c82c2b9 $commit_sha2
+EOF
+
+cat >expect_log_union2 <<EOF
+$commit_sha15 15th
+z notes on 15th commit
+
+y notes on 15th commit
+
+$commit_sha14 14th
+y notes on 14th commit
+
+$commit_sha13 13th
+y notes on 13th commit
+
+$commit_sha12 12th
+y notes on 12th commit
+
+$commit_sha11 11th
+z notes on 11th commit
+
+$commit_sha10 10th
+x notes on 10th commit
+
+$commit_sha9 9th
+
+$commit_sha8 8th
+z notes on 8th commit
+
+$commit_sha7 7th
+
+$commit_sha6 6th
+
+$commit_sha5 5th
+z notes on 5th commit
+
+y notes on 5th commit
+
+$commit_sha4 4th
+y notes on 4th commit
+
+$commit_sha3 3rd
+y notes on 3rd commit
+
+$commit_sha2 2nd
+z notes on 2nd commit
+
+$commit_sha1 1st
+
+EOF
+
+test_expect_success 'merge y into z with "union" strategy => Non-conflicting 3-way merge' '
+	git config core.notesRef refs/notes/z &&
+	git notes merge --strategy=union y &&
+	verify_notes z union2
+'
+
+test_expect_success 'reset to pre-merge state (z)' '
+	git update-ref refs/notes/z refs/notes/z^1 &&
+	# Verify pre-merge state
+	verify_notes z z
+'
+
+cat <<EOF | sort >expect_notes_cat_sort_uniq
+6be90240b5f54594203e25d9f2f64b7567175aee $commit_sha15
+5de7ea7ad4f47e7ff91989fb82234634730f75df $commit_sha14
+3a631fdb6f41b05b55d8f4baf20728ba8f6fccbc $commit_sha13
+a66055fa82f7a03fe0c02a6aba3287a85abf7c62 $commit_sha12
+7e3c53503a3db8dd996cb62e37c66e070b44b54d $commit_sha11
+b8d03e173f67f6505a76f6e00cf93440200dd9be $commit_sha10
+851e1638784a884c7dd26c5d41f3340f6387413a $commit_sha8
+660311d7f78dc53db12ac373a43fca7465381a7e $commit_sha5
+e2bfd06a37dd2031684a59a6e2b033e212239c78 $commit_sha4
+5772f42408c0dd6f097a7ca2d24de0e78d1c46b1 $commit_sha3
+283b48219aee9a4105f6cab337e789065c82c2b9 $commit_sha2
+EOF
+
+cat >expect_log_cat_sort_uniq <<EOF
+$commit_sha15 15th
+y notes on 15th commit
+z notes on 15th commit
+
+$commit_sha14 14th
+y notes on 14th commit
+
+$commit_sha13 13th
+y notes on 13th commit
+
+$commit_sha12 12th
+y notes on 12th commit
+
+$commit_sha11 11th
+z notes on 11th commit
+
+$commit_sha10 10th
+x notes on 10th commit
+
+$commit_sha9 9th
+
+$commit_sha8 8th
+z notes on 8th commit
+
+$commit_sha7 7th
+
+$commit_sha6 6th
+
+$commit_sha5 5th
+y notes on 5th commit
+z notes on 5th commit
+
+$commit_sha4 4th
+y notes on 4th commit
+
+$commit_sha3 3rd
+y notes on 3rd commit
+
+$commit_sha2 2nd
+z notes on 2nd commit
+
+$commit_sha1 1st
+
+EOF
+
+test_expect_success 'merge y into z with "cat_sort_uniq" strategy => Non-conflicting 3-way merge' '
+	git notes merge --strategy=cat_sort_uniq y &&
+	verify_notes z cat_sort_uniq
+'
+
 test_done
-- 
1.7.3.1.104.g92b87a
Previous: Johan HerlandNext: Johan Herland
Message 22 of 25 in “[PATCHv3 00/21] git notes merge”
  1. Johan HerlandOct 9, 2010
  2. 01/21 notes.c: Hexify SHA1 in die() message from init_notes()Johan Herland, Oct 9, 2010
  3. 02/21 (trivial) notes.h: Minor documentation fixes to copy_notes()Johan Herland, Oct 9, 2010
  4. 03/21 notes.h: Make default_notes_ref() available in notes APIJohan Herland, Oct 9, 2010
  5. 04/21 notes.c: Reorder functions in preparation for next commitJohan Herland, Oct 9, 2010
  6. Junio C HamanoOct 13, 2010
  7. Jonathan NiederOct 13, 2010
  8. 05/21 notes.h/c: Clarify the handling of notes objects that are == null_sha1Johan Herland, Oct 9, 2010
  9. 06/21 notes.h/c: Propagate combine_notes_fn return value to add_note() and beyondJohan Herland, Oct 9, 2010
  10. 07/21 (trivial) t3303: Indent with tabs instead of spaces for consistencyJohan Herland, Oct 9, 2010
  11. 08/21 notes.c: Use two newlines (instead of one) when concatenating notesJohan Herland, Oct 9, 2010
  12. 09/21 builtin/notes.c: Split notes ref DWIMmery into a separate functionJohan Herland, Oct 9, 2010
  13. 10/21 git notes merge: Initial implementation handling trivial merges onlyJohan Herland, Oct 9, 2010
  14. 11/21 builtin/notes.c: Refactor creation of notes commits.Johan Herland, Oct 9, 2010
  15. 12/21 git notes merge: Handle real, non-conflicting notes mergesJohan Herland, Oct 9, 2010
  16. 13/21 git notes merge: Add automatic conflict resolvers (ours, theirs, union)Johan Herland, Oct 9, 2010
  17. 14/21 Documentation: Preliminary docs on 'git notes merge'Johan Herland, Oct 9, 2010
  18. 15/21 git notes merge: Manual conflict resolution, part 1/2Johan Herland, Oct 9, 2010
  19. 16/21 git notes merge: Manual conflict resolution, part 2/2Johan Herland, Oct 9, 2010
  20. 17/21 git notes merge: List conflicting notes in notes merge commit messageJohan Herland, Oct 9, 2010
  21. 18/21 git notes merge: --commit should fail if underlying notes ref has movedJohan Herland, Oct 9, 2010
  22. 19/21 git notes merge: Add another auto-resolving strategy: "cat_sort_uniq"Johan Herland, Oct 9, 2010
  23. 20/21 git notes merge: Add testcases for merging notes trees at different fanoutsJohan Herland, Oct 9, 2010
  24. 21/21 Provide 'git notes get-ref' to easily retrieve current notes refJohan Herland, Oct 9, 2010
  25. Sverre RabbelierOct 9, 2010

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