notes: track whether notes_trees were changed at all

Currently, the notes copying is a bit wasteful since it always creates new trees, even if no notes were copied at all. Teach add_note() and remove_note() to flag the affected notes tree as changed ('dirty'). Then teach builtin/notes.c to use this knowledge and avoid committing trees that weren't changed. Signed-off-by: Thomas Rast <trast@student.ethz.ch> Acked-by: Johan Herland <johan@herland.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Thomas Rast committed Mar 12, 2010 at 18:04 UTC 7f710ea98262c7d81006c16c727796d9e6aeaa81

3 files changed +6

builtin-notes.c

@@ -249,6 +249,8 @@ int commit_notes(struct notes_tree *t, const char *msg)

249 t = &default_notes_tree;

250 if (!t->initialized || !t->ref || !*t->ref)

251 die("Cannot commit uninitialized/unreferenced notes tree");

252 + if (!t->dirty)

253 + return 0; /* don't have to commit an unchanged tree */

254

255 /* Prepare commit message and reflog message */

256 strbuf_addstr(&buf, "notes: "); /* commit message starts at index 7 */

notes.c

@@ -933,6 +933,7 @@ void init_notes(struct notes_tree *t, const char *notes_ref,

933 t->ref = notes_ref ? xstrdup(notes_ref) : NULL;

934 t->combine_notes = combine_notes;

935 t->initialized = 1;

936 + t->dirty = 0;

937

938 if (flags & NOTES_INIT_EMPTY || !notes_ref ||

939 read_ref(notes_ref, object_sha1))

@@ -1011,6 +1012,7 @@ void add_note(struct notes_tree *t, const unsigned char *object_sha1,

1012 if (!t)

1013 t = &default_notes_tree;

1014 assert(t->initialized);

1015 + t->dirty = 1;

1016 if (!combine_notes)

1017 combine_notes = t->combine_notes;

1018 l = (struct leaf_node *) xmalloc(sizeof(struct leaf_node));

@@ -1026,6 +1028,7 @@ void remove_note(struct notes_tree *t, const unsigned char *object_sha1)

1028 if (!t)

1029 t = &default_notes_tree;

1030 assert(t->initialized);

1031 + t->dirty = 1;

1032 hashcpy(l.key_sha1, object_sha1);

1033 hashclr(l.val_sha1);

1034 return note_tree_remove(t, t->root, 0, &l);

notes.h

@@ -40,6 +40,7 @@ extern struct notes_tree {

40 char *ref;

41 combine_notes_fn *combine_notes;

42 int initialized;

43 + int dirty;

44 } default_notes_tree;

46 /*