@matheusbsbs / matheus-bagliano / commits / 13528ab37c

list-objects: convert name_path to a strbuf

The "struct name_path" data is examined in only two places: we generate it in process_tree(), and we convert it to a single string in path_name(). Everyone else just passes it through to those functions. We can further note that process_tree() already keeps a single strbuf with the leading tree path, for use with tree_entry_interesting(). Instead of building a separate name_path linked list, let's just use the one we already build in "base". This reduces the amount of code (especially tricky code in path_name() which did not check for integer overflows caused by deep or large pathnames). It is also more efficient in some instances. Any time we were using tree_entry_interesting, we were building up the strbuf anyway, so this is an immediate and obvious win there. In cases where we were not, we trade off storing "pathname/" in a strbuf on the heap for each level of the path, instead of two pointers and an int on the stack (with one pointer into the tree object). On a 64-bit system, the latter is 20 bytes; so if path components are less than that on average, this has lower peak memory usage. In practice it probably doesn't matter either way; we are already holding in memory all of the tree objects leading up to each pathname, and for normal-depth pathnames, we are only talking about hundreds of bytes. This patch leaves "struct name_path" as a thin wrapper around the strbuf, to avoid disrupting callbacks. We should fix them, but leaving it out makes this diff easier to view. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jeff King committed Feb 11, 2016 at 17:26 UTC 13528ab37cadb4d4f7384d0449489760912904b8

3 files changed +15 -36

list-objects.c

+9 -13

@@ -62,7 +62,6 @@ static void process_gitlink(struct rev_info *revs,

62 static void process_tree(struct rev_info *revs,

63 struct tree *tree,

64 show_object_fn show,

65 - struct name_path *path,

65 struct strbuf *base,

66 const char *name,

67 void *cb_data)

@@ -86,17 +85,14 @@ static void process_tree(struct rev_info *revs,

85 return;

86 die("bad tree object %s", oid_to_hex(&obj->oid));

87 }

88 +

89 obj->flags |= SEEN;

90 - show(obj, path, name, cb_data);

91 - me.up = path;

92 - me.elem = name;

93 - me.elem_len = strlen(name);

94 -

95 - if (!match) {

96 - strbuf_addstr(base, name);

97 - if (base->len)

98 - strbuf_addch(base, '/');

99 - }

90 + me.base = base;

91 + show(obj, &me, name, cb_data);

92 +

93 + strbuf_addstr(base, name);

94 + if (base->len)

95 + strbuf_addch(base, '/');

97 init_tree_desc(&desc, tree->buffer, tree->size);

@@ -113,7 +109,7 @@ static void process_tree(struct rev_info *revs,

109 if (S_ISDIR(entry.mode))

110 process_tree(revs,

111 lookup_tree(entry.sha1),

116 - show, &me, base, entry.path,

112 + show, base, entry.path,

113 cb_data);

114 else if (S_ISGITLINK(entry.mode))

115 process_gitlink(revs, entry.sha1,

@@ -220,7 +216,7 @@ void traverse_commit_list(struct rev_info *revs,

216 path = "";

217 if (obj->type == OBJ_TREE) {

218 process_tree(revs, (struct tree *)obj, show_object,

223 - NULL, &base, path, data);

219 + &base, path, data);

220 continue;

221 }

222 if (obj->type == OBJ_BLOB) {

revision.c

+5 -20

@@ -27,26 +27,11 @@ static const char *term_good;

28 char *path_name(const struct name_path *path, const char *name)

29 {

30 - const struct name_path *p;

31 - char *n, *m;

32 - int nlen = strlen(name);

33 - int len = nlen + 1;

34 -

35 - for (p = path; p; p = p->up) {

36 - if (p->elem_len)

37 - len += p->elem_len + 1;

38 - }

39 - n = xmalloc(len);

40 - m = n + len - (nlen + 1);

41 - memcpy(m, name, nlen + 1);

42 - for (p = path; p; p = p->up) {

43 - if (p->elem_len) {

44 - m -= p->elem_len + 1;

45 - memcpy(m, p->elem, p->elem_len);

46 - m[p->elem_len] = '/';

47 - }

48 - }

49 - return n;

30 + struct strbuf ret = STRBUF_INIT;

31 + if (path)

32 + strbuf_addbuf(&ret, path->base);

33 + strbuf_addstr(&ret, name);

34 + return strbuf_detach(&ret, NULL);

35 }

37 void show_object_with_name(FILE *out, struct object *obj,

revision.h

+1 -3

@@ -258,9 +258,7 @@ extern void mark_parents_uninteresting(struct commit *commit);

258 extern void mark_tree_uninteresting(struct tree *tree);

259

260 struct name_path {

261 - struct name_path *up;

262 - int elem_len;

263 - const char *elem;

261 + struct strbuf *base;

262 };

263

264 char *path_name(const struct name_path *path, const char *name);