Commit f3badaed authored by Jeff King's avatar Jeff King Committed by Junio C Hamano

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: default avatarJeff King <peff@peff.net>
Signed-off-by: default avatarJunio C Hamano <gitster@pobox.com>
parent 8eee9f92
......@@ -62,7 +62,6 @@ static void process_gitlink(struct rev_info *revs,
static void process_tree(struct rev_info *revs,
struct tree *tree,
show_object_fn show,
struct name_path *path,
struct strbuf *base,
const char *name,
void *cb_data)
......@@ -86,17 +85,14 @@ static void process_tree(struct rev_info *revs,
return;
die("bad tree object %s", sha1_to_hex(obj->sha1));
}
obj->flags |= SEEN;
show(obj, path, name, cb_data);
me.up = path;
me.elem = name;
me.elem_len = strlen(name);
if (!match) {
strbuf_addstr(base, name);
if (base->len)
strbuf_addch(base, '/');
}
me.base = base;
show(obj, &me, name, cb_data);
strbuf_addstr(base, name);
if (base->len)
strbuf_addch(base, '/');
init_tree_desc(&desc, tree->buffer, tree->size);
......@@ -113,7 +109,7 @@ static void process_tree(struct rev_info *revs,
if (S_ISDIR(entry.mode))
process_tree(revs,
lookup_tree(entry.sha1),
show, &me, base, entry.path,
show, base, entry.path,
cb_data);
else if (S_ISGITLINK(entry.mode))
process_gitlink(revs, entry.sha1,
......@@ -220,7 +216,7 @@ void traverse_commit_list(struct rev_info *revs,
path = "";
if (obj->type == OBJ_TREE) {
process_tree(revs, (struct tree *)obj, show_object,
NULL, &base, path, data);
&base, path, data);
continue;
}
if (obj->type == OBJ_BLOB) {
......
......@@ -23,26 +23,11 @@ volatile show_early_output_fn_t show_early_output;
char *path_name(const struct name_path *path, const char *name)
{
const struct name_path *p;
char *n, *m;
int nlen = strlen(name);
int len = nlen + 1;
for (p = path; p; p = p->up) {
if (p->elem_len)
len += p->elem_len + 1;
}
n = xmalloc(len);
m = n + len - (nlen + 1);
strcpy(m, name);
for (p = path; p; p = p->up) {
if (p->elem_len) {
m -= p->elem_len + 1;
memcpy(m, p->elem, p->elem_len);
m[p->elem_len] = '/';
}
}
return n;
struct strbuf ret = STRBUF_INIT;
if (path)
strbuf_addbuf(&ret, path->base);
strbuf_addstr(&ret, name);
return strbuf_detach(&ret, NULL);
}
void show_object_with_name(FILE *out, struct object *obj,
......
......@@ -257,9 +257,7 @@ extern void mark_parents_uninteresting(struct commit *commit);
extern void mark_tree_uninteresting(struct tree *tree);
struct name_path {
struct name_path *up;
int elem_len;
const char *elem;
struct strbuf *base;
};
char *path_name(const struct name_path *path, const char *name);
......
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