tree-diff: show_tree() is not needed

We don't need special code for showing added/removed subtree, because we
can do the same via diff_tree_sha1, just passing NULL for absent tree.

And compared to show_tree(), which was calling show_entry() for every
tree entry, that would lead to the same show_entry() callings:

show_tree(t):
for e in t.entries:
show_entry(e)

diff_tree_sha1(NULL, new):  /* the same applies to (old, NULL) */
diff_tree(t1=NULL, t2)
...
if (!t1->size)
show_entry(t2)
...

and possible overhead is negligible, since after the patch, timing for

`git log --raw --no-abbrev --no-renames`

for navy.git and `linux.git v3.10..v3.11` is practically the same.

So let's say goodbye to show_tree() - it removes some code, but also,
and what is important, consolidates more code for showing/recursing into
trees into one place.

Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/tree-diff.c b/tree-diff.c
index a8c2aecd1d31587591ca68496a1a0d6b49bdbce5..2ad778884a338f89e03c92ea672b10d3ea21b910 100644 (file)
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -55,25 +55,7 @@ static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2,
        return 0;
 }
 
-/* A whole sub-tree went away or appeared */
-static void show_tree(struct diff_options *opt, const char *prefix,
-                     struct tree_desc *desc, struct strbuf *base)
-{
-       enum interesting match = entry_not_interesting;
-       for (; desc->size; update_tree_entry(desc)) {
-               if (match != all_entries_interesting) {
-                       match = tree_entry_interesting(&desc->entry, base, 0,
-                                                      &opt->pathspec);
-                       if (match == all_entries_not_interesting)
-                               break;
-                       if (match == entry_not_interesting)
-                               continue;
-               }
-               show_entry(opt, prefix, desc, base);
-       }
-}
-
-/* A file entry went away or appeared */
+/* An entry went away or appeared */
 static void show_entry(struct diff_options *opt, const char *prefix,
                       struct tree_desc *desc, struct strbuf *base)
 {
@@ -85,23 +67,12 @@ static void show_entry(struct diff_options *opt, const char *prefix,
 
        strbuf_add(base, path, pathlen);
        if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode)) {
-               enum object_type type;
-               struct tree_desc inner;
-               void *tree;
-               unsigned long size;
-
-               tree = read_sha1_file(sha1, &type, &size);
-               if (!tree || type != OBJ_TREE)
-                       die("corrupt tree sha %s", sha1_to_hex(sha1));
-
                if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE))
                        opt->add_remove(opt, *prefix, mode, sha1, 1, base->buf, 0);
 
                strbuf_addch(base, '/');
-
-               init_tree_desc(&inner, tree, size);
-               show_tree(opt, prefix, &inner, base);
-               free(tree);
+               diff_tree_sha1(*prefix == '-' ? sha1 : NULL,
+                              *prefix == '+' ? sha1 : NULL, base->buf, opt);
        } else
                opt->add_remove(opt, prefix[0], mode, sha1, 1, base->buf, 0);