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authorLinus Torvalds <torvalds@osdl.org>2006-02-16 03:25:32 (GMT)
committerJunio C Hamano <junkio@cox.net>2006-02-16 07:39:11 (GMT)
commit164dcb97f0cd1accaec4ed40c24881f8e9ae4371 (patch)
tree7c77a578961358c38c7d6061f5190a79a8b08765 /merge-tree.c
parent01df529722618a78d2acf6159c7b1e65f565cabc (diff)
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git-merge-tree: generalize the "traverse <n> trees in sync" functionality
It's actually very useful for other things too. Notably, we could do the combined diff a lot more efficiently with this. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
Diffstat (limited to 'merge-tree.c')
-rw-r--r--merge-tree.c120
1 files changed, 67 insertions, 53 deletions
diff --git a/merge-tree.c b/merge-tree.c
index 6381118..768d83a 100644
--- a/merge-tree.c
+++ b/merge-tree.c
@@ -125,44 +125,19 @@ static void unresolved(const char *base, struct name_entry n[3])
printf("3 %06o %s %s%s\n", n[2].mode, sha1_to_hex(n[2].sha1), base, n[2].path);
}
-/*
- * Merge two trees together (t[1] and t[2]), using a common base (t[0])
- * as the origin.
- *
- * This walks the (sorted) trees in lock-step, checking every possible
- * name. Note that directories automatically sort differently from other
- * files (see "base_name_compare"), so you'll never see file/directory
- * conflicts, because they won't ever compare the same.
- *
- * IOW, if a directory changes to a filename, it will automatically be
- * seen as the directory going away, and the filename being created.
- *
- * Think of this as a three-way diff.
- *
- * The output will be either:
- * - successful merge
- * "0 mode sha1 filename"
- * NOTE NOTE NOTE! FIXME! We really really need to walk the index
- * in parallel with this too!
- *
- * - conflict:
- * "1 mode sha1 filename"
- * "2 mode sha1 filename"
- * "3 mode sha1 filename"
- * where not all of the 1/2/3 lines may exist, of course.
- *
- * The successful merge rules are the same as for the three-way merge
- * in git-read-tree.
- */
-static void merge_trees(struct tree_desc t[3], const char *base)
+typedef void (*traverse_callback_t)(int n, unsigned long mask, struct name_entry *entry, const char *base);
+
+static void traverse_trees(int n, struct tree_desc *t, const char *base, traverse_callback_t callback)
{
+ struct name_entry *entry = xmalloc(n*sizeof(*entry));
+
for (;;) {
struct name_entry entry[3];
- unsigned int mask = 0;
+ unsigned long mask = 0;
int i, last;
last = -1;
- for (i = 0; i < 3; i++) {
+ for (i = 0; i < n; i++) {
if (!t[i].size)
continue;
entry_extract(t+i, entry+i);
@@ -182,7 +157,7 @@ static void merge_trees(struct tree_desc t[3], const char *base)
if (cmp < 0)
mask = 0;
}
- mask |= 1u << i;
+ mask |= 1ul << i;
last = i;
}
if (!mask)
@@ -192,38 +167,77 @@ static void merge_trees(struct tree_desc t[3], const char *base)
* Update the tree entries we've walked, and clear
* all the unused name-entries.
*/
- for (i = 0; i < 3; i++) {
- if (mask & (1u << i)) {
+ for (i = 0; i < n; i++) {
+ if (mask & (1ul << i)) {
update_tree_entry(t+i);
continue;
}
entry_clear(entry + i);
}
+ callback(n, mask, entry, base);
+ }
+ free(entry);
+}
- /* Same in both? */
- if (same_entry(entry+1, entry+2)) {
- if (entry[0].sha1) {
- resolve(base, NULL, entry+1);
- continue;
- }
+/*
+ * Merge two trees together (t[1] and t[2]), using a common base (t[0])
+ * as the origin.
+ *
+ * This walks the (sorted) trees in lock-step, checking every possible
+ * name. Note that directories automatically sort differently from other
+ * files (see "base_name_compare"), so you'll never see file/directory
+ * conflicts, because they won't ever compare the same.
+ *
+ * IOW, if a directory changes to a filename, it will automatically be
+ * seen as the directory going away, and the filename being created.
+ *
+ * Think of this as a three-way diff.
+ *
+ * The output will be either:
+ * - successful merge
+ * "0 mode sha1 filename"
+ * NOTE NOTE NOTE! FIXME! We really really need to walk the index
+ * in parallel with this too!
+ *
+ * - conflict:
+ * "1 mode sha1 filename"
+ * "2 mode sha1 filename"
+ * "3 mode sha1 filename"
+ * where not all of the 1/2/3 lines may exist, of course.
+ *
+ * The successful merge rules are the same as for the three-way merge
+ * in git-read-tree.
+ */
+static void threeway_callback(int n, unsigned long mask, struct name_entry *entry, const char *base)
+{
+ /* Same in both? */
+ if (same_entry(entry+1, entry+2)) {
+ if (entry[0].sha1) {
+ resolve(base, NULL, entry+1);
+ return;
}
+ }
- if (same_entry(entry+0, entry+1)) {
- if (entry[2].sha1 && !S_ISDIR(entry[2].mode)) {
- resolve(base, entry+1, entry+2);
- continue;
- }
+ if (same_entry(entry+0, entry+1)) {
+ if (entry[2].sha1 && !S_ISDIR(entry[2].mode)) {
+ resolve(base, entry+1, entry+2);
+ return;
}
+ }
- if (same_entry(entry+0, entry+2)) {
- if (entry[1].sha1 && !S_ISDIR(entry[1].mode)) {
- resolve(base, NULL, entry+1);
- continue;
- }
+ if (same_entry(entry+0, entry+2)) {
+ if (entry[1].sha1 && !S_ISDIR(entry[1].mode)) {
+ resolve(base, NULL, entry+1);
+ return;
}
-
- unresolved(base, entry);
}
+
+ unresolved(base, entry);
+}
+
+static void merge_trees(struct tree_desc t[3], const char *base)
+{
+ traverse_trees(3, t, base, threeway_callback);
}
static void *get_tree_descriptor(struct tree_desc *desc, const char *rev)