path: root/unpack-trees.h
diff options
authorJunio C Hamano <>2010-01-07 22:59:54 (GMT)
committerJunio C Hamano <>2010-01-07 22:59:54 (GMT)
commitda165f470ede6540873d33cb8bc2ff8e13c60520 (patch)
treef17582a9b57a806bea9ba48c128b48f681baf692 /unpack-trees.h
parentcee2d6ae6379e7c76e602d55ccc1d4babc1979c0 (diff)
unpack-trees.c: prepare for looking ahead in the index
This prepares but does not yet implement a look-ahead in the index entries when traverse-trees.c decides to give us tree entries in an order that does not match what is in the index. A case where a look-ahead in the index is necessary happens when merging branch B into branch A while the index matches the current branch A, using a tree O as their common ancestor, and these three trees looks like this: O A B t t t-i t-i t-i t-j t-j t/1 t/2 The traverse_trees() function gets "t", "t-i" and "t" from trees O, A and B first, and notices that A may have a matching "t" behind "t-i" and "t-j" (indeed it does), and tells A to give that entry instead. After unpacking blob "t" from tree B (as it hasn't changed since O in B and A removed it, it will result in its removal), it descends into directory "t/". The side that walked index in parallel to the tree traversal used to be implemented with one pointer, o->pos, that points at the next index entry to be processed. When this happens, the pointer o->pos still points at "t-i" that is the first entry. We should be able to skip "t-i" and "t-j" and locate "t/1" from the index while the recursive invocation of traverse_trees() walks and match entries found there, and later come back to process "t-i". While that look-ahead is not implemented yet, this adds a flag bit, CE_UNPACKED, to mark the entries in the index that has already been processed. o->pos pointer has been renamed to o->cache_bottom and it points at the first entry that may still need to be processed. Signed-off-by: Junio C Hamano <>
Diffstat (limited to 'unpack-trees.h')
1 files changed, 1 insertions, 1 deletions
diff --git a/unpack-trees.h b/unpack-trees.h
index d19df44..9a0733e 100644
--- a/unpack-trees.h
+++ b/unpack-trees.h
@@ -30,7 +30,7 @@ struct unpack_trees_options {
const char *prefix;
- int pos;
+ int cache_bottom;
struct dir_struct *dir;
merge_fn_t fn;
struct unpack_trees_error_msgs msgs;