combine-diff: speed it up, by using multiparent diff tree-walker directly

diff --git a/cache.h b/cache.h
index dc040fb1aa99b7970e85e5b175e60f862ff6a74a..e7f5a0c7c8038336392d33a09df3933c3d72dac9 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -74,6 +74,21 @@ unsigned long git_deflate_bound(git_zstream *, unsigned long);
 #define S_IFGITLINK    0160000
 #define S_ISGITLINK(m) (((m) & S_IFMT) == S_IFGITLINK)
 
+/*
+ * Some mode bits are also used internally for computations.
+ *
+ * They *must* not overlap with any valid modes, and they *must* not be emitted
+ * to outside world - i.e. appear on disk or network. In other words, it's just
+ * temporary fields, which we internally use, but they have to stay in-house.
+ *
+ * ( such approach is valid, as standard S_IF* fits into 16 bits, and in Git
+ *   codebase mode is `unsigned int` which is assumed to be at least 32 bits )
+ */
+
+/* used internally in tree-diff */
+#define S_DIFFTREE_IFXMIN_NEQ  0x80000000
+
+
 /*
  * Intensive research over the course of many years has shown that
  * port 9418 is totally unused by anything else. Or