negotiator/skipping: skip commits during fetch

Introduce a new negotiation algorithm used during fetch that skips
commits in an effort to find common ancestors faster. The skips grow
similarly to the Fibonacci sequence as the commit walk proceeds further
away from the tips. The skips may cause unnecessary commits to be
included in the packfile, but the negotiation step typically ends more
quickly.

Usage of this algorithm is guarded behind the configuration flag
fetch.negotiationAlgorithm.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index 96f84d1..6174756 100644
--- a/Makefile
+++ b/Makefile
@@ -893,6 +893,7 @@ LIB_OBJS += merge-recursive.o
 LIB_OBJS += mergesort.o
 LIB_OBJS += name-hash.o
 LIB_OBJS += negotiator/default.o
+LIB_OBJS += negotiator/skipping.o
 LIB_OBJS += notes.o
 LIB_OBJS += notes-cache.o
 LIB_OBJS += notes-merge.o