cache: add a function to read an object ID from a buffer

In various places throughout the codebase, we need to read data into a
struct object_id from a pack or other unsigned char buffer.  Add an
inline function that does this based on the current hash algorithm in
use, and use it in several places.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/cache.h b/cache.h
index bbaf5c349a..4bca177cf3 100644
--- a/cache.h
+++ b/cache.h
@@ -1008,6 +1008,11 @@ static inline void oidclr(struct object_id *oid)
 	memset(oid->hash, 0, GIT_MAX_RAWSZ);
 }
 
+static inline void oidread(struct object_id *oid, const unsigned char *hash)
+{
+	memcpy(oid->hash, hash, the_hash_algo->rawsz);
+}
+
 
 #define EMPTY_TREE_SHA1_HEX \
 	"4b825dc642cb6eb9a060e54bf8d69288fbee4904"