[PATCH] denser delta header encoding

[git.git] / count-delta.c

diff --git a/count-delta.c b/count-delta.c
index c7f3767..8901034 100644 (file)
--- a/count-delta.c
+++ b/count-delta.c
@@ -11,16 +11,13 @@
 static unsigned long get_hdr_size(const unsigned char **datap)
 {
        const unsigned char *data = *datap;
-       unsigned long size;
-       unsigned char cmd;
-       int i;
-       size = i = 0;
-       cmd = *data++;
-       while (cmd) {
-               if (cmd & 1)
-                       size |= *data++ << i;
-               i += 8;
-               cmd >>= 1;
+       unsigned char cmd = *data++;
+       unsigned long size = cmd & ~0x80;
+       int i = 7;
+       while (cmd & 0x80) {
+               cmd = *data++;
+               size |= (cmd & ~0x80) << i;
+               i += 7;
        }
        *datap = data;
        return size;
@@ -47,8 +44,8 @@ int count_delta(void *delta_buf, unsigned long delta_size,
        unsigned char cmd;
        unsigned long src_size, dst_size, out;
 
-       /* the smallest delta size possible is 6 bytes */
-       if (delta_size < 6)
+       /* the smallest delta size possible is 4 bytes */
+       if (delta_size < 4)
                return -1;
 
        data = delta_buf;