Optimize the common cases of git-read-tree

diff --git a/diffcore-delta.c b/diffcore-delta.c
index 7116df0b83f68b9d31dc8e4c3a89ad365a138a37..d9729e5ec27d2ff2bacf4ed930195f9293f8ca5a 100644 (file)
--- a/diffcore-delta.c
+++ b/diffcore-delta.c
@@ -122,11 +122,14 @@ static struct spanhash_top *add_spanhash(struct spanhash_top *top,
        }
 }
 
-static struct spanhash_top *hash_chars(unsigned char *buf, unsigned int sz)
+static struct spanhash_top *hash_chars(struct diff_filespec *one)
 {
        int i, n;
        unsigned int accum1, accum2, hashval;
        struct spanhash_top *hash;
+       unsigned char *buf = one->data;
+       unsigned int sz = one->size;
+       int is_text = !diff_filespec_is_binary(one);
 
        i = INITIAL_HASH_SIZE;
        hash = xmalloc(sizeof(*hash) + sizeof(struct spanhash) * (1<<i));
@@ -140,6 +143,11 @@ static struct spanhash_top *hash_chars(unsigned char *buf, unsigned int sz)
                unsigned int c = *buf++;
                unsigned int old_1 = accum1;
                sz--;
+
+               /* Ignore CR in CRLF sequence if text */
+               if (is_text && c == '\r' && sz && *buf == '\n')
+                       continue;
+
                accum1 = (accum1 << 7) ^ (accum2 >> 25);
                accum2 = (accum2 << 7) ^ (old_1 >> 25);
                accum1 += c;
@@ -169,14 +177,14 @@ int diffcore_count_changes(struct diff_filespec *src,
        if (src_count_p)
                src_count = *src_count_p;
        if (!src_count) {
-               src_count = hash_chars(src->data, src->size);
+               src_count = hash_chars(src);
                if (src_count_p)
                        *src_count_p = src_count;
        }
        if (dst_count_p)
                dst_count = *dst_count_p;
        if (!dst_count) {
-               dst_count = hash_chars(dst->data, dst->size);
+               dst_count = hash_chars(dst);
                if (dst_count_p)
                        *dst_count_p = dst_count;
        }