[PATCH 2/6] csum-file: make sha1 calculation optional

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 csum-file.c |   16 +++++++++++++---
 csum-file.h |    2 +-
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/csum-file.c b/csum-file.c
index 53f5375..4c517d1 100644
--- a/csum-file.c
+++ b/csum-file.c
@@ -11,6 +11,12 @@
 #include "progress.h"
 #include "csum-file.h"
 
+static void sha1update(struct sha1file *f, const void *data, unsigned offset)
+{
+	if (f->do_sha1)
+		git_SHA1_Update(&f->ctx, data, offset);
+}
+
 static void flush(struct sha1file *f, void *buf, unsigned int count)
 {
 	if (0 <= f->check_fd && count)  {
@@ -47,7 +53,7 @@ void sha1flush(struct sha1file *f)
 	unsigned offset = f->offset;
 
 	if (offset) {
-		git_SHA1_Update(&f->ctx, f->buffer, offset);
+		sha1update(f, f->buffer, offset);
 		flush(f, f->buffer, offset);
 		f->offset = 0;
 	}
@@ -58,7 +64,10 @@ int sha1close(struct sha1file *f, unsigned char *result, unsigned int flags)
 	int fd;
 
 	sha1flush(f);
-	git_SHA1_Final(f->buffer, &f->ctx);
+	if (f->do_sha1)
+		git_SHA1_Final(f->buffer, &f->ctx);
+	else
+		hashclr(f->buffer);
 	if (result)
 		hashcpy(result, f->buffer);
 	if (flags & (CSUM_CLOSE | CSUM_FSYNC)) {
@@ -110,7 +119,7 @@ int sha1write(struct sha1file *f, void *buf, unsigned int count)
 		buf = (char *) buf + nr;
 		left -= nr;
 		if (!left) {
-			git_SHA1_Update(&f->ctx, data, offset);
+			sha1update(f, data, offset);
 			flush(f, data, offset);
 			offset = 0;
 		}
@@ -154,6 +163,7 @@ struct sha1file *sha1fd_throughput(int fd, const char *name, struct progress *tp
 	f->tp = tp;
 	f->name = name;
 	f->do_crc = 0;
+	f->do_sha1 = 1;
 	git_SHA1_Init(&f->ctx);
 	return f;
 }
diff --git a/csum-file.h b/csum-file.h
index 3b540bd..c23ea62 100644
--- a/csum-file.h
+++ b/csum-file.h
@@ -12,7 +12,7 @@ struct sha1file {
 	off_t total;
 	struct progress *tp;
 	const char *name;
-	int do_crc;
+	int do_crc, do_sha1;
 	uint32_t crc32;
 	unsigned char buffer[8192];
 };
-- 
1.7.8.36.g69ee2