csum-file: introduce hashfile_total()

We will need this helper function in a following commit
to give us total number of bytes fed to the hashfile so far.

Signed-off-by: Jeff King <[email protected]>
Signed-off-by: Christian Couder <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: peff

csum-file.h

@@ -42,6 +42,15 @@ void hashflush(struct hashfile *f);
 void crc32_begin(struct hashfile *);
 uint32_t crc32_end(struct hashfile *);
 
+/*
+ * Returns the total number of bytes fed to the hashfile so far (including ones
+ * that have not been written out to the descriptor yet).
+ */
+static inline off_t hashfile_total(struct hashfile *f)
+{
+	return f->total + f->offset;
+}
+
 static inline void hashwrite_u8(struct hashfile *f, uint8_t data)
 {
 	hashwrite(f, &data, sizeof(data));