xcrc32(): create extended crc32 for 64 bit compatibility

On Windows, uInt/uLong are only 32 bits. Create a compatibility function.

Signed-off-by: Philip Oakley <philipoakley@iee.org>

Author: Philip Oakley

cache.h

@@ -1887,4 +1887,10 @@ int print_sha1_ellipsis(void);
 /* Return 1 if the file is empty or does not exists, 0 otherwise. */
 int is_empty_or_missing_file(const char *filename);
 
+/*
+ * Extended crc32 with 64 bit address range
+ * On Windows, uInt/uLong are only 32 bits.
+ */
+extern uLong xcrc32(uLong crc, const unsigned char *buf, size_t bytes);
+
 #endif /* CACHE_H */

wrapper.c

@@ -703,3 +703,19 @@ int is_empty_or_missing_file(const char *filename)
 
 	return !st.st_size;
 }
+
+uLong xcrc32(uLong crc, const unsigned char *buf, size_t bytes)
+{
+	size_t bytes_rem, off;
+	bytes_rem = bytes;
+	off = 0;
+	while (bytes_rem) {
+		int crc_bytes = maximum_signed_value_of_type(int);
+		if (crc_bytes > bytes_rem)
+			crc_bytes = bytes_rem;
+		crc = crc32(crc, buf + off, crc_bytes);
+		off += crc_bytes;
+		bytes_rem -= crc_bytes;
+	}
+	return crc;
+}