Replace direct file I/O with abstraction layer

This should make it easier to use libsquashfs with custom setups that
embedd a squashfs image inside something else. Also, it should make
it easier to port to non unix-like platforms.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 30 insertions, 0 deletions

diff --git a/lib/util/padd_file.c b/lib/util/padd_file.c
index 9a2428d..21950b4 100644
--- a/lib/util/padd_file.c
+++ b/lib/util/padd_file.c
@@ -6,6 +6,7 @@
  */
 #include "config.h"
 
+#include "sqfs/io.h"
 #include "util.h"
 
 #include <stdlib.h>
@@ -39,3 +40,32 @@ fail_errno:
 	perror("padding output file to block size");
 	goto out;
 }
+
+int padd_sqfs(sqfs_file_t *file, uint64_t size, size_t blocksize)
+{
+	size_t padd_sz = size % blocksize;
+	int status = -1;
+	uint8_t *buffer;
+
+	if (padd_sz == 0)
+		return 0;
+
+	padd_sz = blocksize - padd_sz;
+
+	buffer = calloc(1, padd_sz);
+	if (buffer == NULL)
+		goto fail_errno;
+
+	if (file->write_at(file, file->get_size(file),
+			   buffer, padd_sz)) {
+		goto fail_errno;
+	}
+
+	status = 0;
+out:
+	free(buffer);
+	return status;
+fail_errno:
+	perror("padding output file to block size");
+	goto out;
+}