libio: remove ostream_append_sparse and fallback implementation

Instead of a separate append-sparse function, simply accept NULL
as an input for append. For both Unix and Win32, a fallback needs
to be implemented. For XFRM, we can just memset the input buffer
to zero, same for the libsquashfs data writer.

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

2 files changed, 7 insertions, 32 deletions

diff --git a/include/io/file.h b/include/io/file.h
index f3723b2..44fd224 100644
--- a/include/io/file.h
+++ b/include/io/file.h
@@ -18,6 +18,11 @@ typedef HANDLE os_file_t;
 typedef int os_file_t;
 #endif
 
+enum {
+	OSTREAM_OPEN_OVERWRITE = 0x01,
+	OSTREAM_OPEN_SPARSE = 0x02,
+};
+
 #ifdef __cplusplus
 extern "C" {
 #endif
diff --git a/include/io/ostream.h b/include/io/ostream.h
index 8fc8cef..7a57e48 100644
--- a/include/io/ostream.h
+++ b/include/io/ostream.h
@@ -23,15 +23,14 @@ typedef struct ostream_t {
 	 * @brief Append a block of data to an output stream.
 	 *
 	 * @param strm A pointer to an output stream.
-	 * @param data A pointer to the data block to append.
+	 * @param data A pointer to the data block to append. If NULL,
+	 *             synthesize a chunk of zero bytes.
 	 * @param size The number of bytes to append.
 	 *
 	 * @return Zero on success, -1 on failure.
 	 */
 	int (*append)(struct ostream_t *strm, const void *data, size_t size);
 
-	int (*append_sparse)(struct ostream_t *strm, size_t size);
-
 	/**
 	 * @brief Process all pending, buffered data and flush it to disk.
 	 *
@@ -56,33 +55,4 @@ typedef struct ostream_t {
 	const char *(*get_filename)(struct ostream_t *strm);
 } ostream_t;
 
-enum {
-	OSTREAM_OPEN_OVERWRITE = 0x01,
-	OSTREAM_OPEN_SPARSE = 0x02,
-};
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/**
- * @brief Append a number of zero bytes to an output stream.
- *
- * @memberof ostream_t
- *
- * If the unerlying implementation supports sparse files, this function can be
- * used to create a "hole". If the implementation does not support it, a
- * fallback is used that just appends a block of zeros manualy.
- *
- * @param strm A pointer to an output stream.
- * @param size The number of zero bytes to append.
- *
- * @return Zero on success, -1 on failure.
- */
-SQFS_INTERNAL int ostream_append_sparse(ostream_t *strm, size_t size);
-
-#ifdef __cplusplus
-}
-#endif
-
 #endif /* IO_OSTREAM_H */