Implement reading and writing of compressor options

 - gensquashfs simply asks the backend compressor to write its options
   to the file and does accounting
 - rdsquasfs simply asks the backend compressor to transparentyl snort
   the options from the file
 - not implemented in any compressor backend yet

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

1 files changed, 20 insertions, 0 deletions

diff --git a/include/compress.h b/include/compress.h
index 5bb689b..a8542f2 100644
--- a/include/compress.h
+++ b/include/compress.h
@@ -19,6 +19,26 @@ typedef struct compressor_t compressor_t;
  */
 struct compressor_t {
 	/**
+	 * @brief Write compressor options to the output file if necessary
+	 *
+	 * @param cmp A pointer to the compressor object
+	 * @param fd  The file descriptor to write to
+	 *
+	 * @return The number of bytes written or -1 on failure
+	 */
+	int (*write_options)(compressor_t *cmp, int fd);
+
+	/**
+	 * @brief Read compressor options to the input file
+	 *
+	 * @param cmp A pointer to the compressor object
+	 * @param fd  The file descriptor to write to
+	 *
+	 * @return Zero on success, -1 on failure
+	 */
+	int (*read_options)(compressor_t *cmp, int fd);
+
+	/**
 	 * @brief Compress or uncompress a chunk of data
 	 *
 	 * @param cmp     A pointer to the compressor object