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>

3 files changed, 51 insertions, 0 deletions

diff --git a/lib/comp/gzip.c b/lib/comp/gzip.c
index ea634b8..ea86f98 100644
--- a/lib/comp/gzip.c
+++ b/lib/comp/gzip.c
@@ -29,6 +29,21 @@ static void gzip_destroy(compressor_t *base)
 	free(gzip);
 }
 
+static int gzip_write_options(compressor_t *base, int fd)
+{
+	(void)base;
+	(void)fd;
+	return 0;
+}
+
+static int gzip_read_options(compressor_t *base, int fd)
+{
+	(void)base;
+	(void)fd;
+	fputs("gzip extra options are not yet implemented\n", stderr);
+	return -1;
+}
+
 static ssize_t gzip_do_block(compressor_t *base, const uint8_t *in,
 			     size_t size, uint8_t *out, size_t outsize)
 {
@@ -90,6 +105,8 @@ compressor_t *create_gzip_compressor(bool compress, size_t block_size)
 	gzip->block_size = block_size;
 	base->do_block = gzip_do_block;
 	base->destroy = gzip_destroy;
+	base->write_options = gzip_write_options;
+	base->read_options = gzip_read_options;
 
 	if (compress) {
 		ret = deflateInit(&gzip->strm, Z_BEST_COMPRESSION);
diff --git a/lib/comp/lzo.c b/lib/comp/lzo.c
index 30b14cb..95ab485 100644
--- a/lib/comp/lzo.c
+++ b/lib/comp/lzo.c
@@ -14,6 +14,21 @@ typedef struct {
 	uint8_t buffer[LZO1X_999_MEM_COMPRESS];
 } lzo_compressor_t;
 
+static int lzo_write_options(compressor_t *base, int fd)
+{
+	(void)base;
+	(void)fd;
+	return 0;
+}
+
+static int lzo_read_options(compressor_t *base, int fd)
+{
+	(void)base;
+	(void)fd;
+	fputs("lzo extra options are not yet implemented\n", stderr);
+	return -1;
+}
+
 static ssize_t lzo_comp_block(compressor_t *base, const uint8_t *in,
 			      size_t size, uint8_t *out, size_t outsize)
 {
@@ -67,5 +82,7 @@ compressor_t *create_lzo_compressor(bool compress, size_t block_size)
 
 	base->destroy = lzo_destroy;
 	base->do_block = compress ? lzo_comp_block : lzo_uncomp_block;
+	base->write_options = lzo_write_options;
+	base->read_options = lzo_read_options;
 	return base;
 }
diff --git a/lib/comp/xz.c b/lib/comp/xz.c
index 98d740c..dd608ba 100644
--- a/lib/comp/xz.c
+++ b/lib/comp/xz.c
@@ -12,6 +12,21 @@ typedef struct {
 	size_t block_size;
 } xz_compressor_t;
 
+static int xz_write_options(compressor_t *base, int fd)
+{
+	(void)base;
+	(void)fd;
+	return 0;
+}
+
+static int xz_read_options(compressor_t *base, int fd)
+{
+	(void)base;
+	(void)fd;
+	fputs("xz extra options are not yet implemented\n", stderr);
+	return -1;
+}
+
 static ssize_t xz_comp_block(compressor_t *base, const uint8_t *in,
 			       size_t size, uint8_t *out, size_t outsize)
 {
@@ -86,5 +101,7 @@ compressor_t *create_xz_compressor(bool compress, size_t block_size)
 	xz->block_size = block_size;
 	base->destroy = xz_destroy;
 	base->do_block = compress ? xz_comp_block : xz_uncomp_block;
+	base->write_options = xz_write_options;
+	base->read_options = xz_read_options;
 	return base;
 }