Implement a more explicit object system

Make every dynamically allocated, opaque data structure inherit from
a common sqfs_object_t structure with common entry points (e.g. destroy).

This removes tons of public API functions and replaces them with a
simple sqfs_destroy instead. If semantics of the (until now implicit)
object system need to be extended, it can be much more conveniantely
done this way.

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

1 files changed, 13 insertions, 8 deletions

diff --git a/lib/sqfs/data_reader.c b/lib/sqfs/data_reader.c
index c8886c5..8c9bb2e 100644
--- a/lib/sqfs/data_reader.c
+++ b/lib/sqfs/data_reader.c
@@ -21,6 +21,8 @@
 #include <string.h>
 
 struct sqfs_data_reader_t {
+	sqfs_object_t obj;
+
 	sqfs_frag_table_t *frag_tbl;
 	sqfs_compressor_t *cmp;
 	sqfs_file_t *file;
@@ -125,6 +127,16 @@ static int precache_fragment_block(sqfs_data_reader_t *data, size_t idx)
 			 &data->frag_blk_size, &data->frag_block);
 }
 
+static void data_reader_destroy(sqfs_object_t *obj)
+{
+	sqfs_data_reader_t *data = (sqfs_data_reader_t *)obj;
+
+	sqfs_destroy(data->frag_tbl);
+	free(data->data_block);
+	free(data->frag_block);
+	free(data);
+}
+
 sqfs_data_reader_t *sqfs_data_reader_create(sqfs_file_t *file,
 					    size_t block_size,
 					    sqfs_compressor_t *cmp)
@@ -140,6 +152,7 @@ sqfs_data_reader_t *sqfs_data_reader_create(sqfs_file_t *file,
 		return NULL;
 	}
 
+	((sqfs_object_t *)data)->destroy = data_reader_destroy;
 	data->file = file;
 	data->block_size = block_size;
 	data->cmp = cmp;
@@ -164,14 +177,6 @@ int sqfs_data_reader_load_fragment_table(sqfs_data_reader_t *data,
 	return 0;
 }
 
-void sqfs_data_reader_destroy(sqfs_data_reader_t *data)
-{
-	sqfs_frag_table_destroy(data->frag_tbl);
-	free(data->data_block);
-	free(data->frag_block);
-	free(data);
-}
-
 int sqfs_data_reader_get_block(sqfs_data_reader_t *data,
 			       const sqfs_inode_generic_t *inode,
 			       size_t index, size_t *size, sqfs_u8 **out)