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, 21 insertions, 17 deletions

diff --git a/lib/sqfs/xattr_writer.c b/lib/sqfs/xattr_writer.c
index 047e411..827d0c5 100644
--- a/lib/sqfs/xattr_writer.c
+++ b/lib/sqfs/xattr_writer.c
@@ -99,6 +99,8 @@ typedef struct kv_block_desc_t {
 } kv_block_desc_t;
 
 struct sqfs_xattr_writer_t {
+	sqfs_object_t base;
+
 	str_table_t keys;
 	str_table_t values;
 
@@ -113,6 +115,23 @@ struct sqfs_xattr_writer_t {
 };
 
 
+static void xattr_writer_destroy(sqfs_object_t *obj)
+{
+	sqfs_xattr_writer_t *xwr = (sqfs_xattr_writer_t *)obj;
+	kv_block_desc_t *blk;
+
+	while (xwr->kv_blocks != NULL) {
+		blk = xwr->kv_blocks;
+		xwr->kv_blocks = xwr->kv_blocks->next;
+		free(blk);
+	}
+
+	free(xwr->kv_pairs);
+	str_table_cleanup(&xwr->values);
+	str_table_cleanup(&xwr->keys);
+	free(xwr);
+}
+
 sqfs_xattr_writer_t *sqfs_xattr_writer_create(void)
 {
 	sqfs_xattr_writer_t *xwr = calloc(1, sizeof(*xwr));
@@ -129,6 +148,7 @@ sqfs_xattr_writer_t *sqfs_xattr_writer_create(void)
 	if (xwr->kv_pairs == NULL)
 		goto fail_pairs;
 
+	((sqfs_object_t *)xwr)->destroy = xattr_writer_destroy;
 	return xwr;
 fail_pairs:
 	str_table_cleanup(&xwr->values);
@@ -139,22 +159,6 @@ fail_keys:
 	return NULL;
 }
 
-void sqfs_xattr_writer_destroy(sqfs_xattr_writer_t *xwr)
-{
-	kv_block_desc_t *blk;
-
-	while (xwr->kv_blocks != NULL) {
-		blk = xwr->kv_blocks;
-		xwr->kv_blocks = xwr->kv_blocks->next;
-		free(blk);
-	}
-
-	free(xwr->kv_pairs);
-	str_table_cleanup(&xwr->values);
-	str_table_cleanup(&xwr->keys);
-	free(xwr);
-}
-
 int sqfs_xattr_writer_begin(sqfs_xattr_writer_t *xwr)
 {
 	xwr->kv_start = xwr->num_pairs;
@@ -603,6 +607,6 @@ int sqfs_xattr_writer_flush(sqfs_xattr_writer_t *xwr, sqfs_file_t *file,
 				   locations, count);
 out:
 	free(locations);
-	sqfs_meta_writer_destroy(mw);
+	sqfs_destroy(mw);
 	return err;
 }