Change the signature of sqfs_compressor_create to return an error code

Make sure the function has a way of telling the caller *why* it failed.

This way, the function can convey whether it had an internal error, an
allocation failure, whether the arguments are totaly nonsensical, or
simply that the compressor *or specific configuration* is not supported.

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

1 files changed, 7 insertions, 4 deletions

diff --git a/lib/sqfs/comp/lz4.c b/lib/sqfs/comp/lz4.c
index 460ac44..4791746 100644
--- a/lib/sqfs/comp/lz4.c
+++ b/lib/sqfs/comp/lz4.c
@@ -132,20 +132,21 @@ static void lz4_destroy(sqfs_object_t *base)
 	free(base);
 }
 
-sqfs_compressor_t *lz4_compressor_create(const sqfs_compressor_config_t *cfg)
+int lz4_compressor_create(const sqfs_compressor_config_t *cfg,
+			  sqfs_compressor_t **out)
 {
 	sqfs_compressor_t *base;
 	lz4_compressor_t *lz4;
 
 	if (cfg->flags & ~(SQFS_COMP_FLAG_LZ4_ALL |
 			   SQFS_COMP_FLAG_GENERIC_ALL)) {
-		return NULL;
+		return SQFS_ERROR_UNSUPPORTED;
 	}
 
 	lz4 = calloc(1, sizeof(*lz4));
 	base = (sqfs_compressor_t *)lz4;
 	if (lz4 == NULL)
-		return NULL;
+		return SQFS_ERROR_ALLOC;
 
 	lz4->high_compression = (cfg->flags & SQFS_COMP_FLAG_LZ4_HC) != 0;
 	lz4->block_size = cfg->block_size;
@@ -157,5 +158,7 @@ sqfs_compressor_t *lz4_compressor_create(const sqfs_compressor_config_t *cfg)
 	base->read_options = lz4_read_options;
 	((sqfs_object_t *)base)->copy = lz4_create_copy;
 	((sqfs_object_t *)base)->destroy = lz4_destroy;
-	return base;
+
+	*out = base;
+	return 0;
 }