wim.c: replace finalize_wim_struct() with wim_decrement_refcnt()

[wimlib] / src / wim.c

diff --git a/src/wim.c b/src/wim.c
index e77d71704ece213305bf3b45e878793692e19813..b5827171ba91e139d9f7a5c83cc756d8b08041c0 100644 (file)
--- a/src/wim.c
+++ b/src/wim.c
@@ -146,12 +146,12 @@ new_wim_struct(void)
        if (!wim)
                return NULL;
 
+       wim->refcnt = 1;
        filedes_invalidate(&wim->in_fd);
        filedes_invalidate(&wim->out_fd);
        wim->out_solid_compression_type = wim_default_solid_compression_type();
        wim->out_solid_chunk_size = wim_default_solid_chunk_size(
                                        wim->out_solid_compression_type);
-       INIT_LIST_HEAD(&wim->subwims);
        return wim;
 }
 
@@ -867,38 +867,45 @@ can_modify_wim(WIMStruct *wim)
        return 0;
 }
 
-/* API function documented in wimlib.h  */
-WIMLIBAPI void
-wimlib_free(WIMStruct *wim)
+/* Release a reference to a WIMStruct.  If the reference count reaches 0, the
+ * WIMStruct is freed.  */
+void
+wim_decrement_refcnt(WIMStruct *wim)
 {
-       if (!wim)
+       wimlib_assert(wim->refcnt > 0);
+       if (--wim->refcnt != 0)
                return;
-
-       while (!list_empty(&wim->subwims)) {
-               WIMStruct *subwim;
-
-               subwim = list_entry(wim->subwims.next, WIMStruct, subwim_node);
-               list_del(&subwim->subwim_node);
-               wimlib_free(subwim);
-       }
-
        if (filedes_valid(&wim->in_fd))
                filedes_close(&wim->in_fd);
        if (filedes_valid(&wim->out_fd))
                filedes_close(&wim->out_fd);
+       wimlib_free_decompressor(wim->decompressor);
+       xml_free_info_struct(wim->xml_info);
+       FREE(wim->filename);
+       FREE(wim);
+}
 
-       free_blob_table(wim->blob_table);
+/* API function documented in wimlib.h  */
+WIMLIBAPI void
+wimlib_free(WIMStruct *wim)
+{
+       if (!wim)
+               return;
 
-       wimlib_free_decompressor(wim->decompressor);
+       /* The blob table and image metadata are freed immediately, but other
+        * members of the WIMStruct such as the input file descriptor are
+        * retained until no more exported resources reference the WIMStruct. */
 
-       FREE(wim->filename);
-       xml_free_info_struct(wim->xml_info);
-       if (wim->image_metadata) {
-               for (unsigned i = 0; i < wim->hdr.image_count; i++)
+       free_blob_table(wim->blob_table);
+       wim->blob_table = NULL;
+       if (wim->image_metadata != NULL) {
+               for (int i = 0; i < wim->hdr.image_count; i++)
                        put_image_metadata(wim->image_metadata[i], NULL);
                FREE(wim->image_metadata);
+               wim->image_metadata = NULL;
        }
-       FREE(wim);
+
+       wim_decrement_refcnt(wim);
 }
 
 static bool