reference.c: Don't duplicate stream entries unnecessarily

With wimlib_reference_resource_files(), the resource WIMs are never made
accessible to library users, so there is no need to retain copies of all
stream entries in their lookup tables.

diff --git a/src/reference.c b/src/reference.c
index 3238abe464434be1cd5be79e0cfb854ff6122984..c423bdd7ada1d0d669fbca9e8e3dae8e64077828 100644 (file)
--- a/src/reference.c
+++ b/src/reference.c
@@ -36,6 +36,30 @@
 #define WIMLIB_REF_MASK_PUBLIC (WIMLIB_REF_FLAG_GLOB_ENABLE | \
                                WIMLIB_REF_FLAG_GLOB_ERR_ON_NOMATCH)
 
+#define WIMLIB_REF_FLAG_GIFT 0x80000000
+
+struct lookup_tables {
+       struct wim_lookup_table *src_table;
+       struct wim_lookup_table *dest_table;
+};
+
+static int
+lte_gift(struct wim_lookup_table_entry *lte, void *_tables)
+{
+       struct lookup_tables *tables = _tables;
+       struct wim_lookup_table *src_table = tables->src_table;
+       struct wim_lookup_table *dest_table = tables->dest_table;
+
+       lookup_table_unlink(src_table, lte);
+       if (lookup_stream(dest_table, lte->hash)) {
+               free_lookup_table_entry(lte);
+       } else {
+               lte->out_refcnt = 1;
+               lookup_table_insert(dest_table, lte);
+       }
+       return 0;
+}
+
 static int
 lte_clone_if_new(struct wim_lookup_table_entry *lte, void *_lookup_table)
 {
@@ -64,13 +88,49 @@ lte_delete_if_new(struct wim_lookup_table_entry *lte, void *_lookup_table)
        return 0;
 }
 
+static int
+do_wimlib_reference_resources(WIMStruct *wim, WIMStruct **resource_wims,
+                             unsigned num_resource_wims, int ref_flags)
+{
+       unsigned i;
+       int ret;
+
+       if (ref_flags & WIMLIB_REF_FLAG_GIFT) {
+               struct lookup_tables tables;
+
+               tables.dest_table = wim->lookup_table;
+
+               for (i = 0; i < num_resource_wims; i++) {
+
+                       tables.src_table = resource_wims[i]->lookup_table;
+
+                       ret = for_lookup_table_entry(resource_wims[i]->lookup_table,
+                                                    lte_gift, &tables);
+                       if (ret)
+                               goto out_rollback;
+               }
+       } else {
+               for (i = 0; i < num_resource_wims; i++) {
+                       ret = for_lookup_table_entry(resource_wims[i]->lookup_table,
+                                                    lte_clone_if_new, wim->lookup_table);
+                       if (ret)
+                               goto out_rollback;
+               }
+       }
+       return 0;
+
+out_rollback:
+       for_lookup_table_entry(wim->lookup_table, lte_delete_if_new,
+                              wim->lookup_table);
+       return ret;
+}
+
 /* API function documented in wimlib.h  */
 WIMLIBAPI int
 wimlib_reference_resources(WIMStruct *wim,
                           WIMStruct **resource_wims, unsigned num_resource_wims,
                           int ref_flags)
 {
-       int ret;
        unsigned i;
 
        if (wim == NULL)
@@ -86,21 +146,8 @@ wimlib_reference_resources(WIMStruct *wim,
                if (resource_wims[i] == NULL)
                        return WIMLIB_ERR_INVALID_PARAM;
 
-       for_lookup_table_entry(wim->lookup_table, lte_zero_out_refcnt, NULL);
-
-       for (i = 0; i < num_resource_wims; i++) {
-               ret = for_lookup_table_entry(resource_wims[i]->lookup_table,
-                                            lte_clone_if_new,
-                                            wim->lookup_table);
-               if (ret)
-                       goto out_rollback;
-       }
-       return 0;
-
-out_rollback:
-       for_lookup_table_entry(wim->lookup_table, lte_delete_if_new,
-                              wim->lookup_table);
-       return ret;
+       return do_wimlib_reference_resources(wim, resource_wims,
+                                            num_resource_wims, ref_flags);
 }
 
 static int
@@ -128,8 +175,9 @@ reference_resource_paths(WIMStruct *wim,
                        goto out_free_resource_wims;
        }
 
-       ret = wimlib_reference_resources(wim, resource_wims,
-                                        num_resource_wimfiles, ref_flags);
+       ret = do_wimlib_reference_resources(wim, resource_wims,
+                                           num_resource_wimfiles,
+                                           ref_flags | WIMLIB_REF_FLAG_GIFT);
        if (ret)
                goto out_free_resource_wims;