wimlib-imagex, wimlib: Optimize appending new image as update of existing

[wimlib] / src / dentry.c

diff --git a/src/dentry.c b/src/dentry.c
index c9a84d718eee2952197886e634cf1fcb12594335..ca9fe0b18993eedc604eac4d393665535fe1fe6d 100644 (file)
--- a/src/dentry.c
+++ b/src/dentry.c
@@ -1086,6 +1086,19 @@ new_filler_directory(const tchar *name, struct wim_dentry **dentry_ret)
        return 0;
 }
 
+static int
+dentry_clear_inode_visited(struct wim_dentry *dentry, void *_ignore)
+{
+       dentry->d_inode->i_visited = 0;
+       return 0;
+}
+
+void
+dentry_tree_clear_inode_visited(struct wim_dentry *root)
+{
+       for_dentry_in_tree(root, dentry_clear_inode_visited, NULL);
+}
+
 static int
 init_ads_entry(struct wim_ads_entry *ads_entry, const void *name,
               size_t name_nbytes, bool is_utf16le)
@@ -2486,3 +2499,125 @@ wimlib_iterate_dir_tree(WIMStruct *wim, int image, const tchar *path,
        wim->private = &ctx;
        return for_image(wim, image, image_do_iterate_dir_tree);
 }
+
+static bool
+inode_stream_sizes_consistent(const struct wim_inode *inode_1,
+                             const struct wim_inode *inode_2,
+                             const struct wim_lookup_table *lookup_table)
+{
+       if (inode_1->i_num_ads != inode_2->i_num_ads)
+               return false;
+       for (unsigned i = 0; i <= inode_1->i_num_ads; i++) {
+               const struct wim_lookup_table_entry *lte_1, *lte_2;
+
+               lte_1 = inode_stream_lte(inode_1, i, lookup_table);
+               lte_2 = inode_stream_lte(inode_2, i, lookup_table);
+               if (lte_1 && lte_2) {
+                       if (wim_resource_size(lte_1) != wim_resource_size(lte_2))
+                               return false;
+               } else if (lte_1 && wim_resource_size(lte_1)) {
+                       return false;
+               } else if (lte_2 && wim_resource_size(lte_2)) {
+                       return false;
+               }
+       }
+       return true;
+}
+
+static void
+inode_replace_ltes(struct wim_inode *inode,
+                  struct wim_inode *template_inode,
+                  struct wim_lookup_table *lookup_table)
+{
+       for (unsigned i = 0; i <= inode->i_num_ads; i++) {
+               struct wim_lookup_table_entry *lte, *lte_template;
+
+               lte = inode_stream_lte(inode, i, lookup_table);
+               if (lte) {
+                       for (unsigned j = 0; j < inode->i_nlink; j++)
+                               lte_decrement_refcnt(lte, lookup_table);
+                       lte_template = inode_stream_lte(template_inode, i,
+                                                       lookup_table);
+                       if (i == 0)
+                               inode->i_lte = lte_template;
+                       else
+                               inode->i_ads_entries[i - 1].lte = lte_template;
+                       if (lte_template)
+                               lte_template->refcnt += inode->i_nlink;
+               }
+       }
+       inode->i_resolved = 1;
+}
+
+static int
+dentry_reference_template(struct wim_dentry *dentry, void *_wim)
+{
+       int ret;
+       struct wim_dentry *template_dentry;
+       struct wim_inode *inode, *template_inode;
+       WIMStruct *wim = _wim;
+
+       if (dentry->d_inode->i_visited)
+               return 0;
+
+       ret = calculate_dentry_full_path(dentry);
+       if (ret)
+               return ret;
+
+       template_dentry = get_dentry(wim, dentry->_full_path);
+       if (!template_dentry) {
+               DEBUG("\"%"TS"\": newly added file", dentry->_full_path);
+               return 0;
+       }
+
+       inode = dentry->d_inode;
+       template_inode = template_dentry->d_inode;
+
+       if (inode->i_last_write_time == template_inode->i_last_write_time
+           && inode->i_creation_time == template_inode->i_creation_time
+           && inode->i_last_access_time >= template_inode->i_last_access_time
+           && inode_stream_sizes_consistent(inode, template_inode,
+                                            wim->lookup_table))
+       {
+               /*DEBUG("\"%"TS"\": No change detected", dentry->_full_path);*/
+               inode_replace_ltes(inode, template_inode, wim->lookup_table);
+               inode->i_visited = 1;
+       } else {
+               DEBUG("\"%"TS"\": change detected!", dentry->_full_path);
+       }
+       return 0;
+}
+
+/* API function documented in wimlib.h  */
+WIMLIBAPI int
+wimlib_reference_template_image(WIMStruct *wim, int new_image, int template_image,
+                               int flags, wimlib_progress_func_t progress_func)
+{
+       int ret;
+       struct wim_image_metadata *new_imd;
+
+       if (wim->hdr.part_number != 1)
+               return WIMLIB_ERR_SPLIT_UNSUPPORTED;
+
+       if (new_image < 1 || new_image > wim->hdr.image_count)
+               return WIMLIB_ERR_INVALID_IMAGE;
+
+       if (template_image < 1 || template_image > wim->hdr.image_count)
+               return WIMLIB_ERR_INVALID_IMAGE;
+
+       if (new_image == template_image)
+               return WIMLIB_ERR_INVALID_PARAM;
+
+       new_imd = wim->image_metadata[new_image - 1];
+       if (!new_imd->modified)
+               return WIMLIB_ERR_INVALID_PARAM;
+
+       ret = select_wim_image(wim, template_image);
+       if (ret)
+               return ret;
+
+       ret = for_dentry_in_tree(new_imd->root_dentry,
+                                dentry_reference_template, wim);
+       dentry_tree_clear_inode_visited(new_imd->root_dentry);
+       return ret;
+}