Use the model's mtime for validating thumbnails

Saves a syscall, generalizes fiv_thumbnail_lookup(),
wastes a tiny bit of memory per entry.

fiv-browser.c

@@ -86,6 +86,7 @@ struct _FivBrowser {
 
 struct entry {
 	char *uri;                          ///< GIO URI
+	gint64 mtime_msec;                  ///< Modification time in milliseconds
 	cairo_surface_t *thumbnail;         ///< Prescaled thumbnail
 	GIcon *icon;                        ///< If no thumbnail, use this icon
 };
@@ -427,18 +428,20 @@ entry_add_thumbnail(gpointer data, gpointer user_data)
 	g_clear_pointer(&self->thumbnail, cairo_surface_destroy);
 
 	FivBrowser *browser = FIV_BROWSER(user_data);
-	GFile *file = g_file_new_for_uri(self->uri);
 	self->thumbnail = rescale_thumbnail(
-		fiv_thumbnail_lookup(file, browser->item_size), browser->item_height);
+		fiv_thumbnail_lookup(self->uri, self->mtime_msec, browser->item_size),
+		browser->item_height);
 	if (self->thumbnail)
-		goto out;
+		return;
 
 	// Fall back to symbolic icons, though there's only so much we can do
 	// in parallel--GTK+ isn't thread-safe.
+	GFile *file = g_file_new_for_uri(self->uri);
 	GFileInfo *info = g_file_query_info(file,
 		G_FILE_ATTRIBUTE_STANDARD_NAME
 		"," G_FILE_ATTRIBUTE_STANDARD_SYMBOLIC_ICON,
 		G_FILE_QUERY_INFO_NONE, NULL, NULL);
+	g_object_unref(file);
 	if (info) {
 		GIcon *icon = g_file_info_get_symbolic_icon(info);
 		if (icon)
@@ -449,8 +452,6 @@ entry_add_thumbnail(gpointer data, gpointer user_data)
 	// The GVfs backend may not be friendly.
 	if (!self->icon)
 		self->icon = g_icon_new_for_string("text-x-generic-symbolic", NULL);
-out:
-	g_object_unref(file);
 }
 
 static void
@@ -1707,8 +1708,8 @@ on_model_files_changed(FivIoModel *model, FivBrowser *self)
 	gsize len = 0;
 	const FivIoModelEntry *files = fiv_io_model_get_files(self->model, &len);
 	for (gsize i = 0; i < len; i++) {
-		g_array_append_val(self->entries,
-			((Entry) {.thumbnail = NULL, .uri = g_strdup(files[i].uri)}));
+		g_array_append_val(self->entries, ((Entry) {.thumbnail = NULL,
+			.uri = g_strdup(files[i].uri), .mtime_msec = files[i].mtime_msec}));
 	}
 
 	fiv_browser_select(self, selected_uri);

fiv-io.h

@@ -123,8 +123,8 @@ gboolean fiv_io_model_open(FivIoModel *self, GFile *directory, GError **error);
 GFile *fiv_io_model_get_location(FivIoModel *self);
 
 typedef struct {
-	gchar *uri;                         ///< GIO URI
-	gchar *collate_key;                 ///< Collate key for the filename
+	char *uri;                          ///< GIO URI
+	char *collate_key;                  ///< Collate key for the filename
 	gint64 mtime_msec;                  ///< Modification time in milliseconds
 } FivIoModelEntry;
 

fiv-thumbnail.c

@@ -579,18 +579,11 @@ fail_init:
 }
 
 cairo_surface_t *
-fiv_thumbnail_lookup(GFile *target, FivThumbnailSize size)
+fiv_thumbnail_lookup(char *uri, gint64 mtime_msec, FivThumbnailSize size)
 {
 	g_return_val_if_fail(size >= FIV_THUMBNAIL_SIZE_MIN &&
 		size <= FIV_THUMBNAIL_SIZE_MAX, NULL);
 
-	// Local files only, at least for now.
-	GStatBuf st = {};
-	const gchar *path = g_file_peek_path(target);
-	if (!path || g_stat(path, &st))
-		return NULL;
-
-	gchar *uri = g_file_get_uri(target);
 	gchar *sum = g_compute_checksum_for_string(G_CHECKSUM_MD5, uri, -1);
 	gchar *thumbnails_dir = fiv_thumbnail_get_root();
 
@@ -605,7 +598,7 @@ fiv_thumbnail_lookup(GFile *target, FivThumbnailSize size)
 		const char *name = fiv_thumbnail_sizes[use].thumbnail_spec_name;
 		gchar *wide =
 			g_strdup_printf("%s/wide-%s/%s.webp", thumbnails_dir, name, sum);
-		result = read_wide_thumbnail(wide, uri, st.st_mtim.tv_sec, &error);
+		result = read_wide_thumbnail(wide, uri, mtime_msec / 1000, &error);
 		if (error) {
 			g_debug("%s: %s", wide, error->message);
 			g_clear_error(&error);
@@ -621,7 +614,7 @@ fiv_thumbnail_lookup(GFile *target, FivThumbnailSize size)
 
 		gchar *path =
 			g_strdup_printf("%s/%s/%s.png", thumbnails_dir, name, sum);
-		result = read_spng_thumbnail(path, uri, st.st_mtim.tv_sec, &error);
+		result = read_spng_thumbnail(path, uri, mtime_msec / 1000, &error);
 		if (error) {
 			g_debug("%s: %s", path, error->message);
 			g_clear_error(&error);
@@ -639,7 +632,6 @@ fiv_thumbnail_lookup(GFile *target, FivThumbnailSize size)
 
 	g_free(thumbnails_dir);
 	g_free(sum);
-	g_free(uri);
 	return result;
 }
 

fiv-thumbnail.h

@@ -62,7 +62,8 @@ gboolean fiv_thumbnail_produce(GFile *target, FivThumbnailSize max_size,
 
 /// Retrieves a thumbnail of the most appropriate quality and resolution
 /// for the target file.
-cairo_surface_t *fiv_thumbnail_lookup(GFile *target, FivThumbnailSize size);
+cairo_surface_t *fiv_thumbnail_lookup(
+	char *uri, gint64 mtime_msec, FivThumbnailSize size);
 
 /// Invalidate the wide thumbnail cache. May write to standard streams.
 void fiv_thumbnail_invalidate(void);