cache stat(2) calls

When the user requests sorting by size or mtime, do a "soft preload" of
the file list that only calls stat(2) without loading images.
This avoids calling stat(2) repeatedly on the same files when sorting
the file list, and achieves faster startup on slow filesystems.

1 files changed, 54 insertions, 41 deletions

diff --git a/src/filelist.c b/src/filelist.c
index f1e820c..a5ad890 100644
--- a/src/filelist.c
+++ b/src/filelist.c
@@ -53,6 +53,8 @@ feh_file *feh_file_new(char *filename)
 		newfile->name = estrdup(s + 1);
 	else
 		newfile->name = estrdup(filename);
+	newfile->size = -1;
+	newfile->mtime = 0;
 	newfile->info = NULL;
 #ifdef HAVE_LIBEXIF
 	newfile->ed = NULL;
@@ -89,7 +91,6 @@ feh_file_info *feh_file_info_new(void)
 
 	info->width = 0;
 	info->height = 0;
-	info->size = 0;
 	info->pixels = 0;
 	info->has_alpha = 0;
 	info->format = NULL;
@@ -305,7 +306,7 @@ void delete_rm_files(void)
 	return;
 }
 
-gib_list *feh_file_info_preload(gib_list * list)
+gib_list *feh_file_info_preload(gib_list * list, int load_images)
 {
 	gib_list *l;
 	feh_file *file = NULL;
@@ -314,20 +315,27 @@ gib_list *feh_file_info_preload(gib_list * list)
 	for (l = list; l; l = l->next) {
 		file = FEH_FILE(l->data);
 		D(("file %p, file->next %p, file->name %s\n", l, l->next, file->name));
-		if (feh_file_info_load(file, NULL)) {
-			D(("Failed to load file %p\n", file));
-			remove_list = gib_list_add_front(remove_list, l);
-			if (opt.verbose)
-				feh_display_status('x');
-		} else if (((unsigned int)file->info->width < opt.min_width)
-				|| ((unsigned int)file->info->width > opt.max_width)
-				|| ((unsigned int)file->info->height < opt.min_height)
-				|| ((unsigned int)file->info->height > opt.max_height)) {
-			remove_list = gib_list_add_front(remove_list, l);
-			if (opt.verbose)
-				feh_display_status('s');
-		} else if (opt.verbose)
-			feh_display_status('.');
+		if (load_images) {
+			if (feh_file_info_load(file, NULL)) {
+				D(("Failed to load file %p\n", file));
+				remove_list = gib_list_add_front(remove_list, l);
+				if (opt.verbose)
+					feh_display_status('x');
+			} else if (((unsigned int)file->info->width < opt.min_width)
+					|| ((unsigned int)file->info->width > opt.max_width)
+					|| ((unsigned int)file->info->height < opt.min_height)
+					|| ((unsigned int)file->info->height > opt.max_height)) {
+				remove_list = gib_list_add_front(remove_list, l);
+				if (opt.verbose)
+					feh_display_status('s');
+			} else if (opt.verbose)
+				feh_display_status('.');
+		} else {
+			if (feh_file_stat(file)) {
+				D(("Failed to stat file %p\n", file));
+				remove_list = gib_list_add_front(remove_list, l);
+			}
+		}
 		if (sig_exit) {
 			feh_display_status(0);
 			exit(sig_exit);
@@ -348,23 +356,36 @@ gib_list *feh_file_info_preload(gib_list * list)
 	return(list);
 }
 
-int feh_file_info_load(feh_file * file, Imlib_Image im)
+int feh_file_stat(feh_file * file)
 {
 	struct stat st;
+
+	errno = 0;
+	if (stat(file->filename, &st)) {
+		feh_print_stat_error(file->filename);
+		return(1);
+	}
+
+	file->mtime = st.st_mtime;
+
+	file->size = st.st_size;
+
+	return(0);
+}
+
+int feh_file_info_load(feh_file * file, Imlib_Image im)
+{
 	int need_free = 1;
 	Imlib_Image im1;
 
+	if (feh_file_stat(file))
+		return(1);
+
 	D(("im is %p\n", im));
 
 	if (im)
 		need_free = 0;
 
-	errno = 0;
-	if (stat(file->filename, &st)) {
-		feh_print_stat_error(file->filename);
-		return(1);
-	}
-
 	if (im)
 		im1 = im;
 	else if (!feh_load_image(&im1, file) || !im1)
@@ -381,8 +402,6 @@ int feh_file_info_load(feh_file * file, Imlib_Image im)
 
 	file->info->format = estrdup(gib_imlib_image_format(im1));
 
-	file->info->size = st.st_size;
-
 	if (need_free)
 		gib_imlib_free_image_and_decache(im1);
 	return(0);
@@ -434,20 +453,8 @@ int feh_cmp_dirname(void *file1, void *file2)
 /* Return -1 if file1 is _newer_ than file2 */
 int feh_cmp_mtime(void *file1, void *file2)
 {
-	struct stat s1, s2;
-
-	if (stat(FEH_FILE(file1)->filename, &s1)) {
-		feh_print_stat_error(FEH_FILE(file1)->filename);
-		return(-1);
-	}
-
-	if (stat(FEH_FILE(file2)->filename, &s2)) {
-		feh_print_stat_error(FEH_FILE(file2)->filename);
-		return(-1);
-	}
-
 	/* gib_list_sort is not stable, so explicitly return 0 as -1 */
-	return(s1.st_mtime >= s2.st_mtime ? -1 : 1);
+	return(FEH_FILE(file1)->mtime >= FEH_FILE(file2)->mtime ? -1 : 1);
 }
 
 int feh_cmp_width(void *file1, void *file2)
@@ -467,7 +474,7 @@ int feh_cmp_pixels(void *file1, void *file2)
 
 int feh_cmp_size(void *file1, void *file2)
 {
-	return((FEH_FILE(file1)->info->size - FEH_FILE(file2)->info->size));
+	return((FEH_FILE(file1)->size - FEH_FILE(file2)->size));
 }
 
 int feh_cmp_format(void *file1, void *file2)
@@ -486,10 +493,16 @@ void feh_prepare_filelist(void)
 	 * is set and we're in thumbnail mode, we need to filter images first so
 	 * we can create a properly sized thumbnail list.
 	 */
-	if (opt.list || opt.preload || opt.customlist || (opt.sort > SORT_MTIME)
+	if (opt.list || opt.preload || opt.customlist || (opt.sort >= SORT_WIDTH)
 			|| (opt.filter_by_dimensions && (opt.index || opt.thumbs || opt.bgmode))) {
 		/* For these sort options, we have to preload images */
-		filelist = feh_file_info_preload(filelist);
+		filelist = feh_file_info_preload(filelist, TRUE);
+		if (!gib_list_length(filelist))
+			show_mini_usage();
+	} else if (opt.sort >= SORT_SIZE) {
+		/* For these sort options, we need stat(2) information on the files,
+		 * but there is no need to load the images. */
+		filelist = feh_file_info_preload(filelist, FALSE);
 		if (!gib_list_length(filelist))
 			show_mini_usage();
 	}