add support for counting files lazily

 - this should prevent excessive filesystem reading
 and increase performance on slower storage mediums such as
 network drives, mtpfs, etc.

3 files changed, 33 insertions, 6 deletions

diff --git a/src/commands/cursor_move.rs b/src/commands/cursor_move.rs
index 71bb876..3bded3c 100644
--- a/src/commands/cursor_move.rs
+++ b/src/commands/cursor_move.rs
@@ -13,6 +13,36 @@ pub fn cursor_move(new_index: usize, context: &mut AppContext) -> JoshutoResult<
             curr_list.index = Some(new_index);
         }
     }
+
+    let directory_size = match context
+        .tab_context_ref()
+        .curr_tab_ref()
+        .curr_list_ref()
+        .and_then(|l| l.curr_entry_ref())
+    {
+        Some(curr_entry) => {
+            if let Some(_) = curr_entry.metadata.directory_size() {
+                None
+            } else if !curr_entry.metadata.file_type().is_dir() {
+                None
+            } else {
+                let history = context.tab_context_ref().curr_tab_ref().history_ref();
+                history.get(curr_entry.file_path()).map(|d| d.len())
+            }
+        }
+        None => None,
+    };
+
+    if let Some(s) = directory_size {
+        if let Some(curr_entry) = context
+            .tab_context_mut()
+            .curr_tab_mut()
+            .curr_list_mut()
+            .and_then(|l| l.curr_entry_mut())
+        {
+            curr_entry.metadata.update_directory_size(s);
+        }
+    }
     Ok(())
 }
 
diff --git a/src/ui/views/tui_folder_view.rs b/src/ui/views/tui_folder_view.rs
index 1e23aa6..d1e420e 100644
--- a/src/ui/views/tui_folder_view.rs
+++ b/src/ui/views/tui_folder_view.rs
@@ -30,7 +30,6 @@ impl<'a> Widget for TuiFolderView<'a> {
     fn render(self, area: Rect, buf: &mut Buffer) {
         let preview_context = self.context.preview_context_ref();
         let curr_tab = self.context.tab_context_ref().curr_tab_ref();
-        let history = curr_tab.history_ref();
 
         let curr_list = curr_tab.curr_list_ref();
         let parent_list = curr_tab.parent_list_ref();
@@ -128,7 +127,7 @@ impl<'a> Widget for TuiFolderView<'a> {
 
         // render current view
         if let Some(list) = curr_list.as_ref() {
-            TuiDirListDetailed::new(&list, history).render(layout_rect[1], buf);
+            TuiDirListDetailed::new(&list).render(layout_rect[1], buf);
             let rect = Rect {
                 x: 0,
                 y: area.height - 1,
diff --git a/src/ui/widgets/tui_dirlist_detailed.rs b/src/ui/widgets/tui_dirlist_detailed.rs
index 2ecec93..a43d4f6 100644
--- a/src/ui/widgets/tui_dirlist_detailed.rs
+++ b/src/ui/widgets/tui_dirlist_detailed.rs
@@ -4,7 +4,6 @@ use tui::style::{Color, Modifier, Style};
 use tui::widgets::Widget;
 
 use crate::fs::{FileType, JoshutoDirEntry, JoshutoDirList, LinkType};
-use crate::history::JoshutoHistory;
 use crate::util::format;
 use crate::util::string::UnicodeTruncate;
 use crate::util::style;
@@ -16,12 +15,11 @@ const ELLIPSIS: &str = "…";
 
 pub struct TuiDirListDetailed<'a> {
     dirlist: &'a JoshutoDirList,
-    history: &'a JoshutoHistory,
 }
 
 impl<'a> TuiDirListDetailed<'a> {
-    pub fn new(dirlist: &'a JoshutoDirList, history: &'a JoshutoHistory) -> Self {
-        Self { dirlist, history }
+    pub fn new(dirlist: &'a JoshutoDirList) -> Self {
+        Self { dirlist }
     }
 }