cache directory contents(/selections/settings/...)

src/file_browser.rs

@@ -55,6 +55,7 @@ pub struct FileBrowser {
     pub columns: MillerColumns<FileBrowserWidgets>,
     pub cwd: File,
     selections: HashMap<File, File>,
+    cached_files: HashMap<File, Files>,
     core: WidgetCore,
     watcher: INotifyWatcher,
     watches: Vec<PathBuf>,
@@ -196,6 +197,7 @@ impl FileBrowser {
         Ok(FileBrowser { columns: miller,
                          cwd: cwd,
                          selections: HashMap::new(),
+                         cached_files: HashMap::new(),
                          core: core.clone(),
                          watcher: watcher,
                          watches: vec![],
@@ -230,10 +232,17 @@ impl FileBrowser {
         let dir = dir.clone();
         let selected_file = self.get_selection(&dir).ok().cloned();
 
+        self.get_files().and_then(|files| self.cache_files(files)).log();
+        let cached_files = self.get_cached_files(&dir).ok();
         let main_widget = self.main_widget_mut()?;
+
         main_widget.change_to(Box::new(move |stale, core| {
             let path = dir.path();
-            let files = Files::new_from_path_cancellable(&path, stale)?;
+            let cached_files = cached_files.clone();
+
+            let files = cached_files.or_else(|| {
+                Files::new_from_path_cancellable(&path, stale).ok()
+            })?;
 
             let mut list = ListView::new(&core, files);
 
@@ -253,12 +262,19 @@ impl FileBrowser {
     }
 
     pub fn left_widget_goto(&mut self, dir: &File) -> HResult<()> {
+        self.get_left_files().and_then(|files| self.cache_files(files)).log();
+        let cached_files = self.get_cached_files(&dir).ok();
         let dir = dir.clone();
 
         let left_widget = self.left_widget_mut()?;
         left_widget.change_to(Box::new(move |stale, core| {
             let path = dir.path();
-            let files = Files::new_from_path_cancellable(&path, stale)?;
+            let cached_files = cached_files.clone();
+
+            let files = cached_files.or_else(|| {
+                Files::new_from_path_cancellable(&path, stale).ok()
+            })?;
+
             let list = ListView::new(&core, files);
             Ok(list)
         }))?;
@@ -277,8 +293,9 @@ impl FileBrowser {
         if !self.main_widget()?.ready() { return Ok(()) }
         let file = self.selected_file()?.clone();
         let selection = self.get_selection(&file).ok().cloned();
+        let cached_files = self.get_cached_files(&file).ok();
         let preview = self.preview_widget_mut()?;
-        preview.set_file(&file, selection);
+        preview.set_file(&file, selection, cached_files);
         Ok(())
     }
 
@@ -297,6 +314,24 @@ impl FileBrowser {
         Ok(self.selections.get(dir)?)
     }
 
+    pub fn get_files(&mut self) -> HResult<Files> {
+        Ok(self.main_widget()?.widget()?.lock()?.as_ref()?.content.clone())
+    }
+
+    pub fn get_left_files(&mut self) -> HResult<Files> {
+        Ok(self.left_widget()?.widget()?.lock()?.as_ref()?.content.clone())
+    }
+
+    pub fn cache_files(&mut self, files: Files) -> HResult<()> {
+        let dir = files.directory.clone();
+        self.cached_files.insert(dir, files);
+        Ok(())
+    }
+
+    pub fn get_cached_files(&mut self, dir: &File) -> HResult<Files> {
+        Ok(self.cached_files.get(dir)?.clone())
+    }
+
     pub fn save_selection(&mut self) -> HResult<()> {
         let cwd = self.cwd()?.clone();
         if let Ok(main_selection) = self.selected_file() {

src/files.rs

@@ -21,7 +21,7 @@ lazy_static! {
     static ref COLORS: LsColors = LsColors::from_env().unwrap();
 }
 
-#[derive(PartialEq, Clone, Debug)]
+#[derive(PartialEq, Eq, Hash, Clone, Debug)]
 pub struct Files {
     pub directory: File,
     pub files: Vec<File>,
@@ -277,7 +277,7 @@ impl std::fmt::Display for SortBy {
     }
 }
 
-#[derive(Debug, Copy, Clone, PartialEq)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub enum SortBy {
     Name,
     Size,

src/preview.rs

@@ -82,6 +82,11 @@ impl<T: Send + 'static> WillBe<T> where {
         Ok(())
     }
 
+    pub fn take(&mut self) -> HResult<T> {
+        self.check()?;
+        Ok(self.thing.lock()?.take()?)
+    }
+
     pub fn check(&self) -> HResult<()> {
         match *self.state.lock()? {
             State::Is => Ok(()),
@@ -161,6 +166,9 @@ impl<T: Widget + Send + 'static> WillBeWidget<T> {
             _ => false
         }
     }
+    pub fn take(&mut self) -> HResult<T> {
+        self.willbe.take()
+    }
 }
 
 // impl<T: Widget + Send> WillBeWidget<T> {
@@ -230,7 +238,8 @@ pub struct Previewer {
     widget: WillBeWidget<Box<dyn Widget + Send>>,
     core: WidgetCore,
     file: Option<File>,
-    selection: Option<File>
+    selection: Option<File>,
+    cached_files: Option<Files>
 }
 
 
@@ -244,7 +253,8 @@ impl Previewer {
         Previewer { widget: willbe,
                     core: core.clone(),
                     file: None,
-                    selection: None }
+                    selection: None,
+                    cached_files: None }
     }
 
     fn become_preview(&mut self,
@@ -254,10 +264,14 @@ impl Previewer {
         self.widget.set_coordinates(&coordinates).ok();
     }
 
-    pub fn set_file(&mut self, file: &File, selection: Option<File>) {
+    pub fn set_file(&mut self,
+                    file: &File,
+                    selection: Option<File>,
+                    cached_files: Option<Files>) {
         if Some(file) == self.file.as_ref() { return }
         self.file = Some(file.clone());
         self.selection = selection.clone();
+        self.cached_files = cached_files.clone();
 
         let coordinates = self.get_coordinates().unwrap().clone();
         let file = file.clone();
@@ -270,10 +284,12 @@ impl Previewer {
 
             let file = file.clone();
             let selection = selection.clone();
+            let cached_files = cached_files.clone();
 
             if file.kind == Kind::Directory  {
                 let preview = Previewer::preview_dir(&file,
                                                      selection,
+                                                     cached_files,
                                                      &core,
                                                      stale.clone());
                 return preview;
@@ -298,7 +314,8 @@ impl Previewer {
     pub fn reload(&mut self) {
         if let Some(file) = self.file.clone() {
             self.file = None;
-            self.set_file(&file, self.selection.clone());
+            let cache = self.cached_files.take();
+            self.set_file(&file, self.selection.clone(), cache);
         }
     }
 
@@ -308,11 +325,14 @@ impl Previewer {
 
     fn preview_dir(file: &File,
                    selection: Option<File>,
+                   cached_files: Option<Files>,
                    core: &WidgetCore,
                    stale: Arc<Mutex<bool>>)
                    -> Result<WidgetO, HError> {
-        let files = Files::new_from_path_cancellable(&file.path,
-                                                         stale.clone())?;
+        let files = cached_files.or_else(|| {
+            Files::new_from_path_cancellable(&file.path,
+                                             stale.clone()).ok()
+        })?;
         let len = files.len();
 
         if len == 0 || is_stale(&stale)? { return Previewer::preview_failed(&file) }