Reduce memory usage by ~50 MB for large libraries

FlattenedItem now stores only essential fields (path, name, is_dir, depth)
instead of cloning entire FileTreeNode structures. For 500,000 files, this
reduces memory from ~100 MB to ~50 MB for the flattened view.

- Extract only needed fields in flatten_tree()
- Add find_node_by_path() helper to look up full nodes when needed
- Update all UI and state code to use new structure

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cm-player"
-version = "0.1.23"
+version = "0.1.24"
 edition = "2021"
 
 [dependencies]

src/main.rs

@@ -97,8 +97,8 @@ fn main() -> Result<()> {
 
 fn action_toggle_folder(state: &mut AppState) {
     if let Some(item) = state.get_selected_item() {
-        if item.node.is_dir {
-            let path = item.node.path.clone();
+        if item.is_dir {
+            let path = item.path.clone();
             if state.expanded_dirs.contains(&path) {
                 // Folder is open, close it
                 state.collapse_selected();
@@ -936,7 +936,7 @@ fn handle_mouse_event(state: &mut AppState, mouse: MouseEvent, title_bar_area: r
                             if is_double_click {
                                 // Double click = toggle folder or play file
                                 if let Some(item) = state.get_selected_item() {
-                                    if item.node.is_dir {
+                                    if item.is_dir {
                                         action_toggle_folder(state);
                                     } else {
                                         action_play_selection(state, player)?;

src/state/mod.rs

@@ -1,7 +1,7 @@
 use crate::cache::{Cache, FileTreeNode};
 use crate::config::Config;
 use std::collections::HashSet;
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 use std::time::Instant;
 
 // Fuzzy match scoring bonuses
@@ -96,7 +96,9 @@ pub struct AppState {
 
 #[derive(Debug, Clone)]
 pub struct FlattenedItem {
-    pub node: FileTreeNode,
+    pub path: PathBuf,
+    pub name: String,
+    pub is_dir: bool,
     pub depth: usize,
 }
 
@@ -336,11 +338,29 @@ impl AppState {
         self.flattened_items.get(self.selected_index)
     }
 
+    // Helper to find a node in the tree by path
+    fn find_node_by_path<'a>(&'a self, path: &Path) -> Option<&'a FileTreeNode> {
+        fn search_nodes<'a>(nodes: &'a [FileTreeNode], path: &Path) -> Option<&'a FileTreeNode> {
+            for node in nodes {
+                if node.path == path {
+                    return Some(node);
+                }
+                if node.is_dir {
+                    if let Some(found) = search_nodes(&node.children, path) {
+                        return Some(found);
+                    }
+                }
+            }
+            None
+        }
+        search_nodes(&self.cache.file_tree, path)
+    }
+
     pub fn collapse_selected(&mut self) {
         let item = self.get_selected_item().cloned();
         if let Some(item) = item {
-            if item.node.is_dir {
-                let path = item.node.path.clone();
+            if item.is_dir {
+                let path = item.path.clone();
                 let was_expanded = self.expanded_dirs.contains(&path);
 
                 if was_expanded {
@@ -348,7 +368,7 @@ impl AppState {
                     self.expanded_dirs.remove(&path);
                     self.rebuild_flattened_items();
                     // Find the collapsed folder and select it
-                    if let Some(idx) = self.flattened_items.iter().position(|i| i.node.path == path) {
+                    if let Some(idx) = self.flattened_items.iter().position(|i| i.path == path) {
                         self.selected_index = idx;
                     }
                 } else {
@@ -358,19 +378,19 @@ impl AppState {
                         self.expanded_dirs.remove(&parent_buf);
                         self.rebuild_flattened_items();
                         // Jump to parent folder
-                        if let Some(parent_idx) = self.flattened_items.iter().position(|i| i.node.path == parent_buf) {
+                        if let Some(parent_idx) = self.flattened_items.iter().position(|i| i.path == parent_buf) {
                             self.selected_index = parent_idx;
                         }
                     }
                 }
             } else {
                 // Close parent folder when on a file and jump to it
-                if let Some(parent) = item.node.path.parent() {
+                if let Some(parent) = item.path.parent() {
                     let parent_buf = parent.to_path_buf();
                     self.expanded_dirs.remove(&parent_buf);
                     self.rebuild_flattened_items();
                     // Jump to parent folder
-                    if let Some(parent_idx) = self.flattened_items.iter().position(|i| i.node.path == parent_buf) {
+                    if let Some(parent_idx) = self.flattened_items.iter().position(|i| i.path == parent_buf) {
                         self.selected_index = parent_idx;
                     }
                 }
@@ -380,8 +400,8 @@ impl AppState {
 
     pub fn expand_selected(&mut self) {
         if let Some(item) = self.get_selected_item() {
-            if item.node.is_dir {
-                let path = item.node.path.clone();
+            if item.is_dir {
+                let path = item.path.clone();
                 self.expanded_dirs.insert(path);
                 self.rebuild_flattened_items();
             }
@@ -401,8 +421,8 @@ impl AppState {
             self.marked_files.clear();
             // Mark current file
             if let Some(item) = self.get_selected_item() {
-                if !item.node.is_dir {
-                    self.marked_files.insert(item.node.path.clone());
+                if !item.is_dir {
+                    self.marked_files.insert(item.path.clone());
                 }
             }
         }
@@ -418,8 +438,8 @@ impl AppState {
 
         for i in start..=end {
             if let Some(item) = self.flattened_items.get(i) {
-                if !item.node.is_dir {
-                    self.marked_files.insert(item.node.path.clone());
+                if !item.is_dir {
+                    self.marked_files.insert(item.path.clone());
                 }
             }
         }
@@ -439,15 +459,19 @@ impl AppState {
             files.sort();
             self.playlist.extend(files);
         } else if let Some(item) = self.get_selected_item() {
-            let node = item.node.clone();
-            if node.is_dir {
-                // Add all files in directory (allow duplicates)
-                let mut files = collect_files_from_node(&node);
-                files.sort();
-                self.playlist.extend(files);
+            let path = item.path.clone();
+            let is_dir = item.is_dir;
+            if is_dir {
+                // Look up the full node to get children
+                if let Some(node) = self.find_node_by_path(&path) {
+                    // Add all files in directory (allow duplicates)
+                    let mut files = collect_files_from_node(node);
+                    files.sort();
+                    self.playlist.extend(files);
+                }
             } else {
                 // Add single file (allow duplicates)
-                self.playlist.push(node.path.clone());
+                self.playlist.push(path);
             }
         }
     }
@@ -468,22 +492,24 @@ impl AppState {
                 self.current_file = None;
             }
         } else if let Some(item) = self.get_selected_item() {
-            let node = item.node.clone();
-            if node.is_dir {
-                // Play all files in directory
-                self.playlist = collect_files_from_node(&node);
-                self.playlist_index = 0;
-                self.playlist_scroll_offset = 0;
-                self.selected_playlist_index = 0;
-                if let Some(first) = self.playlist.first() {
-                    self.current_file = Some(first.clone());
-                } else {
-                    // Empty directory
-                    self.current_file = None;
+            let path = item.path.clone();
+            let is_dir = item.is_dir;
+            if is_dir {
+                // Play all files in directory - look up node to get children
+                if let Some(node) = self.find_node_by_path(&path) {
+                    self.playlist = collect_files_from_node(node);
+                    self.playlist_index = 0;
+                    self.playlist_scroll_offset = 0;
+                    self.selected_playlist_index = 0;
+                    if let Some(first) = self.playlist.first() {
+                        self.current_file = Some(first.clone());
+                    } else {
+                        // Empty directory
+                        self.current_file = None;
+                    }
                 }
             } else {
                 // Play single file
-                let path = node.path.clone();
                 self.playlist = vec![path.clone()];
                 self.playlist_index = 0;
                 self.playlist_scroll_offset = 0;
@@ -674,7 +700,7 @@ impl AppState {
         }
 
         // Find the best match in the flattened list and jump to it
-        if let Some(idx) = self.flattened_items.iter().position(|item| item.node.path == best_match) {
+        if let Some(idx) = self.flattened_items.iter().position(|item| item.path == best_match) {
             self.selected_index = idx;
 
             // Scroll to show the match
@@ -741,7 +767,7 @@ impl AppState {
             self.rebuild_flattened_items();
 
             // Find first match in flattened list
-            if let Some(idx) = self.flattened_items.iter().position(|item| item.node.path == first_match) {
+            if let Some(idx) = self.flattened_items.iter().position(|item| item.path == first_match) {
                 self.selected_index = idx;
             }
         }
@@ -766,7 +792,7 @@ impl AppState {
             self.rebuild_flattened_items();
 
             // Find the path in current flattened items
-            if let Some(idx) = self.flattened_items.iter().position(|item| item.node.path == target_path) {
+            if let Some(idx) = self.flattened_items.iter().position(|item| item.path == target_path) {
                 self.selected_index = idx;
 
                 // Scroll to show the match
@@ -813,7 +839,7 @@ impl AppState {
             self.rebuild_flattened_items();
 
             // Find the path in current flattened items
-            if let Some(idx) = self.flattened_items.iter().position(|item| item.node.path == target_path) {
+            if let Some(idx) = self.flattened_items.iter().position(|item| item.path == target_path) {
                 self.selected_index = idx;
 
                 // Scroll to show the match
@@ -860,7 +886,7 @@ impl AppState {
         self.rebuild_flattened_items();
 
         // Find and select the match
-        if let Some(idx) = self.flattened_items.iter().position(|item| item.node.path == next_match) {
+        if let Some(idx) = self.flattened_items.iter().position(|item| item.path == next_match) {
             self.selected_index = idx;
 
             // Scroll to show the match
@@ -903,7 +929,7 @@ impl AppState {
         self.rebuild_flattened_items();
 
         // Find and select the match
-        if let Some(idx) = self.flattened_items.iter().position(|item| item.node.path == prev_match) {
+        if let Some(idx) = self.flattened_items.iter().position(|item| item.path == prev_match) {
             self.selected_index = idx;
 
             // Scroll to show the match
@@ -1160,7 +1186,9 @@ fn flatten_tree(nodes: &[FileTreeNode], depth: usize, expanded_dirs: &HashSet<Pa
         let is_expanded = expanded_dirs.contains(&node.path);
 
         result.push(FlattenedItem {
-            node: node.clone(),
+            path: node.path.clone(),
+            name: node.name.clone(),
+            is_dir: node.is_dir,
             depth,
         });
 

src/ui/mod.rs

@@ -142,15 +142,15 @@ fn render_file_panel(frame: &mut Frame, state: &mut AppState, area: Rect) {
         .map(|(display_idx, item)| {
             let idx = state.scroll_offset + display_idx;
             let indent = "  ".repeat(item.depth);
-            let mark = if state.marked_files.contains(&item.node.path) { "* " } else { "" };
+            let mark = if state.marked_files.contains(&item.path) { "* " } else { "" };
 
             // Build name with search highlighting
             // Only show selection bar when file panel has focus
             let is_selected = !state.focus_playlist && idx == state.selected_index;
 
             // Add icon for directories and files
-            let icon = if item.node.is_dir {
-                let is_expanded = state.expanded_dirs.contains(&item.node.path);
+            let icon = if item.is_dir {
+                let is_expanded = state.expanded_dirs.contains(&item.path);
                 // Nerd font folder icons: \u{eaf7} = open, \u{ea83} = closed
                 let icon_char = if is_expanded { "\u{eaf7}  " } else { "\u{ea83}  " };
 
@@ -162,7 +162,7 @@ fn render_file_panel(frame: &mut Frame, state: &mut AppState, area: Rect) {
                 }
             } else {
                 // File icons based on extension
-                let extension = item.node.path.extension()
+                let extension = item.path.extension()
                     .and_then(|e| e.to_str())
                     .unwrap_or("")
                     .to_lowercase();
@@ -184,12 +184,12 @@ fn render_file_panel(frame: &mut Frame, state: &mut AppState, area: Rect) {
                 }
             };
             let name_spans = if in_search && !search_query.is_empty() {
-                highlight_search_matches(&item.node.name, &search_query, is_selected)
+                highlight_search_matches(&item.name, &search_query, is_selected)
             } else {
-                vec![Span::raw(&item.node.name)]
+                vec![Span::raw(&item.name)]
             };
 
-            let suffix = if item.node.is_dir { "/" } else { "" };
+            let suffix = if item.is_dir { "/" } else { "" };
 
             let base_style = if is_selected {
                 // Selection bar: yellow/orange when in search (typing or viewing results), blue otherwise
@@ -198,7 +198,7 @@ fn render_file_panel(frame: &mut Frame, state: &mut AppState, area: Rect) {
                 } else {
                     Theme::selected()
                 }
-            } else if state.marked_files.contains(&item.node.path) {
+            } else if state.marked_files.contains(&item.path) {
                 Theme::marked()
             } else {
                 Theme::secondary()