From ecefa302b9ef5320ad4cce0b606aca70a7b459e2 Mon Sep 17 00:00:00 2001
From: Jack Wills <32690432+mrjackwills@users.noreply.github.com>
Date: Mon, 16 Jun 2025 20:54:40 +0000
Subject: [PATCH] refactor: reduce lines of log cloned

Instead of cloning every single line of logs, now we only clone those logs that are visible +- a padding.

Containers with hunders or thousands of lines of logs can see a huge reducing in CPU and memory usage
---
 src/app_data/container_state.rs | 21 +++++++++--
 src/app_data/mod.rs             | 64 +++++++++++++++++++++++++++++++--
 src/ui/draw_blocks/logs.rs      |  4 ++-
 3 files changed, 82 insertions(+), 7 deletions(-)

diff --git a/src/app_data/container_state.rs b/src/app_data/container_state.rs
index 095c679..7a0e9bb 100644
--- a/src/app_data/container_state.rs
+++ b/src/app_data/container_state.rs
@@ -586,10 +586,25 @@ impl Logs {
         }
     }
 
-    pub fn to_vec(&self) -> Vec<ListItem<'static>> {
-        self.logs.items.clone()
+    /// Get the logs vec, but instead of cloning to whole vec, only clone items with x of the currently selected index
+    /// Where x is the abs different of the index plus the panel height & a padding
+    /// The rest can be just empty list items
+    /// TODO test me, pass in 1000 lines of "something", expect response to be different!
+    pub fn to_vec(&self, height: usize, padding: usize) -> Vec<ListItem<'static>> {
+        let current_index = self.logs.state.selected().unwrap_or_default();
+        self.logs
+            .items
+            .iter()
+            .enumerate()
+            .map(|(index, item)| {
+                if current_index.abs_diff(index) <= height + padding {
+                    item.clone()
+                } else {
+                    ListItem::from("")
+                }
+            })
+            .collect()
     }
-
     /// The rest of the methods are basically forwarding from the underlying StatefulList
     pub fn get_state_title(&self) -> String {
         self.logs.get_state_title()
diff --git a/src/app_data/mod.rs b/src/app_data/mod.rs
index 8bf5ae3..943f67d 100644
--- a/src/app_data/mod.rs
+++ b/src/app_data/mod.rs
@@ -677,12 +677,12 @@ impl AppData {
     }
 
     /// Get mutable Vec of current containers logs
-    pub fn get_logs(&self) -> Vec<ListItem<'static>> {
+    pub fn get_logs(&self, height: u16, padding: usize) -> Vec<ListItem<'static>> {
         self.containers
             .state
             .selected()
             .and_then(|i| self.containers.items.get(i))
-            .map_or(vec![], |i| i.logs.to_vec())
+            .map_or(vec![], |i| i.logs.to_vec(height.into(), padding))
     }
 
     /// Get mutable Option of the currently selected container Logs state
@@ -1953,7 +1953,7 @@ mod tests {
         assert_eq!(result.as_ref().unwrap().selected(), Some(2));
         assert_eq!(result.unwrap().offset(), 0);
 
-        let result = app_data.get_logs();
+        let result = app_data.get_logs(4, 1);
         assert_eq!(result.len(), 3);
 
         let result = app_data.get_log_title();
@@ -2324,4 +2324,62 @@ mod tests {
         let result = app_data.get_log_state();
         assert!(result.is_none());
     }
+
+    // *************** //
+    // Get logs method //
+    // *************** //
+
+    #[test]
+    /// get_logs() returns vec of item, but the items are empty unless they are in the *visible" zone, based on height, index, and padding
+    fn test_app_data_update_get_logs() {
+        let (ids, containers) = gen_containers();
+
+        let mut app_data = gen_appdata(&containers);
+
+        app_data.containers_start();
+        let logs = (0..=999).map(|i| format!("{i} {i}")).collect::<Vec<_>>();
+
+        app_data.update_log_by_id(logs, &ids[0]);
+
+        let result = app_data.get_logs(10, 10);
+        for (index, item) in result.iter().enumerate() {
+            if index < 979 {
+                assert_eq!(item, &ListItem::new(""));
+            } else {
+                assert_eq!(item, &ListItem::new(format!("{index}")));
+            }
+        }
+
+        let result = app_data.get_logs(100, 20);
+        for (index, item) in result.iter().enumerate() {
+            if index < 879 {
+                assert_eq!(item, &ListItem::new(""));
+            } else {
+                assert_eq!(item, &ListItem::new(format!("{index}")));
+            }
+        }
+
+        app_data.log_start();
+        let result = app_data.get_logs(10, 10);
+        for (index, item) in result.iter().enumerate() {
+            if index > 20 {
+                assert_eq!(item, &ListItem::new(""));
+            } else {
+                assert_eq!(item, &ListItem::new(format!("{index}")));
+            }
+        }
+
+        for _ in 0..=500 {
+            app_data.log_next();
+        }
+
+        let result = app_data.get_logs(10, 10);
+        for (index, item) in result.iter().enumerate() {
+            if (481..=521).contains(&index) {
+                assert_eq!(item, &ListItem::new(format!("{index}")));
+            } else {
+                assert_eq!(item, &ListItem::new(""));
+            }
+        }
+    }
 }
diff --git a/src/ui/draw_blocks/logs.rs b/src/ui/draw_blocks/logs.rs
index 71acd1a..6381e5b 100644
--- a/src/ui/draw_blocks/logs.rs
+++ b/src/ui/draw_blocks/logs.rs
@@ -39,7 +39,8 @@ pub fn draw(
         }
         f.render_widget(paragraph, area);
     } else {
-        let logs = app_data.lock().get_logs();
+        let padding = usize::from(area.height / 5);
+        let logs = app_data.lock().get_logs(area.height, padding);
         if logs.is_empty() {
             let mut paragraph = Paragraph::new("no logs found")
                 .block(block)
@@ -52,6 +53,7 @@ pub fn draw(
             let items = List::new(logs)
                 .block(block)
                 .highlight_symbol(RIGHT_ARROW)
+                .scroll_padding(padding)
                 .highlight_style(Style::default().add_modifier(Modifier::BOLD));
             // This should always return Some, as logs is not empty
             if let Some(log_state) = app_data.lock().get_log_state() {