Allocating with capacity

src/core/data.rs

@@ -7,7 +7,7 @@ use crate::data::{
 };
 
 pub fn unify_data(status_page: &StatusPageResponse, heartbeat: &HeartbeatResponse) -> UnifiedData {
-    let mut groups = Vec::new();
+    let mut groups = Vec::with_capacity(status_page.public_group_list.len());
     let heartbeat_map: HashMap<u64, Vec<HeartbeatEntry>> = heartbeat
         .monitors
         .iter()
@@ -21,7 +21,7 @@ pub fn unify_data(status_page: &StatusPageResponse, heartbeat: &HeartbeatRespons
         .collect();
 
     for group in &status_page.public_group_list {
-        let mut monitors = Vec::new();
+        let mut monitors = Vec::with_capacity(group.monitor_list.len());
         for monitor_info in &group.monitor_list {
             let uptime_data = uptime_map.get(&(monitor_info.id, 24)).cloned();
             let heartbeats = heartbeat_map

src/ui/components/monitor_list.rs

@@ -35,7 +35,7 @@ fn layout_groups(area: Rect, groups: &[GroupViewState]) -> Vec<Rect> {
     let line_height = content_height as usize / total_lines;
 
     let mut current_y = area.y + 1;
-    let mut areas = Vec::new();
+    let mut areas = Vec::with_capacity(groups.len());
 
     for group in groups {
         let group_lines = group.monitors.len() + 2;
@@ -185,13 +185,14 @@ fn get_formated_line(text: String, color: Color, modifier: Modifier) -> Line<'st
 }
 
 fn create_status_line_spans(status_history: &[MonitorStatus]) -> Line<'_> {
-    let mut spans = Vec::new();
     let recent_status: Vec<_> = status_history
         .iter()
         .rev()
         .take(STATUS_LINE_LENGTH)
         .collect();
 
+    let mut spans = Vec::with_capacity(recent_status.len());
+
     for status in recent_status.iter().rev() {
         let c = get_status_char(status);
         let color = get_status_color(status);

src/ui/dashboard/model.rs

@@ -47,7 +47,7 @@ impl DashboardViewState {
     }
 
     pub fn from_unified_data(data: UnifiedData) -> Self {
-        let mut groups = Vec::new();
+        let mut groups = Vec::with_capacity(data.groups.len());
 
         for group in data.groups {
             groups.push(GroupViewState {
@@ -92,7 +92,7 @@ fn get_status_history(heartbeats: &[HeartbeatEntry]) -> Vec<MonitorStatus> {
 }
 
 fn add_monitor_view_state(group: UnifiedGroupData) -> Vec<MonitorViewState> {
-    let mut monitors = Vec::new();
+    let mut monitors = Vec::with_capacity(group.monitors.len());
 
     for monitor in group.monitors {
         let status_history = get_status_history(&monitor.heartbeats);