bug: fix reported usage spike at the start on some OSes (#1788)

* bug: fix spike at the start on some OSes

* add clean

* bake things in better I guess

* hmmm no nvm

* tiny sleep

* update changelog

CHANGELOG.md

@@ -25,7 +25,11 @@ That said, these are more guidelines rather than hardset rules, though the proje
 ### Bug Fixes
 
 - [#1776](https://github.com/ClementTsang/bottom/pull/1776): Fix `disk.columns` being incorrectly interpreted as blank.
-- [1787](https://github.com/ClementTsang/bottom/pull/1787): Fix issue with battery widget time and small widths.
+- [#1787](https://github.com/ClementTsang/bottom/pull/1787): Fix issue with battery widget time and small widths.
+
+### Other
+
+- [#1779](https://github.com/ClementTsang/bottom/pull/1779), [#1788](https://github.com/ClementTsang/bottom/pull/1788): Speed up time between startup and displaying data.
 
 ## [0.11.0] - 2025-08-05
 

src/collection.rs

@@ -335,6 +335,9 @@ impl DataCollector {
         }
     }
 
+    /// Update and refresh data.
+    ///
+    /// TODO: separate refresh steps and update steps
     pub fn update_data(&mut self) {
         self.data.collection_time = Instant::now();
 

src/lib.rs

@@ -53,6 +53,8 @@ use tui::{Terminal, backend::CrosstermBackend};
 use utils::logging::*;
 use utils::{cancellation_token::CancellationToken, conversion::*};
 
+use crate::collection::Data;
+
 // Used for heap allocation debugging purposes.
 // #[global_allocator]
 // static ALLOC: dhat::Alloc = dhat::Alloc;
@@ -222,12 +224,18 @@ fn create_collection_thread(
     let update_sleep = app_config_fields.update_rate;
 
     thread::spawn(move || {
-        let mut data_state = collection::DataCollector::new(filters);
+        let mut data_collector = collection::DataCollector::new(filters);
 
-        data_state.set_collection(used_widget_set);
+        data_collector.set_collection(used_widget_set);
-        data_state.set_use_current_cpu_total(use_current_cpu_total);
+        data_collector.set_use_current_cpu_total(use_current_cpu_total);
-        data_state.set_unnormalized_cpu(unnormalized_cpu);
+        data_collector.set_unnormalized_cpu(unnormalized_cpu);
-        data_state.set_show_average_cpu(show_average_cpu);
+        data_collector.set_show_average_cpu(show_average_cpu);
+
+        data_collector.update_data();
+        data_collector.data = Data::default();
+
+        // Tiny sleep I guess? To go between the first update above and the first update in the loop.
+        std::thread::sleep(Duration::from_millis(5));
 
         loop {
             // Check once at the very top... don't block though.
@@ -241,12 +249,12 @@ fn create_collection_thread(
                 // trace!("Received message in collection thread: {message:?}");
                 match message {
                     CollectionThreadEvent::Reset => {
-                        data_state.data.cleanup();
+                        data_collector.data.cleanup();
                     }
                 }
             }
 
-            data_state.update_data();
+            data_collector.update_data();
 
             // Yet another check to bail if needed... do not block!
             if let Some(is_terminated) = cancellation_token.try_check() {
@@ -255,8 +263,9 @@ fn create_collection_thread(
                 }
             }
 
-            let event = BottomEvent::Update(Box::from(data_state.data));
+            let event = BottomEvent::Update(Box::from(data_collector.data));
-            data_state.data = collection::Data::default();
+            data_collector.data = Data::default();
+
             if sender.send(event).is_err() {
                 break;
             }