Only print status when activities change or enough time has passed.

src/error/error.rs

@@ -2,6 +2,7 @@ use std::fmt::Display;
 use std::num::TryFromIntError;
 use std::str::Utf8Error;
 use std::string::FromUtf8Error;
+use std::time::SystemTimeError;
 
 use crate::nix_util::ActivityIdAlreadyInTreeError;
 use crate::nix_util::ActivityIdNotInTreeError;
@@ -24,6 +25,7 @@ pub(crate) enum CustomError {
     TryFromIntError(#[allow(dead_code)] TryFromIntError),
     ActivityIdNotInTreeError(#[allow(dead_code)] ActivityIdNotInTreeError),
     ActivityIdAlreadyInTreeError(#[allow(dead_code)] ActivityIdAlreadyInTreeError),
+    SystemTime(#[allow(dead_code)] SystemTimeError),
 }
 
 impl Display for CustomError {
@@ -127,3 +129,9 @@ impl From<ActivityIdAlreadyInTreeError> for CustomError {
         CustomError::ActivityIdAlreadyInTreeError(value)
     }
 }
+
+impl From<SystemTimeError> for CustomError {
+    fn from(value: SystemTimeError) -> Self {
+        CustomError::SystemTime(value)
+    }
+}

src/nix_util/running_build.rs

@@ -1,4 +1,7 @@
 use std::borrow::Cow;
+use std::time::Duration;
+use std::time::Instant;
+use std::time::SystemTime;
 
 use sqlx::Row;
 use tokio::process::Child;
@@ -37,6 +40,7 @@ use super::nix_output_stream::NixMessage;
 pub(crate) struct RunningBuild<'db> {
     db_handle: &'db DbHandle,
     activity_tree: ActivityTree,
+    last_announce: Option<Instant>,
 }
 
 impl<'db> RunningBuild<'db> {
@@ -44,6 +48,7 @@ impl<'db> RunningBuild<'db> {
         Ok(RunningBuild {
             db_handle,
             activity_tree: ActivityTree::new(),
+            last_announce: None,
         })
     }
 
@@ -55,6 +60,8 @@ impl<'db> RunningBuild<'db> {
     where
         TN: AsRef<str>,
     {
+        let foo = SystemTime::now().duration_since(SystemTime::UNIX_EPOCH)?;
+        let now = Instant::now();
         let build_id: i64 = sqlx::query(
             r#"INSERT INTO build (start_time, target) SELECT unixepoch('now'), ? RETURNING id"#,
         )
@@ -318,7 +325,7 @@ impl<'db> RunningBuild<'db> {
                             activity_result_progress.failed,
                         );
 
-                        self.print_current_status();
+                        self.maybe_print_current_status();
                     }
                     ActivityResultMessage::SetExpected(activity_result_set_expected) => {
                         let activity_id = self
@@ -329,7 +336,7 @@ impl<'db> RunningBuild<'db> {
                             .get_mut_activity()
                             .set_expected(activity_result_set_expected.expected);
 
-                        self.print_current_status();
+                        self.maybe_print_current_status();
                     }
                     ActivityResultMessage::PostBuildLogLine(
                         _activity_result_post_build_log_line,
@@ -341,7 +348,23 @@ impl<'db> RunningBuild<'db> {
         Ok(())
     }
 
-    fn print_current_status(&self) -> () {
+    fn maybe_print_current_status(&mut self) -> () {
+        let last_announce = match self.last_announce {
+            Some(instant) => instant,
+            None => {
+                // If we haven't announced before, always announce.
+                return self.print_current_status();
+            }
+        };
+
+        let now = Instant::now();
+        let time_since_last_announce = now.duration_since(last_announce);
+        if time_since_last_announce > Duration::new(5, 0) {
+            return self.print_current_status();
+        }
+    }
+
+    fn print_current_status(&mut self) -> () {
         let mut tree = String::new();
         let draw_order = self.get_draw_order();
         for dag_entry in draw_order {
@@ -378,6 +401,7 @@ impl<'db> RunningBuild<'db> {
         } else {
             print!("\n{}\n", tree);
         }
+        self.last_announce = Some(Instant::now());
     }
 
     fn get_draw_order(&self) -> Vec<DrawDagEntry> {