From 2a2c0e48290c1f71a08a34d48173fd8d7bccff0f Mon Sep 17 00:00:00 2001
From: RJ <rj@metabrew.com>
Date: Thu, 19 Oct 2023 22:18:32 +0100
Subject: [PATCH] fix oldest frame calculation

---
 src/frame_buffer.rs                  | 31 +++++++++++++++++++++++++++-
 src/systems/prefix_in_rollback.rs    |  8 -------
 src/systems/prefix_start_rollback.rs |  9 +++++---
 3 files changed, 36 insertions(+), 12 deletions(-)

diff --git a/src/frame_buffer.rs b/src/frame_buffer.rs
index 2a15f9d..158dc2e 100644
--- a/src/frame_buffer.rs
+++ b/src/frame_buffer.rs
@@ -69,7 +69,7 @@ where
     /// Theoretically.. value could be None if not inserted yet.
     pub fn oldest_frame(&self) -> FrameNumber {
         self.front_frame
-            .saturating_sub(self.capacity as FrameNumber + 1)
+            .saturating_sub(self.entries.len().saturating_sub(1) as FrameNumber)
     }
 
     /// removes entries for frames larger than `frame`
@@ -210,6 +210,35 @@ where
 mod tests {
     use super::*;
 
+    #[test]
+    fn test_oldest_frame() {
+        let mut fb = FrameBuffer::<u32>::with_capacity(5, "");
+        assert_eq!(fb.oldest_frame(), 0);
+        fb.insert(1, 1).unwrap();
+        assert_eq!(fb.get(1), Some(&1));
+        assert_eq!(fb.oldest_frame(), 1);
+
+        fb.insert(2, 2).unwrap();
+        assert_eq!(fb.get(2), Some(&2));
+        assert_eq!(fb.oldest_frame(), 1);
+
+        fb.insert(3, 3).unwrap();
+        assert_eq!(fb.get(3), Some(&3));
+        assert_eq!(fb.oldest_frame(), 1);
+
+        fb.insert(4, 4).unwrap();
+        assert_eq!(fb.get(4), Some(&4));
+        assert_eq!(fb.oldest_frame(), 1);
+
+        fb.insert(5, 5).unwrap();
+        assert_eq!(fb.get(5), Some(&5));
+        assert_eq!(fb.oldest_frame(), 1);
+
+        fb.insert(6, 6).unwrap();
+        assert_eq!(fb.get(6), Some(&6));
+        assert_eq!(fb.oldest_frame(), 2);
+    }
+
     #[test]
     fn test_frame_buffer() {
         let mut fb = FrameBuffer::<u32>::with_capacity(5, "");
diff --git a/src/systems/prefix_in_rollback.rs b/src/systems/prefix_in_rollback.rs
index 7234485..d9d25cd 100644
--- a/src/systems/prefix_in_rollback.rs
+++ b/src/systems/prefix_in_rollback.rs
@@ -40,10 +40,6 @@ pub(crate) fn rebirth_components_during_rollback<T: TimewarpComponent>(
     for (entity, comp_history) in q.iter() {
         let target_frame = game_clock.frame();
         if comp_history.alive_at_frame(target_frame) {
-            info!(
-                "CHecking if {entity:?} {} alive at {game_clock:?} - YES ",
-                comp_history.type_name()
-            );
             // we could go fishing in SS for this, but it should be here if its alive.
             // i think i'm only hitting this with rollback underflows though, during load?
             // need more investigation and to figure out a test case..
@@ -67,10 +63,6 @@ pub(crate) fn rebirth_components_during_rollback<T: TimewarpComponent>(
             );
             commands.entity(entity).insert(comp_val.clone());
         } else {
-            info!(
-                "CHecking if {entity:?} {} alive at {game_clock:?} - NO ",
-                comp_history.type_name()
-            );
             trace!(
                 "comp not alive at {game_clock:?} for {entity:?} {:?} {}",
                 comp_history.alive_ranges,
diff --git a/src/systems/prefix_start_rollback.rs b/src/systems/prefix_start_rollback.rs
index 1bd6109..cad30e3 100644
--- a/src/systems/prefix_start_rollback.rs
+++ b/src/systems/prefix_start_rollback.rs
@@ -150,12 +150,15 @@ pub(crate) fn rollback_component<T: TimewarpComponent>(
                     let oldest_frame = comp_hist.values.oldest_frame();
 
                     error!(
-                        "HMMMM f @ oldest_frame ({oldest_frame}) comp_val = {:?}",
+                        "HMMMM {entity:?} f @ oldest_frame ({oldest_frame}) comp_val = {:?}",
                         comp_hist.at_frame(oldest_frame)
                     );
-                    error!("HMMMM {game_clock:?} OPT_COMP = {opt_comp:?}");
+                    error!("HMMMM {entity:?} {game_clock:?} OPT_COMP = {opt_comp:?}");
                     for f in (rollback_frame - 2)..=(rollback_frame + 2) {
-                        error!("HMMMM f={f} comp_val = {:?}", comp_hist.at_frame(f));
+                        error!(
+                            "HMMMM {entity:?} f={f} comp_val = {:?}",
+                            comp_hist.at_frame(f)
+                        );
                     }
 
                     panic!("{prefix} {game_clock:?} {entity:?} {provenance:?} {} rollback_frame: {rollback_frame} alive_ranges:{:?} rb:{rb:?} oldest value in comp_hist: {oldest_frame} occ:{:?}\n",