perf: Coalesce better (#1594)

* benchmarks for coalesce/mark_range

* benchmarks for coalesce/mark_range

* Make the exposure conditional, fmt

* Try to get something better im place

* Refactor bench

* Working much better now

* That was tricky

* Fix benches

* Some debug assertions and better comments

* Even better comments and such

* Remove redundant variable

* There is always just one contiguous acked range now

* Better function comments.

* Merge main

* Test thoroughly, guided by coverage

* Commentary

* Tweak commentary.

* Update Cargo.toml

* Revert this bit

* Rebase with upstream

* Removing redundant use statements

---------

Signed-off-by: Lars Eggert <lars@eggert.org>
Co-authored-by: Randell Jesup <rjesup@jesup.org>
Co-authored-by: Lars Eggert <lars@eggert.org>

neqo-transport/benches/range_tracker.rs

@@ -1,16 +1,16 @@
 use criterion::{criterion_group, criterion_main, Criterion}; // black_box
-use neqo_transport::send_stream::{RangeState, RangeTracker};
+use neqo_transport::send_stream::RangeTracker;
 
 const CHUNK: u64 = 1000;
 const END: u64 = 100_000;
 fn build_coalesce(len: u64) -> RangeTracker {
     let mut used = RangeTracker::default();
-    used.mark_range(0, CHUNK as usize, RangeState::Acked);
-    used.mark_range(CHUNK, END as usize, RangeState::Sent);
+    used.mark_acked(0, CHUNK as usize);
+    used.mark_sent(CHUNK, END as usize);
     // leave a gap or it will coalesce here
     for i in 2..=len {
         // These do not get immediately coalesced when marking since they're not at the end or start
-        used.mark_range(i * CHUNK, CHUNK as usize, RangeState::Acked);
+        used.mark_acked(i * CHUNK, CHUNK as usize);
     }
     used
 }
@@ -22,10 +22,10 @@ fn coalesce(c: &mut Criterion, count: u64) {
             b.iter_batched_ref(
                 || build_coalesce(count),
                 |used| {
-                    used.mark_range(CHUNK, CHUNK as usize, RangeState::Acked);
+                    used.mark_acked(CHUNK, CHUNK as usize);
                     let tail = (count + 1) * CHUNK;
-                    used.mark_range(tail, CHUNK as usize, RangeState::Sent);
-                    used.mark_range(tail, CHUNK as usize, RangeState::Acked);
+                    used.mark_sent(tail, CHUNK as usize);
+                    used.mark_acked(tail, CHUNK as usize);
                 },
                 criterion::BatchSize::SmallInput,
             )

neqo-transport/src/connection/mod.rs

@@ -59,13 +59,15 @@ use crate::{
     version::{Version, WireVersion},
     AppError, ConnectionError, Error, Res, StreamId,
 };
+
 mod dump;
 mod idle;
 pub mod params;
 mod saved;
 mod state;
 #[cfg(test)]
 pub mod test_internal;
+
 use dump::dump_packet;
 use idle::IdleTimeout;
 pub use params::ConnectionParameters;