bench: reuse multiline terminator Finder

docs/development.md

@@ -83,7 +83,18 @@ Current response responsibilities:
 
 ## Benchmarks
 
-Published benchmark numbers were intentionally removed from the docs until they are rerun.
+The stock cache-miss E2E harness ran on an AMD Ryzen 9 5950X with 32 logical
+CPUs. `main` commit `145b36c6b86621dccfe965926b0ef501ffd33b06` and Finder
+candidate commit `e176fef31432ed36dc101471dfa1c94cc1650908` each completed
+the default 112-cell matrix twice for Finder (10 GiB per cell, 728,320-byte
+articles, article-only mix, pipeline depth 32). The fresh main control's
+equal-weight mean was 3,546.6 MiB/s; Finder repeats were 3,564.3 MiB/s
+(+0.5%) and 3,560.8 MiB/s (+0.4%). Their paired medians were -0.4% and
++0.4%, geometric means +0.6% and -0.5%, and win/loss counts 50/62 and 63/49.
+Measured proxy CPU changed -0.8% then +0.2%. The fresh main control was 0.8%
+above the older main baseline. The repeats have substantial per-cell spread,
+so they do not demonstrate a reliable end-to-end speedup. The fresh CSVs are
+retained locally and are not committed.
 
 When you want fresh numbers:
 

src/session/multiline_framing.rs

@@ -11,6 +11,7 @@
 use std::borrow::Cow;
 use std::collections::VecDeque;
 use std::ops::Range;
+use std::sync::LazyLock;
 
 use anyhow::Context;
 use smallvec::SmallVec;
@@ -20,6 +21,9 @@ const TERMINATOR: &[u8; 5] = b"\r\n.\r\n";
 const TERMINATOR_TAIL_SIZE: usize = 4;
 const MAX_CAPTURED_MULTILINE_RESPONSE_BYTES: usize = 4 * 1024 * 1024;
 
+static TERMINATOR_FINDER: LazyLock<memchr::memmem::Finder<'static>> =
+    LazyLock::new(|| memchr::memmem::Finder::new(TERMINATOR));
+
 #[must_use]
 pub(crate) fn cached_response_completion() -> std::io::IoSlice<'static> {
     std::io::IoSlice::new(TERMINATOR)
@@ -2056,7 +2060,9 @@ fn find_terminator_end(data: &[u8]) -> Option<usize> {
 
 #[inline]
 fn terminator_ends(data: &[u8]) -> impl Iterator<Item = usize> + '_ {
-    memchr::memmem::find_iter(data, TERMINATOR).map(|found| found + TERMINATOR.len())
+    TERMINATOR_FINDER
+        .find_iter(data)
+        .map(|found| found + TERMINATOR.len())
 }
 
 #[inline]