format: inline the version-1 message loop again (ObjectHeader::parse back to 8f59b2e's speed)

4313917 kept parse_v1_messages out of line (#[inline(never)]) so the generic parser would not carry the loop; since ef428d7 the slice path is compiled once in this crate, and the call itself was the remaining cost of the chunk queue: A/B builds of object_header_parse_x401 with only this attribute changed put #[inline(never)] and no attribute at 24.5-24.9 us and #[inline] at 23.6-24.0 us, with 8f59b2e at 23.6-24.1 us. Lazily creating the chunk list only when a continuation is found (tried too) measured no faster and was not kept. Same code otherwise: every chunk-queue check (65,536 chunks, cycles, file size budget, one chunk buffer at a time, libhdf5 order, overlap allowed) is unchanged. Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>
2026-09-27 22:32:11 -05:00
parent 5c44630ea2
commit 96086add99
1 changed files with 7 additions and 1 deletions
@@ -295,7 +295,13 @@ impl ObjectHeader {
    /// The messages of one version-1 chunk: each checked and appended to
    /// `messages` (NIL ones dropped), each continuation added to `spans`.
    /// Returns how many messages (NIL ones included) the chunk holds.
-    #[inline(never)]
+    ///
+    /// Inlined into the chunk loop: kept out of line (`#[inline(never)]`,
+    /// 4313917), the call cost `ObjectHeader::parse` about 2.5 ns per
+    /// header, 4% on small version-1 headers (A/B builds, 2026-09-27; see
+    /// `BENCHMARKS.md`). Without an attribute the compiler keeps it out of
+    /// line too.
+    #[inline]
    fn parse_v1_messages(
        data: &[u8],
        offset_size: u8,