Highlighter engine returns cached spans by reference; drop unneeded mutexes

kyle/kte

HighlighterEngine::GetLine copied the span vector on every call (twice
on a miss) and did a dynamic_cast per call; it now returns the cached
entry (valid until the next call) and dispatches on Stateful().

PieceTable and HighlighterEngine took a mutex in their read paths while
their writes took none, and PieceTable.h claimed concurrent reads were
safe; they are not (reads update caches). Every Buffer is used from the
main thread only (the swap writer thread receives copies; the regex
large-stack thread runs while its caller waits), so the mutexes are
removed and the headers say so. ASan and the threaded tests under TSan
are clean.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015rcVQiiWyTzoNrsvLSaAfB

This commit is contained in:

Claude

2026-09-24 12:19:59 -07:00

committed by

Kyle Isom

parent 7039c14507

commit d490245f30

8 changed files with 43 additions and 73 deletions

									
										Buffer.h
									
		-1
	
												View File
												
				@@ -44,7 +44,6 @@

				#include <cstdint>

				#include "syntax/HighlighterEngine.h"

				#include "Highlight.h"

				#include <mutex>

				// Edit mode determines which font class is used for a buffer.

				enum class EditMode { Code, Writing };