Files
kte/syntax/HighlighterEngine.h
T
Claude fc9f83966c HighlighterEngine: remove background warm-up thread
The worker read the Buffer (PieceTable pieces and add buffer) while the
main thread edited it with no shared lock, and kept a raw Buffer* that
dangled once the buffer vector reallocated or shifted. PrefetchViewport
now only highlights the visible rows synchronously.

Audit finding M2.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015rcVQiiWyTzoNrsvLSaAfB
2026-09-24 09:16:04 -07:00

68 lines
2.0 KiB
C++

// HighlighterEngine.h - caching layer for per-line highlights
#pragma once
#include <cstdint>
#include <memory>
#include <unordered_map>
#include <vector>
#include <mutex>
#include "../Highlight.h"
#include "LanguageHighlighter.h"
class Buffer;
namespace kte {
class HighlighterEngine {
public:
HighlighterEngine();
~HighlighterEngine();
void SetHighlighter(std::unique_ptr<LanguageHighlighter> hl);
// Retrieve highlights for a given line and buffer version.
// Returns a copy to avoid lifetime issues across threads/renderers.
// If cache is stale, recompute using the current highlighter.
LineHighlight GetLine(const Buffer &buf, int row, std::uint64_t buf_version) const;
// Invalidate cached lines from row (inclusive)
void InvalidateFrom(int row);
bool HasHighlighter() const
{
return static_cast<bool>(hl_);
}
// Compute highlights for the visible range so drawing hits the cache.
// There is deliberately no background warming: a worker thread would read
// the Buffer while the main thread edits it (and could outlive a moved
// Buffer), and the PieceTable is not safe for concurrent read and write.
// warm_margin is accepted for source compatibility and ignored.
void PrefetchViewport(const Buffer &buf, int first_row, int row_count, std::uint64_t buf_version,
int warm_margin = 200) const;
private:
std::unique_ptr<LanguageHighlighter> hl_;
// Simple cache by row index (mutable to allow caching in const GetLine)
mutable std::unordered_map<int, LineHighlight> cache_;
// For stateful highlighters, remember per-line state (state after finishing that row)
struct StateEntry {
std::uint64_t version{0};
// Using the interface type; forward-declare via header
StatefulHighlighter::LineState state;
};
mutable std::unordered_map<int, StateEntry> state_cache_;
// Track best known contiguous state row for a given version to avoid O(n) scans
mutable std::unordered_map<std::uint64_t, int> state_last_contig_;
// Guards the caches above.
mutable std::mutex mtx_;
};
} // namespace kte