fix

engine/include/pdfengine/multi_level_cache.hpp

@@ -0,0 +1,61 @@
+#pragma once
+
+#include <pdfengine/layout_tree.hpp>
+#include <pdfengine/spatial_index.hpp>
+#include <unordered_map>
+#include <mutex>
+#include <optional>
+#include <string>
+#include <memory>
+
+namespace pdfengine {
+
+struct CacheKey {
+    std::string documentId;
+    int pageIndex = 0;
+    size_t contentRevision = 1;
+    size_t layoutRevision = 1;
+
+    bool operator==(const CacheKey& other) const noexcept {
+        return documentId == other.documentId &&
+               pageIndex == other.pageIndex &&
+               contentRevision == other.contentRevision &&
+               layoutRevision == other.layoutRevision;
+    }
+};
+
+struct CacheKeyHash {
+    size_t operator()(const CacheKey& k) const noexcept {
+        size_t h1 = std::hash<std::string>{}(k.documentId);
+        size_t h2 = std::hash<int>{}(k.pageIndex);
+        size_t h3 = std::hash<size_t>{}(k.contentRevision);
+        size_t h4 = std::hash<size_t>{}(k.layoutRevision);
+        return h1 ^ (h2 << 1) ^ (h3 << 2) ^ (h4 << 3);
+    }
+};
+
+class MultiLevelCache {
+public:
+    static MultiLevelCache& instance();
+
+    void putLayoutTree(const CacheKey& key, std::shared_ptr<PhysicalLayoutTree> tree);
+    [[nodiscard]] std::shared_ptr<PhysicalLayoutTree> getLayoutTree(const CacheKey& key) const;
+
+    void putSpatialIndex(const CacheKey& key, std::shared_ptr<MultiIndexSpatialIndex> index);
+    [[nodiscard]] std::shared_ptr<MultiIndexSpatialIndex> getSpatialIndex(const CacheKey& key) const;
+
+    void invalidatePage(const std::string& documentId, int pageIndex);
+    void invalidateDocument(const std::string& documentId);
+    void clear();
+
+    [[nodiscard]] size_t size() const;
+
+private:
+    MultiLevelCache() = default;
+    mutable std::mutex m_mutex;
+
+    std::unordered_map<CacheKey, std::shared_ptr<PhysicalLayoutTree>, CacheKeyHash> m_layoutCache;
+    std::unordered_map<CacheKey, std::shared_ptr<MultiIndexSpatialIndex>, CacheKeyHash> m_spatialCache;
+};
+
+} // namespace pdfengine