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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed
+ * with this work for additional information regarding copyright
+ * ownership. The ASF licenses this file to you under the Apache
+ * License, Version 2.0 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#pragma once
+
+#include <sal/config.h>
+
+#include <memory>
+
+#include <sal/types.h>
+
+#include <store/types.h>
+#include "object.hxx"
+
+namespace rtl { template <class reference_type> class Reference; }
+namespace store { struct PageData; }
+
+namespace store
+{
+
+struct Entry;
+
+class PageCache :
+ public store::OStoreObject
+{
+ static size_t const theTableSize = 32;
+ static_assert((theTableSize & (theTableSize-1)) == 0, "table size should be a power of 2");
+
+ Entry ** m_hash_table;
+ Entry * m_hash_table_0[theTableSize] = {};
+ size_t m_hash_size;
+ size_t m_hash_shift;
+ size_t const m_page_shift;
+
+ size_t m_hash_entries; // total number of entries in table.
+ size_t m_nHit;
+ size_t m_nMissed;
+
+ static int hash_Impl(sal_uInt32 a, size_t s, size_t q, size_t m)
+ {
+ return static_cast<int>(((a + (a >> s) + (a >> (s << 1))) >> q) & m);
+ }
+ int hash_index_Impl (sal_uInt32 nOffset)
+ {
+ return hash_Impl(nOffset, m_hash_shift, m_page_shift, m_hash_size - 1);
+ }
+
+ Entry * lookup_Impl (Entry * entry, sal_uInt32 nOffset);
+ void rescale_Impl (std::size_t new_size);
+
+public:
+ explicit PageCache (sal_uInt16 nPageSize);
+
+ PageCache(const PageCache&) = delete;
+ PageCache& operator=(const PageCache&) = delete;
+
+ storeError lookupPageAt (
+ std::shared_ptr<PageData> & rxPage,
+ sal_uInt32 nOffset);
+
+ storeError insertPageAt (
+ std::shared_ptr<PageData> const & rxPage,
+ sal_uInt32 nOffset);
+
+ storeError updatePageAt (
+ std::shared_ptr<PageData> const & rxPage,
+ sal_uInt32 nOffset);
+
+ storeError removePageAt (
+ sal_uInt32 nOffset);
+
+protected:
+ virtual ~PageCache() override;
+};
+
+storeError PageCache_createInstance (
+ rtl::Reference< store::PageCache > & rxCache,
+ sal_uInt16 nPageSize
+);
+
+} // namespace store
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */