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Diffstat (limited to 'store/source/storcach.hxx')
-rw-r--r-- | store/source/storcach.hxx | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/store/source/storcach.hxx b/store/source/storcach.hxx new file mode 100644 index 0000000000..b787248349 --- /dev/null +++ b/store/source/storcach.hxx @@ -0,0 +1,99 @@ +/* -*- 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: */ |