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Diffstat (limited to 'store/source/stortree.hxx')
| -rw-r--r-- | store/source/stortree.hxx | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/store/source/stortree.hxx b/store/source/stortree.hxx new file mode 100644 index 0000000000..609d1d1ba8 --- /dev/null +++ b/store/source/stortree.hxx @@ -0,0 +1,248 @@ +/* -*- 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 "storbase.hxx" + +namespace store +{ + +class OStorePageBIOS; + +struct OStoreBTreeEntry +{ + typedef OStorePageKey K; + typedef OStorePageLink L; + + K m_aKey; + L m_aLink; + sal_uInt32 m_nAttrib; + + explicit OStoreBTreeEntry ( + K const & rKey = K(), + L const & rLink = L()) + : m_aKey (rKey), + m_aLink (rLink), + m_nAttrib (store::htonl(0)) + {} + + enum CompareResult + { + COMPARE_LESS = -1, + COMPARE_EQUAL = 0, + COMPARE_GREATER = 1 + }; + + CompareResult compare (const OStoreBTreeEntry& rOther) const + { + if (m_aKey < rOther.m_aKey) + return COMPARE_LESS; + else if (m_aKey == rOther.m_aKey) + return COMPARE_EQUAL; + else + return COMPARE_GREATER; + } +}; + +#define STORE_MAGIC_BTREENODE sal_uInt32(0x58190322) + +struct OStoreBTreeNodeData : public store::PageData +{ + typedef PageData base; + typedef OStoreBTreeNodeData self; + + typedef OStorePageGuard G; + typedef OStoreBTreeEntry T; + + G m_aGuard; + T m_pData[1]; + + static const sal_uInt32 theTypeId = STORE_MAGIC_BTREENODE; + + static const size_t theSize = sizeof(G); + static const sal_uInt16 thePageSize = base::theSize + self::theSize; + static_assert(STORE_MINIMUM_PAGESIZE >= self::thePageSize, "got to be at least equal in size"); + + sal_uInt16 capacity() const + { + return static_cast<sal_uInt16>(store::ntohs(base::m_aDescr.m_nSize) - self::thePageSize); + } + + /** capacityCount (must be even). + */ + sal_uInt16 capacityCount() const + { + return sal_uInt16(capacity() / sizeof(T)); + } + + sal_uInt16 usage() const + { + return static_cast<sal_uInt16>(store::ntohs(base::m_aDescr.m_nUsed) - self::thePageSize); + } + + sal_uInt16 usageCount() const + { + return sal_uInt16(usage() / sizeof(T)); + } + void usageCount (sal_uInt16 nCount) + { + size_t const nBytes = self::thePageSize + nCount * sizeof(T); + base::m_aDescr.m_nUsed = store::htons(sal::static_int_cast< sal_uInt16 >(nBytes)); + } + + explicit OStoreBTreeNodeData (sal_uInt16 nPageSize); + + void guard() + { + sal_uInt32 nCRC32 = rtl_crc32 (0, &m_aGuard.m_nMagic, sizeof(sal_uInt32)); + nCRC32 = rtl_crc32 (nCRC32, m_pData, capacity()); + m_aGuard.m_nCRC32 = store::htonl(nCRC32); + } + + storeError verify() const + { + sal_uInt32 nCRC32 = rtl_crc32 (0, &m_aGuard.m_nMagic, sizeof(sal_uInt32)); + nCRC32 = rtl_crc32 (nCRC32, m_pData, capacity()); + if (m_aGuard.m_nCRC32 != store::htonl(nCRC32)) + return store_E_InvalidChecksum; + else + return store_E_None; + } + + sal_uInt32 depth() const + { + return store::ntohl(self::m_aGuard.m_nMagic); + } + void depth (sal_uInt32 nDepth) + { + self::m_aGuard.m_nMagic = store::htonl(nDepth); + } + + bool querySplit() const + { + return usageCount() >= capacityCount(); + } + + sal_uInt16 find (const T& t) const; + void insert (sal_uInt16 i, const T& t); + void remove (sal_uInt16 i); + + /** split (left half copied from right half of left page). + */ + void split (const self& rPageL); + + /** truncate (to n elements). + */ + void truncate (sal_uInt16 n); +}; + +class OStoreBTreeNodeObject : public store::OStorePageObject +{ + typedef OStorePageObject base; + typedef OStoreBTreeNodeObject self; + typedef OStoreBTreeNodeData page; + + typedef OStoreBTreeEntry T; + +public: + explicit OStoreBTreeNodeObject (std::shared_ptr<PageData> const & rxPage = std::shared_ptr<PageData>()) + : OStorePageObject (rxPage) + {} + + virtual storeError guard (sal_uInt32 nAddr) override; + virtual storeError verify (sal_uInt32 nAddr) const override; + + /** split. + * + * @param rxPageL [inout] left child to be split + */ + storeError split ( + sal_uInt16 nIndexL, + PageHolderObject< page > & rxPageL, + OStorePageBIOS & rBIOS); + + /** remove (down to leaf node, recursive). + */ + storeError remove ( + sal_uInt16 nIndexL, + OStoreBTreeEntry & rEntryL, + OStorePageBIOS & rBIOS); +}; + +class OStoreBTreeRootObject : public store::OStoreBTreeNodeObject +{ + typedef OStoreBTreeNodeObject base; + typedef OStoreBTreeNodeData page; + + typedef OStoreBTreeEntry T; + +public: + explicit OStoreBTreeRootObject (std::shared_ptr<PageData> const & rxPage = std::shared_ptr<PageData>()) + : OStoreBTreeNodeObject (rxPage) + {} + + storeError loadOrCreate ( + sal_uInt32 nAddr, + OStorePageBIOS & rBIOS); + + /** find_lookup (w/o split()). + * Precond: root node page loaded. + */ + storeError find_lookup ( + OStoreBTreeNodeObject & rNode, // [out] + sal_uInt16 & rIndex, // [out] + OStorePageKey const & rKey, + OStorePageBIOS & rBIOS) const; + + /** find_insert (possibly with split()). + * Precond: root node page loaded. + */ + storeError find_insert ( + OStoreBTreeNodeObject & rNode, + sal_uInt16 & rIndex, + OStorePageKey const & rKey, + OStorePageBIOS & rBIOS); + +private: + /** testInvariant. + * Precond: root node page loaded. + */ + void testInvariant (char const * message) const; + + /** change (Root). + * + * @param rxPageL [out] prev. root (needs split) + */ + storeError change ( + PageHolderObject< page > & rxPageL, + OStorePageBIOS & rBIOS); +}; + +} // namespace store + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |