Adding upstream version 1:7.0.4.upstream/1%7.0.4upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1095 insertions, 0 deletions

diff --git a/store/source/stordata.cxx b/store/source/stordata.cxx
new file mode 100644
index 000000000..7ce39a9c1
--- /dev/null
+++ b/store/source/stordata.cxx
@@ -0,0 +1,1095 @@
+/* -*- 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 .
+ */
+
+#include "stordata.hxx"
+
+#include <sal/types.h>
+#include <sal/log.hxx>
+
+#include <store/types.h>
+#include "storbase.hxx"
+#include "storbios.hxx"
+
+using namespace store;
+
+/*========================================================================
+ *
+ * OStoreDataPageObject implementation.
+ *
+ *======================================================================*/
+/*
+ * guard.
+ */
+storeError OStoreDataPageObject::guard (sal_uInt32 nAddr)
+{
+    return PageHolderObject< page >::guard (m_xPage, nAddr);
+}
+
+/*
+ * verify.
+ */
+storeError OStoreDataPageObject::verify (sal_uInt32 nAddr) const
+{
+    return PageHolderObject< page >::verify (m_xPage, nAddr);
+}
+
+/*========================================================================
+ *
+ * OStoreIndirectionPageObject implementation.
+ *
+ *======================================================================*/
+/*
+  * store_truncate_Impl (single indirect page).
+  */
+static storeError store_truncate_Impl (
+    sal_uInt32      nAddr,
+    sal_uInt16      nSingle,
+    OStorePageBIOS &rBIOS)
+{
+    if (nAddr != STORE_PAGE_NULL)
+    {
+        // Load single indirect page.
+        OStoreIndirectionPageObject aSingle;
+        storeError eErrCode = rBIOS.loadObjectAt (aSingle, nAddr);
+        if (eErrCode == store_E_None)
+        {
+            // Truncate to 'nSingle' direct pages.
+            eErrCode = aSingle.truncate (nSingle, rBIOS);
+            if (eErrCode != store_E_None)
+                return eErrCode;
+        }
+        else
+        {
+            if (eErrCode != store_E_InvalidChecksum)
+                return eErrCode;
+        }
+
+        // Check for complete truncation.
+        if (nSingle == 0)
+        {
+            // Free single indirect page.
+            eErrCode = rBIOS.free (nAddr);
+            if (eErrCode != store_E_None)
+                return eErrCode;
+        }
+    }
+    return store_E_None;
+}
+
+/*
+ * store_truncate_Impl (double indirect page).
+ */
+static storeError store_truncate_Impl (
+    sal_uInt32       nAddr,
+    sal_uInt16       nDouble,
+    sal_uInt16       nSingle,
+    OStorePageBIOS  &rBIOS)
+{
+    if (nAddr != STORE_PAGE_NULL)
+    {
+        // Load double indirect page.
+        OStoreIndirectionPageObject aDouble;
+        storeError eErrCode = rBIOS.loadObjectAt (aDouble, nAddr);
+        if (eErrCode == store_E_None)
+        {
+            // Truncate to 'nDouble', 'nSingle' pages.
+            eErrCode = aDouble.truncate (nDouble, nSingle, rBIOS);
+            if (eErrCode != store_E_None)
+                return eErrCode;
+        }
+        else
+        {
+            if (eErrCode != store_E_InvalidChecksum)
+                return eErrCode;
+        }
+
+        // Check for complete truncation.
+        if ((nDouble + nSingle) == 0)
+        {
+            // Free double indirect page.
+            eErrCode = rBIOS.free (nAddr);
+            if (eErrCode != store_E_None)
+                return eErrCode;
+        }
+    }
+    return store_E_None;
+}
+
+/*
+ * store_truncate_Impl (triple indirect page).
+ */
+static storeError store_truncate_Impl (
+    sal_uInt32       nAddr,
+    sal_uInt16       nTriple,
+    sal_uInt16       nDouble,
+    sal_uInt16       nSingle,
+    OStorePageBIOS  &rBIOS)
+{
+    if (nAddr != STORE_PAGE_NULL)
+    {
+        // Load triple indirect page.
+        OStoreIndirectionPageObject aTriple;
+        storeError eErrCode = rBIOS.loadObjectAt (aTriple, nAddr);
+        if (eErrCode != store_E_None)
+            return eErrCode;
+
+        // Truncate to 'nTriple', 'nDouble', 'nSingle' pages.
+        eErrCode = aTriple.truncate (nTriple, nDouble, nSingle, rBIOS);
+        if (eErrCode != store_E_None)
+            return eErrCode;
+
+        // Check for complete truncation.
+        if ((nTriple + nDouble + nSingle) == 0)
+        {
+            // Free triple indirect page.
+            eErrCode = rBIOS.free (nAddr);
+            if (eErrCode != store_E_None)
+                return eErrCode;
+        }
+    }
+    return store_E_None;
+}
+
+/*
+ * loadOrCreate.
+ */
+storeError OStoreIndirectionPageObject::loadOrCreate (
+    sal_uInt32       nAddr,
+    OStorePageBIOS & rBIOS)
+{
+    if (nAddr == STORE_PAGE_NULL)
+    {
+        storeError eErrCode = construct<page>(rBIOS.allocator());
+        if (eErrCode != store_E_None)
+            return eErrCode;
+
+        eErrCode = rBIOS.allocate (*this);
+        if (eErrCode != store_E_None)
+            return eErrCode;
+
+        // Save location pending at caller.
+        return store_E_Pending;
+    }
+    return rBIOS.loadObjectAt (*this, nAddr);
+}
+
+/*
+ * guard.
+ */
+storeError OStoreIndirectionPageObject::guard (sal_uInt32 nAddr)
+{
+    return PageHolderObject< page >::guard (m_xPage, nAddr);
+}
+
+/*
+ * verify.
+ */
+storeError OStoreIndirectionPageObject::verify (sal_uInt32 nAddr) const
+{
+    return PageHolderObject< page >::verify (m_xPage, nAddr);
+}
+
+/*
+ * read (single indirect).
+ */
+storeError OStoreIndirectionPageObject::read (
+    sal_uInt16             nSingle,
+    OStoreDataPageObject  &rData,
+    OStorePageBIOS        &rBIOS) const
+{
+    PageHolderObject< page > xImpl (m_xPage);
+    page const & rPage = *xImpl;
+
+    // Check arguments.
+    sal_uInt16 const nLimit = rPage.capacityCount();
+    if (nSingle >= nLimit)
+        return store_E_InvalidAccess;
+
+    // Obtain data page location.
+    sal_uInt32 const nAddr = store::ntohl(rPage.m_pData[nSingle]);
+    if (nAddr == STORE_PAGE_NULL)
+        return store_E_NotExists;
+
+    // Load data page and leave.
+    return rBIOS.loadObjectAt (rData, nAddr);
+}
+
+/*
+ * read (double indirect).
+ */
+storeError OStoreIndirectionPageObject::read (
+    sal_uInt16             nDouble,
+    sal_uInt16             nSingle,
+    OStoreDataPageObject  &rData,
+    OStorePageBIOS        &rBIOS) const
+{
+    PageHolderObject< page > xImpl (m_xPage);
+    page const & rPage = *xImpl;
+
+    // Check arguments.
+    sal_uInt16 const nLimit = rPage.capacityCount();
+    if (!((nDouble < nLimit) && (nSingle < nLimit)))
+        return store_E_InvalidAccess;
+
+    // Check single indirect page location.
+    sal_uInt32 const nAddr = store::ntohl(rPage.m_pData[nDouble]);
+    if (nAddr == STORE_PAGE_NULL)
+        return store_E_NotExists;
+
+    // Load single indirect page.
+    OStoreIndirectionPageObject aSingle;
+    storeError eErrCode = rBIOS.loadObjectAt (aSingle, nAddr);
+    if (eErrCode != store_E_None)
+        return eErrCode;
+
+    // Read single indirect and leave.
+    return aSingle.read (nSingle, rData, rBIOS);
+}
+
+/*
+ * read (triple indirect).
+ */
+storeError OStoreIndirectionPageObject::read (
+    sal_uInt16             nTriple,
+    sal_uInt16             nDouble,
+    sal_uInt16             nSingle,
+    OStoreDataPageObject  &rData,
+    OStorePageBIOS        &rBIOS) const
+{
+    PageHolderObject< page > xImpl (m_xPage);
+    page const & rPage = *xImpl;
+
+    // Check arguments.
+    sal_uInt16 const nLimit = rPage.capacityCount();
+    if (!((nTriple < nLimit) && (nDouble < nLimit) && (nSingle < nLimit)))
+        return store_E_InvalidAccess;
+
+    // Check double indirect page location.
+    sal_uInt32 const nAddr = store::ntohl(rPage.m_pData[nTriple]);
+    if (nAddr == STORE_PAGE_NULL)
+        return store_E_NotExists;
+
+    // Load double indirect page.
+    OStoreIndirectionPageObject aDouble;
+    storeError eErrCode = rBIOS.loadObjectAt (aDouble, nAddr);
+    if (eErrCode != store_E_None)
+        return eErrCode;
+
+    // Read double indirect and leave.
+    return aDouble.read (nDouble, nSingle, rData, rBIOS);
+}
+
+/*
+ * write (single indirect).
+ */
+storeError OStoreIndirectionPageObject::write (
+    sal_uInt16             nSingle,
+    OStoreDataPageObject  &rData,
+    OStorePageBIOS        &rBIOS)
+{
+    PageHolderObject< page > xImpl (m_xPage);
+    page & rPage = *xImpl;
+
+    // Check arguments.
+    sal_uInt16 const nLimit = rPage.capacityCount();
+    if (nSingle >= nLimit)
+        return store_E_InvalidAccess;
+
+    // Obtain data page location.
+    sal_uInt32 const nAddr = store::ntohl(rPage.m_pData[nSingle]);
+    if (nAddr == STORE_PAGE_NULL)
+    {
+        // Allocate data page.
+        storeError eErrCode = rBIOS.allocate (rData);
+        if (eErrCode != store_E_None)
+            return eErrCode;
+
+        // Store data page location.
+        rPage.m_pData[nSingle] = store::htonl(rData.location());
+
+        // Save this page.
+        return rBIOS.saveObjectAt (*this, location());
+    }
+    else
+    {
+        // Save data page.
+        return rBIOS.saveObjectAt (rData, nAddr);
+    }
+}
+
+/*
+ * write (double indirect).
+ */
+storeError OStoreIndirectionPageObject::write (
+    sal_uInt16             nDouble,
+    sal_uInt16             nSingle,
+    OStoreDataPageObject  &rData,
+    OStorePageBIOS        &rBIOS)
+{
+    PageHolderObject< page > xImpl (m_xPage);
+    page & rPage = *xImpl;
+
+    // Check arguments.
+    sal_uInt16 const nLimit = rPage.capacityCount();
+    if (!((nDouble < nLimit) && (nSingle < nLimit)))
+        return store_E_InvalidAccess;
+
+    // Load or create single indirect page.
+    OStoreIndirectionPageObject aSingle;
+    storeError eErrCode = aSingle.loadOrCreate (store::ntohl(rPage.m_pData[nDouble]), rBIOS);
+    if (eErrCode != store_E_None)
+    {
+        if (eErrCode != store_E_Pending)
+            return eErrCode;
+        rPage.m_pData[nDouble] = store::htonl(aSingle.location());
+
+        eErrCode = rBIOS.saveObjectAt (*this, location());
+        if (eErrCode != store_E_None)
+            return eErrCode;
+    }
+
+    // Write single indirect and leave.
+    return aSingle.write (nSingle, rData, rBIOS);
+}
+
+/*
+ * write (triple indirect).
+ */
+storeError OStoreIndirectionPageObject::write (
+    sal_uInt16             nTriple,
+    sal_uInt16             nDouble,
+    sal_uInt16             nSingle,
+    OStoreDataPageObject  &rData,
+    OStorePageBIOS        &rBIOS)
+{
+    PageHolderObject< page > xImpl (m_xPage);
+    page & rPage = *xImpl;
+
+    // Check arguments.
+    sal_uInt16 const nLimit = rPage.capacityCount();
+    if (!((nTriple < nLimit) && (nDouble < nLimit) && (nSingle < nLimit)))
+        return store_E_InvalidAccess;
+
+    // Load or create double indirect page.
+    OStoreIndirectionPageObject aDouble;
+    storeError eErrCode = aDouble.loadOrCreate (store::ntohl(rPage.m_pData[nTriple]), rBIOS);
+    if (eErrCode != store_E_None)
+    {
+        if (eErrCode != store_E_Pending)
+            return eErrCode;
+        rPage.m_pData[nTriple] = store::htonl(aDouble.location());
+
+        eErrCode = rBIOS.saveObjectAt (*this, location());
+        if (eErrCode != store_E_None)
+            return eErrCode;
+    }
+
+    // Write double indirect and leave.
+    return aDouble.write (nDouble, nSingle, rData, rBIOS);
+}
+
+/*
+ * truncate (single indirect).
+ */
+storeError OStoreIndirectionPageObject::truncate (
+    sal_uInt16       nSingle,
+    OStorePageBIOS & rBIOS)
+{
+    PageHolderObject< page > xImpl (m_xPage);
+    page & rPage = *xImpl;
+
+    // Check arguments.
+    sal_uInt16 const nLimit = rPage.capacityCount();
+    if (nSingle >= nLimit)
+        return store_E_InvalidAccess;
+
+    // Truncate.
+    storeError eErrCode = store_E_None;
+    for (sal_uInt16 i = nLimit; i > nSingle; i--)
+    {
+        // Obtain data page location.
+        sal_uInt32 const nAddr = store::ntohl(rPage.m_pData[i - 1]);
+        if (nAddr != STORE_PAGE_NULL)
+        {
+            // Free data page.
+            eErrCode = rBIOS.free (nAddr);
+            if (eErrCode != store_E_None)
+                return eErrCode;
+
+            // Clear pointer to data page.
+            rPage.m_pData[i - 1] = STORE_PAGE_NULL;
+            touch();
+        }
+    }
+
+    // Check for modified page.
+    if (dirty())
+    {
+        // Save this page.
+        eErrCode = rBIOS.saveObjectAt (*this, location());
+    }
+
+    // Done.
+    return eErrCode;
+}
+
+/*
+ * truncate (double indirect).
+ */
+storeError OStoreIndirectionPageObject::truncate (
+    sal_uInt16             nDouble,
+    sal_uInt16             nSingle,
+    OStorePageBIOS        &rBIOS)
+{
+    PageHolderObject< page > xImpl (m_xPage);
+    page & rPage = *xImpl;
+
+    // Check arguments.
+    sal_uInt16 const nLimit = rPage.capacityCount();
+    if (!((nDouble < nLimit) && (nSingle < nLimit)))
+        return store_E_InvalidAccess;
+
+    // Truncate.
+    storeError eErrCode = store_E_None;
+    for (sal_uInt16 i = nLimit; i > nDouble + 1; i--)
+    {
+        // Truncate single indirect page to zero direct pages.
+        eErrCode = store_truncate_Impl (store::ntohl(rPage.m_pData[i - 1]), 0, rBIOS);
+        if (eErrCode != store_E_None)
+            return eErrCode;
+
+        // Clear pointer to single indirect page.
+        rPage.m_pData[i - 1] = STORE_PAGE_NULL;
+        touch();
+    }
+
+    // Truncate last single indirect page to 'nSingle' direct pages.
+    eErrCode = store_truncate_Impl (store::ntohl(rPage.m_pData[nDouble]), nSingle, rBIOS);
+    if (eErrCode != store_E_None)
+        return eErrCode;
+
+    // Check for complete truncation.
+    if (nSingle == 0)
+    {
+        // Clear pointer to last single indirect page.
+        rPage.m_pData[nDouble] = STORE_PAGE_NULL;
+        touch();
+    }
+
+    // Check for modified page.
+    if (dirty())
+    {
+        // Save this page.
+        eErrCode = rBIOS.saveObjectAt (*this, location());
+    }
+
+    // Done.
+    return eErrCode;
+}
+
+/*
+ * truncate (triple indirect).
+ */
+storeError OStoreIndirectionPageObject::truncate (
+    sal_uInt16             nTriple,
+    sal_uInt16             nDouble,
+    sal_uInt16             nSingle,
+    OStorePageBIOS        &rBIOS)
+{
+    PageHolderObject< page > xImpl (m_xPage);
+    page & rPage = *xImpl;
+
+    // Check arguments.
+    sal_uInt16 const nLimit = rPage.capacityCount();
+    if (!((nTriple < nLimit) && (nDouble < nLimit) && (nSingle < nLimit)))
+        return store_E_InvalidAccess;
+
+    // Truncate.
+    storeError eErrCode = store_E_None;
+    for (sal_uInt16 i = nLimit; i > nTriple + 1; i--)
+    {
+        // Truncate double indirect page to zero single indirect pages.
+        eErrCode = store_truncate_Impl (store::ntohl(rPage.m_pData[i - 1]), 0, 0, rBIOS);
+        if (eErrCode != store_E_None)
+            return eErrCode;
+
+        // Clear pointer to double indirect page.
+        rPage.m_pData[i - 1] = STORE_PAGE_NULL;
+        touch();
+    }
+
+    // Truncate last double indirect page to 'nDouble', 'nSingle' pages.
+    eErrCode = store_truncate_Impl (store::ntohl(rPage.m_pData[nTriple]), nDouble, nSingle, rBIOS);
+    if (eErrCode != store_E_None)
+        return eErrCode;
+
+    // Check for complete truncation.
+    if ((nDouble + nSingle) == 0)
+    {
+        // Clear pointer to last double indirect page.
+        rPage.m_pData[nTriple] = STORE_PAGE_NULL;
+        touch();
+    }
+
+    // Check for modified page.
+    if (dirty())
+    {
+        // Save this page.
+        eErrCode = rBIOS.saveObjectAt (*this, location());
+    }
+
+    // Done.
+    return eErrCode;
+}
+
+/*========================================================================
+ *
+ * OStoreDirectoryPageObject implementation.
+ *
+ *======================================================================*/
+/*
+ * guard.
+ */
+storeError OStoreDirectoryPageObject::guard (sal_uInt32 nAddr)
+{
+    return PageHolderObject< page >::guard (m_xPage, nAddr);
+}
+
+/*
+ * verify.
+ */
+storeError OStoreDirectoryPageObject::verify (sal_uInt32 nAddr) const
+{
+    return PageHolderObject< page >::verify (m_xPage, nAddr);
+    // OLD: m_rPage.verifyVersion (STORE_MAGIC_DIRECTORYPAGE);
+}
+
+/*
+ * scope (external data page; private).
+ */
+OStoreDirectoryPageData::ChunkScope
+OStoreDirectoryPageObject::scope (
+    sal_uInt32                       nPage,
+    page::DataBlock::LinkDescriptor &rDescr) const
+{
+    page const & rPage = PAGE();
+
+    sal_uInt32 index0, index1, index2, index3;
+
+    // direct.
+    sal_uInt32 nCount = OStoreDirectoryDataBlock::directCount;
+    sal_uInt32 nLimit = nCount;
+    if (nPage < nLimit)
+    {
+        // Page to index reduction.
+        index0 = nPage;
+
+        // Setup LinkDescriptor indices.
+        rDescr.m_nIndex0 = static_cast<sal_uInt16>(index0 & 0xffff);
+
+        // Done.
+        return page::SCOPE_DIRECT;
+    }
+    nPage -= nLimit;
+
+    // single indirect.
+    sal_uInt32 const nCapacity = indirect::capacityCount(rPage.m_aDescr);
+    nCount = OStoreDirectoryDataBlock::singleCount;
+    nLimit = nCount * nCapacity;
+    if (nPage < nLimit)
+    {
+        // Page to index reduction.
+        sal_uInt32 n = nPage;
+
+        // Reduce to single indirect i(1), direct n = i(0).
+        index1 = n / nCapacity;
+        index0 = n % nCapacity;
+
+        // Verify reduction.
+        n = index1 * nCapacity + index0;
+        if (n != nPage)
+        {
+            SAL_WARN("store", "wrong math on indirect indices");
+            return page::SCOPE_UNKNOWN;
+        }
+
+        // Setup LinkDescriptor indices.
+        rDescr.m_nIndex0 = static_cast<sal_uInt16>(index0 & 0xffff);
+        rDescr.m_nIndex1 = static_cast<sal_uInt16>(index1 & 0xffff);
+
+        // Done.
+        return page::SCOPE_SINGLE;
+    }
+    nPage -= nLimit;
+
+    // double indirect.
+    nCount = OStoreDirectoryDataBlock::doubleCount;
+    nLimit = nCount * nCapacity * nCapacity;
+    if (nPage < nLimit)
+    {
+        // Page to index reduction.
+        sal_uInt32 n = nPage;
+
+        // Reduce to double indirect i(2), single indirect n = i(0).
+        index2 = n / (nCapacity * nCapacity);
+        n      = n % (nCapacity * nCapacity);
+
+        // Reduce to single indirect i(1), direct n = i(0).
+        index1 = n / nCapacity;
+        index0 = n % nCapacity;
+
+        // Verify reduction.
+        n = index2 * nCapacity * nCapacity +
+            index1 * nCapacity + index0;
+        if (n != nPage)
+        {
+            SAL_WARN("store", "wrong math on double indirect indices");
+            return page::SCOPE_UNKNOWN;
+        }
+
+        // Setup LinkDescriptor indices.
+        rDescr.m_nIndex0 = static_cast<sal_uInt16>(index0 & 0xffff);
+        rDescr.m_nIndex1 = static_cast<sal_uInt16>(index1 & 0xffff);
+        rDescr.m_nIndex2 = static_cast<sal_uInt16>(index2 & 0xffff);
+
+        // Done.
+        return page::SCOPE_DOUBLE;
+    }
+    nPage -= nLimit;
+
+    // triple indirect.
+    nCount = OStoreDirectoryDataBlock::tripleCount;
+    nLimit = nCount * nCapacity * nCapacity * nCapacity;
+    if (nPage < nLimit)
+    {
+        // Page to index reduction.
+        sal_uInt32 n = nPage;
+
+        // Reduce to triple indirect i(3), double indirect n.
+        index3 = n / (nCapacity * nCapacity * nCapacity);
+        n      = n % (nCapacity * nCapacity * nCapacity);
+
+        // Reduce to double indirect i(2), single indirect n.
+        index2 = n / (nCapacity * nCapacity);
+        n      = n % (nCapacity * nCapacity);
+
+        // Reduce to single indirect i(1), direct n = i(0).
+        index1 = n / nCapacity;
+        index0 = n % nCapacity;
+
+        // Verify reduction.
+        n = index3 * nCapacity * nCapacity * nCapacity +
+            index2 * nCapacity * nCapacity +
+            index1 * nCapacity + index0;
+        if (n != nPage)
+        {
+            SAL_WARN("store", "wrong math on triple indirect indices");
+            return page::SCOPE_UNKNOWN;
+        }
+
+        // Setup LinkDescriptor indices.
+        rDescr.m_nIndex0 = static_cast<sal_uInt16>(index0 & 0xffff);
+        rDescr.m_nIndex1 = static_cast<sal_uInt16>(index1 & 0xffff);
+        rDescr.m_nIndex2 = static_cast<sal_uInt16>(index2 & 0xffff);
+        rDescr.m_nIndex3 = static_cast<sal_uInt16>(index3 & 0xffff);
+
+        // Done.
+        return page::SCOPE_TRIPLE;
+    }
+
+    // Unreachable (more than triple indirect).
+    return page::SCOPE_UNREACHABLE;
+}
+
+/*
+ * read (external data page).
+ */
+storeError OStoreDirectoryPageObject::read (
+    sal_uInt32             nPage,
+    OStoreDataPageObject  &rData,
+    OStorePageBIOS        &rBIOS) const
+{
+    // Determine scope and link indices.
+    page::DataBlock::LinkDescriptor aLink;
+    page::ChunkScope eScope = scope (nPage, aLink);
+
+    storeError eErrCode = store_E_None;
+    if (eScope == page::SCOPE_DIRECT)
+    {
+        sal_uInt32 const nAddr = directLink (aLink.m_nIndex0);
+        if (nAddr == STORE_PAGE_NULL)
+            return store_E_NotExists;
+
+        eErrCode = rBIOS.loadObjectAt (rData, nAddr);
+    }
+    else if (eScope == page::SCOPE_SINGLE)
+    {
+        sal_uInt32 const nAddr = singleLink (aLink.m_nIndex1);
+        if (nAddr == STORE_PAGE_NULL)
+            return store_E_NotExists;
+
+        OStoreIndirectionPageObject aSingle;
+        eErrCode = rBIOS.loadObjectAt (aSingle, nAddr);
+        if (eErrCode != store_E_None)
+            return eErrCode;
+
+        eErrCode = aSingle.read (aLink.m_nIndex0, rData, rBIOS);
+    }
+    else if (eScope == page::SCOPE_DOUBLE)
+    {
+        sal_uInt32 const nAddr = doubleLink (aLink.m_nIndex2);
+        if (nAddr == STORE_PAGE_NULL)
+            return store_E_NotExists;
+
+        OStoreIndirectionPageObject aDouble;
+        eErrCode = rBIOS.loadObjectAt (aDouble, nAddr);
+        if (eErrCode != store_E_None)
+            return eErrCode;
+
+        eErrCode = aDouble.read (aLink.m_nIndex1, aLink.m_nIndex0, rData, rBIOS);
+    }
+    else if (eScope == page::SCOPE_TRIPLE)
+    {
+        sal_uInt32 const nAddr = tripleLink (aLink.m_nIndex3);
+        if (nAddr == STORE_PAGE_NULL)
+            return store_E_NotExists;
+
+        OStoreIndirectionPageObject aTriple;
+        eErrCode = rBIOS.loadObjectAt (aTriple, nAddr);
+        if (eErrCode != store_E_None)
+            return eErrCode;
+
+        eErrCode = aTriple.read (aLink.m_nIndex2, aLink.m_nIndex1, aLink.m_nIndex0, rData, rBIOS);
+    }
+    else if (eScope == page::SCOPE_UNREACHABLE)
+    {
+        // Out of scope.
+        eErrCode = store_E_CantSeek;
+    }
+    else
+    {
+        // Unknown scope.
+        SAL_WARN("store", "OStoreDirectoryPageObject::get(): scope failed");
+        eErrCode = store_E_Unknown;
+    }
+
+    // Leave.
+    return eErrCode;
+}
+
+/*
+ * write (external data page).
+ */
+storeError OStoreDirectoryPageObject::write (
+    sal_uInt32             nPage,
+    OStoreDataPageObject  &rData,
+    OStorePageBIOS        &rBIOS)
+{
+    // Determine scope and link indices.
+    page::DataBlock::LinkDescriptor aLink;
+    page::ChunkScope eScope = scope (nPage, aLink);
+
+    storeError eErrCode = store_E_None;
+    if (eScope == page::SCOPE_DIRECT)
+    {
+        sal_uInt32 const nAddr = directLink (aLink.m_nIndex0);
+        if (nAddr == STORE_PAGE_NULL)
+        {
+            // Allocate data page.
+            eErrCode = rBIOS.allocate (rData);
+            if (eErrCode != store_E_None)
+                return eErrCode;
+
+            // Store data page location.
+            directLink (aLink.m_nIndex0, rData.location());
+        }
+        else
+        {
+            // Save data page.
+            eErrCode = rBIOS.saveObjectAt (rData, nAddr);
+        }
+    }
+    else if (eScope == page::SCOPE_SINGLE)
+    {
+        OStoreIndirectionPageObject aSingle;
+        eErrCode = aSingle.loadOrCreate (singleLink (aLink.m_nIndex1), rBIOS);
+        if (eErrCode != store_E_None)
+        {
+            if (eErrCode != store_E_Pending)
+                return eErrCode;
+            singleLink (aLink.m_nIndex1, aSingle.location());
+        }
+
+        eErrCode = aSingle.write (aLink.m_nIndex0, rData, rBIOS);
+    }
+    else if (eScope == page::SCOPE_DOUBLE)
+    {
+        OStoreIndirectionPageObject aDouble;
+        eErrCode = aDouble.loadOrCreate (doubleLink (aLink.m_nIndex2), rBIOS);
+        if (eErrCode != store_E_None)
+        {
+            if (eErrCode != store_E_Pending)
+                return eErrCode;
+            doubleLink (aLink.m_nIndex2, aDouble.location());
+        }
+
+        eErrCode = aDouble.write (aLink.m_nIndex1, aLink.m_nIndex0, rData, rBIOS);
+    }
+    else if (eScope == page::SCOPE_TRIPLE)
+    {
+        OStoreIndirectionPageObject aTriple;
+        eErrCode = aTriple.loadOrCreate (tripleLink (aLink.m_nIndex3), rBIOS);
+        if (eErrCode != store_E_None)
+        {
+            if (eErrCode != store_E_Pending)
+                return eErrCode;
+            tripleLink (aLink.m_nIndex3, aTriple.location());
+        }
+
+        eErrCode = aTriple.write (aLink.m_nIndex2, aLink.m_nIndex1, aLink.m_nIndex0, rData, rBIOS);
+    }
+    else if (eScope == page::SCOPE_UNREACHABLE)
+    {
+        // Out of scope.
+        eErrCode = store_E_CantSeek;
+    }
+    else
+    {
+        // Unknown scope.
+        SAL_WARN("store", "OStoreDirectoryPageObject::put(): scope failed");
+        eErrCode = store_E_Unknown;
+    }
+
+    // Leave.
+    return eErrCode;
+}
+
+/*
+ * truncate (external data page).
+ */
+storeError OStoreDirectoryPageObject::truncate (
+    sal_uInt32             nPage,
+    OStorePageBIOS        &rBIOS)
+{
+    // Determine scope and link indices.
+    page::DataBlock::LinkDescriptor aLink;
+    page::ChunkScope eScope = scope (nPage, aLink);
+
+    storeError eErrCode = store_E_None;
+    if (eScope == page::SCOPE_DIRECT)
+    {
+        // Truncate all triple indirect pages.
+        eErrCode = truncate (page::SCOPE_TRIPLE, 0, rBIOS);
+        if (eErrCode != store_E_None)
+            return eErrCode;
+
+        // Truncate all double indirect pages.
+        eErrCode = truncate (page::SCOPE_DOUBLE, 0, rBIOS);
+        if (eErrCode != store_E_None)
+            return eErrCode;
+
+        // Truncate all single indirect pages.
+        eErrCode = truncate (page::SCOPE_SINGLE, 0, rBIOS);
+        if (eErrCode != store_E_None)
+            return eErrCode;
+
+        // Truncate direct pages, including 'aLink.m_nIndex0'.
+        eErrCode = truncate (eScope, aLink.m_nIndex0, rBIOS);
+    }
+    else if (eScope == page::SCOPE_SINGLE)
+    {
+        // Truncate all triple indirect pages.
+        eErrCode = truncate (page::SCOPE_TRIPLE, 0, rBIOS);
+        if (eErrCode != store_E_None)
+            return eErrCode;
+
+        // Truncate all double indirect pages.
+        eErrCode = truncate (page::SCOPE_DOUBLE, 0, rBIOS);
+        if (eErrCode != store_E_None)
+            return eErrCode;
+
+        // Truncate single indirect pages, downto 'aLink.m_nIndex1'.
+        eErrCode = truncate (eScope, aLink.m_nIndex1 + 1, rBIOS);
+        if (eErrCode != store_E_None)
+            return eErrCode;
+
+        // Truncate last single indirect page to ... pages.
+        eErrCode = store_truncate_Impl (singleLink (aLink.m_nIndex1), aLink.m_nIndex0, rBIOS);
+        if (eErrCode != store_E_None)
+            return eErrCode;
+
+        // Check for complete truncation.
+        if (aLink.m_nIndex0 == 0)
+        {
+            // Clear pointer to last single indirect page.
+            singleLink (aLink.m_nIndex1, STORE_PAGE_NULL);
+        }
+    }
+    else if (eScope == page::SCOPE_DOUBLE)
+    {
+        // Truncate all triple indirect pages.
+        eErrCode = truncate (page::SCOPE_TRIPLE, 0, rBIOS);
+        if (eErrCode != store_E_None)
+            return eErrCode;
+
+        // Truncate double indirect pages, downto 'aLink.m_nIndex2'.
+        eErrCode = truncate (eScope, aLink.m_nIndex2 + 1, rBIOS);
+        if (eErrCode != store_E_None)
+            return eErrCode;
+
+        // Truncate last double indirect page to ... pages.
+        eErrCode = store_truncate_Impl (
+            doubleLink (aLink.m_nIndex2), aLink.m_nIndex1, aLink.m_nIndex0, rBIOS);
+        if (eErrCode != store_E_None)
+            return eErrCode;
+
+        // Check for complete truncation.
+        if ((aLink.m_nIndex1 + aLink.m_nIndex0) == 0)
+        {
+            // Clear pointer to last double indirect page.
+            doubleLink (aLink.m_nIndex2, STORE_PAGE_NULL);
+        }
+    }
+    else if (eScope == page::SCOPE_TRIPLE)
+    {
+        // Truncate triple indirect pages, downto 'aLink.m_nIndex3'.
+        eErrCode = truncate (eScope, aLink.m_nIndex3 + 1, rBIOS);
+        if (eErrCode != store_E_None)
+            return eErrCode;
+
+        // Truncate last triple indirect page to ... pages.
+        eErrCode = store_truncate_Impl (
+            tripleLink (aLink.m_nIndex3), aLink.m_nIndex2, aLink.m_nIndex1, aLink.m_nIndex0, rBIOS);
+        if (eErrCode != store_E_None)
+            return eErrCode;
+
+        // Check for complete truncation.
+        if ((aLink.m_nIndex2 + aLink.m_nIndex1 + aLink.m_nIndex0) == 0)
+        {
+            // Clear pointer to last triple indirect page.
+            tripleLink (aLink.m_nIndex3, STORE_PAGE_NULL);
+        }
+    }
+    else if (eScope == page::SCOPE_UNREACHABLE)
+    {
+        // Out of scope.
+        eErrCode = store_E_CantSeek;
+    }
+    else
+    {
+        // Unknown scope.
+        SAL_WARN("store", "OStoreDirectoryPageObject::put(): scope failed");
+        eErrCode = store_E_Unknown;
+    }
+
+    // Leave.
+    return eErrCode;
+}
+
+/*
+ * truncate (external data page scope; private).
+ */
+storeError OStoreDirectoryPageObject::truncate (
+    page::ChunkScope       eScope,
+    sal_uInt16             nRemain,
+    OStorePageBIOS        &rBIOS)
+{
+    // Enter.
+    storeError eErrCode = store_E_None;
+    if (eScope == page::SCOPE_DIRECT)
+    {
+        // Truncate direct data pages.
+        for (sal_uInt16 i = OStoreDirectoryDataBlock::directCount; i > nRemain; i--)
+        {
+            // Obtain data page location.
+            sal_uInt32 nAddr = directLink (i - 1);
+            if (nAddr == STORE_PAGE_NULL) continue;
+
+            // Free data page.
+            eErrCode = rBIOS.free (nAddr);
+            if (eErrCode != store_E_None)
+                break;
+
+            // Clear pointer to data page.
+            directLink (i - 1, STORE_PAGE_NULL);
+        }
+
+        // Done.
+        return eErrCode;
+    }
+
+    if (eScope == page::SCOPE_SINGLE)
+    {
+        // Truncate single indirect pages.
+        for (sal_uInt16 i = OStoreDirectoryDataBlock::singleCount; i > nRemain; i--)
+        {
+            // Truncate single indirect page to zero data pages.
+            eErrCode = store_truncate_Impl (singleLink (i - 1), 0, rBIOS);
+            if (eErrCode != store_E_None)
+                break;
+
+            // Clear pointer to single indirect page.
+            singleLink (i - 1, STORE_PAGE_NULL);
+        }
+
+        // Done.
+        return eErrCode;
+    }
+
+    if (eScope == page::SCOPE_DOUBLE)
+    {
+        // Truncate double indirect pages.
+        for (sal_uInt16 i = OStoreDirectoryDataBlock::doubleCount; i > nRemain; i--)
+        {
+            // Truncate double indirect page to zero single indirect pages.
+            eErrCode = store_truncate_Impl (doubleLink (i - 1), 0, 0, rBIOS);
+            if (eErrCode != store_E_None)
+                break;
+
+            // Clear pointer to double indirect page.
+            doubleLink (i - 1, STORE_PAGE_NULL);
+        }
+
+        // Done.
+        return eErrCode;
+    }
+
+    if (eScope == page::SCOPE_TRIPLE)
+    {
+        // Truncate triple indirect pages.
+        for (sal_uInt16 i = OStoreDirectoryDataBlock::tripleCount; i > nRemain; i--)
+        {
+            // Truncate to zero double indirect pages.
+            eErrCode = store_truncate_Impl (tripleLink (i - 1), 0, 0, 0, rBIOS);
+            if (eErrCode != store_E_None)
+                break;
+
+            // Clear pointer to triple indirect page.
+            tripleLink (i - 1, STORE_PAGE_NULL);
+        }
+
+        // Done.
+        return eErrCode;
+    }
+
+    // Invalid scope.
+    return store_E_InvalidAccess;
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */