diff options
Diffstat (limited to 'sot')
| -rw-r--r-- | sot/source/sdstor/stgstrms.cxx | 127 | ||||
| -rw-r--r-- | sot/source/sdstor/stgstrms.hxx | 2 |
2 files changed, 59 insertions, 70 deletions
diff --git a/sot/source/sdstor/stgstrms.cxx b/sot/source/sdstor/stgstrms.cxx index f8b97766ec13..7bef24381f50 100644 --- a/sot/source/sdstor/stgstrms.cxx +++ b/sot/source/sdstor/stgstrms.cxx @@ -340,38 +340,40 @@ void StgStrm::SetEntry( StgDirEntry& r ) * for this each time build a simple flat in-memory vector list * of pages. */ -bool StgStrm::buildPageChainCache() +void StgStrm::scanBuildPageChainCache(sal_Int32 *pOptionalCalcSize) { if (nSize > 0) m_aPagesCache.reserve(nSize/nPageSize); + bool bError = false; sal_Int32 nBgn = nStart; - while (nBgn >= 0) + sal_Int32 nOldBgn = -1; + sal_Int32 nOptSize = 0; + while( nBgn >= 0 && nBgn != nOldBgn ) { - m_aPagesCache.push_back(nBgn); - sal_Int32 nOldBgn = nBgn; - nBgn = pFat->GetNextPage(nBgn); - if (nBgn == nOldBgn) - return false; + if( nBgn >= 0 ) + m_aPagesCache.push_back(nBgn); + nOldBgn = nBgn; + nBgn = pFat->GetNextPage( nBgn ); + if( nBgn == nOldBgn ) + bError = true; + nOptSize += nPageSize; } - - return true; + if (bError) + { + if (pOptionalCalcSize) + rIo.SetError( ERRCODE_IO_WRONGFORMAT ); + m_aPagesCache.clear(); + } + if (pOptionalCalcSize) + *pOptionalCalcSize = nOptSize; } -//See fdo#47644 for a .doc with a vast amount of pages where seeking around the -//document takes a colossal amount of time -// -//There's a cost to building a page cache, so only build one if the number of -//pages to seek through hits some sufficiently high value where it's worth it. -#define ARBITRARY_LARGE_AMOUNT_OF_PAGES 8 * 512 - // Compute page number and offset for the given byte position. // If the position is behind the size, set the stream right // behind the EOF. - sal_Bool StgStrm::Pos2Page( sal_Int32 nBytePos ) { - sal_Int32 nRel, nBgn; // Values < 0 seek to the end if( nBytePos < 0 || nBytePos >= nSize ) nBytePos = nSize; @@ -385,69 +387,59 @@ sal_Bool StgStrm::Pos2Page( sal_Int32 nBytePos ) if( nOld == nNew ) return sal_True; - if (m_aPagesCache.empty() && nNew > ARBITRARY_LARGE_AMOUNT_OF_PAGES) + // See fdo#47644 for a .doc with a vast amount of pages where seeking around the + // document takes a colossal amount of time + // + // Please Note: we build the pagescache incrementally as we go if necessary, + // so that a corrupted FAT doesn't poison the stream state for earlier reads + size_t nIdx = nNew / nPageSize; + if( nIdx >= m_aPagesCache.size() ) { - SAL_WARN("sot", "kicking off large seek helper\n"); - buildPageChainCache(); - } + // Extend the FAT cache ! ... + size_t nToAdd = nIdx + 1; - if (!m_aPagesCache.empty()) - { - size_t nIdx = nNew / nPageSize; + if (m_aPagesCache.empty()) + m_aPagesCache.push_back( nStart ); - // special case: seek to 1st byte of new, unallocated page - // (in case the file size is a multiple of the page size) - if( nBytePos == nSize && !nOffset && nIdx == m_aPagesCache.size() ) - { - nIdx--; - nOffset = nPageSize; - } + nToAdd -= m_aPagesCache.size(); + + sal_Int32 nBgn = m_aPagesCache.back(); - if (nIdx < m_aPagesCache.size()) + // Start adding pages while we can + while( nToAdd > 0 && nBgn >= 0 ) { - nPage = m_aPagesCache[ nIdx ]; - return sal_Bool( nPage >= 0 ); + nBgn = pFat->GetNextPage( nBgn ); + if( nBgn >= 0 ) + { + m_aPagesCache.push_back( nBgn ); + nToAdd--; + } } } - if( nNew > nOld ) + if ( nIdx > m_aPagesCache.size() ) { - // the new position is after the current, so an incremental - // positioning is OK. Set the page relative position - nRel = nNew - nOld; - nBgn = nPage; + rIo.SetError( SVSTREAM_FILEFORMAT_ERROR ); + nPage = STG_EOF; + nOffset = nPageSize; + return sal_False; } - else + // special case: seek to 1st byte of new, unallocated page + // (in case the file size is a multiple of the page size) + if( nBytePos == nSize && !nOffset && nIdx > 0 && nIdx == m_aPagesCache.size() ) { - // the new position is before the current, so we have to scan - // the entire chain. - nRel = nNew; - nBgn = nStart; + nIdx--; + nOffset = nPageSize; } - // now, traverse the FAT chain. - nRel /= nPageSize; - - sal_Int32 nLast = STG_EOF; - while (nRel && nBgn >= 0) + else if ( nIdx == m_aPagesCache.size() ) { - nLast = nBgn; - nBgn = pFat->GetNextPage( nBgn ); - nRel--; + nPage = STG_EOF; + return sal_False; } - // special case: seek to 1st byte of new, unallocated page - // (in case the file size is a multiple of the page size) - if( nBytePos == nSize && nBgn == STG_EOF && !nRel && !nOffset ) - nBgn = nLast, nOffset = nPageSize; + nPage = m_aPagesCache[ nIdx ]; - if( nBgn < 0 && nBgn != STG_EOF ) - { - rIo.SetError( SVSTREAM_FILEFORMAT_ERROR ); - nBgn = STG_EOF; - nOffset = nPageSize; - } - nPage = nBgn; - return sal_Bool( nRel == 0 && nPage >= 0 ); + return nPage >= 0; } // Retrieve the physical page for a given byte offset. @@ -817,10 +809,7 @@ void StgDataStrm::Init( sal_Int32 nBgn, sal_Int32 nLen ) { // determine the actual size of the stream by scanning // the FAT chain and counting the # of pages allocated - bool bOk = buildPageChainCache(); - if (!bOk) - rIo.SetError( ERRCODE_IO_WRONGFORMAT ); - nSize = m_aPagesCache.size() * nPageSize; + scanBuildPageChainCache( &nSize ); } } diff --git a/sot/source/sdstor/stgstrms.hxx b/sot/source/sdstor/stgstrms.hxx index 125dc67c3798..dff07dfa4d98 100644 --- a/sot/source/sdstor/stgstrms.hxx +++ b/sot/source/sdstor/stgstrms.hxx @@ -79,7 +79,7 @@ protected: short nOffset; // offset into current page short nPageSize; // logical page size std::vector<sal_Int32> m_aPagesCache; - bool buildPageChainCache(); + void scanBuildPageChainCache(sal_Int32 *pOptionalCalcSize = NULL); sal_Bool Copy( sal_Int32 nFrom, sal_Int32 nBytes ); StgStrm( StgIo& ); public: |