diff options
| -rw-r--r-- | comphelper/source/streaming/memorystream.cxx | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/comphelper/source/streaming/memorystream.cxx b/comphelper/source/streaming/memorystream.cxx index a7612bf67b07..2abcb6b1209f 100644 --- a/comphelper/source/streaming/memorystream.cxx +++ b/comphelper/source/streaming/memorystream.cxx @@ -82,7 +82,18 @@ public: virtual void SAL_CALL truncate() override; private: - std::vector< sal_Int8 > maData; + // prevents std::vector from wasting time doing memset on data we are going to overwrite anyway + struct NoInitInt8 + { + sal_Int8 value; + NoInitInt8() noexcept { + // do nothing + static_assert(sizeof(NoInitInt8) == sizeof(sal_Int8), "invalid size"); + static_assert(alignof(NoInitInt8) == alignof(sal_Int8), "invalid alignment"); + } + }; + + std::vector< NoInitInt8 > maData; sal_Int32 mnCursor; }; @@ -132,8 +143,8 @@ sal_Int32 SAL_CALL UNOMemoryStream::readBytes( Sequence< sal_Int8 >& aData, sal_ if( nBytesToRead ) { - sal_Int8* pData = &(*maData.begin()); - sal_Int8* pCursor = &(pData[mnCursor]); + NoInitInt8* pData = &(*maData.begin()); + NoInitInt8* pCursor = &(pData[mnCursor]); memcpy( static_cast<void*>(aData.getArray()), static_cast<void*>(pCursor), nBytesToRead ); mnCursor += nBytesToRead; @@ -205,8 +216,8 @@ void SAL_CALL UNOMemoryStream::writeBytes( const Sequence< sal_Int8 >& aData ) if( static_cast< sal_Int32 >( nNewSize ) > static_cast< sal_Int32 >( maData.size() ) ) maData.resize( nNewSize ); - sal_Int8* pData = &(*maData.begin()); - sal_Int8* pCursor = &(pData[mnCursor]); + NoInitInt8* pData = &(*maData.begin()); + NoInitInt8* pCursor = &(pData[mnCursor]); memcpy( pCursor, aData.getConstArray(), nBytesToWrite ); mnCursor += nBytesToWrite; |