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Diffstat (limited to 'lib/common/PartialReadStream.cpp')
| -rw-r--r-- | lib/common/PartialReadStream.cpp | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/lib/common/PartialReadStream.cpp b/lib/common/PartialReadStream.cpp new file mode 100644 index 00000000..03cd3e50 --- /dev/null +++ b/lib/common/PartialReadStream.cpp @@ -0,0 +1,173 @@ +// distribution boxbackup-0.10 (svn version: 494) +// +// Copyright (c) 2003 - 2006 +// Ben Summers and contributors. All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions +// are met: +// 1. Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// 2. Redistributions in binary form must reproduce the above copyright +// notice, this list of conditions and the following disclaimer in the +// documentation and/or other materials provided with the distribution. +// 3. All use of this software and associated advertising materials must +// display the following acknowledgment: +// This product includes software developed by Ben Summers. +// 4. The names of the Authors may not be used to endorse or promote +// products derived from this software without specific prior written +// permission. +// +// [Where legally impermissible the Authors do not disclaim liability for +// direct physical injury or death caused solely by defects in the software +// unless it is modified by a third party.] +// +// THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR +// IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED +// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE +// DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, +// INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES +// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR +// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, +// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN +// ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +// POSSIBILITY OF SUCH DAMAGE. +// +// +// +// -------------------------------------------------------------------------- +// +// File +// Name: PartialReadStream.h +// Purpose: Read part of another stream +// Created: 2003/08/26 +// +// -------------------------------------------------------------------------- + +#include "Box.h" +#include "PartialReadStream.h" +#include "CommonException.h" + +#include "MemLeakFindOn.h" + +// -------------------------------------------------------------------------- +// +// Function +// Name: PartialReadStream::PartialReadStream(IOStream &, int) +// Purpose: Constructor, taking another stream and the number of bytes +// to be read from it. +// Created: 2003/08/26 +// +// -------------------------------------------------------------------------- +PartialReadStream::PartialReadStream(IOStream &rSource, int BytesToRead) + : mrSource(rSource), + mBytesLeft(BytesToRead) +{ + ASSERT(BytesToRead > 0); +} + +// -------------------------------------------------------------------------- +// +// Function +// Name: PartialReadStream::~PartialReadStream() +// Purpose: Destructor. Won't absorb any unread bytes. +// Created: 2003/08/26 +// +// -------------------------------------------------------------------------- +PartialReadStream::~PartialReadStream() +{ + // Warn in debug mode + if(mBytesLeft != 0) + { + TRACE1("PartialReadStream::~PartialReadStream when mBytesLeft = %d\n", mBytesLeft); + } +} + +// -------------------------------------------------------------------------- +// +// Function +// Name: PartialReadStream::Read(void *, int, int) +// Purpose: As interface. +// Created: 2003/08/26 +// +// -------------------------------------------------------------------------- +int PartialReadStream::Read(void *pBuffer, int NBytes, int Timeout) +{ + // Finished? + if(mBytesLeft <= 0) + { + return 0; + } + + // Asking for more than is allowed? + if(NBytes > mBytesLeft) + { + // Adjust downwards + NBytes = mBytesLeft; + } + + // Route the request to the source + int read = mrSource.Read(pBuffer, NBytes, Timeout); + ASSERT(read <= mBytesLeft); + + // Adjust the count + mBytesLeft -= read; + + // Return the number read + return read; +} + +// -------------------------------------------------------------------------- +// +// Function +// Name: PartialReadStream::BytesLeftToRead() +// Purpose: As interface. +// Created: 2003/08/26 +// +// -------------------------------------------------------------------------- +IOStream::pos_type PartialReadStream::BytesLeftToRead() +{ + return mBytesLeft; +} + +// -------------------------------------------------------------------------- +// +// Function +// Name: PartialReadStream::Write(const void *, int) +// Purpose: As interface. But will exception. +// Created: 2003/08/26 +// +// -------------------------------------------------------------------------- +void PartialReadStream::Write(const void *pBuffer, int NBytes) +{ + THROW_EXCEPTION(CommonException, CantWriteToPartialReadStream) +} + +// -------------------------------------------------------------------------- +// +// Function +// Name: PartialReadStream::StreamDataLeft() +// Purpose: As interface. +// Created: 2003/08/26 +// +// -------------------------------------------------------------------------- +bool PartialReadStream::StreamDataLeft() +{ + return mBytesLeft != 0; +} + +// -------------------------------------------------------------------------- +// +// Function +// Name: PartialReadStream::StreamClosed() +// Purpose: As interface. +// Created: 2003/08/26 +// +// -------------------------------------------------------------------------- +bool PartialReadStream::StreamClosed() +{ + // always closed + return true; +} + |