memorystream.cpp

来自「turecrypt最新6.0版本的源码」· C++ 代码 · 共 48 行

/*
 Copyright (c) 2008 TrueCrypt Foundation. All rights reserved.

 Governed by the TrueCrypt License 2.5 the full text of which is contained
 in the file License.txt included in TrueCrypt binary and source code
 distribution packages.
*/

#include "Exception.h"
#include "MemoryStream.h"

namespace TrueCrypt
{
	MemoryStream::MemoryStream (const ConstBufferPtr &data) :
		ReadPosition (0)
	{
		Data = vector <byte> (data.Size());
		BufferPtr (&Data[0], Data.size()).CopyFrom (data);
	}

	uint64 MemoryStream::Read (const BufferPtr &buffer)
	{
		if (Data.size() == 0)
			throw ParameterIncorrect (SRC_POS);

		ConstBufferPtr streamBuf (*this);
		size_t len = buffer.Size();
		if (streamBuf.Size() - ReadPosition < len)
			len = streamBuf.Size() - ReadPosition;

		BufferPtr(buffer).CopyFrom (streamBuf.GetRange (ReadPosition, len));
		ReadPosition += len;
		return len;
	}

	void MemoryStream::ReadCompleteBuffer (const BufferPtr &buffer)
	{
		if (Read (buffer) != buffer.Size())
			throw InsufficientData (SRC_POS);
	}

	void MemoryStream::Write (const ConstBufferPtr &data)
	{
		for (uint64 i = 0; i < data.Size(); i++)
			Data.push_back (data[i]);
	}
}