xref: /dports/sysutils/boxbackup-devel/boxbackup-0.11_trunk_2979/lib/common/IOStream.cpp

// distribution boxbackup-0.11_trunk_2979 (svn version: 2979)
// Box Backup, http://www.boxbackup.org/
//
// Copyright (c) 2003-2010, Ben Summers and contributors.
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// under this license. See the file COPYING.txt for more information.
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// not necessary to comply with both licenses, only one.
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//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
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// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
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// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
//
// [http://www.gnu.org/licenses/old-licenses/gpl-2.0.html#SEC4]
// --------------------------------------------------------------------------
//
// File
//		Name:    IOStream.cpp
//		Purpose: I/O Stream abstraction
//		Created: 2003/07/31
//
// --------------------------------------------------------------------------

#include "Box.h"
#include "IOStream.h"
#include "CommonException.h"
#include "Guards.h"

#include "MemLeakFindOn.h"

// --------------------------------------------------------------------------
//
// Function
//		Name:    IOStream::IOStream()
//		Purpose: Constructor
//		Created: 2003/07/31
//
// --------------------------------------------------------------------------
IOStream::IOStream()
{
}

// --------------------------------------------------------------------------
//
// Function
//		Name:    IOStream::~IOStream()
//		Purpose: Destructor
//		Created: 2003/07/31
//
// --------------------------------------------------------------------------
IOStream::~IOStream()
{
}

// --------------------------------------------------------------------------
//
// Function
//		Name:    IOStream::Close()
//		Purpose: Close the stream
//		Created: 2003/07/31
//
// --------------------------------------------------------------------------
void IOStream::Close()
{
	// Do nothing by default -- let the destructor clear everything up.
}

// --------------------------------------------------------------------------
//
// Function
//		Name:    IOStream::Seek(int, int)
//		Purpose: Seek in stream (if supported)
//		Created: 2003/07/31
//
// --------------------------------------------------------------------------
void IOStream::Seek(IOStream::pos_type Offset, int SeekType)
{
	THROW_EXCEPTION(CommonException, NotSupported)
}


// --------------------------------------------------------------------------
//
// Function
//		Name:    IOStream::GetPosition()
//		Purpose: Returns current position in stream (if supported)
//		Created: 2003/08/21
//
// --------------------------------------------------------------------------
IOStream::pos_type IOStream::GetPosition() const
{
	THROW_EXCEPTION(CommonException, NotSupported)
}

// --------------------------------------------------------------------------
//
// Function
//		Name:    IOStream::ConvertSeekTypeToOSWhence(int)
//		Purpose: Return an whence arg for lseek given a IOStream seek type
//		Created: 2003/08/21
//
// --------------------------------------------------------------------------
int IOStream::ConvertSeekTypeToOSWhence(int SeekType)
{
	// Should be nicely optimised out as values are choosen in header file to match OS values.
	int ostype = SEEK_SET;
	switch(SeekType)
	{
#ifdef WIN32
	case SeekType_Absolute:
		ostype = FILE_BEGIN;
		break;
	case SeekType_Relative:
		ostype = FILE_CURRENT;
		break;
	case SeekType_End:
		ostype = FILE_END;
		break;
#else // ! WIN32
	case SeekType_Absolute:
		ostype = SEEK_SET;
		break;
	case SeekType_Relative:
		ostype = SEEK_CUR;
		break;
	case SeekType_End:
		ostype = SEEK_END;
		break;
#endif // WIN32

	default:
		THROW_EXCEPTION(CommonException, IOStreamBadSeekType)
	}

	return ostype;
}


// --------------------------------------------------------------------------
//
// Function
//		Name:    IOStream::ReadFullBuffer(void *, int, int)
//		Purpose: Reads bytes into buffer, returning whether or not it managed to
//				 get all the bytes required. Exception and abort use of stream
//				 if this returns false.
//		Created: 2003/08/26
//
// --------------------------------------------------------------------------
bool IOStream::ReadFullBuffer(void *pBuffer, int NBytes, int *pNBytesRead, int Timeout)
{
	int bytesToGo = NBytes;
	char *buffer = (char*)pBuffer;
	if(pNBytesRead) (*pNBytesRead) = 0;

	while(bytesToGo > 0)
	{
		int bytesRead = Read(buffer, bytesToGo, Timeout);
		if(bytesRead == 0)
		{
			// Timeout or something
			return false;
		}
		// Increment things
		bytesToGo -= bytesRead;
		buffer += bytesRead;
		if(pNBytesRead) (*pNBytesRead) += bytesRead;
	}

	// Got everything
	return true;
}


// --------------------------------------------------------------------------
//
// Function
//		Name:    IOStream::WriteAllBuffered()
//		Purpose: Ensures that any data which has been buffered is written to the stream
//		Created: 2003/08/26
//
// --------------------------------------------------------------------------
void IOStream::WriteAllBuffered()
{
}


// --------------------------------------------------------------------------
//
// Function
//		Name:    IOStream::BytesLeftToRead()
//		Purpose: Numbers of bytes left to read in the stream, or
//				 IOStream::SizeOfStreamUnknown if this isn't known.
//		Created: 2003/08/26
//
// --------------------------------------------------------------------------
IOStream::pos_type IOStream::BytesLeftToRead()
{
	return IOStream::SizeOfStreamUnknown;
}

// --------------------------------------------------------------------------
//
// Function
//		Name:    IOStream::CopyStreamTo(IOStream &, int Timeout)
//		Purpose: Copies the entire stream to another stream (reading from this,
//				 writing to rCopyTo). Returns whether the copy completed (ie
//				 StreamDataLeft() returns false)
//		Created: 2003/08/26
//
// --------------------------------------------------------------------------
bool IOStream::CopyStreamTo(IOStream &rCopyTo, int Timeout, int BufferSize)
{
	// Make sure there's something to do before allocating that buffer
	if(!StreamDataLeft())
	{
		return true;	// complete, even though nothing happened
	}

	// Buffer
	MemoryBlockGuard<char*> buffer(BufferSize);

	// Get copying!
	while(StreamDataLeft())
	{
		// Read some data
		int bytes = Read(buffer, BufferSize, Timeout);
		if(bytes == 0 && StreamDataLeft())
		{
			return false;	// incomplete, timed out
		}

		// Write some data
		if(bytes != 0)
		{
			rCopyTo.Write(buffer, bytes);
		}
	}

	return true;	// completed
}

// --------------------------------------------------------------------------
//
// Function
//		Name:    IOStream::Flush(int Timeout)
//		Purpose: Read and discard all remaining data in stream.
//			 Useful for protocol streams which must be flushed
//			 to avoid breaking the protocol.
//		Created: 2008/08/20
//
// --------------------------------------------------------------------------
void IOStream::Flush(int Timeout)
{
	char buffer[4096];

	while(StreamDataLeft())
	{
		Read(buffer, sizeof(buffer), Timeout);
	}
}

void IOStream::Write(const char *pBuffer)
{
	Write(pBuffer, strlen(pBuffer));
}