vmap/libs/stream/filestream.h

/*
   Copyright (C) 2001-2006, William Joseph.
   All Rights Reserved.

   This file is part of GtkRadiant.

   GtkRadiant 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.

   GtkRadiant 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.

   You should have received a copy of the GNU General Public License
   along with GtkRadiant; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#if !defined( INCLUDED_STREAM_FILESTREAM_H )
#define INCLUDED_STREAM_FILESTREAM_H

#include "idatastream.h"
#include <algorithm>
#include <cstdio>

namespace FileStreamDetail
{
inline int whence_for_seekdir( SeekableStream::seekdir direction ){
	switch ( direction )
	{
	case SeekableStream::cur:
		return SEEK_CUR;
	case SeekableStream::end:
		return SEEK_END;
	default:
		break;
	}
	return SEEK_SET;
}
}


/// \brief A wrapper around a file input stream opened for reading in binary mode. Similar to std::ifstream.
///
/// - Maintains a valid file handle associated with a name passed to the constructor.
/// - Implements SeekableInputStream.
class FileInputStream : public SeekableInputStream
{
std::FILE* m_file;
public:
FileInputStream( const char* name ){
	m_file = name[0] == '\0' ? 0 : fopen( name, "rb" );
}
~FileInputStream(){
	if ( !failed() ) {
		fclose( m_file );
	}
}

bool failed() const {
	return m_file == 0;
}

size_type read( byte_type* buffer, size_type length ){
	return fread( buffer, 1, length, m_file );
}

size_type seek( size_type position ){
	return fseek( m_file, static_cast<long>( position ), SEEK_SET );
}
size_type seek( offset_type offset, seekdir direction ){
	return fseek( m_file, offset, FileStreamDetail::whence_for_seekdir( direction ) );
}
size_type tell() const {
	return ftell( m_file );
}

std::FILE* file(){
	return m_file;
}
};

/// \brief A wrapper around a FileInputStream limiting access.
///
/// - Maintains an input stream.
/// - Provides input starting at an offset in the file for a limited range.
class SubFileInputStream : public InputStream
{
FileInputStream& m_istream;
size_type m_remaining;
public:
typedef FileInputStream::position_type position_type;

SubFileInputStream( FileInputStream& istream, position_type offset, size_type size )
	: m_istream( istream ), m_remaining( size ){
	m_istream.seek( offset );
}

size_type read( byte_type* buffer, size_type length ){
	size_type result = m_istream.read( buffer, std::min( length, m_remaining ) );
	m_remaining -= result;
	return result;
}
};


/// \brief A wrapper around a stdc file stream opened for writing in binary mode. Similar to std::ofstream..
///
/// - Maintains a valid file handle associated with a name passed to the constructor.
/// - Implements SeekableInputStream.
class FileOutputStream : public SeekableOutputStream
{
std::FILE* m_file;
public:
FileOutputStream( const char* name ){
	m_file = name[0] == '\0' ? 0 : fopen( name, "wb" );
}
~FileOutputStream(){
	if ( !failed() ) {
		fclose( m_file );
	}
}

bool failed() const {
	return m_file == 0;
}

size_type write( const byte_type* buffer, size_type length ){
	return fwrite( buffer, 1, length, m_file );
}

size_type seek( size_type position ){
	return fseek( m_file, static_cast<long>( position ), SEEK_SET );
}
size_type seek( offset_type offset, seekdir direction ){
	return fseek( m_file, offset, FileStreamDetail::whence_for_seekdir( direction ) );
}
size_type tell() const {
	return ftell( m_file );
}
};

inline bool file_copy( const char* source, const char* target ){
	const std::size_t buffer_size = 1024;
	unsigned char buffer[buffer_size];

	FileInputStream sourceFile( source );
	if ( sourceFile.failed() ) {
		return false;
	}
	FileOutputStream targetFile( target );
	if ( targetFile.failed() ) {
		return false;
	}

	for (;; )
	{
		std::size_t size = sourceFile.read( buffer, buffer_size );
		if ( size == 0 ) {
			break;
		}
		if ( targetFile.write( buffer, size ) != size ) {
			return false;
		}
	}
	return true;
}


#endif