/*

* Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

*

* This program is free software: you can redistribute it and/or modify

* it under the terms of the GNU Lesser General Public License as published by

* the Free Software Foundation, either version 3 of the License, or

* (at your option) any later version.

*

* 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 Lesser General Public License for more details.

* 

* You should have received a copy of the GNU Lesser General Public License

* along with this program.  If not, see <http://www.gnu.org/licenses/>.

*/

#include <fcntl.h>

#include <sys/types.h>

#include <unistd.h>

#include <cassert>

#include "elfromerror.h"

#include "inputfile.h"

InputFile & InputFile::operator=(const InputFile & aInputFile) {

	// Don't copy fd. Force a new to be got.

	iOpened = false;

	// Force size to be re-computed

	iSizeValid = false;

	iOffset = aInputFile.iOffset;

	iPathName = aInputFile.iPathName;

	return *this;

}

InputFile::InputFile(const InputFile & aInputFile){

	*this = aInputFile;

}

InputFile::~InputFile(){

	Close();

}

void InputFile::Open(){

	if (iOpened) return;

	if ((iFd = open(iPathName.c_str(), O_RDONLY|O_BINARY, 0)) < 0)

		errx(EX_NOINPUT, "open \"%s\" failed\n", iPathName.c_str());

	else

		iOpened = true;

}

void InputFile::Close(){

	if (!iOpened) return;

	close(iFd);

	iOpened = false;

	iSizeValid = false;

}

size_t InputFile::Size(){

	if (iSizeValid) return iSize - iOffset;

	SetSize();

	return iSize - iOffset;

}

void InputFile::SetSize(){

	Open();

	if ((iSize = lseek(iFd, (size_t)0, SEEK_END)) == (size_t)-1)

		errx(EX_NOINPUT, "failed to get size of \"%s\"", iPathName.c_str());

	if (lseek(iFd, (size_t)0, SEEK_SET) != 0)

		errx(EX_NOINPUT, "failed to get size of \"%s\"", iPathName.c_str());

	Close();

	iSizeValid = true;

}

char * InputFile::GetData(){

	size_t nbytes = Size();

	return GetData(nbytes);

}

char * InputFile::GetData(size_t nbytes) {

	char * data = new char[nbytes];

	GetData(data, nbytes);

	return data;

}

void InputFile::GetData(void * data, size_t nbytes){

	char * d = (char *)data;

	size_t done = 0;

	ssize_t n;

	Open();

	if (iOffset > 0)

		if ((size_t)lseek(iFd, iOffset, SEEK_SET) != iOffset) {

			Close();

			errx(EX_NOINPUT, "failed to read from \"%s\"", iPathName.c_str());

		}

	while (nbytes){

		n = read(iFd, d+done,nbytes);

		// n must be greater than 0

		if (n <= 0){

			Close();

			errx(EX_NOINPUT, "failed to read from \"%s\"", iPathName.c_str());

		}

		done += n;

		nbytes -= n;

	}

	Close();

}