Renegade/Code/Tools/wdump/rawfilem.cpp

/*
**	Command & Conquer Renegade(tm)
**	Copyright 2025 Electronic Arts Inc.
**
**	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 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 General Public License for more details.
**
**	You should have received a copy of the GNU General Public License
**	along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

/*********************************************************************************************** 
 ***              C O N F I D E N T I A L  ---  W E S T W O O D  S T U D I O S               *** 
 *********************************************************************************************** 
 *                                                                                             * 
 *                 Project Name : G                                      * 
 *                                                                                             * 
 *                     $Archive:: /G/wdump/RAWFILEM.CPP                                       $* 
 *                                                                                             * 
 *                      $Author:: Eric_c                                                      $*
 *                                                                                             * 
 *                     $Modtime:: 7/28/97 3:36p                                               $*
 *                                                                                             * 
 *                    $Revision:: 3                                                           $*
 *                                                                                             *
 *---------------------------------------------------------------------------------------------* 
 * Functions:                                                                                  * 
 *   RawFileMClass::Bias -- Bias a file with a specific starting position and length.           *
 *   RawFileMClass::Close -- Perform a closure of the file.                                     *
 *   RawFileMClass::Create -- Creates an empty file.                                            *
 *   RawFileMClass::Delete -- Deletes the file object from the disk.                            *
 *   RawFileMClass::Error -- Handles displaying a file error message.                           *
 *   RawFileMClass::Get_Date_Time -- Gets the date and time the file was last modified.         *
 *   RawFileMClass::Is_Available -- Checks to see if the specified file is available to open.   *
 *   RawFileMClass::Open -- Assigns name and opens file in one operation.                       *
 *   RawFileMClass::Open -- Opens the file object with the rights specified.                    *
 *   RawFileMClass::RawFileMClass -- Simple constructor for a file object.                       *
 *   RawFileMClass::Raw_Seek -- Performs a seek on the unbiased file                            *
 *   RawFileMClass::Read -- Reads the specified number of bytes into a memory buffer.           *
 *   RawFileMClass::Seek -- Reposition the file pointer as indicated.                           *
 *   RawFileMClass::Set_Date_Time -- Sets the date and time the file was last modified.         *
 *   RawFileMClass::Set_Name -- Manually sets the name for a file object.                       *
 *   RawFileMClass::Size -- Determines size of file (in bytes).                                 *
 *   RawFileMClass::Write -- Writes the specified data to the buffer specified.                 *
 * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

#include	"always.h"
#include	"rawfilem.h"
#include	<direct.h>
#include	<share.h>
#include	<stddef.h>
#include	<stdio.h>
#include	<stdlib.h>
#include	<string.h>


/***********************************************************************************************
 * RawFileMClass::Error -- Handles displaying a file error message.                             *
 *                                                                                             *
 *    Display an error message as indicated. If it is allowed to retry, then pressing a key    *
 *    will return from this function. Otherwise, it will exit the program with "exit()".       *
 *                                                                                             *
 * INPUT:   error    -- The error number (same as the DOSERR.H error numbers).                 *
 *                                                                                             *
 *          canretry -- Can this routine exit normally so that retrying can occur? If this is  *
 *                      false, then the program WILL exit in this routine.                     *
 *                                                                                             *
 *          filename -- Optional filename to report with this error. If no filename is         *
 *                      supplied, then no filename is listed in the error message.             *
 *                                                                                             *
 * OUTPUT:  none, but this routine might not return at all if the "canretry" parameter is      *
 *          false or the player pressed ESC.                                                   *
 *                                                                                             *
 * WARNINGS:   This routine may not return at all. It handles being in text mode as well as    *
 *             if in a graphic mode.                                                           *
 *                                                                                             *
 * HISTORY:                                                                                    *
 *   10/17/1994 JLB : Created.                                                                 *
 *=============================================================================================*/
void RawFileMClass::Error(int, int, char const * )
{
}


/***********************************************************************************************
 * RawFileMClass::RawFileMClass -- Simple constructor for a file object.                         *
 *                                                                                             *
 *    This constructor is called when a file object is created with a supplied filename, but   *
 *    not opened at the same time. In this case, an assumption is made that the supplied       *
 *    filename is a constant string. A duplicate of the filename string is not created since   *
 *    it would be wasteful in that case.                                                       *
 *                                                                                             *
 * INPUT:   filename -- The filename to assign to this file object.                            *
 *                                                                                             *
 * OUTPUT:  none                                                                               *
 *                                                                                             *
 * WARNINGS:   none                                                                            *
 *                                                                                             *
 * HISTORY:                                                                                    *
 *   10/17/1994 JLB : Created.                                                                 *
 *=============================================================================================*/
RawFileMClass::RawFileMClass(char const * filename) :
	Rights(0),
	BiasStart(0),
	BiasLength(-1),
	Handle(NULL_HANDLE),
	Filename(filename),
	Date(0),
	Time(0),
	Allocated(false)
{
}


/***********************************************************************************************
 * RawFileMClass::Set_Name -- Manually sets the name for a file object.                         *
 *                                                                                             *
 *    This routine will set the name for the file object to the name specified. This name is   *
 *    duplicated in free store. This allows the supplied name to be a temporarily constructed  *
 *    text string. Setting the name in this fashion doesn't affect the closed or opened state  *
 *    of the file.                                                                             *
 *                                                                                             *
 * INPUT:   filename -- The filename to assign to this file object.                            *
 *                                                                                             *
 * OUTPUT:  Returns with a pointer to the allocated copy of this filename. This pointer is     *
 *          guaranteed to remain valid for the duration of this file object or until the name  *
 *          is changed -- whichever is sooner.                                                 *
 *                                                                                             *
 * WARNINGS:   Because of the allocation this routine must perform, memory could become        *
 *             fragmented.                                                                     *
 *                                                                                             *
 * HISTORY:                                                                                    *
 *   10/17/1994 JLB : Created.                                                                 *
 *=============================================================================================*/
char const * RawFileMClass::Set_Name(char const * filename)
{
	if (Filename != NULL && Allocated) {
		free((char *)Filename);
		Filename = NULL;
		Allocated = false;
	}

	if (filename == NULL) return(NULL);

	Bias(0);

	Filename = strdup(filename);
	if (Filename == NULL) {
		Error(ENOMEM, false, filename);
	}
	Allocated = true;
	return(Filename);
}


/***********************************************************************************************
 * RawFileMClass::Open -- Assigns name and opens file in one operation.                         *
 *                                                                                             *
 *    This routine will assign the specified filename to the file object and open it at the    *
 *    same time. If the file object was already open, then it will be closed first. If the     *
 *    file object was previously assigned a filename, then it will be replaced with the new    *
 *    name. Typically, this routine is used when an anonymous file object has been crated and  *
 *    now it needs to be assigned a name and opened.                                           *
 *                                                                                             *
 * INPUT:   filename -- The filename to assign to this file object.                            *
 *                                                                                             *
 *          rights   -- The open file access rights to use.                                    *
 *                                                                                             *
 * OUTPUT:  bool; Was the file opened? The return value of this is moot, since the open file   *
 *          is designed to never return unless it succeeded.                                   *
 *                                                                                             *
 * WARNINGS:   none                                                                            *
 *                                                                                             *
 * HISTORY:                                                                                    *
 *   10/17/1994 JLB : Created.                                                                 *
 *=============================================================================================*/
int RawFileMClass::Open(char const * filename, int rights)
{
	Set_Name(filename);
	return(Open(rights));
}


/***********************************************************************************************
 * RawFileMClass::Open -- Opens the file object with the rights specified.                      *
 *                                                                                             *
 *    This routine is used to open the specified file object with the access rights indicated. *
 *    This only works if the file has already been assigned a filename. It is guaranteed, by   *
 *    the error handler, that this routine will always return with success.                    *
 *                                                                                             *
 * INPUT:   rights   -- The file access rights to use when opening this file. This is a        *
 *                      combination of READ and/or WRITE bit flags.                            *
 *                                                                                             *
 * OUTPUT:  bool; Was the file opened successfully? This will always return true by reason of  *
 *          the error handler.                                                                 *
 *                                                                                             *
 * WARNINGS:   none                                                                            *
 *                                                                                             *
 * HISTORY:                                                                                    *
 *   10/17/1994 JLB : Created.                                                                 *
 *=============================================================================================*/
int RawFileMClass::Open(int rights)
{
	Close();

	/*
	**	Verify that there is a filename associated with this file object. If not, then this is a
	**	big error condition.
	*/
	if (Filename == NULL) {
		Error(ENOENT, false);
	}

	/*
	**	Record the access rights used for this open call. These rights will be used if the
	**	file object is duplicated.
	*/
	Rights = rights;

	/*
	**	Repetitively try to open the file. Abort if a fatal error condition occurs.
	*/
	for (;;) {

		/*
		**	Try to open the file according to the access rights specified.
		*/
		switch (rights) {

			/*
			**	If the access rights are not recognized, then report this as
			**	an invalid access code.
			*/
			default:
				Error_Number = EINVAL;
				break;

			case READ:
					Handle = CreateFileA(Filename, GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE,
												NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
				break;

			case WRITE:
					Handle = CreateFileA(Filename, GENERIC_WRITE, 0,
												NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
				break;

			case READ|WRITE:
					Handle = CreateFileA(Filename, GENERIC_READ | GENERIC_WRITE, 0,
												NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
				break;
		}

		/*
		**	Biased files must be positioned past the bias start position.
		*/
		if (BiasStart != 0 || BiasLength != -1) {
			Seek(0, SEEK_SET);
		}

		/*
		**	If the handle indicates the file is not open, then this is an error condition.
		**	For the case of the file cannot be found, then allow a retry. All other cases
		**	are fatal.
		*/
		if (Handle == NULL_HANDLE) {

			return(false);
//			Error(GetLastError(), false, Filename);
//			continue;
		}
		break;
	}

	return(true);
}


/***********************************************************************************************
 * RawFileMClass::Is_Available -- Checks to see if the specified file is available to open.     *
 *                                                                                             *
 *    This routine will examine the disk system to see if the specified file can be opened     *
 *    or not. Use this routine before opening a file in order to make sure that is available   *
 *    or to perform other necessary actions.                                                   *
 *                                                                                             *
 * INPUT:   force -- Should this routine keep retrying until the file becomes available? If    *
 *                   in this case it doesn't become available, then the program will abort.    *
 *                                                                                             *
 * OUTPUT:  bool; Is the file available to be opened?                                          *
 *                                                                                             *
 * WARNINGS:   Depending on the parameter passed in, this routine may never return.            *
 *                                                                                             *
 * HISTORY:                                                                                    *
 *   10/18/1994 JLB : Created.                                                                 *
 *=============================================================================================*/
bool RawFileMClass::Is_Available(int forced)
{
	if (Filename == NULL) return(false);

	/*
	**	If the file is already open, then is must have already passed the availability check.
	**	Return true in this case.
	*/
	if (Is_Open()) return(true);

	/*
	**	If this is a forced check, then go through the normal open channels, since those
	**	channels ensure that the file must exist.
	*/
	if (forced) {
		RawFileMClass::Open(READ);
		RawFileMClass::Close();
		return(true);
	}

	/*
	**	Perform a raw open of the file. If this open fails for ANY REASON, including a missing
	**	CD-ROM, this routine will return a failure condition. In all but the missing file
	**	condition, go through the normal error recover channels.
	*/
	for (;;) {

		Handle = CreateFileA(Filename, GENERIC_READ, FILE_SHARE_READ,
											NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
		if (Handle == NULL_HANDLE) {
			return(false);
		}
		break;
	}

	/*
	**	Since the file could be opened, then close it and return that the file exists.
	*/
	if (!CloseHandle(Handle)) {
		Error(GetLastError(), false, Filename);
	}
	Handle = NULL_HANDLE;

	return(true);
}


/***********************************************************************************************
 * RawFileMClass::Close -- Perform a closure of the file.                                       *
 *                                                                                             *
 *    Close the file object. In the rare case of an error, handle it as appropriate.           *
 *                                                                                             *
 * INPUT:   none                                                                               *
 *                                                                                             *
 * OUTPUT:  none                                                                               *
 *                                                                                             *
 * WARNINGS:   Some rare error conditions may cause this routine to abort the program.         *
 *                                                                                             *
 * HISTORY:                                                                                    *
 *   10/18/1994 JLB : Created.                                                                 *
 *=============================================================================================*/
void RawFileMClass::Close(void)
{
	/*
	**	If the file is open, then close it. If the file is already closed, then just return. This
	**	isn't considered an error condition.
	*/
	if (Is_Open()) {

		/*
		**	Try to close the file. If there was an error (who knows what that could be), then
		**	call the error routine.
		*/
		if (!CloseHandle(Handle)) {
			Error(GetLastError(), false, Filename);
		}

		/*
		**	At this point the file must have been closed. Mark the file as empty and return.
		*/
		Handle = NULL_HANDLE;
	}
}


/***********************************************************************************************
 * RawFileMClass::Read -- Reads the specified number of bytes into a memory buffer.             *
 *                                                                                             *
 *    This routine will read the specified number of bytes and place the data into the buffer  *
 *    indicated. It is legal to call this routine with a request for more bytes than are in    *
 *    the file. This condition can result in fewer bytes being read than requested. Determine  *
 *    this by examining the return value.                                                      *
 *                                                                                             *
 * INPUT:   buffer   -- Pointer to the buffer to read data into. If NULL is passed, no read    *
 *                      is performed.                                                          *
 *                                                                                             *
 *          size     -- The number of bytes to read. If NULL is passed, then no read is        *
 *                      performed.                                                             *
 *                                                                                             *
 * OUTPUT:  Returns with the number of bytes read into the buffer. If this number is less      *
 *          than requested, it indicates that the file has been exhausted.                     *
 *                                                                                             *
 * WARNINGS:   none                                                                            *
 *                                                                                             *
 * HISTORY:                                                                                    *
 *   10/18/1994 JLB : Created.                                                                 *
 *=============================================================================================*/
int RawFileMClass::Read(void * buffer, int size)
{
	long	bytesread = 0;			// Running count of the number of bytes read into the buffer.
	int	opened = false;		// Was the file opened by this routine?

	/*
	**	If the file isn't opened, open it. This serves as a convenience
	**	for the programmer.
	*/
	if (!Is_Open()) {

		/*
		**	The error check here is moot. Open will never return unless it succeeded.
		*/
		if (!Open(READ)) {
			return(0);
		}
		opened = true;
	}

	/*
	**	A biased file has the requested read length limited to the bias length of
	**	the file.
	*/
	if (BiasLength != -1) {
		int remainder = BiasLength - Seek(0);
		size = size < remainder ? size : remainder;
	}

	long total = 0;
	while (size > 0) {
		bytesread = 0;
		if (!ReadFile(Handle, buffer, size, &(unsigned long&)bytesread, NULL)) {
			size -= bytesread;
			total += bytesread;
			Error(GetLastError(), true, Filename);
			continue;
		}
		size -= bytesread;
		total += bytesread;
		if (bytesread == 0) break;
	}
	bytesread = total;

	/*
	**	Close the file if it was opened by this routine and return
	**	the actual number of bytes read into the buffer.
	*/
	if (opened) Close();
	return(bytesread);
}


/***********************************************************************************************
 * RawFileMClass::Write -- Writes the specified data to the buffer specified.                   *
 *                                                                                             *
 *    This routine will write the data specified to the file.                                  *
 *                                                                                             *
 * INPUT:   buffer   -- The buffer that holds the data to write.                               *
 *                                                                                             *
 *          size     -- The number of bytes to write to the file.                              *
 *                                                                                             *
 * OUTPUT:  Returns with the number of bytes written to the file. This routine catches the     *
 *          case of a disk full condition, so this routine will always return with the number  *
 *          matching the size request.                                                         *
 *                                                                                             *
 * WARNINGS:   A fatal file condition could cause this routine to never return.                *
 *                                                                                             *
 * HISTORY:                                                                                    *
 *   10/18/1994 JLB : Created.                                                                 *
 *=============================================================================================*/
int RawFileMClass::Write(void const * buffer, int size)
{
	long	bytesread = 0;
	int	opened = false;		// Was the file manually opened?

	/*
	**	Check to open status of the file. If the file is open, then merely write to
	**	it. Otherwise, open the file for writing and then close the file when the
	**	output is finished.
	*/
	if (!Is_Open()) {
		if (!Open(WRITE)) {
			return(0);
		}
		opened = true;
	}

	if (!WriteFile(Handle, buffer, size, &(unsigned long&)bytesread, NULL)) {
		Error(GetLastError(), false, Filename);
	}

	/*
	**	Fixup the bias length if necessary.
	*/
	if (BiasLength != -1) {
		if (Raw_Seek(0) > BiasStart+BiasLength) {
			BiasLength = Raw_Seek(0) - BiasStart;
		}
	}

	/*
	**	If this routine had to open the file, then close it before returning.
	*/
	if (opened) {
		Close();
	}

	/*
	**	Return with the number of bytes written. This will always be the number of bytes
	**	requested, since the case of the disk being full is caught by this routine.
	*/
	return(bytesread);
}


/***********************************************************************************************
 * RawFileMClass::Seek -- Reposition the file pointer as indicated.                             *
 *                                                                                             *
 *    Use this routine to move the filepointer to the position indicated. It can move either   *
 *    relative to current position or absolute from the beginning or ending of the file. This  *
 *    routine will only return if it successfully performed the seek.                          *
 *                                                                                             *
 * INPUT:   pos   -- The position to seek to. This is interpreted as relative to the position  *
 *                   indicated by the "dir" parameter.                                         *
 *                                                                                             *
 *          dir   -- The relative position to relate the seek to. This can be either SEEK_SET  *
 *                   for the beginning of the file, SEEK_CUR for the current position, or      *
 *                   SEEK_END for the end of the file.                                         *
 *                                                                                             *
 * OUTPUT:  This routine returns the position that the seek ended up at.                       *
 *                                                                                             *
 * WARNINGS:   If there was a file error, then this routine might never return.                *
 *                                                                                             *
 * HISTORY:                                                                                    *
 *   10/18/1994 JLB : Created.                                                                 *
 *=============================================================================================*/
int RawFileMClass::Seek(int pos, int dir)
{

	/*
	**	A file that is biased will have a seek operation modified so that the file appears to
	**	exist only within the bias range. All bytes outside of this range appear to be
	**	non-existant.
	*/
	if (BiasLength != -1) {
		switch (dir) {
			case SEEK_SET:
				if (pos > BiasLength) {
					pos = BiasLength;
				}
				pos += BiasStart;
				break;

			case SEEK_CUR:
				break;

			case SEEK_END:
				dir = SEEK_SET;
				pos += BiasStart + BiasLength;
//				pos = (pos <= BiasStart+BiasLength) ? pos : BiasStart+BiasLength;
//				pos = (pos >= BiasStart) ? pos : BiasStart;
				break;
		}

		/*
		**	Perform the modified raw seek into the file.
		*/
		long newpos = Raw_Seek(pos, dir) - BiasStart;

		/*
		**	Perform a final double check to make sure the file position fits with the bias range.
		*/
		if (newpos < 0) {
			newpos = Raw_Seek(BiasStart, SEEK_SET) - BiasStart;
		}
		if (newpos > BiasLength) {
			newpos = Raw_Seek(BiasStart+BiasLength, SEEK_SET) - BiasStart;
		}
		return(newpos);
	}

	/*
	**	If the file is not biased in any fashion, then the normal seek logic will
	**	work just fine.
	*/
	return(Raw_Seek(pos, dir));
}


/***********************************************************************************************
 * RawFileMClass::Size -- Determines size of file (in bytes).                                   *
 *                                                                                             *
 *    Use this routine to determine the size of the file. The file must exist or this is an    *
 *    error condition.                                                                         *
 *                                                                                             *
 * INPUT:   none                                                                               *
 *                                                                                             *
 * OUTPUT:  Returns with the number of bytes in the file.                                      *
 *                                                                                             *
 * WARNINGS:   This routine handles error conditions and will not return unless the file       *
 *             exists and can successfully be queried for file length.                         *
 *                                                                                             *
 * HISTORY:                                                                                    *
 *   10/18/1994 JLB : Created.                                                                 *
 *=============================================================================================*/
int RawFileMClass::Size(void)
{
	int size = 0;

	/*
	**	A biased file already has its length determined.
	*/
	if (BiasLength != -1) {
		return(BiasLength);
	}

	/*
	**	If the file is open, then proceed normally.
	*/
	if (Is_Open()) {

		size = GetFileSize(Handle, NULL);

		/*
		**	If there was in internal error, then call the error function.
		*/
		if (size == 0xFFFFFFFF) {
			Error(GetLastError(), false, Filename);
		}

	} else {

		/*
		**	If the file wasn't open, then open the file and call this routine again. Count on
		**	the fact that the open function must succeed.
		*/
		if (Open()) {
			size = Size();

			/*
			**	Since we needed to open the file we must remember to close the file when the
			**	size has been determined.
			*/
			Close();
		}
	}

	BiasLength = size-BiasStart;
	return(BiasLength);
}


/***********************************************************************************************
 * RawFileMClass::Create -- Creates an empty file.                                              *
 *                                                                                             *
 *    This routine will create an empty file from the file object. The file object's filename  *
 *    must already have been assigned before this routine will function.                       *
 *                                                                                             *
 * INPUT:   none                                                                               *
 *                                                                                             *
 * OUTPUT:  bool; Was the file successfully created? This routine will always return true.     *
 *                                                                                             *
 * WARNINGS:   A fatal error condition could occur with this routine. Especially if the disk   *
 *             is full or a read-only media was selected.                                      *
 *                                                                                             *
 * HISTORY:                                                                                    *
 *   10/18/1994 JLB : Created.                                                                 *
 *=============================================================================================*/
int RawFileMClass::Create(void)
{
	Close();
	if (Open(WRITE)) {

		/*
		**	A biased file must be at least as long as the bias offset. Seeking to the
		**	appropriate start offset has the effect of lengthening the file to the
		**	correct length.
		*/
		if (BiasLength != -1) {
			Seek(0, SEEK_SET);
		}

		Close();
		return(true);
	}
	return(false);
}


/***********************************************************************************************
 * RawFileMClass::Delete -- Deletes the file object from the disk.                              *
 *                                                                                             *
 *    This routine will delete the file object from the disk. If the file object doesn't       *
 *    exist, then this routine will return as if it had succeeded (since the effect is the     *
 *    same).                                                                                   *
 *                                                                                             *
 * INPUT:   none                                                                               *
 *                                                                                             *
 * OUTPUT:  bool; Was the file deleted? If the file was already missing, the this value will   *
 *                be false.                                                                    *
 *                                                                                             *
 * WARNINGS:   none                                                                            *
 *                                                                                             *
 * HISTORY:                                                                                    *
 *   10/18/1994 JLB : Created.                                                                 *
 *=============================================================================================*/
int RawFileMClass::Delete(void)
{
	/*
	**	If the file was open, then it must be closed first.
	*/
	Close();

	/*
	**	If there is no filename associated with this object, then this indicates a fatal error
	**	condition. Report this and abort.
	*/
	if (!Filename) {
		Error(ENOENT, false);
	}

	/*
	**	Repetitively try to delete the file if possible. Either return with success, or
	**	abort the program with an error.
	*/
	for (;;) {

		/*
		**	If the file is already missing, then return with this fact. No action is necessary.
		**	This can occur as this section loops if the file exists on a floppy and the floppy
		**	was removed, the file deleted on another machine, and then the floppy was
		**	reinserted. Admittedly, this is a rare case, but is handled here.
		*/
		if (!Is_Available()) {
			return(false);
		}

		if (!DeleteFile(Filename)) {
			Error(GetLastError(), false, Filename);
			return(false);
		}
		break;
	}

	/*
	**	DOS reports that the file was successfully deleted. Return with this fact.
	*/
	return(true);
}


/***********************************************************************************************
 * RawFileMClass::Get_Date_Time -- Gets the date and time the file was last modified.           *
 *                                                                                             *
 *    Use this routine to get the date and time of the file.                                   *
 *                                                                                             *
 * INPUT:   none                                                                               *
 *                                                                                             *
 * OUTPUT:  Returns with the file date and time as a long.                                     *
 *          Use the YEAR(long), MONTH(),....                                                   *
 *                                                                                             *
 * WARNINGS:   none                                                                            *
 *                                                                                             *
 * HISTORY:                                                                                    *
 *   11/14/1995 DRD : Created.                                                                 *
 *   07/13/1996 JLB : Handles win32 method.                                                    *
 *=============================================================================================*/
unsigned long RawFileMClass::Get_Date_Time(void)
{
	BY_HANDLE_FILE_INFORMATION info;

	if (GetFileInformationByHandle(Handle, &info)) {
		WORD dosdate;
		WORD dostime;
		FileTimeToDosDateTime(&info.ftLastWriteTime, &dosdate, &dostime);
		return((dosdate << 16) | dostime);
	}
	return(0);
}


/***********************************************************************************************
 * RawFileMClass::Set_Date_Time -- Sets the date and time the file was last modified.           *
 *                                                                                             *
 *    Use this routine to set the date and time of the file.                                   *
 *                                                                                             *
 * INPUT:   the file date and time as a long                                                   *
 *                                                                                             *
 * OUTPUT:  successful or not if the file date and time was changed.                           *
 *                                                                                             *
 * WARNINGS:   none                                                                            *
 *                                                                                             *
 * HISTORY:                                                                                    *
 *   11/14/1995 DRD : Created.                                                                 *
 *   07/13/1996 JLB : Handles win 32 method                                                    *
 *=============================================================================================*/
bool RawFileMClass::Set_Date_Time(unsigned long datetime)
{
	if (RawFileMClass::Is_Open()) {
		BY_HANDLE_FILE_INFORMATION info;

		if (GetFileInformationByHandle(Handle, &info)) {
			FILETIME filetime;
			if (DosDateTimeToFileTime((WORD)(datetime >> 16), (WORD)(datetime & 0x0FFFF), &filetime)) {
				return(SetFileTime(Handle, &info.ftCreationTime, &filetime, &filetime) != 0);
			}
		}
	}
	return(false);
}


/***********************************************************************************************
 * RawFileMClass::Bias -- Bias a file with a specific starting position and length.             *
 *                                                                                             *
 *    This will bias a file by giving it an artificial starting position and length. By        *
 *    using this routine, it is possible to 'fool' the file into ignoring a header and         *
 *    trailing extra data. An example of this would be a file inside of a mixfile.             *
 *                                                                                             *
 * INPUT:   start    -- The starting offset that will now be considered the start of the       *
 *                      file.                                                                  *
 *                                                                                             *
 *          length   -- The forced length of the file. For files that are opened for write,    *
 *                      this serves as the artificial constraint on the file's length. For     *
 *                      files opened for read, this limits the usable file size.               *
 *                                                                                             *
 * OUTPUT:  none                                                                               *
 *                                                                                             *
 * WARNINGS:   none                                                                            *
 *                                                                                             *
 * HISTORY:                                                                                    *
 *   06/02/1996 JLB : Created.                                                                 *
 *=============================================================================================*/
void RawFileMClass::Bias(int start, int length)
{
	if (start == 0) {
		BiasStart = 0;
		BiasLength = -1;
		return;
	}

	BiasLength = RawFileMClass::Size();
	BiasStart += start;
	if (length != -1) {
		BiasLength = BiasLength < length ? BiasLength : length;
	}
	BiasLength = BiasLength > 0 ? BiasLength : 0;

	/*
	**	Move the current file offset to a legal position if necessary and the
	**	file was open.
	*/
	if (Is_Open()) {
		RawFileMClass::Seek(0, SEEK_SET);
	}
}


/***********************************************************************************************
 * RawFileMClass::Raw_Seek -- Performs a seek on the unbiased file                              *
 *                                                                                             *
 *    This will perform a seek on the file as if it were unbiased. This is in spite of any     *
 *    bias setting the file may have. The ability to perform a raw seek in this fasion is      *
 *    necessary to maintain the bias ability.                                                  *
 *                                                                                             *
 * INPUT:   pos   -- The position to seek the file relative to the "dir" parameter.            *
 *                                                                                             *
 *          dir   -- The origin of the seek operation.                                         *
 *                                                                                             *
 * OUTPUT:  Returns with the new position of the seek operation.                               *
 *                                                                                             *
 * WARNINGS:   none                                                                            *
 *                                                                                             *
 * HISTORY:                                                                                    *
 *   08/04/1996 JLB : Created.                                                                 *
 *=============================================================================================*/
int RawFileMClass::Raw_Seek(int pos, int dir)
{
	/*
	**	If the file isn't opened, then this is a fatal error condition.
	*/
	if (!Is_Open()) {
		Error(EBADF, false, Filename);
	}

	switch (dir) {
		case SEEK_SET:
			dir = FILE_BEGIN;
			break;

		case SEEK_CUR:
			dir = FILE_CURRENT;
			break;

		case SEEK_END:
			dir = FILE_END;
			break;
	}

	pos = SetFilePointer(Handle, pos, NULL, dir);

	/*
	**	If there was an error in the seek, then bail with an error condition.
	*/
	if (pos == 0xFFFFFFFF) {
		Error(GetLastError(), false, Filename);
	}

	/*
	**	Return with the new position of the file. This will range between zero and the number of
	**	bytes the file contains.
	*/
	return(pos);
}