/*****************************************************************************\*                     EFSL - Embedded Filesystems Library                     **                     -----------------------------------                     **                                                                             ** Filename : file.c                                                           ** Release  : 0.3 - devel                                                      ** Description : This file contains functions dealing with files such as:      **               fopen, fread and fwrite.                                      **                                                                             ** 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; version 2                     ** of the License.                                                             **                                                                             ** 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.                                **                                                                             ** As a special exception, if other files instantiate templates or             ** use macros or inline functions from this file, or you compile this          ** file and link it with other works to produce a work based on this file,     ** this file does not by itself cause the resulting work to be covered         ** by the GNU General Public License. However the source code for this         ** file must still be made available in accordance with section (3) of         ** the GNU General Public License.                                             **                                                                             ** This exception does not invalidate any other reasons why a work based       ** on this file might be covered by the GNU General Public License.            **                                                                             **                                                    (c)2006 Lennart Yseboodt **                                                    (c)2006 Michael De Nil   *\*****************************************************************************//*****************************************************************************/#include "file.h"/*****************************************************************************//* ****************************************************************************   * euint32 file_fread(File *file,euint32 offset, euint32 size,euint8 *buf) * Description: This function reads 'size' bytes from 'file' starting at * 'offset' and puts the result in '*buf'. * Return value: amount of bytes actually read (can differ from the given * size when the file was smaller*/euint32 file_fread(File *file,euint32 offset, euint32 size,euint8 *buf){	euint32 bytes_read=0,size_left=size,coffset=offset;	euint32 cclus,csec,cbyte;	euint32 rclus,rsec;	euint32 btr;	euint8 *tbuf;			if(!file_getAttr(file,FILE_STATUS_OPEN))return(0);		if(offset>=file->FileSize)		size_left=0; /* Offset check */		if( (offset+size > file->FileSize) && size_left!=0)		size_left=file->FileSize-offset;		while(size_left>0){			cclus = coffset/(512*file->fs->volumeId.SectorsPerCluster);		csec = (coffset/(512))%file->fs->volumeId.SectorsPerCluster;		cbyte = coffset%512;				if(cbyte!=0 || size_left<512){			btr = 512-(coffset%512)>=size_left?size_left:512-(coffset%512);		}else{			btr = 512;		}		if((fat_LogicToDiscCluster(file->fs,&(file->Cache),cclus))!=0){			return(0);		}		rclus=file->Cache.DiscCluster;		rsec=fs_clusterToSector(file->fs,rclus);						if(btr==512){			/*part_readBuf(file->fs->part,rsec+csec,buf+bytes_read);*/			part_directSectorRead(file->fs->part,rsec+csec,buf+bytes_read);		}else{			/*part_readBuf(file->fs->part,rsec+csec,tbuf);*/			tbuf = part_getSect(file->fs->part,rsec+csec,IOM_MODE_READONLY);			memCpy(tbuf+(coffset%512),buf+bytes_read,btr);			part_relSect(file->fs->part,tbuf);		}				coffset+=btr;		bytes_read+=btr;		size_left-=btr;	}			return(bytes_read);}/*****************************************************************************//* ****************************************************************************   * euint32 file_read (File *file,euint32 size,euint8 *buf) * Description: This function reads from a file, taking the FilePtr into account * and advancing it according to the freadcall. * Return value: Value obtained from fread*/euint32 file_read(File *file,euint32 size,euint8 *buf){	euint32 r;		r=file_fread(file,file->FilePtr,size,buf);	file->FilePtr+=r;	return(r);}/*****************************************************************************//* ****************************************************************************   * euint32 file_write(File *file, euint32 size,euint8 *buf) * Description: This function writes to a file, taking FilePtr into account * and advancing it according to the fwritecall. * Return value: Value obtained from fread*/euint32 file_write(File *file, euint32 size,euint8 *buf){	euint32 r;		r=file_fwrite(file,file->FilePtr,size,buf);	file->FilePtr+=r;	return(r);}/*****************************************************************************//* ****************************************************************************   * esint16 file_setpos(File *file,euint32 pos) * Description: This function does a sanity check on the requested position * and changes the fileptr accordingly. * Return value: 0 on success and -1 on failure.*/esint16 file_setpos(File *file,euint32 pos){	if(pos<=file->FileSize){		file->FilePtr=pos;		return(0);	}	return(-1);}/*****************************************************************************//* ****************************************************************************   * euint32 file_fwrite(File* file,euint32 offset,euint32 size,euint8* buf) * Description: This function writes to a file, at offset 'offset' and size 'size'. * It also updates the FileSize in the object, and discstructure. * Return value: Bytes actually written.*/euint32 file_fwrite(File* file,euint32 offset,euint32 size,euint8* buf){	euint32 need_cluster;	euint32 cclus,csec,cbyte;	euint32 size_left=size,bytes_written=0;	euint32 rclus,rsec;	euint32 coffset=offset;	euint16 btr;	euint8 *tbuf;	if(!file_getAttr(file,FILE_STATUS_OPEN) || !file_getAttr(file,FILE_STATUS_WRITE))return(0);		if(offset>file->FileSize){		offset=file->FileSize;	}		need_cluster = file_requiredCluster(file,offset,size);		if(need_cluster){		if(fat_allocClusterChain(file->fs,&(file->Cache),need_cluster+CLUSTER_PREALLOC_FILE)!=0){			return(0);		}	}		while(size_left>0){			cclus = coffset/(512*file->fs->volumeId.SectorsPerCluster);		csec = (coffset/(512))%file->fs->volumeId.SectorsPerCluster;		cbyte = coffset%512;				if(cbyte!=0 || size_left<512){			btr = 512-(coffset%512)>=size_left?size_left:512-(coffset%512);		}else{			btr = 512;		}		if((fat_LogicToDiscCluster(file->fs,&(file->Cache),cclus))!=0){			file->FileSize+=bytes_written;			dir_setFileSize(file->fs,&(file->Location),file->FileSize);			return(bytes_written);		}		rclus=file->Cache.DiscCluster;		rsec=fs_clusterToSector(file->fs,rclus);				if(btr==512){			/*part_writeBuf(file->fs->part,rsec+csec,buf+bytes_written);*/			part_directSectorWrite(file->fs->part,rsec+csec,buf+bytes_written);		}else{			/*part_readBuf(file->fs->part,rsec+csec,tbuf);*/			tbuf = part_getSect(file->fs->part,rsec+csec,IOM_MODE_READWRITE);			memCpy(buf+bytes_written,tbuf+(coffset%512),btr);			/*part_writeBuf(file->fs->part,rsec+csec,tbuf);*/			part_relSect(file->fs->part,tbuf);		}				coffset+=btr;		bytes_written+=btr;		size_left-=btr;	}		if(bytes_written>file->FileSize-offset){		file->FileSize+=bytes_written-(file->FileSize-offset);    }		return(bytes_written);	}/* ***************************************************************************\ * signed eint8 file_fopen(FileSystem *fs,File* file,eint8* filename)       * Description: This functions opens a file.                                * This function is about to be redesigned. No Docs.                        * Return value:*/esint8 file_fopen(File* file,FileSystem *fs,eint8* filename,eint8 mode){    FileLocation loc;    FileRecord wtmp;    eint8 fatfilename[11];    euint32 sec;    dir_getFatFileName(filename,fatfilename);	    switch(mode)	{        case MODE_READ:            if(fs_findFile(fs,filename,&loc,0)==1)			{                dir_getFileStructure(fs,&(file->DirEntry), &loc);                file_initFile(file,fs,&loc);				file_setAttr(file,FILE_STATUS_OPEN,1);				file_setAttr(file,FILE_STATUS_WRITE,0);                return(0);            }            return(-1);            break;        case MODE_WRITE: