bool fatFile::Seek(Bit32u *pos, Bit32u type) {
Bit32s seekto=0;
switch(type) {
case DOS_SEEK_SET:
seekto = (Bit32s)*pos;
break;
case DOS_SEEK_CUR:
/* Is this relative seek signed? */
seekto = (Bit32s)*pos + (Bit32s)seekpos;
break;
case DOS_SEEK_END:
seekto = (Bit32s)filelength + (Bit32s)*pos;
break;
}
// LOG_MSG("Seek to %d with type %d (absolute value %d)", *pos, type, seekto);
if((Bit32u)seekto > filelength) seekto = (Bit32s)filelength;
if(seekto<0) seekto = 0;
seekpos = (Bit32u)seekto;
currentSector = myDrive->getAbsoluteSectFromBytePos(firstCluster, seekpos);
if (currentSector == 0) {
/* not within file size, thus no sector is available */
loadedSector = false;
} else {
curSectOff = seekpos % myDrive->getSectorSize();
myDrive->loadedDisk->Read_AbsoluteSector(currentSector, sectorBuffer);
}
*pos = seekpos;
return true;
}
bool fatFile::Read(Bit8u * data, Bit16u *size) {
Bit16u sizedec, sizecount;
if(seekpos >= filelength) {
*size = 0;
return true;
}
sizedec = *size;
sizecount = 0;
while(sizedec != 0) {
if(seekpos >= filelength) {
*size = sizecount;
return true;
}
data[sizecount] = sectorBuffer[curSectOff];
curSectOff++;
seekpos++;
if(curSectOff >= myDrive->getSectorSize()) {
currentSector = myDrive->getAbsoluteSectFromBytePos(firstCluster, seekpos);
if(currentSector == 0) {
/* EOC reached before EOF */
//LOG_MSG("EOC reached before EOF, seekpos %d, filelen %d", seekpos, filelength);
*size = sizecount;
return true;
}
curSectOff = 0;
myDrive->loadedDisk->Read_AbsoluteSector(currentSector, sectorBuffer);
//LOG_MSG("Reading absolute sector at %d for seekpos %d", currentSector, seekpos);
}
--sizedec;
sizecount++;
}
*size =sizecount;
return true;
}
bool fatFile::Read(Bit8u * data, Bit16u *size) {
if ((this->flags & 0xf) == OPEN_WRITE) { // check if file opened in write-only mode
DOS_SetError(DOSERR_ACCESS_DENIED);
return false;
}
Bit16u sizedec, sizecount;
if(seekpos >= filelength) {
*size = 0;
return true;
}
if (!loadedSector) {
currentSector = myDrive->getAbsoluteSectFromBytePos(firstCluster, seekpos);
if(currentSector == 0) {
/* EOC reached before EOF */
*size = 0;
loadedSector = false;
return true;
}
curSectOff = 0;
myDrive->loadedDisk->Read_AbsoluteSector(currentSector, sectorBuffer);
loadedSector = true;
}
sizedec = *size;
sizecount = 0;
while(sizedec != 0) {
if(seekpos >= filelength) {
*size = sizecount;
return true;
}
data[sizecount++] = sectorBuffer[curSectOff++];
seekpos++;
if(curSectOff >= myDrive->getSectorSize()) {
currentSector = myDrive->getAbsoluteSectFromBytePos(firstCluster, seekpos);
if(currentSector == 0) {
/* EOC reached before EOF */
//LOG_MSG("EOC reached before EOF, seekpos %d, filelen %d", seekpos, filelength);
*size = sizecount;
loadedSector = false;
return true;
}
curSectOff = 0;
myDrive->loadedDisk->Read_AbsoluteSector(currentSector, sectorBuffer);
loadedSector = true;
//LOG_MSG("Reading absolute sector at %d for seekpos %d", currentSector, seekpos);
}
--sizedec;
}
*size =sizecount;
return true;
}
bool fatFile::Write(Bit8u * data, Bit16u *size) {
/* TODO: Check for read-only bit */
direntry tmpentry;
Bit16u sizedec, sizecount;
sizedec = *size;
sizecount = 0;
while(sizedec != 0) {
/* Increase filesize if necessary */
if(seekpos >= filelength) {
if(filelength == 0) {
firstCluster = myDrive->getFirstFreeClust();
myDrive->allocateCluster(firstCluster, 0);
currentSector = myDrive->getAbsoluteSectFromBytePos(firstCluster, seekpos);
myDrive->loadedDisk->Read_AbsoluteSector(currentSector, sectorBuffer);
loadedSector = true;
}
filelength = seekpos+1;
}
sectorBuffer[curSectOff] = data[sizecount];
curSectOff++;
seekpos++;
if(curSectOff >= myDrive->getSectorSize()) {
if(loadedSector) myDrive->loadedDisk->Write_AbsoluteSector(currentSector, sectorBuffer);
currentSector = myDrive->getAbsoluteSectFromBytePos(firstCluster, seekpos);
if(currentSector == 0) {
/* EOC reached before EOF - try to increase file allocation */
myDrive->appendCluster(firstCluster);
/* Try getting sector again */
currentSector = myDrive->getAbsoluteSectFromBytePos(firstCluster, seekpos);
if(currentSector == 0) {
/* No can do. lets give up and go home. We must be out of room */
goto finalizeWrite;
}
}
curSectOff = 0;
myDrive->loadedDisk->Read_AbsoluteSector(currentSector, sectorBuffer);
loadedSector = true;
}
--sizedec;
sizecount++;
}
finalizeWrite:
myDrive->directoryBrowse(dirCluster, &tmpentry, dirIndex);
tmpentry.entrysize = filelength;
tmpentry.loFirstClust = firstCluster;
myDrive->directoryChange(dirCluster, &tmpentry, dirIndex);
*size =sizecount;
return true;
}
bool fatFile::Write(Bit8u * data, Bit16u *size) {
/* TODO: Check for read-only bit */
if ((this->flags & 0xf) == OPEN_READ) { // check if file opened in read-only mode
DOS_SetError(DOSERR_ACCESS_DENIED);
return false;
}
direntry tmpentry;
Bit16u sizedec, sizecount;
sizedec = *size;
sizecount = 0;
while(sizedec != 0) {
/* Increase filesize if necessary */
if(seekpos >= filelength) {
if(filelength == 0) {
firstCluster = myDrive->getFirstFreeClust();
myDrive->allocateCluster(firstCluster, 0);
currentSector = myDrive->getAbsoluteSectFromBytePos(firstCluster, seekpos);
myDrive->loadedDisk->Read_AbsoluteSector(currentSector, sectorBuffer);
loadedSector = true;
}
filelength = seekpos+1;
if (!loadedSector) {
currentSector = myDrive->getAbsoluteSectFromBytePos(firstCluster, seekpos);
if(currentSector == 0) {
/* EOC reached before EOF - try to increase file allocation */
myDrive->appendCluster(firstCluster);
/* Try getting sector again */
currentSector = myDrive->getAbsoluteSectFromBytePos(firstCluster, seekpos);
if(currentSector == 0) {
/* No can do. lets give up and go home. We must be out of room */
goto finalizeWrite;
}
}
curSectOff = 0;
myDrive->loadedDisk->Read_AbsoluteSector(currentSector, sectorBuffer);
loadedSector = true;
}
}
sectorBuffer[curSectOff++] = data[sizecount++];
seekpos++;
if(curSectOff >= myDrive->getSectorSize()) {
if(loadedSector) myDrive->loadedDisk->Write_AbsoluteSector(currentSector, sectorBuffer);
currentSector = myDrive->getAbsoluteSectFromBytePos(firstCluster, seekpos);
if(currentSector == 0) {
/* EOC reached before EOF - try to increase file allocation */
myDrive->appendCluster(firstCluster);
/* Try getting sector again */
currentSector = myDrive->getAbsoluteSectFromBytePos(firstCluster, seekpos);
if(currentSector == 0) {
/* No can do. lets give up and go home. We must be out of room */
loadedSector = false;
goto finalizeWrite;
}
}
curSectOff = 0;
myDrive->loadedDisk->Read_AbsoluteSector(currentSector, sectorBuffer);
loadedSector = true;
}
--sizedec;
}
if(curSectOff>0 && loadedSector) myDrive->loadedDisk->Write_AbsoluteSector(currentSector, sectorBuffer);
finalizeWrite:
myDrive->directoryBrowse(dirCluster, &tmpentry, dirIndex);
tmpentry.entrysize = filelength;
tmpentry.loFirstClust = (Bit16u)firstCluster;
myDrive->directoryChange(dirCluster, &tmpentry, dirIndex);
*size =sizecount;
return true;
}
