uint64_t mfso::vseek(int32_t fd, uint64_t offset, int32_t whence)
{
fdinfo* fi;
FileMapping* fm;
try
{
fi = this->__fdmanager->get(fd);
fm = this->mapFile(fi->node);
if (fm == NULL)
throw std::string("can't allocate fm");
if (whence == 0)
{
if (offset > fm->maxOffset())
{
fm->delref();
return ((uint64_t)-1);
}
else
fi->offset = offset;
}
else if (whence == 1)
{
if ((fi->offset + offset) > fm->maxOffset())
{
fm->delref();
return ((uint64_t)-1);
}
else
fi->offset += offset;
}
else if (whence == 2)
fi->offset = fm->maxOffset();
fm->delref();
return (fi->offset);
}
catch(...)
{
std::cout << "problem while getting fd information" << std::endl;
}
if (fm != NULL)
fm->delref();
return ((uint64_t)-1);
}
int32_t mfso::vread(int32_t fd, void *buff, uint32_t size)
{
fdinfo* fi;
uint64_t realsize;
int32_t bytesread;
FileMapping* fm = NULL;
try
{
fi = this->__fdmanager->get(fd);
if (fi->node != NULL)
fm = this->mapFile(fi->node);
if (fm != NULL)
{
uint64_t fileSize = fm->maxOffset();
if (fi->node->size() <= fileSize)
{
if (size <= (fi->node->size() - fi->offset))
realsize = size;
else
realsize = fi->node->size() - fi->offset;
}
else
{
if (size <= (fileSize - fi->offset))
realsize = size;
else
realsize = fileSize - fi->offset;
}
bytesread = this->readFromMapping(fm, fi, buff, realsize);
fm->delref();
return bytesread;
}
else
{
return (0);
}
}
catch(...)
{
//throw(vfsError("problem while reading file"));
}
if (fm)
fm->delref();
return (0);
}
