profuse/Device/DavexDiskImage.cpp

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#include <cerrno>
#include <cstdlib>
#include <cstring>
#include <unistd.h>
#include <fcntl.h>
#include <cstdio>
#include <algorithm>
#include <Device/DavexDiskImage.h>
#include <File/MappedFile.h>
#include <Device/Adaptor.h>
#include <Endian/Endian.h>
#include <Endian/IOBuffer.h>
#include <Cache/MappedBlockCache.h>
using namespace Device;
using namespace LittleEndian;
using ProFUSE::Exception;
using ProFUSE::POSIXException;
/*
http://www.umich.edu/~archive/apple2/technotes/ftn/FTN.E0.8004
*/
static const char *IdentityCheck = "\x60VSTORE [Davex]\x00";
// private, validation already performed.
DavexDiskImage::DavexDiskImage(MappedFile *file) :
DiskImage(file)
{
// at this point, file is no longer valid.
// 512-bytes header
setBlocks((length() / 512) - 1);
setAdaptor(new POAdaptor(512 + (uint8_t *)address()));
}
DavexDiskImage::~DavexDiskImage()
{
// scan and update usedBlocks?
}
void DavexDiskImage::Validate(MappedFile *f)
{
#undef __METHOD__
#define __METHOD__ "DavexDiskImage::Validate"
size_t size = f->length();
const void * data = f->address();
bool ok = false;
unsigned blocks = (size / 512) - 1;
do {
if (size < 512) break;
if (size % 512) break;
// identity.
if (std::memcmp(data, IdentityCheck, 16))
break;
// file format.
if (Read8(data, 0x10) != 0)
break;
// total blocks
if (Read32(data, 33) != blocks)
break;
// file number -- must be 1
if (Read8(data, 64) != 1)
break;
ok = true;
} while (false);
if (!ok)
throw Exception(__METHOD__ ": Invalid file format.");
}
DavexDiskImage *DavexDiskImage::Open(MappedFile *file)
{
#undef __METHOD__
#define __METHOD__ "DavexDiskImage::Open"
Validate(file);
return new DavexDiskImage(file);
}
DavexDiskImage *DavexDiskImage::Create(const char *name, size_t blocks)
{
return Create(name, blocks, "Untitled");
}
DavexDiskImage *DavexDiskImage::Create(const char *name, size_t blocks, const char *vname)
{
#undef __METHOD__
#define __METHOD__ "DavexDiskImage::Create"
uint8_t *data;
uint8_t tmp[512];
IOBuffer header(tmp,512);
MappedFile *file = MappedFile::Create(name, blocks * 512 + 512);
data = (uint8_t *)file->address();
header.writeBytes(IdentityCheck, 16);
// file Format
header.write8(0);
//version
header.write8(0);
// version
header.write8(0x10);
// reserved.
header.setOffset(32, true);
//deviceNum
header.write8(1);
// total blocks
header.write32(blocks);
// unused blocks
header.write32(0);
// volume Name
if (!vname || !*vname) vname = "Untitled";
unsigned l = std::strlen(vname);
header.write8(std::min(l, 15u));
header.writeBytes(vname, std::min(l, 15u));
// name + reserved.
header.setOffset(64, true);
// file number
header.write8(1);
//starting block
header.write32(0);
// reserved
header.setOffset(512, true);
std::memcpy(file->address(), header.buffer(), 512);
file->sync();
return new DavexDiskImage(file);
}
BlockCache *DavexDiskImage::createBlockCache()
{
return new MappedBlockCache(this, 512 + (uint8_t *)address());
}