profuse/Pascal/VolumeEntry.cpp

1016 lines
22 KiB
C++

#include <memory>
#include <algorithm>
#include <cerrno>
#include <Pascal/Pascal.h>
#include <ProFUSE/auto.h>
#include <ProFUSE/Exception.h>
#include <Endian/Endian.h>
#include <Endian/IOBuffer.h>
#include <Device/BlockDevice.h>
#include <Cache/BlockCache.h>
using namespace LittleEndian;
using namespace Pascal;
using namespace Device;
using ProFUSE::Exception;
using ProFUSE::ProDOSException;
using ProFUSE::POSIXException;
enum {
kMaxFiles = 77
};
// djb hash, case insensitive.
static unsigned NameHash(const char *cp)
{
unsigned hash = 5381;
unsigned c;
while ((c = *cp++))
{
c = std::toupper(c);
hash = ((hash << 5) + hash) + c;
}
return hash & 0x7FFFFFFF;
}
static bool NameEqual(const char *a, const char *b)
{
return ::strcasecmp(a, b) == 0;
}
unsigned VolumeEntry::ValidName(const char *cp)
{
// 7 chars max. Legal values: ascii, printable,
// no space/tab,
// no $=?,:
return Entry::ValidName(cp, 7);
}
VolumeEntry::VolumeEntry()
{
_fileNameLength = 0;
std::memset(_fileName, 0, 8);
_lastVolumeBlock = 0;
_fileCount = 0;
_accessTime = 0;
setInode(1);
_inodeGenerator = 1;
_cache = NULL;
_device = NULL;
}
VolumeEntry::VolumeEntry(const char *name, Device::BlockDevice *device)
{
#undef __METHOD__
#define __METHOD__ "VolumeEntry::VolumeEntry"
unsigned length;
unsigned deviceBlocks = device->blocks();
deviceBlocks = std::min(0xffffu, deviceBlocks);
if (deviceBlocks < 6)
throw Exception(__METHOD__ ": device too small.");
length = ValidName(name);
if (!length)
throw ProDOSException(__METHOD__ ": Invalid volume name.", ProFUSE::badPathSyntax);
_firstBlock = 0;
_lastBlock = 6;
_fileKind = kUntypedFile;
_inode = 1;
_inodeGenerator = 1;
_fileNameLength = length;
std::memset(_fileName, 0, sizeof(_fileName));
for (unsigned i = 0; i < _fileNameLength; ++i)
{
_fileName[i] = std::toupper(name[i]);
}
_lastVolumeBlock = deviceBlocks;
_fileCount = 0;
_accessTime = 0;
_lastBoot = Date::Today();
_cache = BlockCache::Create(device);
_device = device;
_address = 512 * 2;
for (unsigned i = 2; i < 6; ++i)
{
_cache->zeroBlock(i);
}
void *vp = _cache->acquire(2);
IOBuffer b(vp, 512);
writeDirectoryEntry(&b);
_cache->release(2, true);
_cache->sync();
}
VolumeEntry::VolumeEntry(Device::BlockDevice *device)
{
unsigned blockCount;
unsigned deviceBlocks = device->blocks();
ProFUSE::auto_array<uint8_t> buffer(new uint8_t[512]);
// read the header block, then load up all the header
// blocks.
_device = device;
_cache = BlockCache::Create(device);
_address = 512 * 2;
_cache->read(2, buffer.get());
init(buffer.get());
// todo -- verify reasonable values.
//printf("%u %u\n", blocks(), _lastBlock - _firstBlock);
blockCount = blocks();
if (blockCount > 1)
{
buffer.reset(readDirectoryHeader());
}
// now load up all the children.
// if this throws, memory could be lost...
try
{
std::vector<FileEntry *>::iterator iter;
unsigned block;
for (unsigned i = 1; i <= _fileCount; ++i)
{
std::auto_ptr<FileEntry> child;
//
child.reset(new FileEntry(buffer.get() + i * 0x1a));
child->setInode(++_inodeGenerator);
child->_parent = this;
child->_address = 512 * 2 + i * 0x1a;
_files.push_back(child.release());
}
// sanity check _firstBlock, _lastBlock?
block = _lastBlock;
for (iter = _files.begin(); iter != _files.end(); ++iter)
{
FileEntry *e = *iter;
bool error = false;
if (e->_firstBlock > e->_lastBlock)
error = true;
if (e->_firstBlock >= _lastVolumeBlock)
error = true;
if (e->_lastBlock > _lastVolumeBlock)
error = true;
if (e->_firstBlock < block)
error = true;
if (error)
throw ProDOSException(__METHOD__ ": Invalid file entry.", ProFUSE::dirError);
block = e->_lastBlock;
}
calcMaxFileSize();
}
catch (...)
{
std::vector<FileEntry *>::iterator iter;
for(iter = _files.begin(); iter != _files.end(); ++iter)
{
if (*iter) delete *iter;
}
throw;
}
}
VolumeEntry::~VolumeEntry()
{
std::vector<FileEntry *>::iterator iter;
for(iter = _files.begin(); iter != _files.end(); ++iter)
{
if (*iter) delete *iter;
}
delete _cache;
// _device is deleted by _cache.
//delete _device;
}
void VolumeEntry::init(void *vp)
{
#undef __METHOD__
#define __METHOD__ "VolumeEntry::init"
Entry::init(vp);
_fileNameLength = Read8(vp, 6);
// verify filenamelength <= 7
if (_fileNameLength > 7)
throw new ProDOSException(__METHOD__ ": invalid name length", ProFUSE::badPathSyntax);
// verify fileKind == 0
// verify _fileCount reasonable
// verify _lastVolumeBlock reasonable
// verify _blocks reasonable.
std::memcpy(_fileName, 7 + (uint8_t *)vp, _fileNameLength);
_lastVolumeBlock = Read16(vp, 0x0e);
_fileCount = Read16(vp, 0x10);
_accessTime = Read16(vp, 0x12);
_lastBoot = Date(Read16(vp, 0x14));
setInode(1);
_inodeGenerator = 1;
}
FileEntry *VolumeEntry::fileAtIndex(unsigned i) const
{
return i < _files.size() ? _files[i] : NULL;
}
FileEntry *VolumeEntry::fileByName(const char *name) const
{
std::vector<FileEntry *>::const_iterator iter;
for(iter = _files.begin(); iter != _files.end(); ++iter)
{
FileEntry *e = *iter;
if (::strcasecmp(name, e->name()) == 0) return e;
}
return NULL;
}
/*
* Remove a file.
* Returns 0 on succes, -1 (and errno) on failure.
* May also throw a device error.
*/
int VolumeEntry::unlink(const char *name)
{
unsigned index;
std::vector<FileEntry *>::iterator iter;
if (_device->readOnly())
{
errno = EROFS;
return -1;
}
// TODO -- consider having an unordered_map of file names.
for (iter = _files.begin(); iter != _files.end(); ++iter)
{
FileEntry *e = *iter;
if (::strcasecmp(name, e->name()) == 0)
{
// if not the first entry, update the previous entry's
// _maxFileSize.
if (iter != _files.begin())
{
FileEntry *prev = iter[-1];
prev->_maxFileSize += e->_maxFileSize;
}
delete e;
*iter = NULL;
break;
}
}
if (iter == _files.end())
{
errno = ENOENT;
return -1;
}
_files.erase(iter);
_fileCount--;
index = distance(_files.begin(), iter);
// reset addresses.
for ( ; iter != _files.end(); ++iter)
{
FileEntry *e = *iter;
e->_address -= 0x1a;
}
// need to update the header blocks.
ProFUSE::auto_array<uint8_t> buffer(readDirectoryHeader());
// update the filecount.
IOBuffer b(buffer.get(), 512 * blocks());
writeDirectoryEntry(&b);
// move up all the entries.
uint8_t *address = buffer.get() + 0x1a + 0x1a * index;
std::memmove(address, address + 0x1a, 0x1a * (_fileCount - index));
// zero out the memory on the previous entry.
std::memset(buffer.get() + 0x1a + _fileCount * 0x1a, 0, 0x1a);
// now write to disk.
writeDirectoryHeader(buffer.get());
_cache->sync();
return 0;
}
/*
* Renames a file, removing any other file with newName (if present)
* Returns 0 on success, -1 on error (and sets errno)
* May also throw an error of some sort.
*/
int VolumeEntry::rename(const char *oldName, const char *newName)
{
FileEntry *e;
// check if read only.
if (_device->readOnly())
{
errno = EROFS;
return -1;
}
// verify file exists.
e = fileByName(oldName);
if (!e)
{
errno = ENOENT;
return -1;
}
// verify new name is valid.
if (!FileEntry::ValidName(newName))
{
errno = EINVAL; // invalid name, at least.
return -1;
}
// delete the new file
if (unlink(newName) != 0)
{
if (errno != ENOENT) return -1;
}
// update with the new name.
e->setName(newName);
// and commit to disk.
writeEntry(e);
_cache->sync();
return 0;
}
/*
* copy a file (here to simplify copying text files).
* if newName exists, delete it.
*
*/
int VolumeEntry::copy(const char *oldName, const char *newName)
{
FileEntry *oldEntry;
FileEntry *newEntry;
// check if read only.
if (_device->readOnly())
{
errno = EROFS;
return -1;
}
// verify file exists.
oldEntry = fileByName(oldName);
if (!oldEntry)
{
errno = ENOENT;
return -1;
}
// verify new name is valid.
if (!FileEntry::ValidName(newName))
{
errno = EINVAL; // invalid name, at least.
return -1;
}
// if newName does not exist, call create w/ block size and write everything.
// if newName does exist, overwrite it if it will fit. Otherwise, remove it, create a file, etc.
unsigned blocks = oldEntry->blocks();
newEntry = fileByName(newName);
if (newEntry)
{
// if newEntry is large enough, overwrite it.
if (newEntry->_maxFileSize >= blocks * 512)
{
if (newEntry->_pageSize)
{
delete newEntry->_pageSize;
newEntry->_pageSize = NULL;
newEntry->_fileSize = 0;
}
}
else
{
if (maxContiguousBlocks() < blocks)
{
errno = ENOSPC;
return -1;
}
newEntry = NULL;
if (unlink(newName) != 0) return -1;
}
}
if (newEntry == NULL)
{
// newName does not exist (or was just deleted), so create a new file (if possible) and write to it.
if (maxContiguousBlocks() < blocks)
{
errno = ENOSPC;
return -1;
}
newEntry = create(newName, blocks);
if (!newEntry) return -1; // create() sets errno.
}
newEntry->_fileKind = oldEntry->fileKind();
newEntry->_lastByte = oldEntry->lastByte();
newEntry->_lastBlock = newEntry->firstBlock() + blocks;
newEntry->_modification = Date::Today();
for (unsigned i = 0; i < blocks; i++)
{
void *src = loadBlock(oldEntry->firstBlock() + i);
_cache->write(newEntry->firstBlock() + i, src);
unloadBlock(oldEntry->firstBlock() + i, false);
}
_cache->sync();
return 0;
}
/*
* create a file. if blocks is defined, verifies the file could
* expand to fit.
* returns FileEntry on success, NULL (and errno) on failure.
*
*/
/*
* TODO -- if blocks is defined, try to fit in a gap rather than putting at the end.
*
*
*
*/
FileEntry *VolumeEntry::create(const char *name, unsigned blocks)
{
// 0. check read only access.
// 1. verify < 77 file names.
// 2. verify space at end of disk.
// 3. make sure it's a legal file name.
// 4. verify it's not a duplicate file name.
// 6. create the file entry.
// 7. insert into _files, write to disk, update _maxFileSize
unsigned lastBlock = _lastBlock;
std::auto_ptr<FileEntry>entry;
FileEntry *prev = NULL;
FileEntry *curr = NULL;
std::vector<FileEntry *>::iterator iter;
if (readOnly())
{
errno = EROFS;
return NULL;
}
if (_fileCount == kMaxFiles)
{
errno = ENOSPC;
return NULL;
}
if (!FileEntry::ValidName(name))
{
errno = EINVAL;
return NULL;
}
if (fileByName(name))
{
errno = EEXIST;
return NULL;
}
entry.reset(new FileEntry(name, kUntypedFile));
std::auto_ptr<uint8_t> buffer(readDirectoryHeader());
for (iter = _files.begin(); iter != _files.end(); ++iter)
{
FileEntry *e = *iter;
unsigned freeSpace = e->_firstBlock - _lastBlock;
// this could do something stupid like selecting a slot with only 1 free block but too bad.
if (freeSpace < blocks)
{
lastBlock = e->_lastBlock;
prev = e;
continue;
}
// update previous entry max file size.
if (prev)
{
prev->_maxFileSize = prev->blocks() * 512;
}
// insert() inserts an item *before* the current item and returns an iterator to the
// element inserted.
// afterwards, iter will point to curr+1
// keep track of the index *before* the insert.
unsigned index = distance(_files.begin(), iter); // current index.
iter = _files.insert(iter, entry.get());
++_fileCount;
curr = entry.release();
curr->_parent = this;
curr->_firstBlock = lastBlock;
curr->_lastBlock = lastBlock + 1;
curr->_lastByte = 0;
curr->_maxFileSize = freeSpace * 512;
//curr->_address = 2 * 512 + 0x1a + 0x1a * index;
// move all entries after this one up by 0x1a bytes, then write this header.
unsigned count = _fileCount - index - 1;
unsigned offset = index * 0x1a + 0x1a;
std::memmove(buffer.get() + offset + 0x1a, buffer.get() + offset, count * 0x1a);
break;
}
if (iter == _files.end())
{
// check if we can append
unsigned freeSpace = _lastVolumeBlock - lastBlock;
if (freeSpace < blocks)
{
errno = ENOSPC;
return NULL;
}
_files.push_back(entry.get());
_fileCount++;
curr = entry.release();
curr->_parent = this;
curr->_firstBlock = lastBlock;
curr->_lastBlock = lastBlock + 1;
curr->_lastByte = 0;
curr->_maxFileSize = freeSpace * 512;
curr->_address = 2 * 512 + 0x1a * _fileCount; // s/b +1 since entry 0 is the header.
if (prev)
{
prev->_maxFileSize = prev->blocks() * 512;
}
writeEntry(curr);
writeEntry(); // header.
}
else
{
// update all addresses to make life easier.
unsigned address = 2 * 512 + 0x1a;
for (iter = _files.begin(); iter != _files.end(); ++iter, address += 0x1a)
{
FileEntry *e = *iter;
e->_address = address;
}
IOBuffer b(buffer.get(), 4 * 512);
writeDirectoryEntry(&b);
b.setOffset(curr->_address - 2 * 512);
curr->writeDirectoryEntry(&b);
writeDirectoryHeader(buffer.get());
}
_cache->sync();
return curr;
}
/*
* TODO -- consider trying to move files from the end to fill gaps
* if it would reduce the number of blocks that need to be re-arranged.
*
* build a list of gaps, reverse iterate and move last file to first gap
* only 77 files, so can consider all options.
*
*
*
*
*
*/
int VolumeEntry::krunch()
{
unsigned prevBlock;
std::vector<FileEntry *>::const_iterator iter;
bool gap = false;
// sanity check to make sure no weird overlap issues.
prevBlock = lastBlock();
for (iter = _files.begin(); iter != _files.end(); ++iter)
{
FileEntry *e = *iter;
unsigned first = e->firstBlock();
unsigned last = e->lastBlock();
if (first != prevBlock) gap = true;
if (first < prevBlock)
return ProFUSE::damagedBitMap;
if (last < first)
return ProFUSE::damagedBitMap;
if (first < volumeBlocks())
return ProFUSE::damagedBitMap;
prevBlock = last;
}
if (!gap) return 0;
// need to update the header blocks.
ProFUSE::auto_array<uint8_t> buffer(readDirectoryHeader());
IOBuffer b(buffer.get(), 512 * blocks());
prevBlock = lastBlock();
unsigned offset = 0;
for (iter = _files.begin(); iter != _files.end(); ++iter, ++offset)
{
FileEntry *e = *iter;
b.setOffset(0x1a + 0x1a * offset);
unsigned first = e->firstBlock();
unsigned last = e->lastBlock();
unsigned blocks = last - first;
unsigned offset = first - prevBlock;
if (offset == 0)
{
prevBlock = last;
continue;
}
e->_firstBlock = first - offset;
e->_lastBlock = last - offset;
e->writeDirectoryEntry(&b);
for (unsigned i = 0; i < blocks; ++i)
{
uint8_t buffer[512];
_cache->read(first + i, buffer);
_cache->write(prevBlock +i, buffer);
_cache->zeroBlock(first + i);
}
}
// now save the directory entries.
// load up the directory blocks.
writeDirectoryHeader(buffer.get());
_cache->sync();
calcMaxFileSize();
return 0;
}
/*
* return the number of free blocks.
* if krunched is true, returns sum of all free blocks
* if krunched is false, returns free blocks at end.
*
*/
unsigned VolumeEntry::freeBlocks(bool krunched) const
{
unsigned freeBlocks = 0;
unsigned lastBlock = 0;
if (krunched)
{
std::vector<FileEntry *>::const_iterator iter;
lastBlock = _lastBlock;
for (iter = _files.begin(); iter != _files.end(); ++iter)
{
const FileEntry *e = *iter;
freeBlocks += e->_firstBlock - lastBlock;
lastBlock = e->_lastBlock;
}
}
else
{
lastBlock = _fileCount ? _files.back()->_lastBlock : _lastBlock;
}
freeBlocks += _lastVolumeBlock - lastBlock;
return freeBlocks;
}
/*
* return true if there are any gaps, false otherwise.
*
*
*/
bool VolumeEntry::canKrunch() const
{
std::vector<FileEntry *>::const_iterator iter;
unsigned lastBlock = _lastBlock;
for (iter = _files.begin(); iter != _files.end(); ++iter)
{
const FileEntry *e = *iter;
if (e->_lastBlock != lastBlock) return true;
lastBlock = e->_lastBlock;
}
return false;
}
/*
* returns the largest free block.
*
*/
unsigned VolumeEntry::maxContiguousBlocks() const
{
unsigned max = 0;
std::vector<FileEntry *>::const_iterator iter;
unsigned lastBlock = _lastBlock;
for (iter = _files.begin(); iter != _files.end(); ++iter)
{
const FileEntry *e = *iter;
unsigned free = e->_firstBlock - lastBlock;
max = std::max(max, free);
lastBlock = e->_lastBlock;
}
max = std::max(max, _lastVolumeBlock - lastBlock);
return max;
}
void *VolumeEntry::loadBlock(unsigned block)
{
return _cache->acquire(block);
}
void VolumeEntry::unloadBlock(unsigned block, bool dirty)
{
return _cache->release(block, dirty);
}
void VolumeEntry::readBlock(unsigned block, void *buffer)
{
_cache->read(block, buffer);
}
void VolumeEntry::writeBlock(unsigned block, void *buffer)
{
_cache->write(block, buffer);
}
void VolumeEntry::sync()
{
_cache->sync();
}
void VolumeEntry::writeDirectoryEntry(IOBuffer *b)
{
Entry::writeDirectoryEntry(b);
b->write8(0); // reserved
b->write8(_fileNameLength);
b->writeBytes(_fileName, 7);
b->write16(_lastVolumeBlock);
b->write16(_fileCount);
b->write16(_accessTime);
b->write16(_lastBoot);
// rest is reserved.
b->writeZero(4);
}
uint8_t *VolumeEntry::readDirectoryHeader()
{
return readBlocks(2, blocks());
}
void VolumeEntry::writeDirectoryHeader(void *buffer)
{
writeBlocks(buffer, 2, blocks());
}
uint8_t *VolumeEntry::readBlocks(unsigned startingBlock, unsigned count)
{
ProFUSE::auto_array<uint8_t> buffer(new uint8_t[512 * count]);
for (unsigned i = 0; i < count; ++i)
_cache->read(startingBlock + i, buffer.get() + 512 * i);
return buffer.release();
}
void VolumeEntry::writeBlocks(void *buffer, unsigned startingBlock, unsigned count)
{
for (unsigned i = 0; i < count; ++i)
_cache->write(startingBlock + i, (uint8_t *)buffer + 512 * i);
}
// write directory entry, does not sync.
void VolumeEntry::writeEntry()
{
IOBuffer iob(loadBlock(2),512);
writeDirectoryEntry(&iob);
unloadBlock(2, true);
}
// does not sync.
void VolumeEntry::writeEntry(FileEntry *e)
{
unsigned address = e->_address;
unsigned startBlock = address / 512;
unsigned endBlock = (address + 0x1a - 1) / 512;
unsigned offset = address % 512;
if (startBlock == endBlock)
{
void *buffer = _cache->acquire(startBlock);
IOBuffer b((uint8_t *)buffer + offset, 0x1a);
e->writeDirectoryEntry(&b);
_cache->release(startBlock, true);
}
else
{
// crosses page boundaries.
ProFUSE::auto_array<uint8_t> buffer(readBlocks(startBlock, 2));
IOBuffer b(buffer.get() + offset, 0x1a);
e->writeDirectoryEntry(&b);
writeBlocks(buffer.get(), startBlock, 2);
}
}
// set _maxFileSize for all entries.
void VolumeEntry::calcMaxFileSize()
{
std::vector<FileEntry *>::reverse_iterator riter;
unsigned block = _lastVolumeBlock;
for (riter = _files.rbegin(); riter != _files.rend(); ++riter)
{
FileEntry *e = *riter;
e->_maxFileSize = (block - e->_firstBlock) * 512;
block = e->_firstBlock;
}
}