public void Format(DiskDriver disk)
{
// wipe all sectors of disk and create minimum required DRIVE_INFO, DIR_NODE and DATA_SECTOR
FREE_SECTOR free = new FREE_SECTOR(disk.BytesPerSector);
for (int i = 0; i < disk.SectorCount; i++)
{
disk.WriteSector(i, free.RawBytes);
}
// DRIVE_INFO
DRIVE_INFO drive = new DRIVE_INFO(disk.BytesPerSector, ROOT_DIR_SECTOR);
disk.WriteSector(DRIVE_INFO_SECTOR, drive.RawBytes);
// DIR_NODE for root node
DIR_NODE rootDir = new DIR_NODE(disk.BytesPerSector, ROOT_DATA_SECTOR, FSConstants.PATH_SEPARATOR.ToString(), 0);
disk.WriteSector(ROOT_DIR_SECTOR, rootDir.RawBytes);
// DATA_SECTOR for root node
DATA_SECTOR data = new DATA_SECTOR(disk.BytesPerSector, 0, new byte[] { 0 });
disk.WriteSector(ROOT_DATA_SECTOR, data.RawBytes);
}
public void Format(DiskDriver disk)
{
// wipe all sectors of disk and create minimum required DRIVE_INFO, DIR_NODE and DATA_SECTOR
// Wipe all sectors (replace with "zeroes" are FREE_SECTOR)
int bps = disk.BytesPerSector;
FREE_SECTOR free = new FREE_SECTOR(bps);
for (int i = 0; i < disk.SectorCount; i++)
{
disk.WriteSector(i, free.RawBytes);
}
// Create DRIVE_INFO
DRIVE_INFO di = new DRIVE_INFO(bps, ROOT_DIR_SECTOR);
disk.WriteSector(DRIVE_INFO_SECTOR, di.RawBytes);
// Create and write the DIR_NODE for the root node...
DIR_NODE dn = new DIR_NODE(bps, ROOT_DATA_SECTOR, FSConstants.ROOT_DIR_NAME, 0);
disk.WriteSector(ROOT_DIR_SECTOR, dn.RawBytes);
// ... and an empty DATA_SECTOR
DATA_SECTOR ds = new DATA_SECTOR(bps, 0, null); // 0 = no next data sector, nul = empty set
disk.WriteSector(ROOT_DATA_SECTOR, ds.RawBytes);
}
public void Format(DiskDriver disk)
{
// wipe all sectors of disk and create minimum required DRIVE_INFO, DIR_NODE and DATA_SECTOR
//how many sectors
int numSectors = disk.SectorCount;
FREE_SECTOR freeSector = new FREE_SECTOR(disk.BytesPerSector);
for (int lba = 0; lba < numSectors; lba++)
{
disk.WriteSector(lba, freeSector.RawBytes);
}
DRIVE_INFO diSector1 = new DRIVE_INFO(disk.BytesPerSector, ROOT_DIR_SECTOR);
disk.WriteSector(0, diSector1.RawBytes);
DIR_NODE rootDirSector = new DIR_NODE(disk.BytesPerSector, ROOT_DATA_SECTOR, FSConstants.ROOT_DIR_NAME, 0);
disk.WriteSector(ROOT_DIR_SECTOR, rootDirSector.RawBytes);
DATA_SECTOR rootDataSector = new DATA_SECTOR(disk.BytesPerSector, 0, new byte[DATA_SECTOR.MaxDataLength(disk.BytesPerSector)]);
disk.WriteSector(ROOT_DATA_SECTOR, rootDataSector.RawBytes);
}
public VirtualNode CreateDirectoryNode(string name)
{
LoadChildren(); //insure child cached is full
if (children.ContainsKey(name))
{
throw new Exception("Another child with that name already exists");
}
//where do we store new dir? which sector?
//find 2 free sectors
int[] sectors = drive.GetNextFreeSectors(2);
int newDirectoryNodeSectorAt = sectors[0];
int newDirDataSectorAt = sectors[1];
//creat new dir on disk
DIR_NODE newDirNodeSector = new DIR_NODE(drive.Disk.BytesPerSector, newDirDataSectorAt, name, 0);
drive.Disk.WriteSector(newDirectoryNodeSectorAt, newDirNodeSector.RawBytes);
//creat a data sector for dir
DATA_SECTOR newDirDataSector = new DATA_SECTOR(drive.Disk.BytesPerSector, 0, null);
drive.Disk.WriteSector(newDirDataSectorAt, newDirDataSector.RawBytes);
//creat virtual node
VirtualNode newDirectory = new VirtualNode(drive, newDirectoryNodeSectorAt, newDirNodeSector, this);
//add dir to parent
children.Add(name, newDirectory);
CommitChildren();
return(newDirectory);
}
public static NODE CreateFromBytes(byte[] raw)
{
switch (GetTypeFromBytes(raw))
{
case SectorType.DIR_NODE:
return(DIR_NODE.CreateFromBytes(raw));
case SectorType.FILE_NODE:
return(FILE_NODE.CreateFromBytes(raw));
}
throw new Exception("Expected a DIR_NODE or FILE_NODE!");
}
private void LoadChildren()
{
// Ensure that the children cache is correctly put in memory (i.e. reflects what's on the disk)
// Assume if the cache exsists, it is correct at the moment
// So, we need to call CommitChildren()
if (children == null)
{
// Create the cache itself
children = new Dictionary <string, VirtualNode>();
// Read the list of children for this directory from disk
// Instantiate a VirtualNode for each [child?] and add them to the children cache.
// Read the data sector for this directory
DATA_SECTOR dataSector = DATA_SECTOR.CreateFromBytes(drive.Disk.ReadSector(sector.FirstDataAt));
// Extract the list of children from the sata sector
byte[] rawList = dataSector.DataBytes;
// Foreach child in the list...
for (int i = 0; i < ChildCount; i++)
{
// Getthe child's sector address
int childSectorAt = BitConverter.ToInt32(rawList, i * 4);
// Read its sector from disk
// Check if it's a file or directory
byte[] childNodeBytes = drive.Disk.ReadSector(childSectorAt);
NODE childSector;
if (SECTOR.GetTypeFromBytes(childNodeBytes) == SECTOR.SectorType.DIR_NODE)
{
childSector = DIR_NODE.CreateFromBytes(drive.Disk.ReadSector(childSectorAt));
}
else if (SECTOR.GetTypeFromBytes(childNodeBytes) == SECTOR.SectorType.FILE_NODE)
{
childSector = FILE_NODE.CreateFromBytes(drive.Disk.ReadSector(childSectorAt));
}
else
{
throw new Exception("Unexpected sector type whe reading directory's children!");
}
// Construct a VirtualNode
VirtualNode childNode = new VirtualNode(drive, childSectorAt, childSector, this);
// Add the VirtualNode to the children cache
children.Add(childNode.Name, childNode);
}
}
}
public void Mount(DiskDriver disk, string mountPoint)
{
// for the first mounted drive, expect mountPoint to be named FSConstants.PATH_SEPARATOR as the root
if (drives.Count == 0 && mountPoint != FSConstants.PATH_SEPARATOR.ToString())
{
throw new Exception("Expected first mounted dist to be at root directory!");
}
// read drive info from disk, load root node and connect to mountPoint
DRIVE_INFO driveInfo = DRIVE_INFO.CreateFromBytes(disk.ReadSector(DRIVE_INFO_SECTOR));
VirtualDrive drive = new VirtualDrive(disk, DRIVE_INFO_SECTOR, driveInfo);
DIR_NODE rootSector = DIR_NODE.CreateFromBytes(disk.ReadSector(ROOT_DIR_SECTOR));
rootNode = new VirtualNode(drive, ROOT_DIR_SECTOR, rootSector, null);
drives.Add(mountPoint, drive);
}
public void Mount(DiskDriver disk, string mountPoint)
{
// read drive info from disk, load root node and connect to mountPoint
// for the first mounted drive, expect mountPoint to be named FSConstants.ROOT_DIR_NAME as the root
//read drive info for disk to determin what sector contains its root node
DRIVE_INFO diSector = DRIVE_INFO.CreateFromBytes(disk.ReadSector(DRIVE_INFO_SECTOR));
int rootNodeAt = diSector.RootNodeAt;
VirtualDrive drive = new VirtualDrive(disk, DRIVE_INFO_SECTOR, diSector);
DIR_NODE rootNodeSector = DIR_NODE.CreateFromBytes(disk.ReadSector(rootNodeAt));
if (rootNode == null)
{
rootNode = new VirtualNode(drive, rootNodeAt, rootNodeSector, null);
}
drives.Add(mountPoint, drive);
}
public void Mount(DiskDriver disk, string mountPoint)
{
// read drive info from disk, load root node and connect to mountPoint
// for the first mounted drive, expect mountPoint to be named "/", FSConstants.ROOT_DIR_NAME, as the root
try
{
// Step 1: Read infor from the disk to understand it's directory structure
// Read DRIVE_INFO from FRIVE_INFO_SECTOR
DRIVE_INFO di = DRIVE_INFO.CreateFromBytes(disk.ReadSector(DRIVE_INFO_SECTOR));
DIR_NODE dn = DIR_NODE.CreateFromBytes(disk.ReadSector(di.RootNodeAt));
DATA_SECTOR ds = DATA_SECTOR.CreateFromBytes(disk.ReadSector(dn.FirstDataAt));
// Step 2: Join th new disk into the virtual file system structure, at the mount point.
// Create a VistualDrive for the disk
VirtualDrive vd = new VirtualDrive(disk, DRIVE_INFO_SECTOR, di);
if (rootNode == null)
{
// Create a VirtualNode to represent the root dictionaru, at the mount point.
// Set the VFS's root node, if this is the first disk to be mounted.
rootNode = new VirtualNode(vd, di.RootNodeAt, dn, null);
}
else
{
// TODO: Extra Credit: Handle 2nd dick mounted to exsisting VFS
// Create a virtual node for this new disk's root
// "join" the new node to the exsisting node structure at the mount point
}
// Add a new VirtualDrive to drives dictionary, using te mountPoint as the key
drives.Add(mountPoint, vd);
}
catch (Exception ex)
{
throw new Exception("Failed to mount disk");
}
}
public VirtualNode CreateDirectoryNode(string name)
{
// Only create children if we're a directory
if (!IsDirectory)
{
throw new Exception("Must be a directory to create children!");
}
// read current list of children
LoadChildren();
// allocate a new DIR_NODE and DATA_SECTOR on the disk
// Find the first two FREE_SECTORs on the disk
int[] freeSectors = drive.GetNextFreeSectors(2);
//DIR_NODE
DIR_NODE dirSector = new DIR_NODE(drive.Disk.BytesPerSector, freeSectors[1], name, 0);
drive.Disk.WriteSector(freeSectors[0], dirSector.RawBytes);
//DATA_SECTOR
DATA_SECTOR dataSector = new DATA_SECTOR(drive.Disk.BytesPerSector, 0, new byte[] { 0 });
drive.Disk.WriteSector(freeSectors[1], dataSector.RawBytes);
// Create a new virtual node
VirtualNode newNode = new VirtualNode(drive, freeSectors[0], dirSector, this);
// Add it to its parent
children.Add(name, newNode);
CommitChildren();
// Return new node
return(newNode);
}