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); }