public int[] GetNextFreeSectors(int count)
{
// find count available free sectors on the disk and return their addresses
if (count <= 0)
{
throw new Exception("Hey! No Negative!");
}
int[] result = new int[count];
// Itterate over all sectors, starting at the beginning, until we find count FREE_SECTORS
int found = 0;
for (int lba = 0; found < count && lba < disk.SectorCount; lba++)
{
//byte[] bytes = disk.ReadSector(lba);
if (SECTOR.GetTypeFromBytes(disk.ReadSector(lba)) == SECTOR.SectorType.FREE_SECTOR)
{
result[found++] = lba;
}
}
// If we didn't find enough free sectors, just return null
if (found < count)
{
return(null);
}
return(result);
}
public int[] GetNextFreeSectors(int count)
{
// find count available free sectors on the disk and return their addresses
//if not enough free sectors found throw exception
int[] result = new int[count];
count--;
for (int lba = 0; lba < disk.SectorCount && count >= 0; lba++)
{
byte[] raw = disk.ReadSector(lba);
if (SECTOR.GetTypeFromBytes(raw) == SECTOR.SectorType.FREE_SECTOR)
{
result[count] = lba;
count--;
}
}
if (count >= 0)
{
throw new Exception("can't find enough free sectors");
}
return(result);
}
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);
}
static bool TestSector(DiskDriver disk, int lba, byte[] testdata)
{
disk.WriteSector(lba, testdata);
byte[] s = disk.ReadSector(lba);
bool success = Compare(testdata, s);
Console.WriteLine("Compare " + success.ToString());
return(success);
}
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 void Mount(DiskDriver disk, string mountPoint)
{
if (mDrives.Count == 0 && mountPoint.Length != 1 && mountPoint[0] != '/')
{
throw new Exception("First disk must be mounted at the root");
}
//add virtual drive
DRIVE_INFO driveInfo = DRIVE_INFO.CreateFromBytes(disk.ReadSector(Constants.DRIVE_INFO_SECTOR));
VirtualDrive newDrive = new VirtualDrive(disk, Constants.DRIVE_INFO_SECTOR, driveInfo);
mDrives.Add(mountPoint, newDrive);
//add root dir, make node, add it
int rootNodeAt = driveInfo.RootNodeAt;
DIR_NODE newDriveRootDir = DIR_NODE.CreateFromBytes(disk.ReadSector(rootNodeAt));
VirtualNode virtualNode = new VirtualNode(newDrive, rootNodeAt, newDriveRootDir, null);
if (mDrives.Count == 1)
{
mRootNode = virtualNode;
}
}
public int[] GetNextFreeSectors(int count)
{
// find count available free sectors on the disk and return their addresses
int[] result = new int[count];
int foundIndex = 0;
for (int address = 0; address < disk.SectorCount && foundIndex < count; address++)
{
byte[] raw = disk.ReadSector(address);
if (SECTOR.GetTypeFromBytes(raw) == SECTOR.SectorType.FREE_SECTOR)
{
result[foundIndex++] = address;
}
}
return(result);
}
public int[] GetNextFreeSectors(int count)
{
//array for our free sectors...
int[] freeSectors = new int[count];
//search fof free sectors...
for (int i = 0; i < mDisk.SectorCount; i++)
{
byte[] raw = mDisk.ReadSector(i);
if (SECTOR.GetTypeFromBytes(raw) == SECTOR.SectorType.FREE_SECTOR)
{
//add the free sector
freeSectors[--count] = i;
//enough?
if (count <= 0)
{
return(freeSectors);
}
}
}
throw new Exception("Disk is full!");
}
