/// <summary>
/// Initializes a new instance of the <see cref="VirtualFileSystem"/> class.
/// Create new file system.
/// </summary>
internal VirtualFileSystem([NotNull] IDirectDiskAccess diskAccess, ulong newVolumeSize)
{
Validate.ArgumentNotNull(diskAccess, "diskAccess");
_diskAccess = diskAccess;
_record = MasterRecord.CreateNewVolume(diskAccess, newVolumeSize);
_record.Save();
}
/// <summary>
/// Initializes a new instance of the <see cref="VirtualFileSystem"/> class.
/// Load existing file system.
/// </summary>
internal VirtualFileSystem([NotNull] IDirectDiskAccess diskAccess)
{
Validate.ArgumentNotNull(diskAccess, "diskAccess");
_diskAccess = diskAccess;
_record = new MasterRecord(diskAccess);
_record.Load();
}
private readonly MasterRecord _record; // todo: decouple as INodeStorage
#endregion Fields
#region Constructors
/// <summary>
/// Initializes a new instance of the <see cref="DirectoryNode"/> class.
/// </summary>
/// <param name="record">The master record.</param>
/// <param name="address">The directory node address.</param>
/// <param name="diskAccess">The disk access interface.</param>
private DirectoryNode([NotNull] MasterRecord record, [NotNull] Address address, [NotNull] IDirectDiskAccess diskAccess)
: base(record, diskAccess, address, record.GlobalBlocksStartAddress)
{
Validate.ArgumentNotNull(record, "record");
Validate.ArgumentNotNull(address, "address");
Validate.ArgumentNotNull(diskAccess, "diskAccess");
_record = record;
}
public static MasterRecord CreateNewVolume([NotNull] IDirectDiskAccess access, ulong size)
{
Validate.ArgumentNotNull(access, "access");
if (size % Constants.BlockSizeBytes != 0)
{
throw new ArgumentOutOfRangeException("Volume size should be on block size boundary.");
}
if (size <= BlockGroup.ReservedBlocks * Constants.BlockSizeBytes)
{
throw new ArgumentOutOfRangeException(string.Format("Min volume size is {0}", Constants.BlockSizeBytes * (BlockGroup.ReservedBlocks + 1)));
}
var totalBlocks = (uint)(size / Constants.BlockSizeBytes);
uint numberOfFullGroups = totalBlocks / Constants.BlocksPerGroup;
uint remainingBlocks = totalBlocks % Constants.BlocksPerGroup;
if (remainingBlocks > BlockGroup.ReservedBlocks)
{
numberOfFullGroups++;
}
var rec = new MasterRecord(access);
rec._groupsReserved = new BlockGroup[numberOfFullGroups];
var offset = new Address(32 + (BlockGroupDescriptor.RawSizeBytes * numberOfFullGroups));
offset = offset.AlignOnBlockBoundary;
uint totalFreeBlocks = 0;
for (uint i = 0; i < numberOfFullGroups; ++i)
{
bool last = (i == numberOfFullGroups - 1 && remainingBlocks > 0);
var groupSize = last ? remainingBlocks : Constants.BlocksPerGroup;
var newGroup = new BlockGroup(offset, groupSize);
offset = offset.AddBlocks(groupSize);
totalFreeBlocks += newGroup.Descriptor.NumFreeBlocksInGroup;
rec._groupsReserved[i] = newGroup;
}
rec._freeSpaceBlocks = totalFreeBlocks;
rec.VolumeSize = offset.Value;
rec.RootNode = rec.CreateDirectoryNode("\\", null);
return rec;
}
