public void SetSizeInBlocks(int count)
{
if (count < 0)
{
throw new ArgumentOutOfRangeException(nameof(count));
}
var currentBlockCount = provider.UsedEntryCount;
if (count == currentBlockCount)
{
return;
}
if (count > currentBlockCount)
{
provider.SetSizeInBlocks(count / provider.BlockSize + (count % provider.BlockSize == 0 ? 0 : 1));
var allocateBlockCount = count - currentBlockCount;
var blocks = accessParameters.AllocationManager.Allocate(allocateBlockCount);
indexBlockStream.Write(currentBlockCount, blocks);
}
else
{
var releaseBlockCount = currentBlockCount - count;
var blocks = new int[releaseBlockCount];
indexBlockStream.Read(currentBlockCount - releaseBlockCount, blocks);
accessParameters.AllocationManager.Release(blocks);
blocks = new int[releaseBlockCount];
indexBlockStream.Write(currentBlockCount - releaseBlockCount, blocks);
provider.SetSizeInBlocks(count / provider.BlockSize + count % provider.BlockSize == 0 ? 0 : 1);
}
}
public int[] Allocate(int blockCount)
{
if (blockCount <= 0)
{
throw new ArgumentOutOfRangeException(nameof(blockCount));
}
var allocatedFromIndexBlocks = new int[0];
lock (lockObject)
{
var allocatedFromIndexBlockCount = Math.Min(ReleasedBlockCount, blockCount);
if (allocatedFromIndexBlockCount > 0)
{
allocatedFromIndexBlocks = new int[allocatedFromIndexBlockCount];
var position = ReleasedBlockCount - allocatedFromIndexBlockCount;
blockStream.Read(position, allocatedFromIndexBlocks);
blockStream.Write(position, new int[allocatedFromIndexBlockCount]);
ReleasedBlockCount -= allocatedFromIndexBlockCount;
}
var leftBlocks = blockCount - allocatedFromIndexBlockCount;
if (leftBlocks > 0)
{
var blocks = storage.Extend(leftBlocks);
return(allocatedFromIndexBlocks.Concat(blocks).ToArray());
}
}
EraseBlocks(allocatedFromIndexBlocks);
return(allocatedFromIndexBlocks);
}
public IDirectoryEntryInfo[] GetDirectoryEntries()
{
indexLock.EnterReadLock();
try
{
var result = new List <IDirectoryEntryInfo>(itemsCount);
if (itemsCount > 0)
{
var buffer = new DirectoryItem[itemsCount];
blockStream.Read(1, buffer);
var names = new short[lastNameOffset];
nameIndexBlockStream.Read(0, names);
foreach (var item in buffer.Where(x => (x.Entry.Flags & DirectoryFlags.Deleted) == 0))
{
var entry = item.Entry;
var nameLength = names[entry.NameOffset];
var nameBuffer = new char[nameLength];
for (var i = 0; i < nameLength; i++)
{
nameBuffer[i] = (char)names[entry.NameOffset + 1 + i];
}
result.Add(new DirectoryEntryInfo(entry, new string(nameBuffer)));
}
}
return(result.ToArray());
}
finally
{
indexLock.ExitReadLock();
}
}
public void Read(int position, byte[] buffer)
{
if (buffer == null)
{
throw new ArgumentNullException(nameof(buffer));
}
if (position < 0 || position + buffer.Length > Size)
{
throw new ArgumentOutOfRangeException(nameof(position));
}
lockObject.EnterReadLock();
try
{
blockStream.Read(position, buffer);
}
finally
{
lockObject.ExitReadLock();
}
}