public byte[] ReadMap(out int bitmapSizeInBits)
{
byte[] firstBlockBytes = _disk.ReadAllBytesFromBlock(_freeSpaceMapStartingBlock);
var stream = new MemoryStream(firstBlockBytes);
var binaryReader = new BinaryReader(stream);
int freeSpaceLengthInBits = binaryReader.ReadInt32();
int freeSpaceLengthInBytes = SpaceRequirementsCalculator.GetNumberOfChunksNeededToStoreData(
freeSpaceLengthInBits, Constants.NumberOfBitsInByte);
ReadOnlyCollection <BucketDistribution> numberOfBytesToReadFromEachBlock = ItemDistributor.Distribute(freeSpaceLengthInBytes,
_disk.BlockSizeInBytes - Constants.BlockReferenceSizeInBytes,
_disk.BlockSizeInBytes);
var freeSpaceMap = new byte[freeSpaceLengthInBytes];
int numberOfCurrentBlock = _freeSpaceMapStartingBlock;
int initialArrayPosition = 0;
foreach (BucketDistribution distribution in numberOfBytesToReadFromEachBlock)
{
byte[] newArray = _disk.ReadBytesFromBlock(numberOfCurrentBlock + distribution.BucketIndex, distribution.IndexOfFirstItemTheBucketGot,
distribution.NumberOfItemsDistributed);
Array.Copy(newArray, 0, freeSpaceMap, initialArrayPosition, distribution.NumberOfItemsDistributed);
initialArrayPosition += distribution.NumberOfItemsDistributed;
}
bitmapSizeInBits = freeSpaceLengthInBits;
return(freeSpaceMap);
}
private void InitializeSingleIndirectionBlock(int indexOfBlockToCreateIndirectionBlockFrom, int currentCountOfIntegersInBlock, int currentPositionInBlock)
{
byte[] blockContents = _disk.ReadAllBytesFromBlock(indexOfBlockToCreateIndirectionBlockFrom);
_singlyIndirectBlockReferences = new IntegerListConstrained(blockContents, currentCountOfIntegersInBlock, _addressingSystemParameters.DataBlockReferencesCountInSingleIndirectBlock);
_singlyIndirectReferencesEnumerator = _singlyIndirectBlockReferences.GetAddressableEnumerator();
if (currentPositionInBlock != PositionBeforeFirstElement)
{
_singlyIndirectReferencesEnumerator.SetPosition(currentPositionInBlock);
}
}
/// <summary>
///
/// </summary>
/// <typeparam name="TResult"></typeparam>
/// <param name="numberOfBlockToRead"></param>
/// <exception cref="InconsistentDataDetectedException"></exception>
/// <exception cref="ArgumentOutOfRangeException"></exception>
private TResult DeserializeObjectAtBlock <TResult>(int numberOfBlockToRead)
{
try
{
byte[] blockBytes = _virtualDisk.ReadAllBytesFromBlock(numberOfBlockToRead);
int serializedStreamLength = GetSerializedStreamSize(blockBytes);
return((TResult)ReadObject(blockBytes, 4, serializedStreamLength));
}
catch (InvalidCastException exception)
{
throw ConstructGenericCannotReadNodeException(exception);
}
catch (SerializationException exception)
{
throw ConstructGenericCannotReadNodeException(exception);
}
}
public DataStreamStructureBuilderImmutable(IVirtualDisk disk, DataStreamDefinition dataStreamDefinition, AddressingSystemParameters addressingSystemParameters, IFileSystemNodeStorage fileSystemNodeStorage, Node governingNode)
{
if (disk == null)
{
throw new ArgumentNullException("disk");
}
if (dataStreamDefinition == null)
{
throw new ArgumentNullException("dataStreamDefinition");
}
if (addressingSystemParameters == null)
{
throw new ArgumentNullException("addressingSystemParameters");
}
if (fileSystemNodeStorage == null)
{
throw new ArgumentNullException("fileSystemNodeStorage");
}
if (governingNode == null)
{
throw new ArgumentNullException("governingNode");
}
_disk = disk;
_governingNode = governingNode;
_fileSystemNodeStorage = fileSystemNodeStorage;
_addressingSystemParameters = addressingSystemParameters;
_dataStreamDefinition = dataStreamDefinition;
int numberOfBlocks =
SpaceRequirementsCalculator.GetNumberOfChunksNeededToStoreData(
dataStreamDefinition.StreamLengthInBytes, addressingSystemParameters.BlockSize);
_addressingBlockSizesCalculator = new AddressingBlockSizesCalculator(addressingSystemParameters.IndirectBlockReferencesCountInDoubleIndirectBlock,
addressingSystemParameters.DataBlockReferencesCountInSingleIndirectBlock);
_sizesOfLastAddressingBlocks = AddressingBlockSizesCalculator.GetSizesOfAddressingBlocksSufficientToStoreItems(numberOfBlocks);
int doubleIndirectBlockSize = _sizesOfLastAddressingBlocks.DoubleIndirectBlockSize;
_doubleIndirectBlocks = new IntegerListConstrained(disk.ReadAllBytesFromBlock(dataStreamDefinition.ContentsBlockIndex), doubleIndirectBlockSize, _addressingSystemParameters.IndirectBlockReferencesCountInDoubleIndirectBlock);
CalculateAndSetMaximumSize(addressingSystemParameters);
}
