public void TryExpandingTheStreamViaSetLengthAndThenWritingReadingFromIt()
{
DataStreamReadableWritable dataStream = TestCollaboratorsFactory.CreateEmptyDataStream();
const int testArrayLength = 500000;
dataStream.SetLength(testArrayLength);
Assert.AreEqual(testArrayLength, dataStream.Length);
Assert.AreEqual(0, dataStream.Position);
const int halfTestArray = testArrayLength / 2; //на половине пути запишем что-нибудь интересное.
dataStream.SetPosition(halfTestArray);
var bytesToWrite = new byte[halfTestArray];
for (int i = 0; i < bytesToWrite.Length; i++)
{
bytesToWrite[i] = 231;
}
dataStream.Write(bytesToWrite, 0, bytesToWrite.Length);
dataStream.SetPosition(halfTestArray);
var bytesRead = new byte[bytesToWrite.Length];
dataStream.Read(bytesRead, 0, bytesRead.Length);
MakeSureEachByteInArrayIsRight(bytesRead, 231); // и проверим, что записалось что нужно, - новый объем как будто проработан.
}
public void MakeSureShrinkingFreesDiskSpace()
{
var testCollaborators = TestCollaboratorsFactory.CreateCollaboratorsForTestingDataStreams();
DataStreamReadableWritable dataStream =
testCollaborators.VirtualFileSystem.OpenFileForWriting(testCollaborators.FileInfo.FullPath);
int valueCloseToDiskSize = (int)testCollaborators.Disk.DiskSizeInBytes - 25 * testCollaborators.Disk.BlockSizeInBytes;
dataStream.SetLength(valueCloseToDiskSize);
var fileSystem = testCollaborators.VirtualFileSystem;
FileInfo newFileNode = fileSystem.CreateFile(@"\testFile2");
DataStreamReadableWritable newFileNodeStream = fileSystem.OpenFileForWriting(newFileNode.FullPath);
ExceptionAssert.MakeSureExceptionIsRaisedBy <InsufficientSpaceException>(
delegate
{
newFileNodeStream.SetLength(valueCloseToDiskSize);
});
dataStream.SetLength(0);
newFileNodeStream.SetLength(valueCloseToDiskSize);
dataStream.SetPosition(0);
const int answeringToAllQuestionsByte = 42;
byte[] bytesToWrite = ByteBufferFactory.CreateByteBufferWithAllBytesSet(valueCloseToDiskSize, answeringToAllQuestionsByte);
newFileNodeStream.Write(bytesToWrite, 0, bytesToWrite.Length);
newFileNodeStream.SetPosition(0);
var buffer = new byte[valueCloseToDiskSize];
newFileNodeStream.Read(buffer, 0, buffer.Length);
MakeSureEachByteInArrayIsRight(buffer, answeringToAllQuestionsByte);
}
private void ShrinkAndMakeSureDataIsIntact(DataStreamReadableWritable dataStream, int newLength)
{
dataStream.SetLength(newLength);
Assert.AreEqual(newLength, dataStream.Length);
dataStream.SetPosition(0);
byte[] bytesRead = new byte[newLength];
dataStream.Read(bytesRead, 0, bytesRead.Length);
for (int i = 0; i < newLength; i++)
{
Assert.AreEqual(bytesRead[i], (byte)(i / 10000));
}
}
public void TryShrinkingTheStreamAndThenWritingReadingFromIt()
{
DataStreamReadableWritable dataStream = TestCollaboratorsFactory.CreateEmptyDataStream();
const int testArrayLength = 50000;
dataStream.SetLength(testArrayLength);
byte[] bytesToWrite = new byte[testArrayLength];
for (int i = 0; i < bytesToWrite.Length; i++)
{
bytesToWrite[i] = (byte)(i / 10000);
}
dataStream.Write(bytesToWrite, 0, bytesToWrite.Length);
ShrinkAndMakeSureDataIsIntact(dataStream, 40000);
ShrinkAndMakeSureDataIsIntact(dataStream, 34567);
ShrinkAndMakeSureDataIsIntact(dataStream, 25000);
ShrinkAndMakeSureDataIsIntact(dataStream, 9999);
ShrinkAndMakeSureDataIsIntact(dataStream, 24);
ShrinkAndMakeSureDataIsIntact(dataStream, 1);
}
/// <summary>
/// Устанавливает длину потока (беря себе или освобождая соответствующий объем дискового пространства).
/// </summary>
/// <param name="newLength">Новая длина потока</param>
/// <exception cref="InsufficientSpaceException"></exception>
/// <exception cref="ObjectDisposedException"></exception>
public override void SetLength(int newLength)
{
_dataStream.SetLength(newLength);
this.PersistOwningNode();
}