public override int Read(char[] buffer, int index, int count)
{
ValidateReadParameters(buffer, index, count);
if (IsClosed)
{
throw ADP.ObjectDisposed(this);
}
if (_currentTask != null)
{
throw ADP.AsyncOperationPending();
}
int charsRead = 0;
int charsNeeded = count;
// Load in peeked char
if ((charsNeeded > 0) && (HasPeekedChar))
{
Debug.Assert((_peekedChar >= char.MinValue) && (_peekedChar <= char.MaxValue), $"Bad peeked character: {_peekedChar}");
buffer[index + charsRead] = (char)_peekedChar;
charsRead++;
charsNeeded--;
_peekedChar = -1;
}
// If we need more data and there is data avaiable, read
charsRead += InternalRead(buffer, index + charsRead, charsNeeded);
return(charsRead);
}
public override int Read()
{
if (_currentTask != null)
{
throw ADP.AsyncOperationPending();
}
if (IsClosed)
{
throw ADP.ObjectDisposed(this);
}
int readChar = -1;
// If there is already a peeked char, then return it
if (HasPeekedChar)
{
readChar = _peekedChar;
_peekedChar = -1;
}
// If there is data available try to read a char
else
{
char[] tempBuffer = new char[1];
int charsRead = InternalRead(tempBuffer, 0, 1);
if (charsRead == 1)
{
readChar = tempBuffer[0];
}
}
Debug.Assert(readChar == -1 || ((readChar >= char.MinValue) && (readChar <= char.MaxValue)), $"Bad read character: {readChar}");
return(readChar);
}
public override int Peek()
{
if (_currentTask != null)
{
throw ADP.AsyncOperationPending();
}
if (IsClosed)
{
throw ADP.ObjectDisposed(this);
}
if (!HasPeekedChar)
{
_peekedChar = Read();
}
Debug.Assert(_peekedChar == -1 || ((_peekedChar >= char.MinValue) && (_peekedChar <= char.MaxValue)), $"Bad peeked character: {_peekedChar}");
return(_peekedChar);
}
public override int Read(byte[] buffer, int offset, int count)
{
ValidateReadParameters(buffer, offset, count);
if (!CanRead)
{
throw ADP.ObjectDisposed(this);
}
if (_currentTask != null)
{
throw ADP.AsyncOperationPending();
}
try
{
return(_reader.GetBytesInternalSequential(_columnIndex, buffer, offset, count, _readTimeout));
}
catch (SqlException ex)
{
// Stream.Read() can't throw a SqlException - so wrap it in an IOException
throw ADP.ErrorReadingFromStream(ex);
}
}
public override Task <int> ReadAsync(char[] buffer, int index, int count)
{
ValidateReadParameters(buffer, index, count);
TaskCompletionSource <int> completion = new TaskCompletionSource <int>();
if (IsClosed)
{
completion.SetException(ADP.ExceptionWithStackTrace(ADP.ObjectDisposed(this)));
}
else
{
try
{
Task original = Interlocked.CompareExchange <Task>(ref _currentTask, completion.Task, null);
if (original != null)
{
completion.SetException(ADP.ExceptionWithStackTrace(ADP.AsyncOperationPending()));
}
else
{
bool completedSynchronously = true;
int charsRead = 0;
int adjustedIndex = index;
int charsNeeded = count;
// Load in peeked char
if ((HasPeekedChar) && (charsNeeded > 0))
{
// Take a copy of _peekedChar in case it is cleared during close
int peekedChar = _peekedChar;
if (peekedChar >= char.MinValue)
{
Debug.Assert((_peekedChar >= char.MinValue) && (_peekedChar <= char.MaxValue), $"Bad peeked character: {_peekedChar}");
buffer[adjustedIndex] = (char)peekedChar;
adjustedIndex++;
charsRead++;
charsNeeded--;
_peekedChar = -1;
}
}
int byteBufferUsed;
byte[] byteBuffer = PrepareByteBuffer(charsNeeded, out byteBufferUsed);
// Permit a 0 byte read in order to advance the reader to the correct column
if ((byteBufferUsed < byteBuffer.Length) || (byteBuffer.Length == 0))
{
int bytesRead;
var reader = _reader;
if (reader != null)
{
Task <int> getBytesTask = reader.GetBytesAsync(_columnIndex, byteBuffer, byteBufferUsed, byteBuffer.Length - byteBufferUsed, Timeout.Infinite, _disposalTokenSource.Token, out bytesRead);
if (getBytesTask == null)
{
byteBufferUsed += bytesRead;
}
else
{
// We need more data - setup the callback, and mark this as not completed sync
completedSynchronously = false;
getBytesTask.ContinueWith((t) =>
{
_currentTask = null;
// If we completed but the textreader is closed, then report cancellation
if ((t.Status == TaskStatus.RanToCompletion) && (!IsClosed))
{
try
{
int bytesReadFromStream = t.Result;
byteBufferUsed += bytesReadFromStream;
if (byteBufferUsed > 0)
{
charsRead += DecodeBytesToChars(byteBuffer, byteBufferUsed, buffer, adjustedIndex, charsNeeded);
}
completion.SetResult(charsRead);
}
catch (Exception ex)
{
completion.SetException(ex);
}
}
else if (IsClosed)
{
completion.SetException(ADP.ExceptionWithStackTrace(ADP.ObjectDisposed(this)));
}
else if (t.Status == TaskStatus.Faulted)
{
if (t.Exception.InnerException is SqlException)
{
// ReadAsync can't throw a SqlException, so wrap it in an IOException
completion.SetException(ADP.ExceptionWithStackTrace(ADP.ErrorReadingFromStream(t.Exception.InnerException)));
}
else
{
completion.SetException(t.Exception.InnerException);
}
}
else
{
completion.SetCanceled();
}
}, TaskScheduler.Default);
}
if ((completedSynchronously) && (byteBufferUsed > 0))
{
// No more data needed, decode what we have
charsRead += DecodeBytesToChars(byteBuffer, byteBufferUsed, buffer, adjustedIndex, charsNeeded);
}
}
else
{
// Reader is null, close must of happened in the middle of this read
completion.SetException(ADP.ExceptionWithStackTrace(ADP.ObjectDisposed(this)));
}
}
if (completedSynchronously)
{
_currentTask = null;
if (IsClosed)
{
completion.SetCanceled();
}
else
{
completion.SetResult(charsRead);
}
}
}
}
catch (Exception ex)
{
// In case of any errors, ensure that the completion is completed and the task is set back to null if we switched it
completion.TrySetException(ex);
Interlocked.CompareExchange(ref _currentTask, null, completion.Task);
throw;
}
}
return(completion.Task);
}
public override Task <int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
{
ValidateReadParameters(buffer, offset, count);
TaskCompletionSource <int> completion = new TaskCompletionSource <int>();
if (!CanRead)
{
completion.SetException(ADP.ExceptionWithStackTrace(ADP.ObjectDisposed(this)));
}
else
{
try
{
Task original = Interlocked.CompareExchange <Task>(ref _currentTask, completion.Task, null);
if (original != null)
{
completion.SetException(ADP.ExceptionWithStackTrace(ADP.AsyncOperationPending()));
}
else
{
// Set up a combined cancellation token for both the user's and our disposal tokens
CancellationTokenSource combinedTokenSource;
if (!cancellationToken.CanBeCanceled)
{
// Users token is not cancellable - just use ours
combinedTokenSource = _disposalTokenSource;
}
else
{
// Setup registrations from user and disposal token to cancel the combined token
combinedTokenSource = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken, _disposalTokenSource.Token);
}
int bytesRead = 0;
Task <int> getBytesTask = null;
var reader = _reader;
if ((reader != null) && (!cancellationToken.IsCancellationRequested) && (!_disposalTokenSource.Token.IsCancellationRequested))
{
getBytesTask = reader.GetBytesAsync(_columnIndex, buffer, offset, count, _readTimeout, combinedTokenSource.Token, out bytesRead);
}
if (getBytesTask == null)
{
_currentTask = null;
if (cancellationToken.IsCancellationRequested)
{
completion.SetCanceled();
}
else if (!CanRead)
{
completion.SetException(ADP.ExceptionWithStackTrace(ADP.ObjectDisposed(this)));
}
else
{
completion.SetResult(bytesRead);
}
if (combinedTokenSource != _disposalTokenSource)
{
combinedTokenSource.Dispose();
}
}
else
{
getBytesTask.ContinueWith((t) =>
{
_currentTask = null;
// If we completed, but _reader is null (i.e. the stream is closed), then report cancellation
if ((t.Status == TaskStatus.RanToCompletion) && (CanRead))
{
completion.SetResult((int)t.Result);
}
else if (t.Status == TaskStatus.Faulted)
{
if (t.Exception.InnerException is SqlException)
{
// Stream.ReadAsync() can't throw a SqlException - so wrap it in an IOException
completion.SetException(ADP.ExceptionWithStackTrace(ADP.ErrorReadingFromStream(t.Exception.InnerException)));
}
else
{
completion.SetException(t.Exception.InnerException);
}
}
else if (!CanRead)
{
completion.SetException(ADP.ExceptionWithStackTrace(ADP.ObjectDisposed(this)));
}
else
{
completion.SetCanceled();
}
if (combinedTokenSource != _disposalTokenSource)
{
combinedTokenSource.Dispose();
}
}, TaskScheduler.Default);
}
}
}
catch (Exception ex)
{
// In case of any errors, ensure that the completion is completed and the task is set back to null if we switched it
completion.TrySetException(ex);
Interlocked.CompareExchange(ref _currentTask, null, completion.Task);
throw;
}
}
return(completion.Task);
}
