/// <summary>
/// Connects or reconnects to Spanner, fast forwarding to where we left off based on
/// our _resumeToken and _resumeSkipCount.
/// </summary>
private async Task <bool> ReliableConnectAsync(CancellationToken cancellationToken)
{
if (_currentCall == null)
{
await WithTiming(ConnectAsync(), "ConnectAsync").ConfigureAwait(false);
Debug.Assert(_currentCall != null, "_currentCall != null");
for (int i = 0; i <= _resumeSkipCount; i++)
{
ThrowIfCancellationRequested(cancellationToken);
_isReading = await WithTiming(
_currentCall.ResponseStream.MoveNext(cancellationToken)
.WithSessionChecking(() => _session),
"ResponseStream.MoveNext")
.ConfigureAwait(false);
if (!_isReading || _currentCall.ResponseStream.Current == null)
{
return(false);
}
if (_metadata == null)
{
_metadata = _currentCall.ResponseStream.Current.Metadata;
}
}
RecordResumeToken();
RecordStatistics();
}
return(_isReading);
}
/// <summary>
/// Connects or reconnects to Spanner, fast forwarding to where we left off based on
/// our _resumeToken and _resumeSkipCount.
/// </summary>
/// <returns></returns>
private async Task <bool> ReliableConnectAsync(CancellationToken cancellationToken)
{
if (_currentCall == null)
{
await ConnectAsync().ConfigureAwait(false);
Debug.Assert(_currentCall != null, "_currentCall != null");
cancellationToken.ThrowIfCancellationRequested();
for (int i = 0; i <= _resumeSkipCount; i++)
{
//This calls a simple movenext on purpose. If we get an error here, we'll fail out.
_isReading = await _currentCall.ResponseStream.MoveNext(cancellationToken).WithSessionChecking(() => _session).ConfigureAwait(false);
if (!_isReading || _currentCall.ResponseStream.Current == null)
{
return(false);
}
if (_metadata == null)
{
_metadata = _currentCall.ResponseStream.Current.Metadata;
}
}
RecordResumeToken();
}
return(_isReading);
}
/// <summary>
/// Connects or reconnects to Spanner, fast forwarding to where we left off based on
/// our _resumeToken and _resumeSkipCount.
/// </summary>
/// <returns></returns>
private async Task <bool> ReliableConnectAsync(CancellationToken cancellationToken)
{
if (_currentCall == null)
{
await WithTiming(ConnectAsync(), "ConnectAsync").ConfigureAwait(false);
Debug.Assert(_currentCall != null, "_currentCall != null");
for (int i = 0; i <= _resumeSkipCount; i++)
{
ThrowIfCancellationRequested(cancellationToken);
//This calls a simple movenext on purpose. If we get an error here, we'll fail out.
//TODO(benwu): Fix cancel on MoveNext in a subsequent change targeting spanner GA
_isReading = await WithTiming(
_currentCall.ResponseStream.MoveNext(CancellationToken.None)
.WithSessionChecking(() => _session),
"ResponseStream.MoveNext")
.ConfigureAwait(false);
if (!_isReading || _currentCall.ResponseStream.Current == null)
{
return(false);
}
if (_metadata == null)
{
_metadata = _currentCall.ResponseStream.Current.Metadata;
}
}
RecordResumeToken();
}
return(_isReading);
}
// Note: internal infrastructure will optimize this to return a singleton completed task when
// we're already initialized.
private async Task EnsureInitializedAsync(CancellationToken cancellationToken)
{
if (_initialized)
{
return;
}
await MoveNextAsync(cancellationToken).ConfigureAwait(false);
_metadata = _currentResultSet?.Metadata;
_initialized = true;
}
/// <summary>
/// Connects or reconnects to Spanner, fast forwarding to where we left off based on
/// our _resumeToken and _resumeSkipCount.
/// </summary>
private async Task <bool> ReliableConnectAsync(CancellationToken cancellationToken)
{
if (_currentCall == null)
{
await WithTiming(ConnectAsync(), "ConnectAsync").ConfigureAwait(false);
GaxPreconditions.CheckState(_currentCall != null, "Failed to connect");
bool success = false;
try
{
for (int i = 0; i <= _resumeSkipCount; i++)
{
ThrowIfCancellationRequested(cancellationToken);
_isReading = await WithTiming(
_currentCall.ResponseStream.MoveNext(cancellationToken)
.WithSessionExpiryChecking(_session),
"ResponseStream.MoveNext")
.ConfigureAwait(false);
if (!_isReading || _currentCall.ResponseStream.Current == null)
{
return(false);
}
if (_metadata == null)
{
_metadata = _currentCall.ResponseStream.Current.Metadata;
}
}
RecordResumeToken();
RecordStatistics();
success = true;
}
finally
{
// If we failed at any point, dispose the call and forget it.
if (!success)
{
_currentCall?.Dispose();
_currentCall = null;
}
}
}
return(_isReading);
}
