public override async Task InitializeAsync(CancellationToken cancellationToken = default)
{
if (_rows != null)
{
throw new InvalidOperationException("Cannot initialize more than once.");
}
if (ResponseStream != null)
{
var body = await _deserializer.DeserializeAsync <ViewResultData>(ResponseStream, cancellationToken).ConfigureAwait(false);
MetaData = new ViewMetaData
{
TotalRows = body.total_rows
};
_rows = body.rows?.Select(p => new ViewRow <TKey, TValue>
{
Id = p.id,
Key = p.key,
Value = p.value
}) ?? Enumerable.Empty <IViewRow <TKey, TValue> >();
}
else
{
_rows = Enumerable.Empty <IViewRow <TKey, TValue> >();
}
DecodeSpan?.Finish();
}
/// <summary>
/// Returns an enumerator that iterates through the collection.
/// </summary>
/// <returns>
/// An enumerator that can be used to iterate through the collection.
/// </returns>
public IEnumerator <T> GetEnumerator()
{
if (_forcedRead)
{
// Return the cached results from the previous call to ForceRead
foreach (var row in Rows)
{
yield return(row);
}
yield break;
}
if (_hasReadResults)
{
// Don't allow enumeration more than once, unless stream was force read into memory
throw new StreamAlreadyReadException();
}
// Ensure that reading has begun and we're ready to deserialize result rows
CheckRead();
if (!_hasFinishedReading)
{
// Read isn't complete, so the stream is currently waiting to deserialize the results
while (_reader.Read())
{
if (_reader.Depth == 2)
{
yield return(ReadItem <T>(_reader));
}
if (_reader.Path == "results" && _reader.TokenType == JsonToken.EndArray)
{
break;
}
}
// Read any remaining attributes after the results
ReadResponseAttributes();
}
if (QueryTimer != null)
{
QueryTimer.ClusterElapsedTime = Metrics.ElaspedTime;
}
if (DecodeSpan != null)
{
DecodeSpan.SetPeerLatencyTag(Metrics.ElaspedTime);
DecodeSpan.Finish();
}
_hasReadResults = true;
}
public override async IAsyncEnumerator <IViewRow <TKey, TValue> > GetAsyncEnumerator(CancellationToken cancellationToken = default)
#pragma warning restore 8425
{
if (_hasReadRows)
{
// Don't allow enumeration more than once
throw new StreamAlreadyReadException();
}
if (_hasFinishedReading)
{
// empty collection
_hasReadRows = true;
yield break;
}
if (!_hasReadToRows)
{
throw new InvalidOperationException(
$"{nameof(StreamingViewResult<TKey, TValue>)} has not been initialized, call InitializeAsync first");
}
if (_reader == null)
{
// Should not be possible
throw new InvalidOperationException("_reader is null");
}
await foreach (var row in _reader.ReadObjectsAsync <ViewRowData>(cancellationToken).ConfigureAwait(false))
{
yield return(new ViewRow <TKey, TValue>
{
Id = row.id,
Key = row.key,
Value = row.value
});
}
// we've reached the end of the stream, so mark it as finished reading
_hasReadRows = true;
// Read any remaining attributes after the results
await ReadResponseAttributes(cancellationToken).ConfigureAwait(false);
// if we have a decode span, finish it
DecodeSpan?.Dispose();
}
public virtual void Dispose()
{
ResponseStream?.Dispose();
DecodeSpan?.Dispose();
}
