/// <summary>
/// Parse Flux CSV response to <see cref="IFluxResponseConsumer"/>.
/// </summary>
/// <param name="source">CSV Data source</param>
/// <param name="cancellable">to cancel parsing</param>
/// <param name="consumer">to accept <see cref="FluxTable"/> or <see cref="FluxRecord"/></param>
public void ParseFluxResponse(Stream source, ICancellable cancellable, IFluxResponseConsumer consumer)
{
Arguments.CheckNotNull(source, "source");
using var csv = new CsvReader(new StreamReader(source), CultureInfo.InvariantCulture);
var state = new ParseFluxResponseState {
csv = csv
};
while (csv.Read())
{
if (cancellable != null && cancellable.IsCancelled())
{
return;
}
foreach (var(table, record) in ParseNextFluxResponse(state))
{
if (record == null)
{
consumer.Accept(state.tableIndex, cancellable, table);
}
else
{
consumer.Accept(state.tableIndex - 1, cancellable, record);
}
}
}
}
/// <summary>
/// Parse Flux CSV response to <see cref="IAsyncEnumerable{T}"/>.
/// </summary>
/// <param name="reader">CSV Data source reader</param>
/// <param name="cancellationToken">cancellation token</param>
public async IAsyncEnumerable <(FluxTable, FluxRecord)> ParseFluxResponseAsync(StringReader reader, [EnumeratorCancellation] CancellationToken cancellationToken)
{
Arguments.CheckNotNull(reader, nameof(reader));
using var csv = new CsvReader(reader, CultureInfo.InvariantCulture);
var state = new ParseFluxResponseState {
csv = csv
};
while (await csv.ReadAsync() && !cancellationToken.IsCancellationRequested)
{
foreach (var response in ParseNextFluxResponse(state))
{
yield return(response);
}
}
}
private IEnumerable <(FluxTable, FluxRecord)> ParseNextFluxResponse(ParseFluxResponseState state)
{
//
// Response has HTTP status ok, but response is error.
//
if ("error".Equals(state.csv[1]) && "reference".Equals(state.csv[2]))
{
state.parsingState = ParsingState.InError;
yield break;
}
//
// Throw InfluxException with error response
//
if (ParsingState.InError.Equals(state.parsingState))
{
var error = state.csv[1];
var referenceValue = state.csv[2];
var reference = 0;
if (referenceValue != null && !String.IsNullOrEmpty(referenceValue))
{
reference = Convert.ToInt32(referenceValue);
}
throw new FluxQueryException(error, reference);
}
var token = state.csv[0];
//// start new table
if ("#datatype".Equals(token))
{
state.startNewTable = true;
state.table = new FluxTable();
yield return(state.table, null);
state.tableIndex++;
state.tableId = -1;
}
else if (state.table == null)
{
throw new FluxCsvParserException(
"Unable to parse CSV response. FluxTable definition was not found.");
}
//#datatype,string,long,dateTime:RFC3339,dateTime:RFC3339,dateTime:RFC3339,double,string,string,string
if ("#datatype".Equals(token))
{
AddDataTypes(state.table, state.csv);
}
else if ("#group".Equals(token))
{
AddGroups(state.table, state.csv);
}
else if ("#default".Equals(token))
{
AddDefaultEmptyValues(state.table, state.csv);
}
else
{
// parse column names
if (state.startNewTable)
{
AddColumnNamesAndTags(state.table, state.csv);
state.startNewTable = false;
yield break;
}
int currentId;
try
{
currentId = Convert.ToInt32(state.csv[1 + 1]);
}
catch (Exception)
{
throw new FluxCsvParserException("Unable to parse CSV response.");
}
if (state.tableId == -1)
{
state.tableId = currentId;
}
if (state.tableId != currentId)
{
//create new table with previous column headers settings
var fluxColumns = state.table.Columns;
state.table = new FluxTable();
state.table.Columns.AddRange(fluxColumns);
yield return(state.table, null);
state.tableIndex++;
state.tableId = currentId;
}
yield return(state.table, ParseRecord(state.tableIndex - 1, state.table, state.csv));
}
}
