public async Task ExecuteRequestAsync(RequestContext context)
{
try {
// validate
if (string.IsNullOrWhiteSpace(context.RawRequest.Query))
{
throw new GraphQLException("Query may not be empty.");
}
Events.OnRequestStarting(context);
var handler = new RequestHandler(this, context);
await handler.ExecuteAsync();
} catch (AbortRequestException) {
return; // error already added to response
} catch (InvalidInputException inpEx) {
context.AddInputError(inpEx);
} catch (Exception ex) {
context.AddError(ex);
} finally {
context.Metrics.Duration = AppTime.GetDuration(context.StartTimestamp);
if (context.Failed)
{
Events.OnRequestError(context);
}
Events.OnRequestCompleted(context);
}
}
private async Task ExecuteOperationAsync(GraphQLOperation op, OutputObjectScope topScope)
{
var mappedTopSubset = op.SelectionSubset.MappedSubSets[0];
var topMappedItems = mappedTopSubset.MappedItems;
var parallel = _parallelQueryEnabled && op.OperationType == OperationType.Query &&
op.SelectionSubset.Items.Count > 1;
var executers = new List <OperationFieldExecuter>();
foreach (var mappedItem in topMappedItems)
{
switch (mappedItem)
{
case MappedFragmentSpread mfs:
_requestContext.AddInputError($"Top selection items may not be fragments", mfs.Spread);
return;
case MappedSelectionField mappedField:
var opExecuter = new OperationFieldExecuter(_requestContext, mappedField, topScope);
executers.Add(opExecuter);
break;
}
}
if (parallel)
{
await ExecuteAllParallel(executers);
}
else
{
await ExecuteAllNonParallel(executers);
}
// Save results from op fields into top scope; we do it here, after all threads finished, to avoid concurrency issues
// and preserve output field order
foreach (var ex in executers)
{
topScope.SetValue(ex.ResultKey, ex.Result);
}
}