private static async Task <TResult> ExecuteSingletonAsyncQuery <TResult>(
QueryContext queryContext,
Func <QueryContext, IAsyncEnumerable <TResult> > compiledQuery,
IInterceptingLogger <LoggerCategory.Query> logger,
Type contextType)
{
try
{
var asyncEnumerable = compiledQuery(queryContext);
using (var asyncEnumerator = asyncEnumerable.GetEnumerator())
{
await asyncEnumerator.MoveNext(queryContext.CancellationToken);
return(asyncEnumerator.Current);
}
}
catch (Exception exception)
{
logger
.LogError(
CoreEventId.DatabaseError,
() => new DatabaseErrorLogState(contextType),
exception,
e => CoreStrings.LogExceptionDuringQueryIteration(Environment.NewLine, e));
throw;
}
}
private static Func <QueryContext, TResult> CompileQueryCore <TResult>(
Expression query, INodeTypeProvider nodeTypeProvider, IDatabase database, IInterceptingLogger <LoggerCategory.Query> logger, Type contextType)
{
var queryModel
= CreateQueryParser(nodeTypeProvider)
.GetParsedQuery(query);
var resultItemType
= (queryModel.GetOutputDataInfo()
as StreamedSequenceInfo)?.ResultItemType
?? typeof(TResult);
if (resultItemType == typeof(TResult))
{
var compiledQuery = database.CompileQuery <TResult>(queryModel);
return(qc =>
{
try
{
return compiledQuery(qc).First();
}
catch (Exception exception)
{
logger
.LogError(
CoreEventId.DatabaseError,
() => new DatabaseErrorLogState(contextType),
exception,
e => CoreStrings.LogExceptionDuringQueryIteration(Environment.NewLine, e));
throw;
}
});
}
try
{
return((Func <QueryContext, TResult>)CompileQueryMethod
.MakeGenericMethod(resultItemType)
.Invoke(database, new object[] { queryModel }));
}
catch (TargetInvocationException e)
{
ExceptionDispatchInfo.Capture(e.InnerException).Throw();
throw;
}
}
