/// <summary>
/// Traces both a begin and an end trace around a specified asynchronous operation.
/// </summary>
/// <remarks>The end trace will occur when the asynchronous operation completes, either success or failure.</remarks>
/// <param name="traceWriter">The <see cref="ITraceWriter"/>.</param>
/// <param name="request">The <see cref="HttpRequestMessage"/> with which to associate the trace. It may be null.</param>
/// <param name="category">The logical category of the trace.</param>
/// <param name="level">The <see cref="TraceLevel"/> of the trace.</param>
/// <param name="operatorName">The name of the object performing the operation. It may be null.</param>
/// <param name="operationName">The name of the operation being performed. It may be null.</param>
/// <param name="beginTrace">The <see cref="Action"/> to invoke prior to performing the operation,
/// allowing the given <see cref="TraceRecord"/> to be filled in. It may be null.</param>
/// <param name="execute">An <see cref="Func{Task}"/> that returns the <see cref="Task"/> that will perform the operation.</param>
/// <param name="endTrace">The <see cref="Action"/> to invoke after successfully performing the operation,
/// allowing the given <see cref="TraceRecord"/> to be filled in. It may be null.</param>
/// <param name="errorTrace">The <see cref="Action"/> to invoke if an error was encountered performing the operation,
/// allowing the given <see cref="TraceRecord"/> to be filled in. It may be null.</param>
/// <returns>The <see cref="Task"/> returned by the operation.</returns>
public static Task TraceBeginEndAsync(this ITraceWriter traceWriter,
HttpRequestMessage request,
string category,
TraceLevel level,
string operatorName,
string operationName,
Action <TraceRecord> beginTrace,
Func <Task> execute,
Action <TraceRecord> endTrace,
Action <TraceRecord> errorTrace)
{
if (traceWriter == null)
{
throw System.Web.Http.Error.ArgumentNull("traceWriter");
}
if (execute == null)
{
throw System.Web.Http.Error.ArgumentNull("execute");
}
traceWriter.Trace(
request,
category,
level,
(TraceRecord traceRecord) =>
{
traceRecord.Kind = TraceKind.Begin;
traceRecord.Operator = operatorName;
traceRecord.Operation = operationName;
if (beginTrace != null)
{
beginTrace(traceRecord);
}
});
try
{
Task task = execute();
// If the operation returned a null Task, we cannot do any
// further tracing. Return that null to the caller as
// would happen if tracing were not enabled.
if (task == null)
{
return(task);
}
return(traceWriter.TraceBeginEndAsyncCore(request, category, level, operatorName, operationName, endTrace, errorTrace, task));
}
catch (Exception exception)
{
traceWriter.TraceError(exception, request, category, operatorName, operationName, errorTrace);
throw;
}
}
public static Task <TResult> TraceBeginEndAsync <TResult>(this ITraceWriter traceWriter, HandlerRequest request, string category, TraceLevel level, string operatorName, string operationName, Action <TraceRecord> beginTrace, Func <Task <TResult> > execute, Action <TraceRecord, TResult> endTrace, Action <TraceRecord> errorTrace)
{
if (traceWriter == null)
{
throw Internal.Error.ArgumentNull("traceWriter");
}
if (execute == null)
{
throw Internal.Error.ArgumentNull("execute");
}
Stopwatch stopwatch = Stopwatch.StartNew();
traceWriter.Trace(
request,
category,
level,
traceRecord =>
{
traceRecord.Kind = TraceKind.Begin;
traceRecord.Operator = operatorName;
traceRecord.Operation = operationName;
if (beginTrace != null)
{
beginTrace(traceRecord);
}
});
try
{
Task <TResult> task = execute();
// If the operation returned a null Task, we cannot do any
// further tracing. Return that null to the caller as
// would happen if tracing were not enabled.
if (task == null)
{
return(null);
}
return(traceWriter.TraceBeginEndAsyncCore(request, category, level, operatorName, operationName, stopwatch.Elapsed, endTrace, errorTrace, task));
}
catch (Exception exception)
{
traceWriter.TraceError(exception, request, category, operatorName, operationName, errorTrace);
throw;
}
}
