/// <summary>
/// Parses filterAndPayloadSpecs which is a list of lines each of which has the from
///
/// DiagnosticSourceName/EventName:PAYLOAD_SPEC
///
/// where PAYLOADSPEC is a semicolon separated list of specifications of the form
///
/// OutputName=Prop1.Prop2.PropN
///
/// Into linked list of FilterAndTransform that together forward events from the given
/// DiagnosticSource's to 'eventSource'. Sets the 'specList' variable to this value
/// (destroying anything that was there previously).
///
/// By default any serializable properties of the payload object are also included
/// in the output payload, however this feature and be tuned off by prefixing the
/// PAYLOADSPEC with a '-'.
/// </summary>
public static void CreateFilterAndTransformList(ref FilterAndTransform specList, string filterAndPayloadSpecs, DiagnosticSourceEventSource eventSource)
{
DestroyFilterAndTransformList(ref specList); // Stop anything that was on before.
if (filterAndPayloadSpecs == null)
{
filterAndPayloadSpecs = "";
}
// Points just beyond the last point in the string that has yet to be parsed. Thus we start with the whole string.
int endIdx = filterAndPayloadSpecs.Length;
for (;;)
{
// Skip trailing whitespace.
while (0 < endIdx && char.IsWhiteSpace(filterAndPayloadSpecs[endIdx - 1]))
{
--endIdx;
}
int newlineIdx = filterAndPayloadSpecs.LastIndexOf('\n', endIdx - 1, endIdx);
int startIdx = 0;
if (0 <= newlineIdx)
{
startIdx = newlineIdx + 1; // starts after the newline, or zero if we don't find one.
}
// Skip leading whitespace
while (startIdx < endIdx && char.IsWhiteSpace(filterAndPayloadSpecs[startIdx]))
{
startIdx++;
}
specList = new FilterAndTransform(filterAndPayloadSpecs, startIdx, endIdx, eventSource, specList);
endIdx = newlineIdx;
if (endIdx < 0)
{
break;
}
}
}
/// <summary>
/// Creates one FilterAndTransform specification from filterAndPayloadSpec starting at 'startIdx' and ending just before 'endIdx'.
/// This FilterAndTransform will subscribe to DiagnosticSources specified by the specification and forward them to 'eventSource.
/// For convenience, the 'Next' field is set to the 'next' parameter, so you can easily form linked lists.
/// </summary>
public FilterAndTransform(string filterAndPayloadSpec, int startIdx, int endIdx, DiagnosticSourceEventSource eventSource, FilterAndTransform next)
{
Debug.Assert(filterAndPayloadSpec != null && startIdx >= 0 && startIdx <= endIdx && endIdx <= filterAndPayloadSpec.Length);
Next = next;
_eventSource = eventSource;
string listenerNameFilter = null; // Means WildCard.
string eventNameFilter = null; // Means WildCard.
string activityName = null;
var startTransformIdx = startIdx;
var endEventNameIdx = endIdx;
var colonIdx = filterAndPayloadSpec.IndexOf(':', startIdx, endIdx - startIdx);
if (0 <= colonIdx)
{
endEventNameIdx = colonIdx;
startTransformIdx = colonIdx + 1;
}
// Parse the Source/Event name into listenerNameFilter and eventNameFilter
var slashIdx = filterAndPayloadSpec.IndexOf('/', startIdx, endEventNameIdx - startIdx);
if (0 <= slashIdx)
{
listenerNameFilter = filterAndPayloadSpec.Substring(startIdx, slashIdx - startIdx);
var atIdx = filterAndPayloadSpec.IndexOf('@', slashIdx + 1, endEventNameIdx - slashIdx - 1);
if (0 <= atIdx)
{
activityName = filterAndPayloadSpec.Substring(atIdx + 1, endEventNameIdx - atIdx - 1);
eventNameFilter = filterAndPayloadSpec.Substring(slashIdx + 1, atIdx - slashIdx - 1);
}
else
{
eventNameFilter = filterAndPayloadSpec.Substring(slashIdx + 1, endEventNameIdx - slashIdx - 1);
}
}
else if (startIdx < endEventNameIdx)
{
listenerNameFilter = filterAndPayloadSpec.Substring(startIdx, endEventNameIdx - startIdx);
}
_eventSource.Message("DiagnosticSource: Enabling '" + (listenerNameFilter ?? "*") + "/" + (eventNameFilter ?? "*") + "'");
// If the transform spec begins with a - it means you don't want implicit transforms.
if (startTransformIdx < endIdx && filterAndPayloadSpec[startTransformIdx] == '-')
{
_eventSource.Message("DiagnosticSource: suppressing implicit transforms.");
_noImplicitTransforms = true;
startTransformIdx++;
}
// Parse all the explicit transforms, if present
if (startTransformIdx < endIdx)
{
for (;;)
{
int specStartIdx = startTransformIdx;
int semiColonIdx = filterAndPayloadSpec.LastIndexOf(';', endIdx - 1, endIdx - startTransformIdx);
if (0 <= semiColonIdx)
{
specStartIdx = semiColonIdx + 1;
}
// Ignore empty specifications.
if (specStartIdx < endIdx)
{
if (_eventSource.IsEnabled(EventLevel.Informational, Keywords.Messages))
{
_eventSource.Message("DiagnosticSource: Parsing Explicit Transform '" + filterAndPayloadSpec.Substring(specStartIdx, endIdx - specStartIdx) + "'");
}
_explicitTransforms = new TransformSpec(filterAndPayloadSpec, specStartIdx, endIdx, _explicitTransforms);
}
if (startTransformIdx == specStartIdx)
{
break;
}
endIdx = semiColonIdx;
}
}
Action <string, string, IEnumerable <KeyValuePair <string, string> > > writeEvent = null;
if (activityName != null && activityName.Contains("Activity"))
{
MethodInfo writeEventMethodInfo = typeof(DiagnosticSourceEventSource).GetTypeInfo().GetDeclaredMethod(activityName);
if (writeEventMethodInfo != null)
{
// This looks up the activityName (which needs to be a name of an event on DiagnosticSourceEventSource
// like Activity1Start and returns that method). This allows us to have a number of them and this code
// just works.
try
{
writeEvent = (Action <string, string, IEnumerable <KeyValuePair <string, string> > >)
writeEventMethodInfo.CreateDelegate(typeof(Action <string, string, IEnumerable <KeyValuePair <string, string> > >), _eventSource);
}
catch (Exception) { }
}
if (writeEvent == null)
{
_eventSource.Message("DiagnosticSource: Could not find Event to log Activity " + activityName);
}
}
if (writeEvent == null)
{
#if !NO_EVENTSOURCE_COMPLEX_TYPE_SUPPORT
writeEvent = _eventSource.Event;
#else
writeEvent = delegate(string sourceName, string eventName, IEnumerable <KeyValuePair <string, string> > arguments)
{
_eventSource.EventJson(sourceName, eventName, ToJson(arguments));
};
#endif
}
// Set up a subscription that watches for the given Diagnostic Sources and events which will call back
// to the EventSource.
_diagnosticsListenersSubscription = DiagnosticListener.AllListeners.Subscribe(new CallbackObserver <DiagnosticListener>(delegate(DiagnosticListener newListener)
{
if (listenerNameFilter == null || listenerNameFilter == newListener.Name)
{
_eventSource.NewDiagnosticListener(newListener.Name);
Predicate <string> eventNameFilterPredicate = null;
if (eventNameFilter != null)
{
eventNameFilterPredicate = (string eventName) => eventNameFilter == eventName;
}
var subscription = newListener.Subscribe(new CallbackObserver <KeyValuePair <string, object> >(delegate(KeyValuePair <string, object> evnt)
{
// The filter given to the DiagnosticSource may not work if users don't is 'IsEnabled' as expected.
// Thus we look for any events that may have snuck through and filter them out before forwarding.
if (eventNameFilter != null && eventNameFilter != evnt.Key)
{
return;
}
var outputArgs = this.Morph(evnt.Value);
var eventName = evnt.Key;
writeEvent(newListener.Name, eventName, outputArgs);
}), eventNameFilterPredicate);
_liveSubscriptions = new Subscriptions(subscription, _liveSubscriptions);
}
}));
}
/// <summary>
/// Creates one FilterAndTransform specification from filterAndPayloadSpec starting at 'startIdx' and ending just before 'endIdx'.
/// This FilterAndTransform will subscribe to DiagnosticSources specified by the specification and forward them to 'eventSource.
/// For convenience, the 'Next' field is set to the 'next' parameter, so you can easily form linked lists.
/// </summary>
public FilterAndTransform(string filterAndPayloadSpec, int startIdx, int endIdx, DiagnosticSourceEventSource eventSource, FilterAndTransform next)
{
#if DEBUG
string spec = filterAndPayloadSpec.Substring(startIdx, endIdx - startIdx);
#endif
Next = next;
_eventSource = eventSource;
string listenerNameFilter = null; // Means WildCard.
string eventNameFilter = null; // Means WildCard.
var startTransformIdx = startIdx;
var endEventNameIdx = endIdx;
var colonIdx = filterAndPayloadSpec.IndexOf(':', startIdx, endIdx - startIdx);
if (0 <= colonIdx)
{
endEventNameIdx = colonIdx;
startTransformIdx = colonIdx + 1;
}
// Parse the Source/Event name into listenerNameFilter and eventNameFilter
var slashIdx = filterAndPayloadSpec.IndexOf('/', startIdx, endEventNameIdx - startIdx);
if (0 <= slashIdx)
{
listenerNameFilter = filterAndPayloadSpec.Substring(startIdx, slashIdx - startIdx);
eventNameFilter = filterAndPayloadSpec.Substring(slashIdx + 1, endEventNameIdx - slashIdx - 1);
}
else if (startIdx < endEventNameIdx)
{
listenerNameFilter = filterAndPayloadSpec.Substring(startIdx, endEventNameIdx - startIdx);
}
_eventSource.Message("DiagnosticSource: Enabling '" + (listenerNameFilter ?? "*") + "/" + (eventNameFilter ?? "*") + "'");
// If the transform spec begins with a - it means you don't want implicit transforms.
if (startTransformIdx < endIdx && filterAndPayloadSpec[startTransformIdx] == '-')
{
_eventSource.Message("DiagnosticSource: suppressing implicit transforms.");
_noImplicitTransforms = true;
startTransformIdx++;
}
// Parse all the explicit transforms, if present
if (startTransformIdx < endIdx)
{
for (;;)
{
int specStartIdx = startTransformIdx;
int semiColonIdx = filterAndPayloadSpec.LastIndexOf(';', endIdx - 1, endIdx - startTransformIdx);
if (0 <= semiColonIdx)
{
specStartIdx = semiColonIdx + 1;
}
// Ignore empty specifications.
if (specStartIdx < endIdx)
{
if (_eventSource.IsEnabled(EventLevel.Informational, Keywords.Messages))
{
_eventSource.Message("DiagnosticSource: Parsing Explicit Transform '" + filterAndPayloadSpec.Substring(specStartIdx, endIdx - specStartIdx) + "'");
}
_explicitTransforms = new TransformSpec(filterAndPayloadSpec, specStartIdx, endIdx, _explicitTransforms);
}
if (startTransformIdx == specStartIdx)
{
break;
}
endIdx = semiColonIdx;
}
}
// Set up a subscription that watches for the given Diagnostic Sources and events which will call back
// to the EventSource.
_diagnosticsListenersSubscription = DiagnosticListener.AllListeners.Subscribe(new CallbackObserver <DiagnosticListener>(delegate(DiagnosticListener newListener)
{
if (listenerNameFilter == null || listenerNameFilter == newListener.Name)
{
Predicate <string> eventNameFilterPredicate = null;
if (eventNameFilter != null)
{
eventNameFilterPredicate = (string eventName) => eventNameFilter == eventName;
}
var subscription = newListener.Subscribe(new CallbackObserver <KeyValuePair <string, object> >(delegate(KeyValuePair <string, object> evnt)
{
// The filter given to the DiagnosticSource may not work if users don't is 'IsEnabled' as expected.
// Thus we look for any events that may have snuck through and filter them out before forwarding.
if (eventNameFilter != null && eventNameFilter != evnt.Key)
{
return;
}
var outputArgs = this.Morph(evnt.Value);
#if !NO_EVENTSOURCE_COMPLEX_TYPE_SUPPORT
_eventSource.Event(newListener.Name, evnt.Key, outputArgs);
#else
_eventSource.EventJson(newListener.Name, evnt.Key, ToJson(outputArgs));
#endif
}), eventNameFilterPredicate);
_liveSubscriptions = new Subscriptions(subscription, _liveSubscriptions);
}
}));
}