/// <summary>
/// Constructs <see cref="Switch"/> instances for the current
/// `system.diagnostics/switches` configuration.
/// </summary>
/// <param name="configurationSection"></param>
/// <returns></returns>
private static IDictionary <string, Switch> InstantiateSwitches(
SystemDiagnosticsConfigurationSection configurationSection)
{
var switches = new Dictionary <string, Switch>(StringComparer.OrdinalIgnoreCase);
if (configurationSection.Switches != null)
{
foreach (SwitchElement switchElement in configurationSection.Switches)
{
// multiple rules dictate switch type
var @switch = default(Switch);
if (bool.TryParse(switchElement.Value, out bool boolValue))
{
// if value is a `bool`, use `BooleanSwitch`
@switch = new BooleanSwitch(switchElement.Name, "", switchElement.Value);
}
else if (Enum.TryParse(switchElement.Value, out TraceLevel traceLevel))
{
// if value is a `TraceLevel`, use `TraceSwitch`
@switch = new TraceSwitch(switchElement.Name, "", switchElement.Value);
}
else
{
throw new Exception(
$"Unsupported Value '{switchElement.Value}' for Switch '{switchElement.Name}'.");
}
switches.Add(switchElement.Name, @switch);
}
}
return(switches);
}
/// <summary>
/// Configure `System.Diagnostics` using specified <paramref name="systemDiagnosticsConfigurationSection"/>.
/// </summary>
/// <param name="systemDiagnosticsConfigurationSection"></param>
internal static ConfigurationSection Configure(
SystemDiagnosticsConfigurationSection systemDiagnosticsConfigurationSection)
{
_preferredConfigurationSection = systemDiagnosticsConfigurationSection;
if (systemDiagnosticsConfigurationSection != null)
{
_switches = InstantiateSwitches(systemDiagnosticsConfigurationSection);
_listeners = InstantiateSharedListeners(systemDiagnosticsConfigurationSection);
InitializeTraceTraceListeners(systemDiagnosticsConfigurationSection);
_sources = InstantiateSources(systemDiagnosticsConfigurationSection, _switches, _listeners);
}
return(systemDiagnosticsConfigurationSection);
}
/// <summary>
/// Initialize the Trace Listeners assigned to <see cref="System.Diagnostics.Trace.Listeners"/>.
/// </summary>
/// <param name="systemDiagnosticsConfigurationSection"></param>
private static void InitializeTraceTraceListeners(
SystemDiagnosticsConfigurationSection systemDiagnosticsConfigurationSection)
{
// TODO: support `<clear/>`
foreach (TraceListenerElement listenerElement in systemDiagnosticsConfigurationSection.Trace.Listeners)
{
if (_listeners.TryGetValue(listenerElement.Name, out TraceListener traceListener))
{
Trace.Listeners.Remove(listenerElement.Name);
Trace.Listeners.Add(traceListener);
}
}
}
/// <summary>
/// Constructs shared <see cref="TraceListener"/> instances for the
/// current `system.diagnostics/sharedListeners` configuration.
/// </summary>
/// <param name="configurationSection"></param>
/// <returns></returns>
private static IDictionary <string, TraceListener> InstantiateSharedListeners(
SystemDiagnosticsConfigurationSection configurationSection)
{
var sharedListeners = new Dictionary <string, TraceListener>(StringComparer.OrdinalIgnoreCase);
if (configurationSection.SharedListeners != null)
{
foreach (TraceListenerElement traceListenerElement in configurationSection.SharedListeners)
{
try
{
var traceListener = InstantiateTraceListener(traceListenerElement);
sharedListeners.Add(traceListener.Name, traceListener);
}
catch (Exception)
{
// NOP: failure to instanciate a trace listener
// should not result in a log line.
}
}
}
return(sharedListeners);
}
/// <summary>
/// Constructs <see cref="TraceSource"/> instances for the current
/// `system.diagnostics/trace` configuration.
/// </summary>
/// <param name="systemDiagnosticsConfigurationSection"></param>
/// <param name="switches"></param>
/// <param name="sharedListeners"></param>
/// <returns></returns>
private static IDictionary <string, TraceSource> InstantiateSources(
SystemDiagnosticsConfigurationSection systemDiagnosticsConfigurationSection,
IDictionary <string, Switch> switches,
IDictionary <string, TraceListener> sharedListeners)
{
// TODO: `system.diagnostics/switches` are not properly evaluated
// at run-time, and cannot be used to control
// `system.diagnostics/sources`, although this bootstrapper
// does make an attempt to transpose switch values and most
// developers will not know the difference.
var sources = new Dictionary <string, TraceSource>(StringComparer.OrdinalIgnoreCase);
if (systemDiagnosticsConfigurationSection.Sources != null)
{
foreach (SourceElement sourceElement in systemDiagnosticsConfigurationSection.Sources)
{
var traceSource = new TraceSource(sourceElement.Name);
var switchValue = !string.IsNullOrWhiteSpace(sourceElement.SwitchValue)
? sourceElement.SwitchValue
: $"{SourceLevels.All}";
if (!string.IsNullOrWhiteSpace(sourceElement.SwitchType))
{
try
{
traceSource.Switch =
Activator.CreateInstance(
Type.GetType(sourceElement.SwitchType),
sourceElement.SwitchName ?? $"{sourceElement.Name}",
switchValue)
as SourceSwitch;
}
catch (Exception ex)
{
throw new Exception($"Failed to load SourceSwitch '{sourceElement.SwitchName ?? sourceElement.Name}': {sourceElement.SwitchType}", ex);
}
}
else if (switches.TryGetValue(sourceElement.SwitchName, out Switch @switch))
{
if (@switch is TraceSwitch traceSwitch)
{
traceSource.Switch = new SourceSwitch(
sourceElement.SwitchName,
Enum.Parse(typeof(SourceLevels), Convert.ToString(traceSwitch.Level)).ToString());
}
else if (@switch is BooleanSwitch booleanSwitch)
{
traceSource.Switch = new SourceSwitch(
sourceElement.SwitchName,
booleanSwitch.Enabled
? $"{SourceLevels.All}"
: $"{SourceLevels.Off}");
}
else
{
// TODO: need to look through reference source
// and understand how switch configuration
// is done in net45 -- this behavior here
// is actually incorrect (and the behavior
// above is also not entirely proper, but
// does allow the use of switches as most
// developers would expect them to work via
// the config file.)
traceSource.Switch = new SourceSwitch(
sourceElement.SwitchName,
switchValue);
}
}
else
{
traceSource.Switch.Level = Enum.TryParse(switchValue, out SourceLevels sourceLevel)
? sourceLevel
: SourceLevels.All;
}
foreach (TraceListenerElement traceListenerElement in sourceElement.Listeners)
{
traceSource.Listeners.Remove(traceListenerElement.Name);
if (string.IsNullOrWhiteSpace(traceListenerElement.TypeName))
{
if (sharedListeners.TryGetValue(traceListenerElement.Name, out TraceListener traceListener))
{
traceSource.Listeners.Add(traceListener);
}
else
{
throw new Exception(
$"Source '{sourceElement.Name}' references shared listener '{traceListenerElement.Name}' which does not exist in `<sharedListeners/>`.");
}
}
else
{
traceSource.Listeners.Add(
InstantiateTraceListener(traceListenerElement));
}
}
sources.Add(traceSource.Name, traceSource);
}
}
return(sources);
}
