private IEnumerable <Type> PrepareComposerTypes()
{
// create a list, remove those that cannot be enabled due to runtime level
var composerTypeList = _composerTypes
.Where(x =>
{
// use the min/max levels specified by the attribute if any
// otherwise, min: user composers are Run, anything else is Unknown (always run)
// max: everything is Run (always run)
var attr = x.GetCustomAttribute <RuntimeLevelAttribute>();
var minLevel = attr?.MinLevel ?? (x.Implements <IUserComposer>() ? RuntimeLevel.Run : RuntimeLevel.Unknown);
var maxLevel = attr?.MaxLevel ?? RuntimeLevel.Run;
return(_composition.RuntimeState.Level >= minLevel && _composition.RuntimeState.Level <= maxLevel);
})
.ToList();
// enable or disable composers
EnableDisableComposers(composerTypeList);
// sort the composers according to their dependencies
var requirements = new Dictionary <Type, List <Type> >();
foreach (var type in composerTypeList)
{
requirements[type] = null;
}
foreach (var type in composerTypeList)
{
GatherRequirementsFromRequireAttribute(type, composerTypeList, requirements);
GatherRequirementsFromRequiredByAttribute(type, composerTypeList, requirements);
}
// only for debugging, this is verbose
//_logger.Debug<Composers>(GetComposersReport(requirements));
// sort composers
var graph = new TopoGraph <Type, KeyValuePair <Type, List <Type> > >(kvp => kvp.Key, kvp => kvp.Value);
graph.AddItems(requirements);
List <Type> sortedComposerTypes;
try
{
sortedComposerTypes = graph.GetSortedItems().Select(x => x.Key).ToList();
}
catch (Exception e)
{
// in case of an error, force-dump everything to log
_logger.Info <Composers>("Composer Report:\r\n{ComposerReport}", GetComposersReport(requirements));
_logger.Error <Composers>(e, "Failed to sort composers.");
throw;
}
// bit verbose but should help for troubleshooting
//var text = "Ordered Composers: " + Environment.NewLine + string.Join(Environment.NewLine, sortedComposerTypes) + Environment.NewLine;
_logger.Debug <Composers>("Ordered Composers: {SortedComposerTypes}", sortedComposerTypes);
return(sortedComposerTypes);
}
internal IEnumerable <Type> SortComposers(Dictionary <Type, List <Type> > requirements)
{
// sort composers
var graph = new TopoGraph <Type, KeyValuePair <Type, List <Type> > >(kvp => kvp.Key, kvp => kvp.Value);
graph.AddItems(requirements);
List <Type> sortedComposerTypes;
try
{
sortedComposerTypes = graph.GetSortedItems().Select(x => x.Key).Where(x => !x.IsInterface).ToList();
}
catch (Exception e)
{
// in case of an error, force-dump everything to log
_logger.LogInformation("Composer Report:\r\n{ComposerReport}", GetComposersReport(requirements));
_logger.LogError(e, "Failed to sort composers.");
throw;
}
return(sortedComposerTypes);
}