Much of the application's architecture is implemented through a series of classes that descend from the IApplicationActivity and IApplicationEvent interfaces. An activity is responsible for performing work in the processing pipeline. The pipline is set up so that more than one activity can be run at a time, controled by the number of worker processes that are handling the activities. Once an activity is done with its work, it generates an event. Events are responsible for knowing what activity should be dispatched next.
This approach allows us to have chunks of the application's processing pipeline isolated into neat chunks. Each one is easy to test and easy to reason about. Complications arise when we attempt to try to figure out how all the different activities and events are interacting with each other. The diagram below attempts to address this problem.
Here are some things to keep in mind when viewing the graph:
- Each box is a class that implements either the
IApplicationActivityorIApplicationEventinterface. - Each arrow with a solid line represents a "creates" relationship. The source class creates an instance of the destination class.
- Each arrow with a dotted line represents an "is a" relationship. The source class inherits from the destination class.
flowchart TD;
AgentsDetectedEvent -.-> ApplicationEventBase
AgentsDetectedEvent
DetectAgentsActivity --> AgentsDetectedEvent
NoAgentsDetectedFailureEvent -.-> FailureEvent
NoAgentsDetectedFailureEvent
AgentDetectedForDetectManifestEvent -.-> ApplicationEventBase
AgentDetectedForDetectManifestEvent --> DetectManifestsUsingAgentActivity
AgentDetectedForDetectManifestEvent --> FireHistoryStopPointProcessingErrorActivity
AnalysisFailureLoggedEvent -.-> ApplicationEventBase
AnalysisFailureLoggedEvent
AnalysisIdNotFoundEvent -.-> FailureEvent
AnalysisIdNotFoundEvent
AnalysisStartedEvent -.-> ApplicationEventBase
AnalysisStartedEvent --> CreateAnalysisApiActivity
CacheDoesNotExistEvent -.-> ErrorEvent
CacheDoesNotExistEvent --> PrepareCacheForAnalysisActivity
CachePreparedForAnalysisEvent -.-> ApplicationEventBase
CachePreparedForAnalysisEvent --> RestartAnalysisActivity
CachePrepareFailedForAnalysisEvent -.-> FailureEvent
CachePrepareFailedForAnalysisEvent
DetectAgentsForDetectManifestsActivity --> NoAgentsDetectedFailureEvent
DetectAgentsForDetectManifestsActivity --> AgentDetectedForDetectManifestEvent
DetectAgentsForDetectManifestsActivity --> HistoryStopPointProcessingFailedEvent
DetectManifestsUsingAgentActivity --> ManifestDetectedEvent
DetectManifestsUsingAgentActivity --> NoManifestsDetectedEvent
DetectManifestsUsingAgentActivity --> HistoryStopPointProcessingFailedEvent
ErrorEvent -.-> ApplicationEventBase
ErrorEvent
FailureEvent -.-> ErrorEvent
FailureEvent --> LogAnalysisFailureActivity
InvalidHistoryIntervalEvent -.-> FailureEvent
InvalidHistoryIntervalEvent
LogAnalysisFailureActivity --> AnalysisFailureLoggedEvent
ManifestDetectedEvent -.-> ApplicationEventBase
ManifestDetectedEvent --> GenerateBillOfMaterialsActivity
ManifestDetectedEvent --> FireHistoryStopPointProcessingErrorActivity
NoManifestsDetectedEvent -.-> ApplicationEventBase
NoManifestsDetectedEvent
PrepareCacheForAnalysisActivity --> CachePreparedForAnalysisEvent
PrepareCacheForAnalysisActivity --> CachePrepareFailedForAnalysisEvent
RestartAnalysisActivity -.-> StartAnalysisActivityBase
RestartAnalysisActivity --> UnableToRestartAnalysisEvent
StartAnalysisActivity -.-> StartAnalysisActivityBase
StartAnalysisActivity --> CacheDoesNotExistEvent
StartAnalysisActivityBase --> AnalysisStartedEvent
StartAnalysisActivityBase --> InvalidHistoryIntervalEvent
UnableToRestartAnalysisEvent -.-> FailureEvent
UnableToRestartAnalysisEvent
UnhandledExceptionEvent -.-> FailureEvent
UnhandledExceptionEvent
AnalysisApiCreatedEvent -.-> ApplicationEventBase
AnalysisApiCreatedEvent --> VerifyGitRepositoryInLocalDirectoryActivity
AnalysisApiCreatedEvent --> CloneGitRepositoryActivity
AnalysisApiStatusUpdatedEvent -.-> ApplicationEventBase
AnalysisApiStatusUpdatedEvent
ApiHistoryStopCreatedEvent -.-> ApplicationEventBase
ApiHistoryStopCreatedEvent --> CheckoutHistoryActivity
ApiPackageLibYearCreatedEvent -.-> ApplicationEventBase
ApiPackageLibYearCreatedEvent
CreateAnalysisApiActivity --> AnalysisApiCreatedEvent
CreateApiHistoryStopActivity --> ApiHistoryStopCreatedEvent
CreateApiPackageLibYearActivity --> ApiPackageLibYearCreatedEvent
CreateApiPackageLibYearActivity --> HistoryStopPointProcessingFailedEvent
UpdateAnalysisStatusActivity --> AnalysisApiStatusUpdatedEvent
AddLibYearMetadataDataToBomActivity --> LibYearMetadataAddedToBomEvent
AddLibYearMetadataDataToBomActivity --> HistoryStopPointProcessingFailedEvent
BillOfMaterialsGeneratedEvent -.-> ApplicationEventBase
BillOfMaterialsGeneratedEvent --> DeterminePackagesFromBomActivity
BillOfMaterialsGeneratedEvent --> FireHistoryStopPointProcessingErrorActivity
GenerateBillOfMaterialsActivity --> BillOfMaterialsGeneratedEvent
GenerateBillOfMaterialsActivity --> HistoryStopPointProcessingFailedEvent
LibYearMetadataAddedToBomEvent
PackagesFromBomProcessedEvent --> AddLibYearMetadataDataToBomActivity
PackagesFromBomProcessedEvent --> FireHistoryStopPointProcessingErrorActivity
CacheDestroyedEvent -.-> ApplicationEventBase
CacheDestroyedEvent
CacheDestroyFailedEvent -.-> ApplicationEventBase
CacheDestroyFailedEvent
CachePreparedEvent -.-> ApplicationEventBase
CachePreparedEvent
CachePrepareFailedEvent -.-> FailureEvent
CachePrepareFailedEvent
DestroyCacheActivity --> CacheDestroyedEvent
DestroyCacheActivity --> CacheDestroyFailedEvent
PrepareCacheActivity --> CachePreparedEvent
PrepareCacheActivity --> CachePrepareFailedEvent
LoadServiceProviderActivity
ThrowExceptionActivity
ApplicationEventBase
CloneGitRepositoryActivity --> AnalysisIdNotFoundEvent
CloneGitRepositoryActivity --> GitRepositoryCloneStartedEvent
CloneGitRepositoryActivity --> GitRepositoryClonedEvent
CloneGitRepositoryActivity --> CloneGitRepositoryFailedEvent
CloneGitRepositoryFailedEvent -.-> FailureEvent
CloneGitRepositoryFailedEvent
DirectoryDoesNotExistFailureEvent -.-> FailureEvent
DirectoryDoesNotExistFailureEvent
DirectoryIsNotGitInitializedFailureEvent -.-> FailureEvent
DirectoryIsNotGitInitializedFailureEvent
GitRepositoryClonedEvent -.-> ApplicationEventBase
GitRepositoryClonedEvent --> ComputeHistoryActivity
GitRepositoryCloneStartedEvent -.-> ApplicationEventBase
GitRepositoryCloneStartedEvent
GitRepositoryInLocalDirectoryVerifiedEvent -.-> ApplicationEventBase
GitRepositoryInLocalDirectoryVerifiedEvent --> ComputeHistoryActivity
VerifyGitRepositoryInLocalDirectoryActivity --> DirectoryDoesNotExistFailureEvent
VerifyGitRepositoryInLocalDirectoryActivity --> DirectoryIsNotGitInitializedFailureEvent
VerifyGitRepositoryInLocalDirectoryActivity --> GitRepositoryInLocalDirectoryVerifiedEvent
CheckoutHistoryActivity --> HistoryStopCheckedOutEvent
CheckoutHistoryActivity --> HistoryStopPointProcessingCompletedEvent
CheckoutHistoryActivity --> UnhandledExceptionEvent
ComputeHistoryActivity --> AnalysisIdNotFoundEvent
ComputeHistoryActivity --> InvalidHistoryIntervalEvent
ComputeHistoryActivity --> HistoryIntervalStopFoundEvent
FireHistoryStopPointProcessingErrorActivity --> HistoryStopPointProcessingFailedEvent
HistoryIntervalStopFoundEvent -.-> ApplicationEventBase
HistoryIntervalStopFoundEvent --> CreateApiHistoryStopActivity
HistoryStopCheckedOutEvent -.-> ApplicationEventBase
HistoryStopCheckedOutEvent --> DetectAgentsForDetectManifestsActivity
HistoryStopPointProcessingCompletedEvent -.-> ApplicationEventBase
HistoryStopPointProcessingCompletedEvent
HistoryStopPointProcessingFailedEvent -.-> UnhandledExceptionEvent
HistoryStopPointProcessingFailedEvent
ComputeLibYearForPackageActivity --> LibYearComputedForPackageEvent
ComputeLibYearForPackageActivity --> HistoryStopPointProcessingFailedEvent
DeterminePackagesFromBomActivity --> PackageFoundEvent
DeterminePackagesFromBomActivity --> NoPackagesFoundEvent
DeterminePackagesFromBomActivity --> HistoryStopPointProcessingFailedEvent
DeterminePackagesFromBomActivity --> PackagesFromBomProcessedEvent
DeterminePackagesFromBomActivity --> UnhandledExceptionEvent
LibYearComputationForBomStartedEvent -.-> ApplicationEventBase
LibYearComputationForBomStartedEvent
LibYearComputedForPackageEvent -.-> ApplicationEventBase
LibYearComputedForPackageEvent --> CreateApiPackageLibYearActivity
LibYearComputedForPackageEvent --> FireHistoryStopPointProcessingErrorActivity
NoPackagesFoundEvent -.-> ApplicationEventBase
NoPackagesFoundEvent
PackageFoundEvent -.-> ApplicationEventBase
PackageFoundEvent --> ComputeLibYearForPackageActivity