Package io.camunda.zeebe.engine

Class Engine

java.lang.Object

io.camunda.zeebe.engine.Engine

All Implemented Interfaces:

RecordProcessor<EngineContext>

public class Engine
extends Object
implements RecordProcessor<EngineContext>

Constructor Summary

Constructors

Constructor	Description
Engine()

Method Summary

Modifier and Type	Method	Description
void	init(EngineContext engineContext)	Called by platform to initialize the processor
ProcessingResult	onProcessingError(Throwable processingException, TypedRecord record, ProcessingResultBuilder processingResultBuilder)	Called by platform when a processing error occurred
ProcessingResult	process(TypedRecord record, ProcessingResultBuilder processingResultBuilder)	Called by platform to process a single record
void	replay(TypedRecord event)	Called by platform in order to replay a single record

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Engine

public Engine()

Method Details

init

public void init(EngineContext engineContext)

Description copied from interface: RecordProcessor

Called by platform to initialize the processor

Specified by:

init in interface RecordProcessor<EngineContext>

Parameters:

engineContext - context object to initialize the processor

replay

public void replay(TypedRecord event)

Description copied from interface: RecordProcessor

Called by platform in order to replay a single record

Contract

• Record will be an event
• Will be called before processing is called
• Implementors can write to the database. Transaction is provided by platform, which also takes care of lifecycle of the transaction
• Implementors must not write to the log stream
• Implementors must not schedule post commit tasks

Specified by:

replay in interface RecordProcessor<EngineContext>

Parameters:

event - the record to replay

process

public ProcessingResult process(TypedRecord record,
 ProcessingResultBuilder processingResultBuilder)

Description copied from interface: RecordProcessor

Called by platform to process a single record

Contract * *

*
• Record will be a command
• Will be called after replay is called
• Implementors can write to the database. Transaction is provided by platform, which also * takes care of lifecycle of the transaction
• Implementors must ensure that if they generate follow up events, these are applied to the database while this method is called
• Implementors can produce follow up commands and events, client responses and on commit tasks via processingResultBuilder
• Implementors can indicate that the record should be skipped by returning EmptyProcessingResult.INSTANCE

Specified by:

process in interface RecordProcessor<EngineContext>

Returns:

the result of the processing; must be generated via processingResultBuilder.build()

onProcessingError

public ProcessingResult onProcessingError(Throwable processingException,
 TypedRecord record,
 ProcessingResultBuilder processingResultBuilder)

Description copied from interface: RecordProcessor

Called by platform when a processing error occurred

Specified by:

onProcessingError in interface RecordProcessor<EngineContext>

Returns:

the result of the processing; must be generated via ProcessingResultBuilder processingResultBuilder