Package org.apache.heron.streamlet.impl

Class ContextImpl

java.lang.Object

org.apache.heron.streamlet.impl.ContextImpl

All Implemented Interfaces:

Context

public class ContextImpl
extends Object
implements Context

Context is the information available at runtime for operators like transform. It contains basic things like config, runtime information like task, the stream that it is operating on, ProcessState, etc.

Constructor Summary

Constructors

Constructor	Description
ContextImpl(TopologyContext topologyContext, Map<String,Object> topologyConfig, State<Serializable,Serializable> state)

Method Summary

Modifier and Type	Method	Description
Map<String,Object>	getConfig()	Fetches the config of the computation
State<Serializable,Serializable>	getState()	The state where components can store any of their local state
String	getStreamName()	The stream name that we are operating on
int	getStreamPartition()	The partition number that we are operating on
int	getTaskId()	Fetches the task id of the current instance of the operator
<T> void	registerMetric(String metricName, int collectionInterval, Supplier<T> metricFn)	Register a metric function.

Methods inherited from class java.lang.Object

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

Constructor Detail

ContextImpl

public ContextImpl(TopologyContext topologyContext,
                   Map<String,Object> topologyConfig,
                   State<Serializable,Serializable> state)

Method Detail

getTaskId

public int getTaskId()

Description copied from interface: Context

Fetches the task id of the current instance of the operator

Specified by:

getTaskId in interface Context

Returns:

the task id.

getConfig

public Map<String,Object> getConfig()

Description copied from interface: Context

Fetches the config of the computation

Specified by:

getConfig in interface Context

Returns:

config

getStreamName

public String getStreamName()

Description copied from interface: Context

The stream name that we are operating on

Specified by:

getStreamName in interface Context

Returns:

the stream name that we are operating on

getStreamPartition

public int getStreamPartition()

Description copied from interface: Context

The partition number that we are operating on

Specified by:

getStreamPartition in interface Context

Returns:

the partition number

registerMetric

public <T> void registerMetric(String metricName,
                               int collectionInterval,
                               Supplier<T> metricFn)

Description copied from interface: Context

Register a metric function. This function will be called by the system every collectionInterval seconds and the resulting value will be collected

Specified by:

registerMetric in interface Context

getState

public State<Serializable,Serializable> getState()

Description copied from interface: Context

The state where components can store any of their local state

Specified by:

getState in interface Context

Returns:

The state interface where users can store their local state