backtype.storm.task

Class TopologyContext

java.lang.Object

backtype.storm.task.GeneralTopologyContext

backtype.storm.task.WorkerTopologyContext

backtype.storm.task.TopologyContext

All Implemented Interfaces:

IMetricsContext, org.json.simple.JSONAware

Direct Known Subclasses:

BoltTopologyContext, SpoutTopologyContext

public class TopologyContext
extends WorkerTopologyContext
implements IMetricsContext

A TopologyContext is given to bolts and spouts in their "prepare" and "open" methods, respectively. This object provides information about the component's place within the topology, such as task ids, inputs and outputs, etc.

The TopologyContext is also used to declare ISubscribedState objects to synchronize state with StateSpouts this object is subscribed to.

Constructor Summary

Constructors

Constructor and Description
TopologyContext(StormTopology topology, java.util.Map<java.lang.String,java.lang.Object> stormConf, java.util.Map<java.lang.Integer,java.lang.String> taskToComponent, java.util.Map<java.lang.String,java.util.List<java.lang.Integer>> componentToSortedTasks, java.util.Map<java.lang.String,java.util.Map<java.lang.String,Fields>> componentToStreamToFields, java.lang.String stormId, java.lang.String codeDir, java.lang.String pidDir, java.lang.Integer taskId, java.lang.Integer workerPort, java.util.List<java.lang.Integer> workerTasks, java.util.Map<java.lang.String,java.lang.Object> defaultResources, java.util.Map<java.lang.String,java.lang.Object> userResources, java.util.Map<java.lang.String,java.lang.Object> executorData, java.util.Map<java.lang.String,java.lang.Object> registeredMetrics, clojure.lang.Atom openOrPrepareWasCalled)
TopologyContext(TopologyContext delegate)

Method Summary

Modifier and Type	Method and Description
void	addTaskHook(ITaskHook newHook)
java.util.Collection<ITaskHook>	getHooks()
java.lang.Object	getTaskData(java.lang.String name)
java.lang.String	getThisComponentId() Gets the component id for this task.
Fields	getThisOutputFields(java.lang.String streamId) Gets the declared output fields for the specified stream id for the component this task is a part of.
java.util.Set<java.lang.String>	getThisStreams() Gets the set of streams declared for the component of this task.
int	getThisTaskId() Gets the task id of this task.
int	getThisTaskIndex() Gets the index of this task id in getComponentTasks(getThisComponentId()).
CombinedMetric	registerMetric(java.lang.String name, ICombiner combiner, int timeBucketSizeInSecs)
ReducedMetric	registerMetric(java.lang.String name, IReducer reducer, int timeBucketSizeInSecs)
<T extends IMetric> T	registerMetric(java.lang.String name, T metric, int timeBucketSizeInSecs)
void	setTaskData(java.lang.String name, java.lang.Object data)

Methods inherited from class backtype.storm.task.WorkerTopologyContext

getCodeDir, getPIDDir, getResource, getSharedExecutor, getThisWorkerPort, getThisWorkerTasks

Methods inherited from class backtype.storm.task.GeneralTopologyContext

getComponentId, getComponentIds, getComponentOutputFields, getComponentStreams, getComponentTasks, getStormId, getTaskToComponent, toJSONString

Methods inherited from class java.lang.Object

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

Constructor Detail

TopologyContext

public TopologyContext(StormTopology topology,
                       java.util.Map<java.lang.String,java.lang.Object> stormConf,
                       java.util.Map<java.lang.Integer,java.lang.String> taskToComponent,
                       java.util.Map<java.lang.String,java.util.List<java.lang.Integer>> componentToSortedTasks,
                       java.util.Map<java.lang.String,java.util.Map<java.lang.String,Fields>> componentToStreamToFields,
                       java.lang.String stormId,
                       java.lang.String codeDir,
                       java.lang.String pidDir,
                       java.lang.Integer taskId,
                       java.lang.Integer workerPort,
                       java.util.List<java.lang.Integer> workerTasks,
                       java.util.Map<java.lang.String,java.lang.Object> defaultResources,
                       java.util.Map<java.lang.String,java.lang.Object> userResources,
                       java.util.Map<java.lang.String,java.lang.Object> executorData,
                       java.util.Map<java.lang.String,java.lang.Object> registeredMetrics,
                       clojure.lang.Atom openOrPrepareWasCalled)

TopologyContext

public TopologyContext(TopologyContext delegate)

Method Detail

getThisTaskId

public int getThisTaskId()

Gets the task id of this task.

Returns:

the task id

getThisComponentId

public java.lang.String getThisComponentId()

Gets the component id for this task. The component id maps to a component id specified for a Spout or Bolt in the topology definition.

getThisOutputFields

public Fields getThisOutputFields(java.lang.String streamId)

Gets the declared output fields for the specified stream id for the component this task is a part of.

getThisStreams

public java.util.Set<java.lang.String> getThisStreams()

Gets the set of streams declared for the component of this task.

getThisTaskIndex

public int getThisTaskIndex()

Gets the index of this task id in getComponentTasks(getThisComponentId()). An example use case for this method is determining which task accesses which resource in a distributed resource to ensure an even distribution.

setTaskData

public void setTaskData(java.lang.String name,
                        java.lang.Object data)

getTaskData

public java.lang.Object getTaskData(java.lang.String name)

addTaskHook

public void addTaskHook(ITaskHook newHook)

getHooks

public java.util.Collection<ITaskHook> getHooks()

registerMetric

public <T extends IMetric> T registerMetric(java.lang.String name,
                                            T metric,
                                            int timeBucketSizeInSecs)

Specified by:

registerMetric in interface IMetricsContext

registerMetric

public ReducedMetric registerMetric(java.lang.String name,
                                    IReducer reducer,
                                    int timeBucketSizeInSecs)

Specified by:

registerMetric in interface IMetricsContext

registerMetric

public CombinedMetric registerMetric(java.lang.String name,
                                     ICombiner combiner,
                                     int timeBucketSizeInSecs)

Specified by:

registerMetric in interface IMetricsContext