com.pervasive.datarush.operators

Interface ExecutionContext

All Superinterfaces:

MetadataContext

public interface ExecutionContext
extends MetadataContext

Execution context passed to ExecutableOperator.execute(ExecutionContext). This contains methods for looking up physical ports associated with logical ports and other execution-time information.

See Also:

ExecutableOperator

Method Summary

Modifier and Type	Method and Description
Path	allocateTemporaryStorage() Allocates space for storing a temporary file or files.
DistributedCallableContext	getDistributedCallableContext() Public only as a matter if implementation; operator authors should not invoke this method.
FileClient	getFileClient() Returns the file client to be used within the graph
PhysicalInputPort	getInputPort(LogicalPort logicalPort) Returns the physical port for the given logical port.
PhysicalInputPort	getInputPort(LogicalPort logicalPort, int copyNumber) Returns the physical port for the given logical port.
IOMonitoringContext	getIOMonitor() Returns a monitoring context to allow I/O operators to report statistics.
NodeAllocationPlan	getNodeAllocation() Returns the initial node allocation for the graph to which this operator belongs.
PhysicalOutputPort	getOutputPort(LogicalPort logicalPort) Returns the physical port for the given logical port.
PartitionInstanceInfo	getPartitionInfo() Returns partition id information for the partition being executed.
RecordInputSelector	getRecordInputSelector(List<RecordInput> inputs) Creates a selector over the specified inputs.
StatisticsRegistry	getStatisticsRegistry() Returns a statistics registry that can be used for registering custom statistics.
LogicalGraph	newSubgraph() Creates a new subgraph to use within this execution context.
LogicalGraph	newSubgraph(String name) Creates a new subgraph to use within this execution context.

Methods inherited from interface com.pervasive.datarush.operators.MetadataContext

getCombinedMetadata, getEngineConfig, getMaxParallelism, getPath, getRequiredMetadata, getSourceMaxParallelism, getSourceMetadata, isParallel, isSourceConnected, isSourceParallel

Method Detail

getFileClient

FileClient getFileClient()

Returns the file client to be used within the graph

The resulting client is initially instrumented using the monitoring context returned from getIOMonitor(). Therefore file I/O statistics will be collected by default on any file opened using the client.

Specified by:

getFileClient in interface MetadataContext

Returns:

the file client to be used for all file access

getPartitionInfo

PartitionInstanceInfo getPartitionInfo()

Returns partition id information for the partition being executed. Most operators should not need to call this method since their output will tend to be a function of the input. This is commonly used for I/O operators which, for example, must chose the output file name based on the partition ID.

Returns:

partition id information for the partition being executed.

getInputPort

PhysicalInputPort getInputPort(LogicalPort logicalPort)

Returns the physical port for the given logical port. Note that operators should generally not call this method directly. Rather they should use one of the type-safe/convenience methods on the various subclasses of LogicalPort. For example:

    //get the physical port for the "input" RecordPort
    input.getInput(ctx)
 

Parameters:

logicalPort - the logical input port

Returns:

the physical port

getInputPort

PhysicalInputPort getInputPort(LogicalPort logicalPort,
                               int copyNumber)

Returns the physical port for the given logical port. This is a rarely-used method, for processes that need multiple readers for a given input. Note that operators should generally not call this method directly. Rather they should use one of the type-safe/convenience methods on the various subclasses of LogicalPort. For example:

    //get the physical port for the "input" RecordPort
    input.getInput(ctx,copyNumber)
 

Parameters:

logicalPort - the logical input port

copyNumber - the copy number

Returns:

the physical port

getOutputPort

PhysicalOutputPort getOutputPort(LogicalPort logicalPort)

Returns the physical port for the given logical port. Note that operators should generally not call this method directly. Rather they should use one of the type-safe/convenience methods on the various subclasses of LogicalPort. For example:

    //get the physical port for the "output" RecordPort
    output.getOutput(ctx)
 

Parameters:

logicalPort - the logical output port

Returns:

the physical port

getIOMonitor

IOMonitoringContext getIOMonitor()

Returns a monitoring context to allow I/O operators to report statistics.

Returns:

a monitoring context

getNodeAllocation

NodeAllocationPlan getNodeAllocation()

Returns the initial node allocation for the graph to which this operator belongs.

Returns:

the node allocation

allocateTemporaryStorage

Path allocateTemporaryStorage()

Allocates space for storing a temporary file or files. The returned path is guaranteed to be unique and can be safely used as a file or as a base path for temporary files. Files so created are stored within the temporary storage locations specified by the engine configuration.

The temporary storage is not valid for use outside the scope of the ExecutableOperator.execute(ExecutionContext) method. The caller is responsible for cleaning up any files written in the allocated location, even on failure of the executing graph. It is therefore recommended to wrap the using code in the scope of a try-finally block.

Returns:

a path to use as the base location for any temporary files

getDistributedCallableContext

DistributedCallableContext getDistributedCallableContext()

Public only as a matter if implementation; operator authors should not invoke this method.

Returns the distributed callable context in which we are being executed.

Returns:

the distributed context

getStatisticsRegistry

StatisticsRegistry getStatisticsRegistry()

Returns a statistics registry that can be used for registering custom statistics.

Returns:

the statistics registry.

newSubgraph

LogicalGraph newSubgraph()

Creates a new subgraph to use within this execution context. The subgraph will have its default engine config set to the same value returned by MetadataContext.getEngineConfig(). Statistics calculated by the subgraph will be aggregated and will appear in the statistics of this operator.

Returns:

a new subgraph

newSubgraph

LogicalGraph newSubgraph(String name)

Creates a new subgraph to use within this execution context. The subgraph will have its default engine config set to the same value returned by MetadataContext.getEngineConfig(). Statistics calculated by the subgraph will be aggregated and will appear in the statistics of this operator.

Parameters:

name - the name of the subgraph

Returns:

a new subgraph

getRecordInputSelector

RecordInputSelector getRecordInputSelector(List<RecordInput> inputs)

Creates a selector over the specified inputs. This selector can be used to wait for data to arrive on any of the input ports.

Parameters:

inputs - the set of input ports to register with the selector

Returns:

a new selector for waiting on inputs