org.cloudgraph.rdb.graph

Class ParallelGraphAssembler

java.lang.Object

org.cloudgraph.store.lang.AssemblerSupport

org.cloudgraph.store.lang.DefaultAssembler

org.cloudgraph.rdb.graph.ParallelGraphAssembler

All Implemented Interfaces:

LangStoreGraphAssembler, org.plasma.sdo.access.DataGraphAssembler

public class ParallelGraphAssembler
extends DefaultAssembler
implements LangStoreGraphAssembler

Constructs a data graph in parallel starting with a given root SDO type based on a given "selection graph", where processing proceeds as a breadth-first traversal and tasks/threads are dynamically added based on availability within a shared thread pool.

While the result graph may be of any arbitrary size or depth, because the traversal is breadth-first, many tasks are typically spawned at the "base" of the graph, exhausting the available pool threads. Each subgraph task can spawn further sub tasks based on thread availability, but typically this means each task will traverse and process a healthy segment of the total graph. Since the actual size or depth of the result graph is not known until discovered on traversal, a fixed number of parallel tasks cannot be initially created, but must be dynamically spawned during graph discovery.

The assembly is triggered by calling the GraphAssembler#assemble(List results) method which initializes the graph root and begins a breadth first traversal of the selection graph as represented in the underlying data store.

Various metrics for the assembly are collected using GraphMetricVisitor and are available as SDO instance properties.

Since:

0.6.2

Author:

Scott Cinnamond

See Also:

Selection, ParallelSubgraphTask, GraphMetricVisitor

Field Summary

Fields inherited from class org.cloudgraph.store.lang.DefaultAssembler

dataObjectMap, EMPTY_DATA_OBJECT_LIST, EMPTY_PROPERTY_SET, nameComparator, root, rootType, snapshotDate

Fields inherited from class org.cloudgraph.store.lang.AssemblerSupport

collector, statementExecutor, statementFactory

Constructor Summary

Constructors

Constructor and Description
ParallelGraphAssembler(org.plasma.sdo.PlasmaType rootType, org.plasma.query.collector.SelectionCollector collector, Timestamp snapshotDate, ConfigProps config, Connection con) Constructor.

Method Summary

Modifier and Type	Method and Description
void	assemble(List<org.plasma.sdo.access.provider.common.PropertyPair> results) Recursively re-constitutes a data graph distributed across multiple tables and/or rows, starting with the given result row.
protected void	assemble(org.plasma.sdo.PlasmaType targetType, org.plasma.sdo.PlasmaDataObject source, org.plasma.sdo.PlasmaProperty sourceProperty, List<org.plasma.sdo.access.provider.common.PropertyPair> childKeyPairs, int level)
protected org.plasma.sdo.PlasmaDataObject	createDataObject(List<org.plasma.sdo.access.provider.common.PropertyPair> row, org.plasma.sdo.PlasmaDataObject source, org.plasma.sdo.PlasmaProperty sourceProperty)
ConfigProps	getConfig()
ThreadPoolExecutor	getExecutorService()
protected void	link(org.plasma.sdo.PlasmaDataObject target, org.plasma.sdo.PlasmaDataObject source, org.plasma.sdo.PlasmaProperty sourceProperty)
void	logPoolStatistics()
int	numThreadsAvailable()
boolean	threadsAvailable()

Methods inherited from class org.cloudgraph.store.lang.DefaultAssembler

clear, collectResults, createHashKey, findDataObject, getDataGraph, initRoot

Methods inherited from class org.cloudgraph.store.lang.AssemblerSupport

findNextKeyValue, getChildKeyPairs, getChildKeyPairs, getChildKeyProps, getNextKeyPairs, getPredicateResult, getStatementExecutor, getStatementFactory, throwPriKeyError

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.plasma.sdo.access.DataGraphAssembler

clear, getDataGraph

Constructor Detail

ParallelGraphAssembler

public ParallelGraphAssembler(org.plasma.sdo.PlasmaType rootType,
                              org.plasma.query.collector.SelectionCollector collector,
                              Timestamp snapshotDate,
                              ConfigProps config,
                              Connection con)

Constructor.

Parameters:

rootType - the SDO root type for the result data graph

collector - selected SDO properties. Properties are mapped by selected types required in the result graph.

snapshotDate - the query snapshot date which is populated into every data object in the result data graph.

minPoolSize - the minimum or core size of the underlying thread pool used for all tasks executed under this assembler

maxPoolSize - the maximum size of the underlying thread pool used for all tasks executed under this assembler

con -

Method Detail

getExecutorService

public ThreadPoolExecutor getExecutorService()

getConfig

public ConfigProps getConfig()

link

protected void link(org.plasma.sdo.PlasmaDataObject target,
                    org.plasma.sdo.PlasmaDataObject source,
                    org.plasma.sdo.PlasmaProperty sourceProperty)

Overrides:

link in class DefaultAssembler

createDataObject

protected org.plasma.sdo.PlasmaDataObject createDataObject(List<org.plasma.sdo.access.provider.common.PropertyPair> row,
                                                           org.plasma.sdo.PlasmaDataObject source,
                                                           org.plasma.sdo.PlasmaProperty sourceProperty)

Overrides:

createDataObject in class DefaultAssembler

assemble

public void assemble(List<org.plasma.sdo.access.provider.common.PropertyPair> results)

Recursively re-constitutes a data graph distributed across multiple tables and/or rows, starting with the given result row.

To retrieve the graph use DefaultAssembler.getDataGraph().

Specified by:

assemble in interface LangStoreGraphAssembler

Specified by:

assemble in class DefaultAssembler

Parameters:

results - the result row.

assemble

protected void assemble(org.plasma.sdo.PlasmaType targetType,
                        org.plasma.sdo.PlasmaDataObject source,
                        org.plasma.sdo.PlasmaProperty sourceProperty,
                        List<org.plasma.sdo.access.provider.common.PropertyPair> childKeyPairs,
                        int level)

Specified by:

assemble in class DefaultAssembler

logPoolStatistics

public void logPoolStatistics()

threadsAvailable

public boolean threadsAvailable()

numThreadsAvailable

public int numThreadsAvailable()