org.cloudgraph.hbase.graph

Class DistributedAssembler

java.lang.Object

org.cloudgraph.hbase.graph.DefaultAssembler

org.cloudgraph.hbase.graph.DistributedAssembler

All Implemented Interfaces:

HBaseGraphAssembler, org.plasma.sdo.access.DataGraphAssembler

Direct Known Subclasses:

GraphAssembler, GraphSliceAssembler, ParallelGraphAssembler, ParallelGraphSliceAssembler

public abstract class DistributedAssembler
extends DefaultAssembler
implements HBaseGraphAssembler

Supports the assembly of a directed data graph which may span multiple HBase tables and/or rows by maintaining a stack of row readers annotated with graph "level" and other information. This allows a specific row reader to be determined for any data object within a graph based entirely or in part on its level within the graph. This is essential for data object types which are not configured as root types within any table, and yet a specific row reader must be determined.

Since:

0.5.1

Author:

Scott Cinnamond

See Also:

DistributedReader, TableReader, RowReader

Field Summary

Fields

Modifier and Type	Field and Description
protected DistributedReader	distributedReader

Fields inherited from class org.cloudgraph.hbase.graph.DefaultAssembler

charset, graph, keyFactories, root, rootTableReader, rootType, selection, snapshotDate

Constructor Summary

Constructors

Constructor and Description
DistributedAssembler(org.plasma.sdo.PlasmaType rootType, org.plasma.query.collector.Selection selection, DistributedReader distributedReader, Timestamp snapshotDate) Constructor.

Method Summary

Modifier and Type	Method and Description
void	assemble(CellValues resultRow) Recursively re-constitutes a data graph distributed across multiple HBase tables and/or rows, starting with the given HBase client result row.
protected abstract void	assemble(org.plasma.sdo.PlasmaDataObject target, long targetSequence, EdgeReader collection, org.plasma.sdo.PlasmaDataObject source, org.plasma.sdo.PlasmaProperty sourceProperty, RowReader rowReader, int level) Populates the given data object target, recursively fetching data for and linking related data objects which make up the resulting directed graph.
protected void	assembleEdge(long childSequence, EdgeReader collection, RowReader childRowReader, org.plasma.sdo.PlasmaDataObject source, long sourceSequence, org.plasma.sdo.PlasmaProperty sourceProperty, int level)
protected void	assembleExternalEdge(CellValues childValues, EdgeReader edgeReader, TableReader childTableReader, org.plasma.sdo.PlasmaDataObject source, long sourceSequence, org.plasma.sdo.PlasmaProperty sourceProperty, int level)
void	clear() Resets the assembler.

Methods inherited from class org.cloudgraph.hbase.graph.DefaultAssembler

assembleData, assembleUUID, createChild, createChild, createChild, createRoot, fetchGraph, fetchRootType, fetchRootUUID, fetchType, fetchUUID, findMetaDataColumnValue, findMetaDataColumnValue, findRootType, findRootUUID, getDataColumnValue, getDataColumnValue, getDataGraph, getKeyFactory, getMetaDataColumnValue, getMetaDataColumnValue, getProperties, getProperties, link

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

getDataGraph

Field Detail

distributedReader

protected DistributedReader distributedReader

Constructor Detail

DistributedAssembler

public DistributedAssembler(org.plasma.sdo.PlasmaType rootType,
                            org.plasma.query.collector.Selection selection,
                            DistributedReader distributedReader,
                            Timestamp snapshotDate)

Constructor.

Parameters:

rootType - the distributed graph root type

selection - the selection collector

distributedReader - the distributed reader

snapshotDate - the query snapshot date

Method Detail

assemble

public void assemble(CellValues resultRow)

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

To retrieve the graph use DefaultAssembler.getDataGraph(). a map of selected SDO properties. Properties are mapped by selected types required in the result graph.

Specified by:

assemble in interface HBaseGraphAssembler

Parameters:

resultRow - the HBase client result (row).

assemble

protected abstract void assemble(org.plasma.sdo.PlasmaDataObject target,
                                 long targetSequence,
                                 EdgeReader collection,
                                 org.plasma.sdo.PlasmaDataObject source,
                                 org.plasma.sdo.PlasmaProperty sourceProperty,
                                 RowReader rowReader,
                                 int level)
                          throws IOException

Populates the given data object target, recursively fetching data for and linking related data objects which make up the resulting directed graph.

Parameters:

targetSequence - the current data object sequence

source - the source or parent data object

sourceProperty - the source (reference) property

rowReader - the current row reader

level - the current graph level

Throws:

IOException - if a remote or network exception occurs.

assembleEdge

protected void assembleEdge(long childSequence,
                            EdgeReader collection,
                            RowReader childRowReader,
                            org.plasma.sdo.PlasmaDataObject source,
                            long sourceSequence,
                            org.plasma.sdo.PlasmaProperty sourceProperty,
                            int level)
                     throws IOException

Throws:

IOException

assembleExternalEdge

protected void assembleExternalEdge(CellValues childValues,
                                    EdgeReader edgeReader,
                                    TableReader childTableReader,
                                    org.plasma.sdo.PlasmaDataObject source,
                                    long sourceSequence,
                                    org.plasma.sdo.PlasmaProperty sourceProperty,
                                    int level)
                             throws IOException

Throws:

IOException

clear

public void clear()

Resets the assembler.

Specified by:

clear in interface org.plasma.sdo.access.DataGraphAssembler