/**
* CloudGraph Community Edition (CE) License
*
* This is a community release of CloudGraph, a dual-license suite of
* Service Data Object (SDO) 2.1 services designed for relational and
* big-table style "cloud" databases, such as HBase and others.
* This particular copy of the software is released under the
* version 2 of the GNU General Public License. CloudGraph was developed by
* TerraMeta Software, Inc.
*
* Copyright (c) 2013, TerraMeta Software, Inc. All rights reserved.
*
* General License information can be found below.
*
* This distribution may include materials developed by third
* parties. For license and attribution notices for these
* materials, please refer to the documentation that accompanies
* this distribution (see the "Licenses for Third-Party Components"
* appendix) or view the online documentation at
* <http://cloudgraph.org/licenses/>.
*/
package org.cloudgraph.hbase.io;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.UUID;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.cloudgraph.common.CloudGraphConstants;
import org.cloudgraph.hbase.key.CompositeRowKeyFactory;
import org.plasma.sdo.PlasmaDataGraph;
import org.plasma.sdo.PlasmaDataObject;
import org.plasma.sdo.PlasmaType;
import org.plasma.sdo.core.CoreDataObject;
import commonj.sdo.DataObject;
public abstract class WriterSupport {
private static Log log = LogFactory.getLog(WriterSupport.class);
protected Map<DataObject, RowWriter> rowWriterMap = new HashMap<DataObject, RowWriter>();
protected WriterSupport() {
}
/**
* Finds and return the row writer associated with the container
* for the given target data object
* @param target the target data object
* @return the row writer associated with the container
* for the given target data object
* @throws OperationException if no row writer found
*/
protected RowWriter getContainerRowWriter(DataObject target) {
RowWriter result = findContainerRowWriter(target);
if (result == null)
throw new OperationException("no row writer associated with data object, "
+ String.valueOf(target) + ", or its containment ancestry");
return result;
}
/**
* Finds and return the row writer associated with the
* given target data object
* @param target the target data object
* @return the row writer associated with the
* given target data object, or null if no writer found
*/
protected RowWriter findContainerRowWriter(DataObject target) {
RowWriter result = null;
DataObject container = target.getContainer();
while (container != null) {
if (log.isDebugEnabled())
log.debug("checking " + container + " container for " + target);
result = this.rowWriterMap.get(container);
if (result != null)
return result;
container = container.getContainer();
}
return null;
}
/**
* Traverses the container links for the given data object
* returning the ancestry as an ordered list.
* @param target
* @return
*/
protected List<DataObject> getContainerAncestry(DataObject target) {
List<DataObject> result = new ArrayList<DataObject>();
DataObject source = target.getContainer();
while (source != null) {
result.add(source);
source = source.getContainer();
}
return result;
}
/**
* Creates and returns a new row writer for the given (row root) data object.
* If an existing row key is set into the
* instance property collection for the (row root) data object, the existing
* row key is used, otherwise a row key is generated. For objects
* flagged as deleted in the SDO change summary, re-generating a row key
* may not be possible, as for deleted operations
* SDO requires the removal of all properties (other than
* read-only) for all deleted data objects. If such removed
* properties are required for a row key, this makes re-generation
* for the row key impossible, and the key generator will throw an error.
* @param tableWriter the table writer
* @param target the target (row root) data object
* @return the new row writer
* @throws IOException
*/
protected RowWriter createRowWriter(TableWriter tableWriter, DataObject target) throws IOException
{
CoreDataObject coreObject = (CoreDataObject)target;
byte[] rowKey = (byte[])coreObject.getValueObject().get(
CloudGraphConstants.ROW_KEY);
if (rowKey == null) {
CompositeRowKeyFactory rowKeyGen = new CompositeRowKeyFactory(
(PlasmaType)target.getType());
rowKey = rowKeyGen.createRowKeyBytes(target);
coreObject.getValueObject().put(
CloudGraphConstants.ROW_KEY, rowKey);
if (target.getDataGraph().getRootObject().equals(target)) // graph root object
((PlasmaDataGraph)target.getDataGraph()).setId(rowKey); // FIXME: snapshot map for this?
}
RowWriter rowWriter = this.createRowWriter(tableWriter,
target, rowKey);
return rowWriter;
}
/**
* Creates and returns a new row writer for the given (row root) data object.
* @param tableContext the table context
* @param dataObject the (row root) data object
* @param rowKey the existing row key
* @return the new row writer
* @throws IOException
*/
protected RowWriter createRowWriter(TableWriter tableContext,
DataObject dataObject,
byte[] rowKey) throws IOException
{
RowWriter rowContext =
new GraphRowWriter(rowKey, dataObject, tableContext);
UUID uuid = ((PlasmaDataObject)dataObject).getUUID();
tableContext.addRowWriter(uuid, rowContext);
return rowContext;
}
/**
* Creates adds and returns a new row writer for the given (row root)
* data object. If an existing row key is set into the
* instance property collection for the (row root) data object, the existing
* row key is used, otherwise a row key is generated. For objects
* flagged as deleted in the SDO change summary, re-generating a row key
* may not be possible, as for deleted operations
* SDO requires the removal of all properties (other than
* read-only) for all deleted data objects. If such removed
* properties are required for a row key, this makes re-generation
* for the row key impossible, and the key generator will throw an error.
* @param dataObject the target (row root) data object
* @param tableContext the table context
* @return the new row writer
* @throws IOException
*/
protected RowWriter addRowWriter(
DataObject dataObject,
TableWriter tableContext) throws IOException
{
byte[] rowKey = null;
CoreDataObject coreObject = (CoreDataObject)dataObject;
rowKey = (byte[])coreObject.getValueObject().get(
CloudGraphConstants.ROW_KEY);
if (rowKey == null) {
CompositeRowKeyFactory rowKeyGen = new CompositeRowKeyFactory(
(PlasmaType)dataObject.getType());
rowKey = rowKeyGen.createRowKeyBytes(dataObject);
coreObject.getValueObject().put(
CloudGraphConstants.ROW_KEY, rowKey);
}
RowWriter rowContext = new GraphRowWriter(
rowKey, dataObject, tableContext);
UUID uuid = ((PlasmaDataObject)dataObject).getUUID();
tableContext.addRowWriter(uuid, rowContext);
return rowContext;
}
}