/**
* 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.graph;
import java.io.IOException;
import java.sql.Timestamp;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import java.util.UUID;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.filter.FilterList;
import org.apache.hadoop.hbase.util.Bytes;
import org.cloudgraph.common.CloudGraphConstants;
import org.cloudgraph.config.TableConfig;
import org.cloudgraph.hbase.filter.GraphFetchColumnFilterAssembler;
import org.cloudgraph.hbase.io.RowReader;
import org.cloudgraph.hbase.io.TableReader;
import org.cloudgraph.hbase.service.HBaseDataConverter;
import org.cloudgraph.hbase.util.FilterUtil;
import org.cloudgraph.state.GraphState;
import org.cloudgraph.store.service.GraphServiceException;
import org.plasma.query.collector.Selection;
import org.plasma.sdo.PlasmaDataGraph;
import org.plasma.sdo.PlasmaDataObject;
import org.plasma.sdo.PlasmaProperty;
import org.plasma.sdo.PlasmaType;
import org.plasma.sdo.core.CoreConstants;
import org.plasma.sdo.core.CoreNode;
import org.plasma.sdo.helper.PlasmaDataFactory;
import commonj.sdo.DataObject;
import commonj.sdo.Property;
/**
* Supports both distributed and non-distributed graph assemblers by
* providing default functionality.
* @author Scott Cinnamond
* @since 0.5.1
*/
public abstract class DefaultAssembler {
private static Log log = LogFactory.getLog(DefaultAssembler.class);
protected PlasmaType rootType;
protected PlasmaDataObject root;
protected TableReader rootTableReader;
protected Selection selection;
protected Timestamp snapshotDate;
@SuppressWarnings("unused")
private DefaultAssembler() {}
/**
* Constructor.
* @param rootType the SDO root type for the result data graph
* @param selection the selection properties for the graph to assemble.
* @param snapshotDate the query snapshot date which is populated
* into every data object in the result data graph.
*/
public DefaultAssembler(PlasmaType rootType,
Selection selection,
TableReader rootTableReader,
Timestamp snapshotDate) {
this.rootType = rootType;
this.selection = selection;
this.rootTableReader = rootTableReader;
this.snapshotDate = snapshotDate;
if (this.snapshotDate == null)
throw new IllegalArgumentException("expected snapshotDate");
}
/**
* Returns the assembled data graph.
*/
public PlasmaDataGraph getDataGraph() {
return (PlasmaDataGraph)this.root.getDataGraph();
}
protected PlasmaDataObject createRoot(Result resultRow) {
// build the graph
PlasmaDataGraph dataGraph = PlasmaDataFactory.INSTANCE.createDataGraph();
dataGraph.setId(resultRow.getRow());
PlasmaDataObject rootObject = (PlasmaDataObject)dataGraph.createRootObject(this.rootType);
CoreNode rootNode = (CoreNode)rootObject;
// add concurrency fields
rootNode.setValue(CoreConstants.PROPERTY_NAME_SNAPSHOT_TIMESTAMP, snapshotDate);
rootNode.getValueObject().put(
CloudGraphConstants.GRAPH_NODE_THREAD_NAME,
Thread.currentThread().getName());
// need to reconstruct the original graph, so need original UUID
byte[] rootUuid = resultRow.getValue(Bytes.toBytes(
this.rootTableReader.getTableConfig().getDataColumnFamilyName()),
Bytes.toBytes(GraphState.ROOT_UUID_COLUMN_NAME));
if (rootUuid == null)
throw new GraphServiceException("expected column: "
+ this.rootTableReader.getTableConfig().getDataColumnFamilyName() + ":"
+ GraphState.ROOT_UUID_COLUMN_NAME);
String uuidStr = null;
uuidStr = new String(rootUuid,
this.rootTableReader.getTableConfig().getCharset());
UUID uuid = UUID.fromString(uuidStr);
rootObject.resetUUID(uuid);
return rootObject;
}
/**
* Populates data properties for the given target data object using
* the given property name list.
* @param target the data object to populate
* @param names the property names
* @param rowReader the row reader
* @throws IOException if a remote or network exception occurs.
*/
protected void assembleData(PlasmaDataObject target,
Set<Property> props,
RowReader rowReader) throws IOException
{
CoreNode targetDataNode = (CoreNode)target;
TableReader tableReader = rowReader.getTableReader();
TableConfig tableConfig = tableReader.getTableConfig();
// add concurrency fields
targetDataNode.setValue(CoreConstants.PROPERTY_NAME_SNAPSHOT_TIMESTAMP, snapshotDate);
// data props
for (Property p : props) {
PlasmaProperty prop = (PlasmaProperty)p;
if (!prop.getType().isDataType())
continue;
byte[] keyValue = getColumnValue(target, prop,
tableConfig, rowReader);
if (keyValue == null || keyValue.length == 0 ) {
continue; // zero length can happen on modification or delete as we keep cell history
}
Object value = HBaseDataConverter.INSTANCE.fromBytes(prop,
keyValue);
if (log.isDebugEnabled())
log.debug("set: (" + prop.getName() + ") " + String.valueOf(value));
if (!prop.isReadOnly()) {
target.set(prop, value);
}
else {
targetDataNode.setValue(prop.getName(),
value);
}
}
}
/**
* Returns a value for the given property from the given row reader
* by generating a column qualifier based on column key model
* configurations settings, graph state information and other
* factors. Returns null if the qualifier does not exist.
* @param target the data object
* @param prop the property
* @param tableConfig the table configuration
* @param rowReader the row reader
* @return a value for the given property from the given row reader
* by generating a column qualifier based on column key model
* configurations settings, graph state information and other factors.
* @throws IOException if a remote or network exception occurs.
*/
protected byte[] getColumnValue(PlasmaDataObject target,
PlasmaProperty prop, TableConfig tableConfig,
RowReader rowReader) throws IOException
{
byte[] family = tableConfig.getDataColumnFamilyNameBytes();
byte[] qualifier = rowReader.getColumnKeyFactory().getColumnKey(
target, prop);
if (!rowReader.getRow().containsColumn(family, qualifier)) {
if (log.isDebugEnabled()) {
String qualifierStr = Bytes.toString(qualifier);
log.debug("qualifier not found: "
+ qualifierStr + " - continuing...");
}
return null;
}
return rowReader.getRow().getColumnValue(
family, qualifier);
}
/**
* Associates the source data object with the target as a non-containment
* reference.
* @param target the data object target
* @param source the data object source
* @param sourceProperty the reference property
* @throws IllegalStateException if the target data object does not have a container
*/
@SuppressWarnings("unchecked")
protected void link(PlasmaDataObject target, PlasmaDataObject source,
Property sourceProperty)
{
if (log.isDebugEnabled())
log.debug("linking source/target (" + source.toString() + "->("
+ target.toString());
if (sourceProperty.isMany()) {
PlasmaProperty opposite = (PlasmaProperty)sourceProperty.getOpposite();
if (opposite != null && !opposite.isMany() && target.isSet(opposite)) {
PlasmaDataObject existingOpposite = (PlasmaDataObject)target.get(opposite);
if (existingOpposite != null) {
if (log.isDebugEnabled())
log.debug("found existing opposite value (" + existingOpposite.toString()
+ ") for source/target "
+ sourceProperty.toString() + "->"
+ target.toString() + " - no link created");
return;
}
}
List<DataObject> list = source.getList(sourceProperty);
if (list == null)
list = new ArrayList<DataObject>();
if (!list.contains(target)) {
// check if any existing list members already have the opposite property set
for (DataObject existing : list) {
if (opposite != null && !opposite.isMany() && existing.isSet(opposite)) {
PlasmaDataObject existingOpposite = (PlasmaDataObject)existing.get(opposite);
if (existingOpposite != null) {
if (log.isDebugEnabled())
log.debug("(2)found existing opposite value (" + existingOpposite.toString()
+ ") for source/target "
+ sourceProperty.toString() + "->"
+ target.toString() + " - no link created");
return;
}
}
}
if (log.isDebugEnabled())
log.debug("adding target " + source.toString()
+ "." + sourceProperty.getName() + "->" + target.toString());
if (target.getContainer() == null) {
if (source.getDataGraph().getRootObject().equals(target)) {
log.warn("linking root object, " + target.toString() + " to source, "
+ source.toString());
}
else
throw new IllegalStateException("the given target has no container: " + target.toString());
}
list.add(target);
source.setList(sourceProperty, list);
}
}
else {
PlasmaDataObject existing = (PlasmaDataObject)source.get(sourceProperty);
if (existing == null) {
if (target.getContainer() == null) {
if (source.getDataGraph().getRootObject().equals(target)) {
log.warn("linking root object, " + target.toString() + " to source, "
+ source.toString());
}
else
throw new IllegalStateException("the given target has no container: " + target.toString());
}
source.set(sourceProperty, target);
}
else
if (!existing.equals(target))
if (log.isDebugEnabled())
log.debug("found existing value (" + existing.toString()
+ ") while creating source/target link " + source.toString()
+ "." + sourceProperty.toString() + "->"
+ target.toString());
}
}
/**
* Returns the selection graph as a single result.
* @param rowKey the row key
* @param tableReader the table reader
* @param dataObject the
* @return the selection graph as a single result.
* @throws IOException if a remote or network exception occurs.
* @see GraphFetchColumnFilterAssembler
*/
protected Result fetchGraph(byte[] rowKey, TableReader tableReader,
PlasmaType type) throws IOException {
Get row = new Get(rowKey);
FilterList rootFilter = new FilterList(
FilterList.Operator.MUST_PASS_ALL);
row.setFilter(rootFilter);
GraphFetchColumnFilterAssembler columnFilterAssembler =
new GraphFetchColumnFilterAssembler(
this.selection, type);
rootFilter.addFilter(columnFilterAssembler.getFilter());
long before = System.currentTimeMillis();
if (log.isDebugEnabled() )
log.debug("filter: " + FilterUtil.printFilterTree(rootFilter));
if (log.isDebugEnabled() )
log.debug("executing get...");
Result result = tableReader.getTable().get(row);
if (result == null || result.isEmpty())
throw new GraphServiceException("expected result from table "
+ tableReader.getTableConfig().getName() + " for row '"
+ new String(rowKey) + "'");
if (log.isTraceEnabled()) {
log.trace("row: " + new String(result.getRow()));
for (KeyValue keyValue : result.list()) {
log.trace("\tkey: "
+ new String(keyValue.getQualifier())
+ "\tvalue: " + new String(keyValue.getValue()));
}
}
long after = System.currentTimeMillis();
if (log.isDebugEnabled() )
log.debug("assembled 1 results ("
+ String.valueOf(after - before) + ")");
return result;
}
}