/**
* 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.cassandra.graph;
import java.sql.Timestamp;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.cloudgraph.cassandra.filter.CQLStatementExecutor;
import org.cloudgraph.cassandra.filter.CQLStatementFactory;
import org.cloudgraph.common.CloudGraphConstants;
import org.cloudgraph.common.concurrent.GraphMetricVisitor;
import org.cloudgraph.store.lang.DefaultAssembler;
import org.cloudgraph.store.lang.LangStoreGraphAssembler;
import org.plasma.query.collector.SelectionCollector;
import org.plasma.sdo.PlasmaDataObject;
import org.plasma.sdo.PlasmaProperty;
import org.plasma.sdo.PlasmaType;
import org.plasma.sdo.access.provider.common.PropertyPair;
import org.plasma.sdo.core.CoreNode;
import com.datastax.driver.core.Session;
import commonj.sdo.DataGraph;
import commonj.sdo.Property;
/**
* Constructs a data graph starting with a given root SDO type based on
* a "selection graph" of selected SDO properties, where properties are mapped by
* selected types required in the result graph.
* <p>
* The assembly is triggered by calling the
* {@link GraphAssembler#assemble(List<PropertyPair> results)} method which initializes
* the graph root and begins a breadth first traversal of the selection graph as
* represented in the underlying data store.
* <p>
* Various metrics for the assembly are collected using {@link GraphMetricVisitor} and
* are available as SDO instance properties.
*
* @see GraphMetricVisitor
*
* @author Scott Cinnamond
* @since 0.6.2
*/
public class GraphAssembler extends DefaultAssembler
implements LangStoreGraphAssembler {
private static Log log = LogFactory.getLog(GraphAssembler.class);
public GraphAssembler(PlasmaType rootType, SelectionCollector collector,
Timestamp snapshotDate, Session con) {
super(rootType, collector,
new CQLStatementFactory(), new CQLStatementExecutor(con),
new HashMap<Integer, PlasmaDataObject>(),
snapshotDate);
}
/**
* Initiates the assembly of a data graph based on the
* given results list.
* @param results the results list
*
* @see DataGraphAssembler.getDataGraph()
*/
@Override
public void assemble(List<PropertyPair> results) {
long before = System.currentTimeMillis();
DataGraph dataGraph = initRoot(results);
CoreNode rootNode = (CoreNode)dataGraph.getRootObject();
// singular reference props
for (PropertyPair pair : results) {
if (pair.getProp().isMany() || pair.getProp().getType().isDataType())
continue;
List<PropertyPair> childKeyProps = this.getChildKeyPairs(pair);
assemble((PlasmaType)pair.getProp().getType(),
(PlasmaDataObject)this.root, pair.getProp(),
childKeyProps, 1);
}
// multi reference props (not found in results)
Set<Property> props = this.collector.getProperties(this.rootType);
for (Property p : props) {
PlasmaProperty prop = (PlasmaProperty)p;
if (prop.isMany() && !prop.getType().isDataType()) {
List<PropertyPair> childKeyProps = this.getChildKeyPairs(root, prop);
assemble((PlasmaType)prop.getType(),
(PlasmaDataObject)this.root, prop,
childKeyProps, 1);
}
}
long after = System.currentTimeMillis();
rootNode.getValueObject().put(
CloudGraphConstants.GRAPH_ASSEMBLY_TIME,
Long.valueOf(after - before));
GraphMetricVisitor visitor = new GraphMetricVisitor();
this.root.accept(visitor);
rootNode.getValueObject().put(
CloudGraphConstants.GRAPH_NODE_COUNT,
Long.valueOf(visitor.getCount()));
rootNode.getValueObject().put(
CloudGraphConstants.GRAPH_DEPTH,
Long.valueOf(visitor.getDepth()));
rootNode.getValueObject().put(
CloudGraphConstants.GRAPH_THREAD_COUNT,
Long.valueOf(visitor.getThreadCount()));
}
/**
* Assembles a data object of the given target type by first forming a query using the
* given key/property pairs. If an existing data object is mapped for the given
* key pairs, the existing data object is linked.
* @param targetType the type for the data object to be assembled
* @param source the source data object
* @param sourceProperty the source property
* @param childKeyPairs the key pairs for the data object to be assembled
*/
protected void assemble(PlasmaType targetType, PlasmaDataObject source, PlasmaProperty sourceProperty,
List<PropertyPair> childKeyPairs, int level) {
Set<Property> props = this.collector.getProperties(targetType, level);
if (props == null)
props = EMPTY_PROPERTY_SET;
if (log.isDebugEnabled())
log.debug(String.valueOf(level) + ":assemble: " + source.getType().getName()
+ "." + sourceProperty.getName() + "->" + targetType.getName() + ": "
+ props);
List<List<PropertyPair>> result = this.getPredicateResult(targetType, sourceProperty,
props, childKeyPairs);
if (log.isDebugEnabled())
log.debug(String.valueOf(level) + ":results: " + result.size());
Map<PlasmaDataObject, List<PropertyPair>> resultMap = this.collectResults(
targetType, source, sourceProperty, result);
// now traverse
Iterator<PlasmaDataObject> iter = resultMap.keySet().iterator();
while (iter.hasNext()) {
PlasmaDataObject target = iter.next();
List<PropertyPair> row = resultMap.get(target);
// traverse singular results props
for (PropertyPair pair : row) {
if (pair.getProp().isMany() || pair.getProp().getType().isDataType())
continue; // only singular reference props
if (!pair.isQueryProperty())
continue; // property is a key or other property not explicitly cited in the source query, don't traverse it
List<PropertyPair> nextKeyPairs = this.getNextKeyPairs(target, pair, level);
if (log.isDebugEnabled())
log.debug(String.valueOf(level) + ":traverse: (" + pair.getProp().isMany()
+ ") " + pair.getProp().toString() + ":" + String.valueOf(pair.getValue()));
assemble((PlasmaType)pair.getProp().getType(),
target, pair.getProp(), nextKeyPairs, level+1);
}
// traverse multi props based, not on the results
// row, but on keys within this data object
for (Property p : props) {
PlasmaProperty prop = (PlasmaProperty)p;
if (!prop.isMany() || prop.getType().isDataType())
continue; // only many reference props
List<PropertyPair> childKeyProps = this.getChildKeyProps(target, targetType, prop);
if (log.isDebugEnabled())
log.debug(String.valueOf(level) + ":traverse: (" + prop.isMany()
+ ") " + prop.toString() + " - " + childKeyProps.toArray().toString());
assemble((PlasmaType)prop.getType(),
target, prop,
childKeyProps, level+1);
}
}
}
}