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Core package for Neo4j Procedures
/*
* Copyright (c) "Neo4j"
* Neo4j Sweden AB [http://neo4j.com]
*
* This file is part of Neo4j.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package apoc.nodes;
import static java.util.Collections.*;
import apoc.Pools;
import apoc.result.VirtualNode;
import apoc.result.VirtualRelationship;
import apoc.util.Util;
import apoc.util.collection.Iterables;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import org.neo4j.graphdb.*;
import org.neo4j.logging.Log;
import org.neo4j.procedure.Context;
import org.neo4j.procedure.Description;
import org.neo4j.procedure.Name;
import org.neo4j.procedure.NotThreadSafe;
import org.neo4j.procedure.Procedure;
/**
* @author mh
* @since 14.06.17
*/
public class Grouping {
private static final int BATCHSIZE = 10000;
@Context
public GraphDatabaseService db;
@Context
public Transaction tx;
@Context
public Log log;
@Context
public Pools pools;
public static class GroupResult {
public List nodes;
public List relationships;
public Node node;
public Relationship relationship;
public GroupResult(Node node, Relationship relationship) {
this.node = node;
this.relationship = relationship;
this.nodes = singletonList(node);
this.relationships = singletonList(relationship);
}
public GroupResult(Node node, List relationships) {
this.nodes = singletonList(node);
this.relationships = relationships;
this.node = node;
this.relationship = relationships.isEmpty() ? null : relationships.get(0);
}
public Stream spread() {
return Stream.concat(Stream.of(this), relationships.stream().skip(1).map(r -> new GroupResult(node, r)));
}
}
@NotThreadSafe
@Procedure("apoc.nodes.group")
@Description("Allows for the aggregation of `NODE` values based on the given properties.\n"
+ "This procedure returns virtual `NODE` values.")
public Stream group(
@Name("labels") List labelNames,
@Name("groupByProperties") List groupByProperties,
@Name(value = "aggregations", defaultValue = "[{`*`:\"count\"},{`*`:\"count\"}]")
List> aggregations,
@Name(value = "config", defaultValue = "{}") Map config) {
Set labels = new HashSet<>(labelNames);
if (labels.remove("*"))
labels.addAll(Iterables.stream(tx.getAllLabels()).map(Label::name).collect(Collectors.toSet()));
String[] keys = groupByProperties.toArray(new String[groupByProperties.size()]);
if (aggregations == null || aggregations.isEmpty()) {
aggregations = Arrays.asList(singletonMap("*", "count"), singletonMap("*", "count"));
}
Map> nodeAggNames =
(aggregations.size() > 0) ? toStringListMap(aggregations.get(0)) : emptyMap();
String[] nodeAggKeys = keyArray(nodeAggNames, "*");
Map> relAggNames =
(aggregations.size() > 1) ? toStringListMap(aggregations.get(1)) : emptyMap();
String[] relAggKeys = keyArray(relAggNames, "*");
// todo bitset
Set includeRels = computeIncludedRels(config);
/*
config:{orphans:false,selfRels:false,limitNodes:100, limitRels:1000, filter:{Person.count_*.min,10,Person.sum_age.max,200,KNOWS.count_*.min:5}}
*/
boolean orphans = (boolean) config.getOrDefault("orphans", true);
boolean selfRels = (boolean) config.getOrDefault("selfRels", true);
long limitNodes = (long) config.getOrDefault("limitNodes", -1L);
long limitRels = (long) config.getOrDefault("limitRels", -1L);
long relsPerNode = (long) config.getOrDefault("relsPerNode", -1L);
// filter min, max on aggregated properties
// (TYPE.)prop.min: value,(TYPE.)prop.max: value,
// also filter (esp. max) during aggregation?
Map filter = configuredFilter(config);
Map> grouped = new ConcurrentHashMap<>();
Map virtualNodes = new ConcurrentHashMap<>();
Map virtualRels = new ConcurrentHashMap<>();
List futures = new ArrayList<>(1000);
ExecutorService pool = pools.getDefaultExecutorService();
for (String labelName : labels) {
Label label = Label.label(labelName);
Label[] singleLabel = {label};
try (ResourceIterator nodes =
(labelName.equals("*")) ? tx.getAllNodes().iterator() : tx.findNodes(label)) {
while (nodes.hasNext()) {
List batch = Util.take(nodes, BATCHSIZE);
futures.add(Util.inTxFuture(pool, db, txInThread -> {
try {
for (Node node : batch) {
final Node boundNode = Util.rebind(txInThread, node);
NodeKey key = keyFor(boundNode, labelName, keys);
grouped.compute(key, (k, v) -> {
if (v == null) v = new HashSet<>();
v.add(boundNode);
return v;
});
virtualNodes.compute(key, (k, v) -> {
if (v == null) {
v = new VirtualNode(singleLabel, propertiesFor(boundNode, keys));
}
VirtualNode vn = v;
if (!nodeAggNames.isEmpty()) {
aggregate(
vn,
nodeAggNames,
nodeAggKeys.length > 0
? boundNode.getProperties(nodeAggKeys)
: Collections.emptyMap());
}
return vn;
});
}
} catch (Exception e) {
log.error("Error grouping nodes", e);
}
return null;
}));
Util.removeFinished(futures);
}
}
}
Util.waitForFutures(futures);
futures.clear();
Iterator>> entries = grouped.entrySet().iterator();
int size = 0;
List>> batch = new ArrayList<>();
while (entries.hasNext()) {
Map.Entry> outerEntry = entries.next();
batch.add(outerEntry);
size += outerEntry.getValue().size();
if (size > BATCHSIZE || !entries.hasNext()) {
ArrayList>> submitted = new ArrayList<>(batch);
batch.clear();
size = 0;
futures.add(Util.inTxFuture(pool, db, txInThread -> {
try {
for (Map.Entry> entry : submitted) {
for (Node node : entry.getValue()) {
node = Util.rebind(txInThread, node);
NodeKey startKey = entry.getKey();
VirtualNode v1 = virtualNodes.get(startKey);
for (Relationship rel : node.getRelationships(Direction.OUTGOING)) {
if (includeRels != null
&& !includeRels.contains(
rel.getType().name())) continue;
Node endNode = rel.getEndNode();
for (NodeKey endKey : keysFor(endNode, labels, keys)) {
VirtualNode v2 = virtualNodes.get(endKey);
if (v2 == null) continue;
if (!selfRels && startKey.equals(endKey)) continue;
virtualRels.compute(new RelKey(startKey, endKey, rel), (rk, vRel) -> {
if (vRel == null) vRel = v1.createRelationshipTo(v2, rel.getType());
if (!relAggNames.isEmpty()) {
aggregate(
vRel,
relAggNames,
relAggKeys.length > 0
? rel.getProperties(relAggKeys)
: Collections.emptyMap());
}
return vRel;
});
}
}
}
}
} catch (Exception e) {
log.error("Error grouping relationships", e);
}
return null;
}));
Util.removeFinished(futures);
}
}
Util.waitForFutures(futures);
Stream stream = fixAggregates(virtualNodes.values()).stream();
// apply filter
if (filter != null) stream = stream.filter(n -> filter(n.getLabels(), n.getAllProperties(), filter));
if (limitNodes > -1) stream = stream.limit(limitNodes);
Stream groupResultStream =
stream.map(n -> new GroupResult(n, getRelationships(n, filter, (int) relsPerNode)));
if (!orphans)
groupResultStream = groupResultStream.filter(
g -> g.relationships != null && !g.relationships.isEmpty() && g.node.getDegree() > 0);
groupResultStream = groupResultStream.flatMap(GroupResult::spread);
if (limitRels > -1) groupResultStream = groupResultStream.limit(limitRels);
return groupResultStream;
}
private Map configuredFilter(Map config) {
Map filter = (Map) config.get("filter");
if (filter == null || filter.isEmpty()) return null;
return filter;
}
private boolean filter(String type, Map props, Map filter) {
if (filter == null || props.isEmpty()) return true;
return filterProps(type, props, filter);
}
private boolean filter(Iterable