javeme commented on code in PR #285: URL: https://github.com/apache/incubator-hugegraph-computer/pull/285#discussion_r1401740599
########## computer-algorithm/src/main/java/org/apache/hugegraph/computer/algorithm/path/shortest/ShortestPathValue.java: ########## @@ -0,0 +1,110 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with this + * work for additional information regarding copyright ownership. The ASF + * licenses this file to You 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 org.apache.hugegraph.computer.algorithm.path.shortest; + +import java.io.IOException; +import java.util.List; + +import org.apache.hugegraph.computer.core.graph.value.DoubleValue; +import org.apache.hugegraph.computer.core.graph.value.IdList; +import org.apache.hugegraph.computer.core.graph.value.ListValue; +import org.apache.hugegraph.computer.core.graph.value.Value; +import org.apache.hugegraph.computer.core.graph.vertex.Vertex; +import org.apache.hugegraph.computer.core.io.RandomAccessInput; +import org.apache.hugegraph.computer.core.io.RandomAccessOutput; + +public class ShortestPathValue implements Value.CustomizeValue<List<Object>> { + + /** + * path + */ + private final IdList path; + + /** + * weight of path + */ + private final ListValue<DoubleValue> pathWeight; Review Comment: seems we don't need to store every weights, can we just store the totalWeight member? ########## computer-algorithm/src/main/java/org/apache/hugegraph/computer/algorithm/path/shortest/SourceTargetShortestPath.java: ########## @@ -0,0 +1,197 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with this + * work for additional information regarding copyright ownership. The ASF + * licenses this file to You 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 org.apache.hugegraph.computer.algorithm.path.shortest; + +import java.util.Iterator; + +import org.apache.commons.lang3.StringUtils; +import org.apache.hugegraph.computer.core.common.exception.ComputerException; +import org.apache.hugegraph.computer.core.config.Config; +import org.apache.hugegraph.computer.core.graph.edge.Edge; +import org.apache.hugegraph.computer.core.graph.value.DoubleValue; +import org.apache.hugegraph.computer.core.graph.value.Value; +import org.apache.hugegraph.computer.core.graph.vertex.Vertex; +import org.apache.hugegraph.computer.core.worker.Computation; +import org.apache.hugegraph.computer.core.worker.ComputationContext; +import org.apache.hugegraph.util.Log; +import org.slf4j.Logger; + +public class SourceTargetShortestPath implements Computation<ShortestPathMessage> { + + private static final Logger LOG = Log.logger(SourceTargetShortestPath.class); + + public static final String OPTION_SOURCE_ID = "source_target_shortest_path.source_id"; + public static final String OPTION_TARGET_ID = "source_target_shortest_path.target_id"; + public static final String OPTION_WEIGHT_PROPERTY = + "source_target_shortest_path.weight_property"; + public static final String OPTION_DEFAULT_WEIGHT = + "source_target_shortest_path.default_weight"; + + /** + * source vertex id + */ + private String sourceId; + + /** + * target vertex id + */ + private String targetId; + + /** + * weight property. + * weight value must be a positive number. + */ + private String weightProperty; + + /** + * default weight. + * default 1 + */ + private Double defaultWeight; + + @Override + public String category() { + return "path"; + } + + @Override + public String name() { + return "source_target_shortest_path"; + } + + @Override + public void init(Config config) { + this.sourceId = config.getString(OPTION_SOURCE_ID, ""); + if (StringUtils.isBlank(this.sourceId)) { + throw new ComputerException("The param %s must not be blank, ", OPTION_SOURCE_ID); + } + + this.targetId = config.getString(OPTION_TARGET_ID, ""); + if (StringUtils.isBlank(this.targetId)) { + throw new ComputerException("The param %s must not be blank, ", OPTION_TARGET_ID); + } + + this.weightProperty = config.getString(OPTION_WEIGHT_PROPERTY, ""); + + this.defaultWeight = config.getDouble(OPTION_DEFAULT_WEIGHT, 1); + if (this.defaultWeight <= 0) { + throw new ComputerException("The param %s must be greater than 0, " + + "actual got '%s'", + OPTION_DEFAULT_WEIGHT, this.defaultWeight); + } + } + + @Override + public void compute0(ComputationContext context, Vertex vertex) { + ShortestPathValue value = new ShortestPathValue(); + vertex.value(value); + + // start from source vertex + if (!this.idEquals(vertex, this.sourceId)) { + vertex.inactivate(); + return; + } + + value.updatePath(vertex, 0); // source vertex + + // source vertex == target vertex + if (this.sourceId.equals(this.targetId)) { + LOG.info("source vertex {} equals target vertex {}", this.sourceId, this.targetId); + vertex.inactivate(); + return; + } + + if (vertex.numEdges() <= 0) { + // isolated vertex + LOG.info("source vertex {} can not reach target vertex {}", + this.sourceId, this.targetId); + vertex.inactivate(); + return; + } + + vertex.edges().forEach(edge -> { + ShortestPathMessage message = new ShortestPathMessage(); + message.addToPath(vertex, this.getEdgeWeight(edge)); + + context.sendMessage(edge.targetId(), message); + }); + + vertex.inactivate(); + } + + @Override + public void compute(ComputationContext context, Vertex vertex, + Iterator<ShortestPathMessage> messages) { + while (messages.hasNext()) { + ShortestPathMessage message = messages.next(); + ShortestPathValue value = vertex.value(); + + if (message.totalWeight() < value.totalWeight()) { + // find a shorter path + value.updatePath(message.path(), message.pathWeight(), vertex); + } else { + continue; + } + + // reach target vertex or nowhere to go + if (this.idEquals(vertex, this.targetId) || vertex.numEdges() <= 0) { + continue; + } + + vertex.edges().forEach(edge -> { + ShortestPathMessage forwardMessage = new ShortestPathMessage(); Review Comment: can we reuse ShortestPathValue instead of ShortestPathMessage? -- This is an automated message from the Apache Git Service. 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