Java Messenger类代码示例

import org.apache.tinkerpop.gremlin.process.computer.Messenger; //导入依赖的package包/类
@Override
public void safeExecute(final Vertex vertex, Messenger<PathMessage> messenger, final Memory memory) {
    if (memory.isInitialIteration()) {
        // The type of id will likely have to change as we support more and more vendors
        String id = getVertexId(vertex);
        if (persistentProperties.get(SOURCE).equals(id)) {
            LOGGER.debug("Found source vertex");
            vertex.property(VISITED_IN_ITERATION, 1);
            sendMessage(messenger, PathMessage.of(FROM_SOURCE, id));
        } else if (persistentProperties.get(DESTINATION).equals(id)) {
            LOGGER.debug("Found destination vertex");
            vertex.property(VISITED_IN_ITERATION, -1);
            sendMessage(messenger, PathMessage.of(FROM_DESTINATION, id));
        }
    } else {
        if (memory.<Boolean>get(FOUND_PATH)) {
            if (messenger.receiveMessages().hasNext() && vertex.property(VISITED_IN_ITERATION).isPresent()) {
                recordPredecessors(vertex, messenger, memory);
            }
        } else if (messenger.receiveMessages().hasNext()) {
            updateInstance(vertex, messenger, memory);
        }
    }
}
 

import org.apache.tinkerpop.gremlin.process.computer.Messenger; //导入依赖的package包/类
private void updateEntityAndAttribute(Vertex vertex, Messenger<String> messenger, Memory memory) {
    if (vertex.property(CLUSTER_LABEL).isPresent()) {
        String id = vertex.value(Schema.VertexProperty.ID.name());
        int messageCount = getMessageCount(messenger, id) +
                (vertex.property(IMPLICIT_MESSAGE_COUNT).isPresent() ?
                        (int) vertex.value(IMPLICIT_MESSAGE_COUNT) : 0);

        if (messageCount >= k) {
            LOGGER.trace("Sending msg from " + id);
            sendMessage(messenger, id);
            memory.add(K_CORE_EXIST, true);
        } else {
            LOGGER.trace("Removing label of " + id);
            vertex.property(CLUSTER_LABEL).remove();
            memory.add(K_CORE_STABLE, false);
        }
    }
}
 

import org.apache.tinkerpop.gremlin.process.computer.Messenger; //导入依赖的package包/类
@Override
public void safeExecute(final Vertex vertex, Messenger<Long> messenger, final Memory memory) {
    switch (memory.getIteration()) {
        case 0:
            degreeStatisticsStepResourceOwner(vertex, messenger, ofLabelIds);
            break;
        case 1:
            degreeStatisticsStepResourceRelation(vertex, messenger, ofLabelIds);
            break;
        case 2:
            degreeStatisticsStepResource(vertex, messenger, ofLabelIds);
            break;
        default:
            throw CommonUtil.unreachableStatement("Exceeded expected maximum number of iterations");
    }
}
 

import org.apache.tinkerpop.gremlin.process.computer.Messenger; //导入依赖的package包/类
@Override
public void execute(final Vertex vertex, Messenger<Double> messenger, final Memory memory) {
    if (memory.isInitialIteration()) {
        messenger.sendMessage(this.countMessageScope, 1.0d);
    } else if (1 == memory.getIteration()) {
        double initialPageRank = (null == this.initialRankTraversal ?
                1.0d :
                TraversalUtil.apply(vertex, this.initialRankTraversal.get()).doubleValue()) / this.vertexCountAsDouble;
        double edgeCount = IteratorUtils.reduce(messenger.receiveMessages(), 0.0d, (a, b) -> a + b);
        vertex.property(VertexProperty.Cardinality.single, this.property, initialPageRank);
        vertex.property(VertexProperty.Cardinality.single, EDGE_COUNT, edgeCount);
        if (!this.terminate(memory)) // don't send messages if this is the last iteration
            messenger.sendMessage(this.incidentMessageScope, initialPageRank / edgeCount);
    } else {
        double newPageRank = IteratorUtils.reduce(messenger.receiveMessages(), 0.0d, (a, b) -> a + b);
        newPageRank = (this.alpha * newPageRank) + ((1.0d - this.alpha) / this.vertexCountAsDouble);
        vertex.property(VertexProperty.Cardinality.single, this.property, newPageRank);
        if (!this.terminate(memory)) // don't send messages if this is the last iteration
            messenger.sendMessage(this.incidentMessageScope, newPageRank / vertex.<Double>value(EDGE_COUNT));
    }
}
 

import org.apache.tinkerpop.gremlin.process.computer.Messenger; //导入依赖的package包/类
@Override
public void execute(Vertex vertex, Messenger<Double> messenger, Memory memory) {
    if (memory.isInitialIteration()) {
        messenger.sendMessage(inE, 1D);
    } else if (1 == memory.getIteration()) {
        double initialPageRank = 1D / vertexCount;
        double edgeCount = IteratorUtils.stream(messenger.receiveMessages()).reduce(0D, (a, b) -> a + b);
        vertex.property(VertexProperty.Cardinality.single, PAGE_RANK, initialPageRank);
        vertex.property(VertexProperty.Cardinality.single, OUTGOING_EDGE_COUNT, edgeCount);
        messenger.sendMessage(outE, initialPageRank / edgeCount);
    } else {
        double newPageRank = IteratorUtils.stream(messenger.receiveMessages()).reduce(0D, (a, b) -> a + b);
        newPageRank =  (dampingFactor * newPageRank) + ((1D - dampingFactor) / vertexCount);
        vertex.property(VertexProperty.Cardinality.single, PAGE_RANK, newPageRank);
        messenger.sendMessage(outE, newPageRank / vertex.<Double>value(OUTGOING_EDGE_COUNT));
    }
}
 

import org.apache.tinkerpop.gremlin.process.computer.Messenger; //导入依赖的package包/类
private static Map<String, Set<String>> getPredecessors(Vertex vertex, Messenger<PathMessage> messenger) {
    Set<String> predecessors = new HashSet<>();
    Iterator<PathMessage> iterator = messenger.receiveMessages();
    while (iterator.hasNext()) {
        PathMessage message = iterator.next();
        if (message.direction() == FROM_MIDDLE) {
            predecessors.add(message.id());
        }
    }
    if (predecessors.isEmpty()) return Collections.emptyMap();

    Map<String, Set<String>> predecessorMap = new HashMap<>();
    predecessorMap.put(getVertexId(vertex), predecessors);
    return predecessorMap;
}
 

import org.apache.tinkerpop.gremlin.process.computer.Messenger; //导入依赖的package包/类
@Override
public void execute(Vertex vertex, Messenger<T> messenger, Memory memory) {
    // try to deal with ghost vertex issues by ignoring them
    if (Utility.isAlive(vertex)) {
        safeExecute(vertex, messenger, memory);
    }
}
 

import org.apache.tinkerpop.gremlin.process.computer.Messenger; //导入依赖的package包/类
@Override
public void safeExecute(final Vertex vertex, Messenger<String> messenger, final Memory memory) {
    if (memory.isInitialIteration()) {
        String id = vertex.value(Schema.VertexProperty.ID.name());
        vertex.property(CLUSTER_LABEL, id);
        messenger.sendMessage(messageScopeIn, id);
        messenger.sendMessage(messageScopeOut, id);
    } else {
        updateClusterLabel(vertex, messenger, memory);
    }
}
 

import org.apache.tinkerpop.gremlin.process.computer.Messenger; //导入依赖的package包/类
private static void updateClusterLabel(Vertex vertex, Messenger<String> messenger, Memory memory) {
    String currentMax = vertex.value(CLUSTER_LABEL);
    String max = IteratorUtils.reduce(messenger.receiveMessages(), currentMax,
            (a, b) -> a.compareTo(b) > 0 ? a : b);
    if (max.compareTo(currentMax) > 0) {
        vertex.property(CLUSTER_LABEL, max);
        messenger.sendMessage(messageScopeIn, max);
        messenger.sendMessage(messageScopeOut, max);
        memory.add(VOTE_TO_HALT, false);
    }
}
 

import org.apache.tinkerpop.gremlin.process.computer.Messenger; //导入依赖的package包/类
private static void relayOrSaveMessages(Vertex vertex, Messenger<String> messenger) {
    if (messenger.receiveMessages().hasNext()) {
        if (vertex.label().equals(Schema.BaseType.RELATIONSHIP.name())) {
            // relay the messages
            messenger.receiveMessages().forEachRemaining(msg -> sendMessage(messenger, msg));
        } else if ((vertex.label().equals(Schema.BaseType.ENTITY.name()) ||
                vertex.label().equals(Schema.BaseType.ATTRIBUTE.name())) &&
                vertex.property(CLUSTER_LABEL).isPresent()) {
            // messages received via implicit edge, save the count for next iteration
            vertex.property(IMPLICIT_MESSAGE_COUNT, Iterators.size(messenger.receiveMessages()));
        }
    }
}
 

import org.apache.tinkerpop.gremlin.process.computer.Messenger; //导入依赖的package包/类
private static void updateClusterLabel(Vertex vertex, Messenger<String> messenger, Memory memory) {
    String currentMax = vertex.value(CLUSTER_LABEL);
    String max = IteratorUtils.reduce(messenger.receiveMessages(), currentMax,
            (a, b) -> a.compareTo(b) > 0 ? a : b);
    if (!max.equals(currentMax)) {
        LOGGER.trace("Cluster label of " + vertex + " changed from " + currentMax + " to " + max);
        vertex.property(CLUSTER_LABEL, max);
        sendMessage(messenger, max);
        memory.add(VOTE_TO_HALT, false);
    } else {
        LOGGER.trace("Cluster label of " + vertex + " is still " + currentMax);
    }
}
 

import org.apache.tinkerpop.gremlin.process.computer.Messenger; //导入依赖的package包/类
private static void relayClusterLabel(Messenger<String> messenger, Memory memory) {
    String firstMessage = messenger.receiveMessages().next();
    String max = IteratorUtils.reduce(messenger.receiveMessages(), firstMessage,
            (a, b) -> a.compareTo(b) > 0 ? a : b);
    sendMessage(messenger, max);
    memory.add(VOTE_TO_HALT, false);
}
 

import org.apache.tinkerpop.gremlin.process.computer.Messenger; //导入依赖的package包/类
@Override
public void safeExecute(final Vertex vertex, Messenger<Long> messenger, final Memory memory) {
    switch (memory.getIteration()) {
        case 0:
            degreeMessagePassing(messenger);
            break;
        case 1:
            degreeMessageCounting(messenger, vertex);
            break;
        default:
            throw CommonUtil.unreachableStatement("Exceeded expected maximum number of iterations");
    }
}
 

import org.apache.tinkerpop.gremlin.process.computer.Messenger; //导入依赖的package包/类
static void degreeStatisticsStepResourceOwner(Vertex vertex, Messenger<Long> messenger, Set<LabelId> ofLabelIds) {
    LabelId labelId = Utility.getVertexTypeId(vertex);
    if (labelId.isValid() && !ofLabelIds.contains(labelId)) {
        messenger.sendMessage(messageScopeShortcutIn, 1L);
        messenger.sendMessage(messageScopeResourceOut, 1L);
    }
}
 

import org.apache.tinkerpop.gremlin.process.computer.Messenger; //导入依赖的package包/类
static void degreeStatisticsStepResourceRelation(Vertex vertex, Messenger<Long> messenger, Set<LabelId> ofLabelIds) {
    if (messenger.receiveMessages().hasNext()) {
        if (vertex.label().equals(Schema.BaseType.RELATIONSHIP.name())) {
            messenger.sendMessage(messageScopeOut, 1L);
        } else if (ofLabelIds.contains(Utility.getVertexTypeId(vertex))) {
            vertex.property(DEGREE, getMessageCount(messenger));
        }
    }
}