Java Code Examples for org.apache.tinkerpop.gremlin.util.iterator.IteratorUtils#reduce()

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);
    }
}
 

@Override
Number reduceValues(Iterator<Number> values) {
    if (usingLong()) {
        return IteratorUtils.reduce(values, Long.MAX_VALUE, (a, b) -> Math.min(a.longValue(), b.longValue()));
    } else {
        return IteratorUtils.reduce(values, Double.MAX_VALUE, (a, b) -> Math.min(a.doubleValue(), b.doubleValue()));
    }
}
 

private static void updateClusterLabel(Vertex vertex, Messenger<String> messenger, Memory memory) {
    String currentMax = vertex.value(K_CORE_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 {} changed from {} to {}", vertex, currentMax, max);
        vertex.property(K_CORE_LABEL, max);
        sendMessage(messenger, max);
        memory.add(VOTE_TO_HALT, false);
    } else {
        LOGGER.trace("Cluster label of {} is still {}", vertex, currentMax);
    }
}
 

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);
}
 

@Override
Map<String, Double> reduceValues(Iterator<Map<String, Double>> values) {
    Map<String, Double> emptyTuple = new HashMap<>(2);
    emptyTuple.put(SUM, 0D);
    emptyTuple.put(COUNT, 0D);
    return IteratorUtils.reduce(values, emptyTuple,
            (a, b) -> {
                a.put(COUNT, a.get(COUNT) + b.get(COUNT));
                a.put(SUM, a.get(SUM) + b.get(SUM));
                return a;
            });
}
 

@Override
Number reduceValues(Iterator<Number> values) {
    if (usingLong()) {
        return IteratorUtils.reduce(values, Long.MIN_VALUE, (a, b) -> Math.max(a.longValue(), b.longValue()));
    } else {
        return IteratorUtils.reduce(values, Double.MIN_VALUE, (a, b) -> Math.max(a.doubleValue(), b.doubleValue()));
    }
}
 

@Override
Map<String, Double> reduceValues(Iterator<Map<String, Double>> values) {
    Map<String, Double> emptyTuple = new HashMap<>(3);
    emptyTuple.put(SUM, 0D);
    emptyTuple.put(SQUARE_SUM, 0D);
    emptyTuple.put(COUNT, 0D);
    return IteratorUtils.reduce(values, emptyTuple,
            (a, b) -> {
                a.put(COUNT, a.get(COUNT) + b.get(COUNT));
                a.put(SUM, a.get(SUM) + b.get(SUM));
                a.put(SQUARE_SUM, a.get(SQUARE_SUM) + b.get(SQUARE_SUM));
                return a;
            });
}
 

@Override
Number reduceValues(Iterator<Number> values) {
    if (usingLong()) {
        return IteratorUtils.reduce(values, 0L, (a, b) -> a.longValue() + b.longValue());
    } else {
        return IteratorUtils.reduce(values, 0D, (a, b) -> a.doubleValue() + b.doubleValue());
    }
}
 

@Override
public void execute(final Vertex vertex, Messenger<Double> messenger, final Memory memory) {
    if (memory.isInitialIteration()) {
        messenger.sendMessage(this.countMessageScope, 1.0d);
        memory.add(VERTEX_COUNT, 1.0d);
    } else {
        final double vertexCount = memory.<Double>get(VERTEX_COUNT);
        final double edgeCount;
        double pageRank;
        if (1 == memory.getIteration()) {
            edgeCount = IteratorUtils.reduce(messenger.receiveMessages(), 0.0d, (a, b) -> a + b);
            vertex.property(VertexProperty.Cardinality.single, EDGE_COUNT, edgeCount);
            pageRank = null == this.initialRankTraversal ?
                    0.0d :
                    TraversalUtil.apply(vertex, this.initialRankTraversal.get()).doubleValue();
        } else {
            edgeCount = vertex.value(EDGE_COUNT);
            pageRank = IteratorUtils.reduce(messenger.receiveMessages(), 0.0d, (a, b) -> a + b);
        }
        //////////////////////////
        final double teleporationEnergy = memory.get(TELEPORTATION_ENERGY);
        if (teleporationEnergy > 0.0d) {
            final double localTerminalEnergy = teleporationEnergy / vertexCount;
            pageRank = pageRank + localTerminalEnergy;
            memory.add(TELEPORTATION_ENERGY, -localTerminalEnergy);
        }
        final double previousPageRank = vertex.<Double>property(this.property).orElse(0.0d);
        memory.add(CONVERGENCE_ERROR, Math.abs(pageRank - previousPageRank));
        vertex.property(VertexProperty.Cardinality.single, this.property, pageRank);
        memory.add(TELEPORTATION_ENERGY, (1.0d - this.alpha) * pageRank);
        pageRank = this.alpha * pageRank;
        if (edgeCount > 0.0d)
            messenger.sendMessage(this.incidentMessageScope, pageRank / edgeCount);
        else
            memory.add(TELEPORTATION_ENERGY, pageRank);
    }
}
 

@Override
public void execute(Vertex vertex, Messenger<Long> messenger, Memory memory) {
    switch (memory.getIteration()) {
        case 0:
            if (vertex.value("name").equals("josh")) {
                messenger.sendMessage(this.countMessageScopeIn, 2L);
                messenger.sendMessage(this.countMessageScopeOut, 1L);
            }
            break;
        case 1:
            long edgeCount = IteratorUtils.reduce(messenger.receiveMessages(), 0L, (a, b) -> a + b);
            vertex.property(MEMORY_KEY, edgeCount);
            break;
    }
}
 

@Override
public void execute(Vertex vertex, Messenger<Long> messenger, Memory memory) {
    switch (memory.getIteration()) {
        case 0:
            if (vertex.value("name").equals("josh")) {
                messenger.sendMessage(this.countMessageScopeIn, 2L);
                messenger.sendMessage(this.countMessageScopeOut, 1L);
            }
            break;
        case 1:
            long edgeCount = IteratorUtils.reduce(messenger.receiveMessages(), 0L, (a, b) -> a + b);
            vertex.property(MEMORY_KEY, edgeCount);
            break;
    }
}
 

static long getMessageCount(Messenger<Long> messenger) {
    return IteratorUtils.reduce(messenger.receiveMessages(), 0L, (a, b) -> a + b);
}
 

@Override
Long reduceValues(Iterator<Long> values) {
    return IteratorUtils.reduce(values, 0L, (a, b) -> a + b);
}
 

@Override
Long reduceValues(Iterator<Long> values) {
    return IteratorUtils.reduce(values, 0L, (a, b) -> a + b);
}