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

@Override
public <K, V> Iterator<KeyValue<K, V>> head(final String location, final String memoryKey, final Class readerClass, final int totalLines) {
    final Configuration configuration = new BaseConfiguration();
    configuration.setProperty(Constants.GREMLIN_HADOOP_INPUT_LOCATION, location);
    configuration.setProperty(Constants.GREMLIN_HADOOP_GRAPH_READER, readerClass.getCanonicalName());
    try {
        if (InputRDD.class.isAssignableFrom(readerClass)) {
            return IteratorUtils.map(((InputRDD) readerClass.getConstructor().newInstance()).readMemoryRDD(configuration, memoryKey, new JavaSparkContext(Spark.getContext())).take(totalLines).iterator(), tuple -> new KeyValue(tuple._1(), tuple._2()));
        } else if (InputFormat.class.isAssignableFrom(readerClass)) {
            return IteratorUtils.map(new InputFormatRDD().readMemoryRDD(configuration, memoryKey, new JavaSparkContext(Spark.getContext())).take(totalLines).iterator(), tuple -> new KeyValue(tuple._1(), tuple._2()));
        }
    } catch (final Exception e) {
        throw new IllegalArgumentException(e.getMessage(), e);
    }
    throw new IllegalArgumentException("The provided parserClass must be an " + InputFormat.class.getCanonicalName() + " or an " + InputRDD.class.getCanonicalName() + ": " + readerClass.getCanonicalName());
}
 

@Override
public Iterator<Vertex> head(final String location, final Class readerClass, final int totalLines) {
    final Configuration configuration = new BaseConfiguration();
    configuration.setProperty(Constants.GREMLIN_HADOOP_INPUT_LOCATION, location);
    configuration.setProperty(Constants.GREMLIN_HADOOP_GRAPH_READER, readerClass.getCanonicalName());
    try {
        if (InputRDD.class.isAssignableFrom(readerClass)) {
            return IteratorUtils.map(((InputRDD) readerClass.getConstructor().newInstance()).readGraphRDD(configuration, new JavaSparkContext(Spark.getContext())).take(totalLines).iterator(), tuple -> tuple._2().get());
        } else if (InputFormat.class.isAssignableFrom(readerClass)) {
            return IteratorUtils.map(new InputFormatRDD().readGraphRDD(configuration, new JavaSparkContext(Spark.getContext())).take(totalLines).iterator(), tuple -> tuple._2().get());
        }
    } catch (final Exception e) {
        throw new IllegalArgumentException(e.getMessage(), e);
    }
    throw new IllegalArgumentException("The provided parserClass must be an " + InputFormat.class.getCanonicalName() + " or an " + InputRDD.class.getCanonicalName() + ": " + readerClass.getCanonicalName());
}
 

@Override
public Iterator<Vertex> vertices(final Direction direction, final String... edgeLabels) {
    Iterator<Edge> edges = edges(direction, edgeLabels);
    if (direction == Direction.IN) {
        return IteratorUtils.map(edges, Edge::outVertex);
    } else if (direction == Direction.OUT) {
        return IteratorUtils.map(edges, Edge::inVertex);
    } else if (direction == Direction.BOTH) {
        return IteratorUtils.concat(vertices(Direction.IN, edgeLabels), vertices(Direction.OUT, edgeLabels));
    } else {
        return Collections.emptyIterator();
    }
}
 

@Override
public <V> Iterator<Property<V>> properties(final String... propertyKeys) {
    Iterable<String> keys = getPropertyKeys();
    Iterator<String> filter = IteratorUtils.filter(keys.iterator(),
            key -> ElementHelper.keyExists(key, propertyKeys));
    return IteratorUtils.map(filter,
            key -> new HBaseProperty<>(graph, this, key, getProperty(key)));
}
 

@Override
public <V> Iterator<VertexProperty<V>> properties(final String... propertyKeys) {
    Iterable<String> keys = getPropertyKeys();
    Iterator<String> filter = IteratorUtils.filter(keys.iterator(),
            key -> ElementHelper.keyExists(key, propertyKeys));
    return IteratorUtils.map(filter,
            key -> new HBaseVertexProperty<>(graph, this, key, getProperty(key)));
}
 

@Override
public Iterator<Vertex> vertices(final Direction direction, final String... edgeLabels) {
    return TinkerHelper.inComputerMode(this.graph) ?
            direction.equals(Direction.BOTH) ?
                    IteratorUtils.concat(
                            IteratorUtils.map(this.edges(Direction.OUT, edgeLabels), Edge::inVertex),
                            IteratorUtils.map(this.edges(Direction.IN, edgeLabels), Edge::outVertex)) :
                    IteratorUtils.map(this.edges(direction, edgeLabels), edge -> edge.vertices(direction.opposite()).next()) :
            (Iterator) TinkerHelper.getVertices(this, direction, edgeLabels);
}
 

@Override
public <K, V> Iterator<KeyValue<K, V>> writeMemoryRDD(final Configuration configuration, final String memoryKey, final JavaPairRDD<K, V> memoryRDD) {
    if (!configuration.getBoolean(Constants.GREMLIN_SPARK_PERSIST_CONTEXT, false))
        LOGGER.warn("The SparkContext should be persisted in order for the RDD to persist across jobs. To do so, set " + Constants.GREMLIN_SPARK_PERSIST_CONTEXT + " to true");
    if (!configuration.containsKey(Constants.GREMLIN_HADOOP_OUTPUT_LOCATION))
        throw new IllegalArgumentException("There is no provided " + Constants.GREMLIN_HADOOP_OUTPUT_LOCATION + " to write the persisted RDD to");
    final String memoryRDDName = Constants.getMemoryLocation(configuration.getString(Constants.GREMLIN_HADOOP_OUTPUT_LOCATION), memoryKey);
    Spark.removeRDD(memoryRDDName);
    memoryRDD.setName(memoryRDDName).persist(StorageLevel.fromString(configuration.getString(Constants.GREMLIN_SPARK_PERSIST_STORAGE_LEVEL, "MEMORY_ONLY")))
            // call action to eager store rdd
            .count();
    Spark.refresh(); // necessary to do really fast so the Spark GC doesn't clear out the RDD
    return IteratorUtils.map(memoryRDD.collect().iterator(), tuple -> new KeyValue<>(tuple._1(), tuple._2()));
}
 

@Override
public Iterator<Vertex> vertices(final Direction direction, final String... edgeLabels) {
    return TinkerHelper.inComputerMode(this.graph) ?
            direction.equals(Direction.BOTH) ?
                    IteratorUtils.concat(
                            IteratorUtils.map(this.edges(Direction.OUT, edgeLabels), Edge::inVertex),
                            IteratorUtils.map(this.edges(Direction.IN, edgeLabels), Edge::outVertex)) :
                    IteratorUtils.map(this.edges(direction, edgeLabels), edge -> edge.vertices(direction.opposite()).next()) :
            (Iterator) TinkerHelper.getVertices(this, direction, edgeLabels);
}
 

@Override
public Iterator<Vertex> vertices(final Direction direction, final String... edgeLabels) {
    if (direction.equals(Direction.OUT))
        return IteratorUtils.map(this.edges(direction, edgeLabels), Edge::inVertex);
    else if (direction.equals(Direction.IN))
        return IteratorUtils.map(this.edges(direction, edgeLabels), Edge::outVertex);
    else
        return IteratorUtils.concat(this.vertices(Direction.IN, edgeLabels), this.vertices(Direction.OUT, edgeLabels));
}
 

/**
 * Parses {@link Bytecode} to find {@link TraversalStrategy} objects in the source instructions.
 */
public static <A extends TraversalStrategy> Iterator<A> findStrategies(final Bytecode bytecode, final Class<A> clazz) {
    return IteratorUtils.map(
            IteratorUtils.filter(bytecode.getSourceInstructions().iterator(),
                    s -> s.getOperator().equals(TraversalSource.Symbols.withStrategies) && clazz.isAssignableFrom(s.getArguments()[0].getClass())),
            os -> (A) os.getArguments()[0]);
}
 

public Iterator<Traverser.Admin<S>> attach(final Iterator<Traverser.Admin<S>> iterator, final Graph graph) {
    return IteratorUtils.map(iterator, traverser -> {
        traverser.setSideEffects(this.getTraversal().getSideEffects());   // necessary to ensure no NPE
        if (this.attachElements && (traverser.get() instanceof Attachable) && !(traverser.get() instanceof Property))
            traverser.set((S) ((Attachable<Element>) traverser.get()).attach(Attachable.Method.get(graph)));
        return traverser;
    });
}
 

@Override
public Iterator<String> head(final String location, final int totalLines) {
    return IteratorUtils.map(Spark.getRDD(location).toJavaRDD().take(totalLines).iterator(), Object::toString);
}
 

@Override
public Iterator<Vertex> vertices(final Direction direction, final String... edgeLabels) {
    if (state.equals(State.MAP_REDUCE))
        throw GraphComputer.Exceptions.incidentAndAdjacentElementsCanNotBeAccessedInMapReduce();
    return IteratorUtils.map(this.getBaseVertex().vertices(direction, edgeLabels), v -> v.equals(starVertex) ? starVertex : new ComputerAdjacentVertex(v));
}
 

@Override
public <V> Iterator<V> values(final String... propertyKeys) {
    return IteratorUtils.map(this.<V>properties(propertyKeys), property -> property.value());
}
 

/**
 * Get the values of properties as an {@link Iterator}.
 */
public default <V> Iterator<V> values(final String... propertyKeys) {
    return IteratorUtils.map(this.<V>properties(propertyKeys), property -> property.value());
}
 

@Override
public Iterator iterator() {
    return IteratorUtils.map(this.getKeys(), k -> new Pair<>(k, this.getProperty(k)));
}
 

@Override
public <U> Iterator<Property<U>> properties(final String... propertyKeys) {
    return IteratorUtils.<Property<U>, Property<U>>map(this.getBaseVertexProperty().properties(propertyKeys), property -> new HadoopProperty<>(property, HadoopVertexProperty.this));
}
 

@Override
public <V> Iterator<VertexProperty<V>> properties(final String... propertyKeys) {
    return IteratorUtils.<VertexProperty<V>, VertexProperty<V>>map(this.getBaseVertex().properties(propertyKeys), property -> new HadoopVertexProperty<>(property, HadoopVertex.this));
}
 

@Override
public Iterator<Vertex> vertices(final Direction direction, final String... edgeLabels) {
    return IteratorUtils.map(this.getBaseVertex().vertices(direction, edgeLabels), vertex -> HadoopVertex.this.graph.vertices(vertex.id()).next());
}
 

@Override
public <V> Iterator<Property<V>> properties(final String... propertyKeys) {
    return IteratorUtils.<Property<V>, Property<V>>map(this.getBaseEdge().properties(propertyKeys), property -> new HadoopProperty<>(property, HadoopEdge.this));
}