Examples with Traverser com.hazelcast.jet.Traverser used on opensource projects

Example 11 with Traverser

use of com.hazelcast.jet.Traverser in project hazelcast by hazelcast.

the class Planner method fuseFlatMapTransforms.

@SuppressWarnings("rawtypes")
private static Transform fuseFlatMapTransforms(List<Transform> chain) {
    assert chain.size() > 1 : "chain.size()=" + chain.size();
    assert chain.get(0).upstream().size() == 1;
    int lastFlatMap = 0;
    FunctionEx<Object, Traverser> flatMapFn = null;
    for (int i = 0; i < chain.size(); i++) {
        if (chain.get(i) instanceof FlatMapTransform) {
            FunctionEx<Object, Traverser> function = ((FlatMapTransform) chain.get(i)).flatMapFn();
            FunctionEx<Object, Object> inputMapFn = mergeMapFunctions(chain.subList(lastFlatMap, i));
            if (inputMapFn != null) {
                flatMapFn = flatMapFn == null ? (Object t) -> {
                    Object mappedValue = inputMapFn.apply(t);
                    return mappedValue != null ? function.apply(mappedValue) : Traversers.empty();
                } : flatMapFn.andThen(r -> r.map(inputMapFn).flatMap(function));
            } else {
                flatMapFn = flatMapFn == null ? function::apply : flatMapFn.andThen(r -> r.flatMap(function));
            }
            lastFlatMap = i + 1;
        }
    }
    FunctionEx trailingMapFn = mergeMapFunctions(chain.subList(lastFlatMap, chain.size()));
    String name = chain.stream().map(Transform::name).collect(Collectors.joining(", ", "fused(", ")"));
    Transform fused;
    if (flatMapFn == null) {
        fused = new MapTransform(name, chain.get(0).upstream().get(0), trailingMapFn);
    } else {
        if (trailingMapFn != null) {
            flatMapFn = flatMapFn.andThen(t -> t.map(trailingMapFn));
        }
        fused = new FlatMapTransform(name, chain.get(0).upstream().get(0), flatMapFn);
    }
    // if the first stage of the chain is rebalanced, then we set
    // the rebalance flag of the created fused stage. Only consider
    // the case when first element of the chain is rebalanced
    // because there isn't any other case. If any stage in the
    // middle includes rebalance, then those stages are not fused
    // by findFusableChain().
    fused.setRebalanceInput(0, chain.get(0).shouldRebalanceInput(0));
    return fused;
}

Example 12 with Traverser

use of com.hazelcast.jet.Traverser in project hazelcast by hazelcast.

the class ElasticSourceP method init.

@Override
protected void init(@Nonnull Context context) throws Exception {
    super.init(context);
    logger = context.logger();
    logger.fine("init");
    client = configuration.clientFn().get();
    SearchRequest sr = configuration.searchRequestFn().get();
    sr.scroll(configuration.scrollKeepAlive());
    if (configuration.isSlicingEnabled()) {
        if (configuration.isCoLocatedReadingEnabled()) {
            int sliceId = context.localProcessorIndex();
            int totalSlices = context.localParallelism();
            if (totalSlices > 1) {
                logger.fine("Slice id=" + sliceId + ", max=" + totalSlices);
                sr.source().slice(new SliceBuilder(sliceId, totalSlices));
            }
        } else {
            int sliceId = context.globalProcessorIndex();
            int totalSlices = context.totalParallelism();
            if (totalSlices > 1) {
                logger.fine("Slice id=" + sliceId + ", max=" + totalSlices);
                sr.source().slice(new SliceBuilder(sliceId, totalSlices));
            }
        }
    }
    if (configuration.isCoLocatedReadingEnabled()) {
        logger.fine("Assigned shards: " + shards);
        if (shards.isEmpty()) {
            traverser = Traversers.empty();
            return;
        }
        Node node = createLocalElasticNode();
        client.getLowLevelClient().setNodes(singleton(node));
        String preference = "_shards:" + shards.stream().map(shard -> String.valueOf(shard.getShard())).collect(joining(",")) + "|_only_local";
        sr.preference(preference);
    }
    scrollTraverser = new ElasticScrollTraverser(configuration, client, sr, logger);
    traverser = scrollTraverser.map(configuration.mapToItemFn());
}

Example 13 with Traverser

use of com.hazelcast.jet.Traverser in project hazelcast by hazelcast.

the class CreateDagVisitor method onSlidingWindow.

public Vertex onSlidingWindow(SlidingWindowPhysicalRel rel) {
    int orderingFieldIndex = rel.orderingFieldIndex();
    FunctionEx<ExpressionEvalContext, SlidingWindowPolicy> windowPolicySupplier = rel.windowPolicyProvider();
    // this vertex is used only if there's no aggregation by a window bound
    Vertex vertex = dag.newUniqueVertex("Sliding-Window", flatMapUsingServiceP(ServiceFactories.nonSharedService(ctx -> {
        ExpressionEvalContext evalContext = ExpressionEvalContext.from(ctx);
        SlidingWindowPolicy windowPolicy = windowPolicySupplier.apply(evalContext);
        return row -> WindowUtils.addWindowBounds(row, orderingFieldIndex, windowPolicy);
    }), (BiFunctionEx<Function<JetSqlRow, Traverser<JetSqlRow>>, JetSqlRow, Traverser<JetSqlRow>>) Function::apply));
    connectInput(rel.getInput(), vertex, null);
    return vertex;
}

Example 14 with Traverser

use of com.hazelcast.jet.Traverser in project hazelcast by hazelcast.

the class StreamKafkaP method saveToSnapshot.

@Override
public boolean saveToSnapshot() {
    if (!emitFromTraverser(traverser)) {
        return false;
    }
    if (snapshotTraverser == null) {
        Stream<Entry<BroadcastKey<?>, ?>> snapshotStream = offsets.entrySet().stream().flatMap(entry -> IntStream.range(0, entry.getValue().length).filter(partition -> entry.getValue()[partition] >= 0).mapToObj(partition -> {
            TopicPartition key = new TopicPartition(entry.getKey(), partition);
            long offset = entry.getValue()[partition];
            long watermark = eventTimeMapper.getWatermark(currentAssignment.get(key));
            return entry(broadcastKey(key), new long[] { offset, watermark });
        }));
        snapshotTraverser = traverseStream(snapshotStream).onFirstNull(() -> {
            snapshotTraverser = null;
            if (getLogger().isFinestEnabled()) {
                getLogger().finest("Finished saving snapshot." + " Saved offsets: " + offsets() + ", Saved watermarks: " + watermarks());
            }
        });
        if (processorIndex == 0) {
            Entry<BroadcastKey<?>, ?> partitionCountsItem = entry(broadcastKey(PARTITION_COUNTS_SNAPSHOT_KEY), topics.stream().collect(Collectors.toMap(topic -> topic, topic -> offsets.get(topic).length)));
            snapshotTraverser = snapshotTraverser.append(partitionCountsItem);
        }
    }
    return emitFromTraverserToSnapshot(snapshotTraverser);
}

Example 15 with Traverser

use of com.hazelcast.jet.Traverser in project hazelcast by hazelcast.

the class AppendableTraverserTest method test_flatMapperUsage.

@Test
public void test_flatMapperUsage() {
    // an instance of AppendableTraverser is repeatedly returned
    // from a flatMap function
    Traverser tt = Traversers.traverseItems(10, 20).flatMap(item -> {
        assertTrue(t.isEmpty());
        t.append(item);
        t.append(item + 1);
        return t;
    });
    assertEquals(10, tt.next());
    assertEquals(11, tt.next());
    assertEquals(20, tt.next());
    assertEquals(21, tt.next());
    assertNull(tt.next());
}