Examples with FinishedCallback org.apache.storm.coordination.CoordinatedBolt.FinishedCallback used on opensource projects

Example 1 with FinishedCallback

use of org.apache.storm.coordination.CoordinatedBolt.FinishedCallback in project storm by apache.

the class LinearDRPCTopologyBuilder method createTopology.

private StormTopology createTopology(DRPCSpout spout) {
    final String SPOUT_ID = "spout";
    final String PREPARE_ID = "prepare-request";
    TopologyBuilder builder = new TopologyBuilder();
    builder.setSpout(SPOUT_ID, spout);
    builder.setBolt(PREPARE_ID, new PrepareRequest()).noneGrouping(SPOUT_ID);
    int i = 0;
    for (; i < _components.size(); i++) {
        Component component = _components.get(i);
        Map<String, SourceArgs> source = new HashMap<String, SourceArgs>();
        if (i == 1) {
            source.put(boltId(i - 1), SourceArgs.single());
        } else if (i >= 2) {
            source.put(boltId(i - 1), SourceArgs.all());
        }
        IdStreamSpec idSpec = null;
        if (i == _components.size() - 1 && component.bolt instanceof FinishedCallback) {
            idSpec = IdStreamSpec.makeDetectSpec(PREPARE_ID, PrepareRequest.ID_STREAM);
        }
        BoltDeclarer declarer = builder.setBolt(boltId(i), new CoordinatedBolt(component.bolt, source, idSpec), component.parallelism);
        for (Map<String, Object> conf : component.componentConfs) {
            declarer.addConfigurations(conf);
        }
        if (idSpec != null) {
            declarer.fieldsGrouping(idSpec.getGlobalStreamId().get_componentId(), PrepareRequest.ID_STREAM, new Fields("request"));
        }
        if (i == 0 && component.declarations.isEmpty()) {
            declarer.noneGrouping(PREPARE_ID, PrepareRequest.ARGS_STREAM);
        } else {
            String prevId;
            if (i == 0) {
                prevId = PREPARE_ID;
            } else {
                prevId = boltId(i - 1);
            }
            for (InputDeclaration declaration : component.declarations) {
                declaration.declare(prevId, declarer);
            }
        }
        if (i > 0) {
            declarer.directGrouping(boltId(i - 1), Constants.COORDINATED_STREAM_ID);
        }
    }
    IRichBolt lastBolt = _components.get(_components.size() - 1).bolt;
    OutputFieldsGetter getter = new OutputFieldsGetter();
    lastBolt.declareOutputFields(getter);
    Map<String, StreamInfo> streams = getter.getFieldsDeclaration();
    if (streams.size() != 1) {
        throw new RuntimeException("Must declare exactly one stream from last bolt in LinearDRPCTopology");
    }
    String outputStream = streams.keySet().iterator().next();
    List<String> fields = streams.get(outputStream).get_output_fields();
    if (fields.size() != 2) {
        throw new RuntimeException("Output stream of last component in LinearDRPCTopology must contain exactly two fields. The first should be the request id, and the second should be the result.");
    }
    builder.setBolt(boltId(i), new JoinResult(PREPARE_ID)).fieldsGrouping(boltId(i - 1), outputStream, new Fields(fields.get(0))).fieldsGrouping(PREPARE_ID, PrepareRequest.RETURN_STREAM, new Fields("request"));
    i++;
    builder.setBolt(boltId(i), new ReturnResults()).noneGrouping(boltId(i - 1));
    return builder.createTopology();
}