for(Map 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();
}