聊聊storm trident的operations

public interface Function extends EachOperation {
    /**
     * Performs the function logic on an individual tuple and emits 0 or more tuples.
     *
     * @param tuple The incoming tuple
     * @param collector A collector instance that can be used to emit tuples
     */
    void execute(TridentTuple tuple, TridentCollector collector);
}

public interface Filter extends EachOperation {

    /**
     * Determines if a tuple should be filtered out of a stream
     *
     * @param tuple the tuple being evaluated
     * @return `false` to drop the tuple, `true` to keep the tuple
     */
    boolean isKeep(TridentTuple tuple);
}

    /**
     * Filters out fields from a stream, resulting in a Stream containing only the fields specified by `keepFields`.
     *
     * For example, if you had a Stream `mystream` containing the fields `["a", "b", "c","d"]`, calling"
     *
     * 
     * mystream.project(new Fields("b", "d"))
     * 
     *
     * would produce a stream containing only the fields `["b", "d"]`.
     *
     *
     * @param keepFields The fields in the Stream to keep
     * @return
     */
    public Stream project(Fields keepFields) {
        projectionValidation(keepFields);
        return _topology.addSourcedNode(this, new ProcessorNode(_topology.getUniqueStreamId(), _name, keepFields, new Fields(), new ProjectedProcessor(keepFields)));
    }

    /**
     * ## Repartitioning Operation
     *
     * @param partitioner
     * @return
     */
    public Stream partition(CustomStreamGrouping partitioner) {
        return partition(Grouping.custom_serialized(Utils.javaSerialize(partitioner)));
    }

    /**
     * ## Repartitioning Operation
     *
     * @param fields
     * @return
     */
    public Stream partitionBy(Fields fields) {
        projectionValidation(fields);
        return partition(Grouping.fields(fields.toList()));
    }

    /**
     * ## Repartitioning Operation
     *
     * @return
     */
    public Stream identityPartition() {
        return partition(new IdentityGrouping());
    }

    /**
     * ## Repartitioning Operation
     *
     * Use random round robin algorithm to evenly redistribute tuples across all target partitions
     *
     * @return
     */
    public Stream shuffle() {
        return partition(Grouping.shuffle(new NullStruct()));
    }

    /**
     * ## Repartitioning Operation
     *
     * Use random round robin algorithm to evenly redistribute tuples across all target partitions, with a preference
     * for local tasks.
     *
     * @return
     */
    public Stream localOrShuffle() {
        return partition(Grouping.local_or_shuffle(new NullStruct()));
    }

    /**
     * ## Repartitioning Operation
     *
     * All tuples are sent to the same partition. The same partition is chosen for all batches in the stream.
     * @return
     */
    public Stream global() {
        // use this instead of storm's built in one so that we can specify a singleemitbatchtopartition
        // without knowledge of storm's internals
        return partition(new GlobalGrouping());
    }

    /**
     * ## Repartitioning Operation
     *
     *  All tuples in the batch are sent to the same partition. Different batches in the stream may go to different
     *  partitions.
     *
     * @return
     */
    public Stream batchGlobal() {
        // the first field is the batch id
        return partition(new IndexHashGrouping(0));
    }

    /**
     * ## Repartitioning Operation
     *
     * Every tuple is replicated to all target partitions. This can useful during DRPC – for example, if you need to do
     * a stateQuery on every partition of data.
     *
     * @return
     */
    public Stream broadcast() {
        return partition(Grouping.all(new NullStruct()));
    }

    /**
     * ## Grouping Operation
     *
     * @param fields
     * @return
     */
    public GroupedStream groupBy(Fields fields) {
        projectionValidation(fields);
        return new GroupedStream(this, fields);
    }

    //partition aggregate
    public Stream partitionAggregate(Aggregator agg, Fields functionFields) {
        return partitionAggregate(null, agg, functionFields);
    }

    public Stream partitionAggregate(CombinerAggregator agg, Fields functionFields) {
        return partitionAggregate(null, agg, functionFields);
    }

    public Stream partitionAggregate(Fields inputFields, CombinerAggregator agg, Fields functionFields) {
        projectionValidation(inputFields);
        return chainedAgg()
               .partitionAggregate(inputFields, agg, functionFields)
               .chainEnd();
    }

    public Stream partitionAggregate(ReducerAggregator agg, Fields functionFields) {
        return partitionAggregate(null, agg, functionFields);
    }

    public Stream partitionAggregate(Fields inputFields, ReducerAggregator agg, Fields functionFields) {
        projectionValidation(inputFields);
        return chainedAgg()
               .partitionAggregate(inputFields, agg, functionFields)
               .chainEnd();
    }

    //aggregate
    public Stream aggregate(Fields inputFields, Aggregator agg, Fields functionFields) {
        projectionValidation(inputFields);
        return chainedAgg()
               .aggregate(inputFields, agg, functionFields)
               .chainEnd();
    }

    public Stream aggregate(Fields inputFields, CombinerAggregator agg, Fields functionFields) {
        projectionValidation(inputFields);
        return chainedAgg()
               .aggregate(inputFields, agg, functionFields)
               .chainEnd();
    }

    public Stream aggregate(Fields inputFields, ReducerAggregator agg, Fields functionFields) {
        projectionValidation(inputFields);
        return chainedAgg()
                .aggregate(inputFields, agg, functionFields)
                .chainEnd();
    }

    //persistent aggregate
    public TridentState persistentAggregate(StateFactory stateFactory, CombinerAggregator agg, Fields functionFields) {
        return persistentAggregate(new StateSpec(stateFactory), agg, functionFields);
    }

    public TridentState persistentAggregate(StateSpec spec, CombinerAggregator agg, Fields functionFields) {
        return persistentAggregate(spec, null, agg, functionFields);
    }

    public TridentState persistentAggregate(StateFactory stateFactory, Fields inputFields, CombinerAggregator agg, Fields functionFields) {
        return persistentAggregate(new StateSpec(stateFactory), inputFields, agg, functionFields);
    }

    public TridentState persistentAggregate(StateSpec spec, Fields inputFields, CombinerAggregator agg, Fields functionFields) {
        projectionValidation(inputFields);
        // replaces normal aggregation here with a global grouping because it needs to be consistent across batches 
        return new ChainedAggregatorDeclarer(this, new GlobalAggScheme())
                .aggregate(inputFields, agg, functionFields)
                .chainEnd()
               .partitionPersist(spec, functionFields, new CombinerAggStateUpdater(agg), functionFields);
    }

    public TridentState persistentAggregate(StateFactory stateFactory, ReducerAggregator agg, Fields functionFields) {
        return persistentAggregate(new StateSpec(stateFactory), agg, functionFields);
    }

    public TridentState persistentAggregate(StateSpec spec, ReducerAggregator agg, Fields functionFields) {
        return persistentAggregate(spec, null, agg, functionFields);
    }

    public TridentState persistentAggregate(StateFactory stateFactory, Fields inputFields, ReducerAggregator agg, Fields functionFields) {
        return persistentAggregate(new StateSpec(stateFactory), inputFields, agg, functionFields);
    }

    public TridentState persistentAggregate(StateSpec spec, Fields inputFields, ReducerAggregator agg, Fields functionFields) {
        projectionValidation(inputFields);
        return global().partitionPersist(spec, inputFields, new ReducerAggStateUpdater(agg), functionFields);
    }

public interface Aggregator<T> extends Operation {
    T init(Object batchId, TridentCollector collector);
    void aggregate(T val, TridentTuple tuple, TridentCollector collector);
    void complete(T val, TridentCollector collector);
}

public interface CombinerAggregator<T> extends Serializable {
    T init(TridentTuple tuple);
    T combine(T val1, T val2);
    T zero();
}

public interface ReducerAggregator<T> extends Serializable {
    T init();
    T reduce(T curr, TridentTuple tuple);
}

    public Stream join(Stream s1, Fields joinFields1, Stream s2, Fields joinFields2, Fields outFields) {
        return join(Arrays.asList(s1, s2), Arrays.asList(joinFields1, joinFields2), outFields);        
    }

    public Stream join(List<Stream> streams, List<Fields> joinFields, Fields outFields) {
        return join(streams, joinFields, outFields, JoinType.INNER);        
    }

    public Stream join(Stream s1, Fields joinFields1, Stream s2, Fields joinFields2, Fields outFields, JoinType type) {
        return join(Arrays.asList(s1, s2), Arrays.asList(joinFields1, joinFields2), outFields, type);        
    }

    public Stream join(List<Stream> streams, List<Fields> joinFields, Fields outFields, JoinType type) {
        return join(streams, joinFields, outFields, repeat(streams.size(), type));
    }

    public Stream join(Stream s1, Fields joinFields1, Stream s2, Fields joinFields2, Fields outFields, List<JoinType> mixed) {
        return join(Arrays.asList(s1, s2), Arrays.asList(joinFields1, joinFields2), outFields, mixed);

    }

    public Stream join(List<Stream> streams, List<Fields> joinFields, Fields outFields, List<JoinType> mixed) {
        return join(streams, joinFields, outFields, mixed, JoinOutFieldsMode.COMPACT);
    }

    public Stream join(Stream s1, Fields joinFields1, Stream s2, Fields joinFields2, Fields outFields, JoinOutFieldsMode mode) {
        return join(Arrays.asList(s1, s2), Arrays.asList(joinFields1, joinFields2), outFields, mode);
    }

    public Stream join(List<Stream> streams, List<Fields> joinFields, Fields outFields, JoinOutFieldsMode mode) {
        return join(streams, joinFields, outFields, JoinType.INNER, mode);
    }

    public Stream join(Stream s1, Fields joinFields1, Stream s2, Fields joinFields2, Fields outFields, JoinType type, JoinOutFieldsMode mode) {
        return join(Arrays.asList(s1, s2), Arrays.asList(joinFields1, joinFields2), outFields, type, mode);
    }

    public Stream join(List<Stream> streams, List<Fields> joinFields, Fields outFields, JoinType type, JoinOutFieldsMode mode) {
        return join(streams, joinFields, outFields, repeat(streams.size(), type), mode);
    }

    public Stream join(Stream s1, Fields joinFields1, Stream s2, Fields joinFields2, Fields outFields, List<JoinType> mixed, JoinOutFieldsMode mode) {
        return join(Arrays.asList(s1, s2), Arrays.asList(joinFields1, joinFields2), outFields, mixed, mode);

    }

    public Stream join(List<Stream> streams, List<Fields> joinFields, Fields outFields, List<JoinType> mixed, JoinOutFieldsMode mode) {
        switch (mode) {
            case COMPACT:
                return multiReduce(strippedInputFields(streams, joinFields),
                        groupedStreams(streams, joinFields),
                        new JoinerMultiReducer(mixed, joinFields.get(0).size(), strippedInputFields(streams, joinFields)),
                        outFields);

            case PRESERVE:
                return multiReduce(strippedInputFields(streams, joinFields),
                        groupedStreams(streams, joinFields),
                        new PreservingFieldsOrderJoinerMultiReducer(mixed, joinFields.get(0).size(),
                                getAllOutputFields(streams), joinFields, strippedInputFields(streams, joinFields)),
                        outFields);

            default:
                throw new IllegalArgumentException("Unsupported out-fields mode: " + mode);
        }
    }

    public Stream merge(Fields outputFields, Stream... streams) {
        return merge(outputFields, Arrays.asList(streams));
    }

    public Stream merge(Stream... streams) {
        return merge(Arrays.asList(streams));
    }

    public Stream merge(List<Stream> streams) {
        return merge(streams.get(0).getOutputFields(), streams);
    } 

    public Stream merge(Fields outputFields, List<Stream> streams) {
        return multiReduce(streams, new IdentityMultiReducer(), outputFields);
    }

    public Stream multiReduce(Stream s1, Stream s2, MultiReducer function, Fields outputFields) {
        return multiReduce(Arrays.asList(s1, s2), function, outputFields);        
    }

    public Stream multiReduce(Fields inputFields1, Stream s1, Fields inputFields2, Stream s2, MultiReducer function, Fields outputFields) {
        return multiReduce(Arrays.asList(inputFields1, inputFields2), Arrays.asList(s1, s2), function, outputFields);        
    }    

    public Stream multiReduce(GroupedStream s1, GroupedStream s2, GroupedMultiReducer function, Fields outputFields) {
        return multiReduce(Arrays.asList(s1, s2), function, outputFields);        
    }

    public Stream multiReduce(Fields inputFields1, GroupedStream s1, Fields inputFields2, GroupedStream s2, GroupedMultiReducer function, Fields outputFields) {
        return multiReduce(Arrays.asList(inputFields1, inputFields2), Arrays.asList(s1, s2), function, outputFields);        
    } 

    public Stream multiReduce(List<Stream> streams, MultiReducer function, Fields outputFields) {
        return multiReduce(getAllOutputFields(streams), streams, function, outputFields);
    }

    public Stream multiReduce(List<GroupedStream> streams, GroupedMultiReducer function, Fields outputFields) {
        return multiReduce(getAllOutputFields(streams), streams, function, outputFields);        
    }    

    public Stream multiReduce(List<Fields> inputFields, List<GroupedStream> groupedStreams, GroupedMultiReducer function, Fields outputFields) {
        List<Fields> fullInputFields = new ArrayList<>();
        List<Stream> streams = new ArrayList<>();
        List<Fields> fullGroupFields = new ArrayList<>();
        for(int i=0; i<groupedStreams.size(); i++) {
            GroupedStream gs = groupedStreams.get(i);
            Fields groupFields = gs.getGroupFields();
            fullGroupFields.add(groupFields);
            streams.add(gs.toStream().partitionBy(groupFields));
            fullInputFields.add(TridentUtils.fieldsUnion(groupFields, inputFields.get(i)));

        }
        return multiReduce(fullInputFields, streams, new GroupedMultiReducerExecutor(function, fullGroupFields, inputFields), outputFields);
    }

    public Stream multiReduce(List<Fields> inputFields, List<Stream> streams, MultiReducer function, Fields outputFields) {
        List<String> names = new ArrayList<>();
        for(Stream s: streams) {
            if(s._name!=null) {
                names.add(s._name);
            }
        }
        Node n = new ProcessorNode(getUniqueStreamId(), Utils.join(names, "-"), outputFields, outputFields, new MultiReducerProcessor(inputFields, function));
        return addSourcedNode(streams, n);
    }