@SuppressWarnings("unchecked")
public static <K, I, O> List<StreamId> repartitionAndReduce(
DataGraph graph,
LocallySortedDataset<K, I> input,
StreamReducers.Reducer<K, I, O, ?> reducer,
List<Partition> partitions) {
Function<I, K> keyFunction = input.keyFunction();
List<StreamId> outputStreamIds = new ArrayList<>();
List<NodeShard<K, I>> sharders = new ArrayList<>();
for (StreamId inputStreamId : input.channels(graph)) {
Partition partition = graph.getPartition(inputStreamId);
NodeShard<K, I> sharder = new NodeShard<>(keyFunction, inputStreamId);
graph.addNode(partition, sharder);
sharders.add(sharder);
}
for (Partition partition : partitions) {
NodeReduce<K, O, Object> streamReducer =
new NodeReduce<>( // TODO
input.keyComparator());
graph.addNode(partition, streamReducer);
for (NodeShard<K, I> sharder : sharders) {
StreamId sharderOutput = sharder.newPartition();
graph.addNodeStream(sharder, sharderOutput);
StreamId reducerInput = forwardChannel(graph, input.valueType(), sharderOutput, partition);
streamReducer.addInput(
reducerInput, keyFunction, (StreamReducers.Reducer<K, I, O, Object>) reducer);
}
outputStreamIds.add(streamReducer.getOutput());
}
return outputStreamIds;
}
private static <T> StreamId forwardChannel(
DataGraph graph,
Class<T> type,
Partition sourcePartition,
Partition targetPartition,
StreamId sourceStreamId) {
NodeUpload<T> nodeUpload = new NodeUpload<>(type, sourceStreamId);
NodeDownload<T> nodeDownload =
new NodeDownload<>(type, sourcePartition.getAddress(), sourceStreamId);
graph.addNode(sourcePartition, nodeUpload);
graph.addNode(targetPartition, nodeDownload);
return nodeDownload.getOutput();
}
public static <T> StreamId forwardChannel(
DataGraph graph, Class<T> type, StreamId sourceStreamId, Partition targetPartition) {
Partition sourcePartition = graph.getPartition(sourceStreamId);
return forwardChannel(graph, type, sourcePartition, targetPartition, sourceStreamId);
}