@SuppressWarnings("rawtypes")
private static void removeMergeBeforeFlatten(StreamGraph streamGraph) {
Set<Entry<Integer, StreamInvokable<?, ?>>> invokables = streamGraph.getInvokables();
List<Integer> flatteners = new ArrayList<Integer>();
for (Entry<Integer, StreamInvokable<?, ?>> entry : invokables) {
if (entry.getValue() instanceof WindowFlattener) {
flatteners.add(entry.getKey());
}
}
for (Integer flattener : flatteners) {
// Flatteners should have exactly one input
Integer input = streamGraph.getInEdges(flattener).get(0);
// Check whether the flatten is applied after a merge
if (streamGraph.getInvokable(input) instanceof WindowMerger) {
// Mergers should have exactly one input
Integer mergeInput = streamGraph.getInEdges(input).get(0);
streamGraph.setEdge(
mergeInput, flattener, new DistributePartitioner(true), 0, new ArrayList<String>());
// If the merger is only connected to the flattener we delete it
// completely, otherwise we only remove the edge
if (streamGraph.getOutEdges(input).size() > 1) {
streamGraph.removeEdge(input, flattener);
} else {
streamGraph.removeVertex(input);
}
streamGraph.setParallelism(flattener, streamGraph.getParallelism(mergeInput));
}
}
}
private static void replaceDiscretizer(
StreamGraph streamGraph, Integer toReplace, Integer replaceWith) {
// Convert to array to create a copy
List<Integer> outEdges = new ArrayList<Integer>(streamGraph.getOutEdges(toReplace));
int numOutputs = outEdges.size();
// Reconnect outputs
for (int i = 0; i < numOutputs; i++) {
Integer output = outEdges.get(i);
streamGraph.setEdge(
replaceWith,
output,
streamGraph.getOutPartitioner(toReplace, output),
0,
new ArrayList<String>());
streamGraph.removeEdge(toReplace, output);
}
List<Integer> inEdges = new ArrayList<Integer>(streamGraph.getInEdges(toReplace));
// Remove inputs
for (Integer input : inEdges) {
streamGraph.removeEdge(input, toReplace);
}
streamGraph.removeVertex(toReplace);
}