/*
* Copyright (C) 2015 SoftIndex LLC.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.datakernel.datagraph.dataset.impl;
import com.google.common.base.Predicate;
import io.datakernel.datagraph.dataset.Dataset;
import io.datakernel.datagraph.graph.DataGraph;
import io.datakernel.datagraph.graph.StreamId;
import io.datakernel.datagraph.node.NodeFilter;
import java.util.ArrayList;
import java.util.List;
public final class DatasetFilter<T> extends Dataset<T> {
private final Dataset<T> input;
private final Predicate<T> predicate;
public DatasetFilter(Dataset<T> input, Predicate<T> predicate, Class<T> resultType) {
super(resultType);
this.input = input;
this.predicate = predicate;
}
@Override
public List<StreamId> channels(DataGraph graph) {
List<StreamId> outputStreamIds = new ArrayList<>();
List<StreamId> streamIds = input.channels(graph);
for (StreamId streamId : streamIds) {
NodeFilter<T> node = new NodeFilter<>(predicate, streamId);
graph.addNode(graph.getPartition(streamId), node);
outputStreamIds.add(node.getOutput());
}
return outputStreamIds;
}
}