| /** |
| * Copyright (C) 2015 DataTorrent, Inc. |
| * |
| * 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 com.datatorrent.stram.engine; |
| |
| import com.datatorrent.stram.tuple.Tuple; |
| import com.datatorrent.api.Sink; |
| import com.datatorrent.netlet.util.CircularBuffer; |
| import java.util.HashMap; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * <p>Abstract MuxReservoir class.</p> |
| * |
| * @since 0.3.2 |
| */ |
| public abstract class MuxReservoir |
| { |
| @SuppressWarnings("VolatileArrayField") |
| private volatile SubReservoir[] reservoirs = new SubReservoir[0]; |
| private HashMap<String, SubReservoir> reservoirMap = new HashMap<String, SubReservoir>(); |
| |
| public SweepableReservoir acquireReservoir(String id, int capacity) |
| { |
| SubReservoir r = reservoirMap.get(id); |
| if (r == null) { |
| reservoirMap.put(id, r = new SubReservoir(capacity)); |
| SubReservoir[] newReservoirs = new SubReservoir[reservoirs.length + 1]; |
| newReservoirs[reservoirs.length] = r; |
| for (int i = reservoirs.length; i-- > 0;) { |
| newReservoirs[i] = reservoirs[i]; |
| } |
| reservoirs = newReservoirs; |
| } |
| |
| return r; |
| } |
| |
| public SweepableReservoir releaseReservoir(String id) |
| { |
| SubReservoir r = reservoirMap.remove(id); |
| if (r != null) { |
| SubReservoir[] newReservoirs = new SubReservoir[reservoirs.length - 1]; |
| |
| int j = 0; |
| for (int i = 0; i < reservoirs.length; i++) { |
| if (reservoirs[i] != r) { |
| newReservoirs[j++] = reservoirs[i]; |
| } |
| } |
| |
| reservoirs = newReservoirs; |
| } |
| |
| return r; |
| } |
| |
| public abstract Reservoir getMasterReservoir(); |
| |
| class SubReservoir extends CircularBuffer<Object> implements SweepableReservoir |
| { |
| int count; |
| private Sink<Object> sink; |
| |
| SubReservoir(int capacity) |
| { |
| super(capacity); |
| } |
| |
| @Override |
| public Sink<Object> setSink(Sink<Object> sink) |
| { |
| try { |
| return this.sink; |
| } |
| finally { |
| this.sink = sink; |
| } |
| } |
| |
| @Override |
| public Tuple sweep() |
| { |
| final int size = size(); |
| if (size > 0) { |
| for (int i = 0; i < size; i++) { |
| if (peekUnsafe() instanceof Tuple) { |
| count += i; |
| return (Tuple)peekUnsafe(); |
| } |
| sink.put(pollUnsafe()); |
| } |
| |
| count += size; |
| } |
| |
| final Reservoir masterReservoir = getMasterReservoir(); |
| synchronized (masterReservoir) { |
| /* find out the minimum remaining capacity in all the other buffers and consume those many tuples from bufferserver */ |
| int min = masterReservoir.size(); |
| if (min == 0) { |
| return null; |
| } |
| |
| for (int i = reservoirs.length; i-- > 0;) { |
| if (reservoirs[i].remainingCapacity() < min) { |
| min = reservoirs[i].remainingCapacity(); |
| } |
| } |
| |
| while (min-- > 0) { |
| Object o = masterReservoir.remove(); |
| for (int i = reservoirs.length; i-- > 0;) { |
| reservoirs[i].add(o); |
| } |
| } |
| } |
| |
| return null; |
| } |
| |
| @Override |
| public int getCount(boolean reset) |
| { |
| try { |
| return count; |
| } |
| finally { |
| if (reset) { |
| count = 0; |
| } |
| } |
| } |
| |
| } |
| |
| private static final Logger logger = LoggerFactory.getLogger(MuxReservoir.class); |
| } |