| /* |
| * Copyright (C) 2011 The Android Open Source Project |
| * |
| * 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 android.filterfw.core; |
| |
| import java.util.Set; |
| |
| import android.filterfw.core.Filter; |
| import android.filterfw.core.Scheduler; |
| |
| /** |
| * @hide |
| */ |
| public class RoundRobinScheduler extends Scheduler { |
| |
| private int mLastPos = -1; |
| |
| public RoundRobinScheduler(FilterGraph graph) { |
| super(graph); |
| } |
| |
| @Override |
| public void reset() { |
| mLastPos = -1; |
| } |
| |
| @Override |
| public Filter scheduleNextNode() { |
| Set<Filter> all_filters = getGraph().getFilters(); |
| if (mLastPos >= all_filters.size()) mLastPos = -1; |
| int pos = 0; |
| Filter first = null; |
| int firstNdx = -1; |
| for (Filter filter : all_filters) { |
| if (filter.canProcess()) { |
| if (pos <= mLastPos) { |
| if (first == null) { |
| // store the first available filter |
| first = filter; |
| firstNdx = pos; |
| } |
| } else { |
| // return the next available filter since last |
| mLastPos = pos; |
| return filter; |
| } |
| } |
| pos ++; |
| } |
| // going around from the beginning |
| if (first != null ) { |
| mLastPos = firstNdx; |
| return first; |
| } |
| // if there is nothing to be scheduled, still keep the previous |
| // position. |
| return null; |
| } |
| } |