| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 org.apache.pig.newplan; |
| |
| import java.util.ArrayList; |
| import java.util.Iterator; |
| import java.util.Map; |
| |
| import org.apache.pig.impl.util.MultiMap; |
| import org.apache.pig.impl.util.Pair; |
| |
| public class PlanEdge extends MultiMap<Operator, Operator> { |
| |
| private static final long serialVersionUID = 1L; |
| |
| public PlanEdge() { |
| super(); |
| } |
| |
| /** |
| * @param size Initial size of the map |
| */ |
| public PlanEdge(int size) { |
| super(size); |
| } |
| |
| /** |
| * Add an element to the map. |
| * @param key The key to store the value under. If the key already |
| * exists the value will be added to the collection for that key, it |
| * will not replace the existing value (as in a standard map). |
| * @param value value to store. |
| * @param pos position in the arraylist to store the new value at. |
| * Positions are zero based. |
| */ |
| public void put(Operator key, Operator value, int pos) { |
| ArrayList<Operator> list = mMap.get(key); |
| if (list == null) { |
| list = new ArrayList<Operator>(); |
| if (pos != 0) { |
| throw new IndexOutOfBoundsException( |
| "First edge cannot have position greater than 1"); |
| } |
| list.add(value); |
| mMap.put(key, list); |
| } else { |
| list.add(pos, value); |
| } |
| } |
| |
| /** |
| * Remove one value from an existing key and return which position in |
| * the arraylist the value was at.. If that is the last value |
| * for the key, then remove the key too. |
| * @param key Key to remove the value from. |
| * @param value Value to remove. |
| * @return A pair containing the value being removed and an integer |
| * indicating the position, or null if the key or value does |
| * not exist. Positions are zero based. |
| */ |
| public Pair<Operator, Integer> removeWithPosition(Operator key, |
| Operator value) { |
| ArrayList<Operator> list = mMap.get(key); |
| if (list == null) return null; |
| |
| int index = -1; |
| Iterator<Operator> i = list.iterator(); |
| Operator keeper = null; |
| for (int j = 0; i.hasNext(); j++) { |
| keeper = i.next(); |
| //if (keeper.equals(value)) { |
| if (keeper == value) { |
| i.remove(); |
| index = j; |
| break; |
| } |
| } |
| |
| if (index == -1) return null; |
| |
| if (list.size() == 0) { |
| mMap.remove(key); |
| } |
| |
| return new Pair<Operator, Integer>(keeper, index); |
| } |
| |
| public PlanEdge shallowClone() { |
| // shallow clone: elements not cloned |
| PlanEdge result = new PlanEdge(); |
| for (Map.Entry<Operator, ArrayList<Operator>> entry : mMap.entrySet()) { |
| ArrayList<Operator> list = new ArrayList<Operator>(); |
| list.addAll(entry.getValue()); |
| result.put(entry.getKey(), list); |
| } |
| return result; |
| } |
| } |