java/java-impl/src/com/intellij/slicer/DuplicateMap.java

   1 /*
   2  * Copyright 2000-2009 JetBrains s.r.o.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package com.intellij.slicer;
  17
  18 import com.intellij.usageView.UsageInfo;
  19 import gnu.trove.THashMap;
  20 import gnu.trove.TObjectHashingStrategy;
  21
  22 import java.util.Map;
  23
  24 /**
  25 * @author cdr
  26 */ // rehash map on each PSI modification since SmartPsiPointer's hashCode() and equals() are changed
  27 class DuplicateMap {
  28   private static final TObjectHashingStrategy<SliceUsage> USAGEINFO_EQUALITY = new TObjectHashingStrategy<SliceUsage>() {
  29     public int computeHashCode(SliceUsage object) {
  30       UsageInfo info = object.getUsageInfo();
  31       return info.startOffset + info.endOffset * 31;
  32     }
  33
  34     public boolean equals(SliceUsage o1, SliceUsage o2) {
  35       return o1.getUsageInfo().equals(o2.getUsageInfo());
  36     }
  37   };
  38   private final Map<SliceUsage, SliceNode> myDuplicates = new THashMap<SliceUsage, SliceNode>(USAGEINFO_EQUALITY);
  39
  40   public SliceNode putNodeCheckDupe(SliceNode node) {
  41     SliceUsage usage = node.getValue();
  42     SliceNode eq = myDuplicates.get(usage);
  43     if (eq == null) {
  44       myDuplicates.put(usage, node);
  45     }
  46     return eq;
  47   }
  48
  49   public void clear() {
  50     myDuplicates.clear();
  51   }
  52 }