1 /*
   2  * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 package org.graalvm.compiler.debug.internal;
  24 
  25 import java.util.ArrayList;
  26 import java.util.Collections;
  27 import java.util.HashMap;
  28 import java.util.List;
  29 import java.util.Map;
  30 
  31 /**
  32  * Registry for allocating a globally unique integer id to each {@link DebugValue}.
  33  */
  34 public class KeyRegistry {
  35 
  36     private static final Map<String, Integer> keyMap = new HashMap<>();
  37     private static final List<DebugValue> debugValues = new ArrayList<>();
  38 
  39     /**
  40      * Ensures a given debug value is registered.
  41      *
  42      * @return the globally unique id for {@code value}
  43      */
  44     public static synchronized int register(DebugValue value) {
  45         String name = value.getName();
  46         if (!keyMap.containsKey(name)) {
  47             keyMap.put(name, debugValues.size());
  48             debugValues.add(value);
  49         }
  50         return keyMap.get(name);
  51     }
  52 
  53     /**
  54      * Gets a immutable view of the registered debug values.
  55      *
  56      * @return a list where {@code get(i).getIndex() == i}
  57      */
  58     public static synchronized List<DebugValue> getDebugValues() {
  59         return Collections.unmodifiableList(debugValues);
  60     }
  61 }