content: /*
   * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
   * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  
  package openjdk.tools.javac.comp;
  
  import java.util.Collection;
  import java.util.HashMap;
  import openjdk.tools.javac.code.Symbol.TypeSymbol;
  import openjdk.tools.javac.util.Context;
  
  /** This class contains the type environments used by Enter, MemberEnter,
   *  Attr, DeferredAttr, and Lower.
   *
   *  <p><b>This is NOT part of any supported API.
   *  If you write code that depends on this, you do so at your own risk.
   *  This code and its internal interfaces are subject to change or
   *  deletion without notice.</b>
   */
  class TypeEnvs {
      private static final long serialVersionUID = 571524752489954631L;
  
      protected static final Context.Key<TypeEnvs> typeEnvsKey = new Context.Key<>();
      public static TypeEnvs instance(Context context) {
          TypeEnvs instance = context.get(typeEnvsKey);
          if (instance == null)
              instance = new TypeEnvs(context);
          return instance;
      }
  
      private HashMap<TypeSymbol,Env<AttrContext>> map;
      protected TypeEnvs(Context context) {
          map = new HashMap<>();
          context.put(typeEnvsKey, this);
      }
  
      Env<AttrContext> get(TypeSymbol sym) { return map.get(sym); }
      Env<AttrContext> put(TypeSymbol sym, Env<AttrContext> env) { return map.put(sym, env); }
      Env<AttrContext> remove(TypeSymbol sym) { return map.remove(sym); }
      Collection<Env<AttrContext>> values() { return map.values(); }
      void clear() { map.clear(); }
  }
  