content: /*
   * Copyright (c) 2001, 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 openjdk.tools.javac.code.Symbol.TypeSymbol;
  import openjdk.tools.javac.tree.JCTree;
  import java.util.AbstractQueue;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.LinkedList;
  import java.util.Map;
  import java.util.Queue;
  import jdkx.tools.JavaFileObject;
  
  import openjdk.tools.javac.util.Context;
  
  /** A queue of all as yet unattributed classes.
   *
   *  <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>
   */
  public class Todo extends AbstractQueue<Env<AttrContext>> {
      /** The context key for the todo list. */
      protected static final Context.Key<Todo> todoKey = new Context.Key<>();
  
      /** Get the Todo instance for this context. */
      public static Todo instance(Context context) {
          Todo instance = context.get(todoKey);
          if (instance == null)
              instance = new Todo(context);
          return instance;
      }
  
      /** Create a new todo list. */
      protected Todo(Context context) {
          context.put(todoKey, this);
      }
  
      public void append(Env<AttrContext> env) {
          add(env);
      }
  
      @Override
      public Iterator<Env<AttrContext>> iterator() {
          return contents.iterator();
      }
  
      @Override
      public int size() {
          return contents.size();
      }
  
      public boolean offer(Env<AttrContext> e) {
          if (contents.add(e)) {
              if (contentsByFile != null)
                  addByFile(e);
              return true;
          } else {
              return false;
          }
      }
  
      /**
       * Removes all unattributed classes except those belonging to the given
       * collection of files.
       *
       * @param sourceFiles The source files of the classes to keep.
       */
      public void retainFiles(Collection<? extends JavaFileObject> sourceFiles) {
          for (Iterator<Env<AttrContext>> it = contents.iterator(); it.hasNext(); ) {
              Env<AttrContext> env = it.next();
              if (!sourceFiles.contains(env.toplevel.sourcefile)) {
                  if (contentsByFile != null) removeByFile(env);
                  it.remove();
              }
          }
      }
  
      public Env<AttrContext> poll() {
          if (size() == 0)
              return null;
          Env<AttrContext> env = contents.remove(0);
          if (contentsByFile != null)
              removeByFile(env);
          return env;
      }
  
      public Env<AttrContext> peek() {
          return (size() == 0 ? null : contents.get(0));
      }
  
      public Queue<Queue<Env<AttrContext>>> groupByFile() {
          if (contentsByFile == null) {
              contentsByFile = new LinkedList<>();
              for (Env<AttrContext> env: contents) {
                  addByFile(env);
              }
          }
          return contentsByFile;
      }
  
      void remove(TypeSymbol sym) {
          for (Iterator<Env<AttrContext>> it = contents.listIterator(); it.hasNext();) {
              Env<AttrContext> env = it.next();
              if (env.tree != null && (env.tree.hasTag(JCTree.Tag.CLASSDEF) && ((JCTree.JCClassDecl)env.tree).sym == sym
                      || env.tree.hasTag(JCTree.Tag.PACKAGEDEF) && ((JCTree.JCPackageDecl)env.tree).packge == sym)) {
                  it.remove();
                  if (contentsByFile != null)
                      removeByFile(env);
              }
          }
      }
  
      private void addByFile(Env<AttrContext> env) {
          JavaFileObject file = env.toplevel.sourcefile;
          if (fileMap == null)
              fileMap = new HashMap<>();
          FileQueue fq = fileMap.get(file);
          if (fq == null) {
              fq = new FileQueue();
              fileMap.put(file, fq);
              contentsByFile.add(fq);
          }
          fq.fileContents.add(env);
      }
  
      private void removeByFile(Env<AttrContext> env) {
          JavaFileObject file = env.toplevel.sourcefile;
          FileQueue fq = fileMap.get(file);
          if (fq == null)
              return;
          if (fq.fileContents.remove(env)) {
              if (fq.isEmpty()) {
                  fileMap.remove(file);
                  contentsByFile.remove(fq);
              }
          }
      }
  
      LinkedList<Env<AttrContext>> contents = new LinkedList<>();
      LinkedList<Queue<Env<AttrContext>>> contentsByFile;
      Map<JavaFileObject, FileQueue> fileMap;
  
      class FileQueue extends AbstractQueue<Env<AttrContext>> {
          @Override
          public Iterator<Env<AttrContext>> iterator() {
              return fileContents.iterator();
          }
  
          @Override
          public int size() {
              return fileContents.size();
          }
  
          public boolean offer(Env<AttrContext> e) {
              if (fileContents.offer(e)) {
                  contents.add(e);
                  return true;
              }
              return false;
          }
  
          public Env<AttrContext> poll() {
              if (fileContents.size() == 0)
                  return null;
              Env<AttrContext> env = fileContents.remove(0);
              contents.remove(env);
              return env;
          }
  
          public Env<AttrContext> peek() {
              return (fileContents.size() == 0 ? null : fileContents.get(0));
          }
  
          LinkedList<Env<AttrContext>> fileContents = new LinkedList<>();
      }
  }
  