content: /*
   * Copyright (c) 2011, 2013, 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.code;
  
  import java.util.HashMap;
  import java.util.Map;
  
  import openjdk.tools.javac.tree.EndPosTable;
  import openjdk.tools.javac.tree.JCTree;
  import openjdk.tools.javac.util.Assert;
  import openjdk.tools.javac.util.Context;
  import openjdk.tools.javac.util.JCDiagnostic.DiagnosticPosition;
  import openjdk.tools.javac.util.ListBuffer;
  
  /**
   *
   * <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 DeferredLintHandler {
      protected static final Context.Key<DeferredLintHandler> deferredLintHandlerKey = new Context.Key<>();
  
      public static DeferredLintHandler instance(Context context) {
          DeferredLintHandler instance = context.get(deferredLintHandlerKey);
          if (instance == null)
              instance = new DeferredLintHandler(context);
          return instance;
      }
  
      protected DeferredLintHandler(Context context) {
          context.put(deferredLintHandlerKey, this);
          this.currentPos = IMMEDIATE_POSITION;
      }
  
      /**An interface for deferred lint reporting - loggers passed to
       * {@link #report(LintLogger) } will be called when
       * {@link #flush(DiagnosticPosition) } is invoked.
       */
      public interface LintLogger {
          void report();
      }
  
      private DiagnosticPosition currentPos;
      private Map<DiagnosticPosition, ListBuffer<LintLogger>> loggersQueue = new HashMap<>();
  
      /**Associate the given logger with the current position as set by {@link #setPos(DiagnosticPosition) }.
       * Will be invoked when {@link #flush(DiagnosticPosition) } will be invoked with the same position.
       * <br>
       * Will invoke the logger synchronously if {@link #immediate() } was called
       * instead of {@link #setPos(DiagnosticPosition) }.
       */
      public void report(LintLogger logger) {
          if (currentPos == IMMEDIATE_POSITION) {
              logger.report();
          } else {
              ListBuffer<LintLogger> loggers = loggersQueue.get(currentPos);
              if (loggers == null) {
                  loggersQueue.put(currentPos, loggers = new ListBuffer<>());
              }
              loggers.append(logger);
          }
      }
  
      /**Invoke all {@link LintLogger}s that were associated with the provided {@code pos}.
       */
      public void flush(DiagnosticPosition pos) {
          ListBuffer<LintLogger> loggers = loggersQueue.get(pos);
          if (loggers != null) {
              for (LintLogger lintLogger : loggers) {
                  lintLogger.report();
              }
              loggersQueue.remove(pos);
          }
      }
  
      /**Sets the current position to the provided {@code currentPos}. {@link LintLogger}s
       * passed to subsequent invocations of {@link #report(LintLogger) } will be associated
       * with the given position.
       */
      public DiagnosticPosition setPos(DiagnosticPosition currentPos) {
          DiagnosticPosition prevPosition = this.currentPos;
          this.currentPos = currentPos;
          return prevPosition;
      }
  
      /**{@link LintLogger}s passed to subsequent invocations of
       * {@link #report(LintLogger) } will be invoked immediately.
       */
      public DiagnosticPosition immediate() {
          return setPos(IMMEDIATE_POSITION);
      }
  
      private static final DiagnosticPosition IMMEDIATE_POSITION = new DiagnosticPosition() {
          @Override
          public JCTree getTree() {
              Assert.error();
              return null;
          }
  
          @Override
          public int getStartPosition() {
              Assert.error();
              return -1;
          }
  
          @Override
          public int getPreferredPosition() {
              Assert.error();
              return -1;
          }
  
          @Override
          public int getEndPosition(EndPosTable endPosTable) {
              Assert.error();
              return -1;
          }
      };
  }
  