code: /**
   * Copyright 2018 Alexey Ragozin
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.gridkit.jvmtool.parser.jstack;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.io.Reader;
  import java.util.Iterator;
  import java.util.List;
  
  import org.gridkit.jvmtool.codec.stacktrace.ThreadSnapshotEvent;
  import org.gridkit.jvmtool.event.Event;
  import org.gridkit.jvmtool.event.EventDumpParser;
  import org.gridkit.jvmtool.event.EventMorpher;
  import org.gridkit.jvmtool.event.EventReader;
  import org.gridkit.jvmtool.event.MorphingEventReader;
  
  public class JStackThreadDumpLoader implements EventDumpParser {
  
      @Override
      public boolean isFunctional() {
          return true;
      }
  
      @Override
      public EventReader<Event> open(InputStreamSource source) throws IOException {
          InputStream is = source.open();
          Reader reader = new InputStreamReader(is);
          JStackDumpParser parser = new JStackDumpParser(reader);
          try {
              is.close();
          }
          catch(IOException e) {
          }
          if (parser.isValid()) {
              List<ThreadSnapshotEvent> list = parser.getThreads();
              final Iterator<Event> it = iterator(list);
              return new DumpReader(it).morph(new EventMorpher<Event, Event>() {
                  @Override
                  public Event morph(Event event) {
                      return event;
                  }
              });
          }
          else {
              return null;
          }
      }
  
      @SuppressWarnings({ "unchecked", "rawtypes" })
      private Iterator<Event> iterator(List<ThreadSnapshotEvent> list) {
          return (Iterator)list.iterator();
      }
  
      @Override
      public String toString() {
          return "JStack dump parser";
      }
  
      private static final class DumpReader implements EventReader<Event> {
  
          private final Iterator<Event> it;
  
          private DumpReader(Iterator<Event> it) {
              this.it = it;
          }
  
          @Override
          public Iterator<Event> iterator() {
              return it;
          }
  
          @Override
          public boolean hasNext() {
              return it.hasNext();
          }
  
          @Override
          public Event next() {
              return it.next();
          }
  
          @Override
          public void remove() {
              throw new UnsupportedOperationException();
          }
  
          @Override
          public <M extends Event> EventReader<M> morph(EventMorpher<Event, M> morpher) {
              return MorphingEventReader.morph(this, morpher);
          }
  
          @Override
          public Event peekNext() {
              throw new UnsupportedOperationException();
          }
  
          @Override
          public void dispose() {
          }
      }
  }
  