content: package backtype.storm.tuple;
  
  import backtype.storm.utils.Utils;
  import backtype.storm.utils.WritableUtils;
  import java.io.DataInputStream;
  import java.io.DataOutputStream;
  import java.io.IOException;
  import java.util.HashMap;
  import java.util.Map;
  import java.util.Map.Entry;
  import java.util.Set;
  
  public class MessageId {
      private Map<Long, Long> _anchorsToIds;
      
      public static long generateId() {
          return Utils.randomLong();
      }
  
      public static MessageId makeUnanchored() {
          return makeId(new HashMap<Long, Long>());
      }
          
      public static MessageId makeId(Map<Long, Long> anchorsToIds) {
          return new MessageId(anchorsToIds);
      }
          
      public static MessageId makeRootId(long id, long val) {
          Map<Long, Long> anchorsToIds = new HashMap<Long, Long>();
          anchorsToIds.put(id, val);
          return new MessageId(anchorsToIds);
      }
      
      protected MessageId(Map<Long, Long> anchorsToIds) {
          _anchorsToIds = anchorsToIds;
      }
  
      public Map<Long, Long> getAnchorsToIds() {
          return _anchorsToIds;
      }
  
      public Set<Long> getAnchors() {
          return _anchorsToIds.keySet();
      }    
      
      @Override
      public int hashCode() {
          return _anchorsToIds.hashCode();
      }
  
      @Override
      public boolean equals(Object other) {
          if(other instanceof MessageId) {
              return _anchorsToIds.equals(((MessageId) other)._anchorsToIds);
          } else {
              return false;
          }
      }
  
      @Override
      public String toString() {
          return _anchorsToIds.toString();
      }
  
      public void serialize(DataOutputStream out) throws IOException {
          WritableUtils.writeVInt(out, _anchorsToIds.size());
          for(Entry<Long, Long> anchorToId: _anchorsToIds.entrySet()) {
              out.writeLong(anchorToId.getKey());
              out.writeLong(anchorToId.getValue());
          }
      }
  
      public static MessageId deserialize(DataInputStream in) throws IOException {
          int numAnchors = WritableUtils.readVInt(in);
          Map<Long, Long> anchorsToIds = new HashMap<Long, Long>();
          for(int i=0; i<numAnchors; i++) {
              anchorsToIds.put(in.readLong(), in.readLong());
          }
          return new MessageId(anchorsToIds);
      }
  }