Loop log entries

LogTable.java

import java.util.*;

/**
 * Created with IntelliJ IDEA.
 * User: afernand
 * Date: 11/30/12
 * Time: 2:21 PM
 * To change this template use File | Settings | File Templates.
 */
public class LogTable {

  public static void main(String[] arg) {
    LogTable test = new LogTable();
    test.add("foo", 100, true);  // foo: 50 - 10 - 10 = 30
    test.add("bar", 120, true);  //  +-- bar: 10 - 0 - 5 = 5
    test.add("boo", 125, true);  //  \    +-- boo: 0
    test.add("boo", 125, false); //  \    |
    test.add("bah", 125, true);  //  \    +-- bah: 5
    test.add("bah", 130, false); //  \
    test.add("bar", 130, false); //  \
    test.add("baz", 135, true);  //  +-- baz: 10
    test.add("baz", 145, false); //
    test.add("foo", 150, false);
    Map<String, Row> output = test.timetable();
    System.out.println(output);
  }

  public Map<String, Row> timetable() {
    for(Entry curr: entries) {
      curr.analyze();
    }
    return timetable;
  }

  class Entry {
    void analyze() {
      if(status) { // tag starts
        stack.push(id);
        timetable.put(id, new Row(time));
      } else { // tag ends
        stack.pop();
        int diff = timetable.get(id).mark(time); // tag ends
        if(!stack.empty()) {
          timetable.get(stack.peek()).adjust(diff); // adjust parent
        }
      }
    }

    Entry(String id, int time, boolean status) {
      this.id = id;
      this.time = time;
      this.status = status;
    }

    final String id;
    final int time;
    final boolean status;
  }

  public static class Row {
    @Override
    public String toString() {
      return String.valueOf(delta);
    }

    // skip default constructor and getters/setters

    int mark(int time) {
      delta += time;
      return time - start;
    }

    void adjust(int time) {
      delta -= time;
    }

    Row(int start) {
      this.start = start;
      this.delta = -start;
    }

    private int start;
    private int delta;
  }

  public void add(String id, int time, boolean status) {
    entries.add(new Entry(id, time, status));
  }

  private Map<String, Row> timetable = new HashMap<String, Row>();
  private Stack<String> stack = new Stack<String>();
  private List<Entry> entries = new ArrayList<Entry>();
}