package org.webslinger.lang;

 import java.util.Formatter;

 public final class StopWatch {

     private static final Formatter formatter = new Formatter(System.err);

     private static final ThreadLocal<ThreadStopWatch> tl = new ThreadLocal<ThreadStopWatch>();

     private StopWatch() {

     }

     public static final long mark(String format, Object... args) {

         return mark(0, format, args);

     }

     public static final long mark(long lastMarkTime, String format, Object... args) {

         ThreadStopWatch tsw = tl.get();

         if (tsw == null) {

             tsw = new ThreadStopWatch();

             ExecutionPool.addAtExit(tsw);

             tl.set(tsw);

         }

         return tsw.mark(lastMarkTime, format, args);

     }

     private static final class ThreadStopWatch implements ThreadSingletonState {

         private final long startTime = System.nanoTime();

         private long lastTime = startTime;

         private final String threadName = Thread.currentThread().getName();

         public final void start() {

             mark(0, "thread start");

         }

         public final void finish() {

             long diff = System.nanoTime() - startTime;

             synchronized (formatter) {

                 formatter.format("%09.6f[%s]: thread done\n", ((double)diff / (double)1000000000), threadName);

             }

             tl.set(null);

         }

         protected final long mark(long lastMarkTime, String format, Object... args) {

             long curTime = System.nanoTime();

             long diff = curTime - lastTime;

             lastTime = curTime;

             synchronized (formatter) {

                 if (lastMarkTime != 0) {

                     formatter.format("%09.6f(%09.6f)[%s]: ", ((double)diff / (double)1000000000), ((double)(curTime - lastMarkTime) / (double)1000000000), threadName);

                 } else {

                     formatter.format("%09.6f[%s]: ", ((double)diff / (double)1000000000), threadName);

                 }

                 formatter.format(format, args);

                 System.err.println();

             }

             return curTime;

         }

     }

 }