From d09fc511e24ef6416b026441e68269a7189c0328 Mon Sep 17 00:00:00 2001
From: Max Schaefer <mschaefer@us.ibm.com>
Date: Tue, 20 Nov 2012 10:45:56 -0500
Subject: [PATCH] Added a logging stopwatch for debugging.

---
 .../ibm/wala/util/debug/LoggingStopwatch.java | 43 +++++++++++++++++++
 1 file changed, 43 insertions(+)
 create mode 100644 com.ibm.wala.util/src/com/ibm/wala/util/debug/LoggingStopwatch.java

diff --git a/com.ibm.wala.util/src/com/ibm/wala/util/debug/LoggingStopwatch.java b/com.ibm.wala.util/src/com/ibm/wala/util/debug/LoggingStopwatch.java
new file mode 100644
index 000000000..401f2d0ff
--- /dev/null
+++ b/com.ibm.wala.util/src/com/ibm/wala/util/debug/LoggingStopwatch.java
@@ -0,0 +1,43 @@
+package com.ibm.wala.util.debug;
+
+/**
+ * A stop watch that prints log messages.
+ * 
+ * @author mschaefer
+ *
+ */
+public class LoggingStopwatch {
+  private long start;
+
+  /**
+   * Start the stopwatch.
+   */
+  public void start() {
+    this.start = System.nanoTime();
+  }
+
+  /**
+   * Mark the completion of a task, print the time it took to complete,
+   * and optionally restart the stopwatch.
+   * 
+   * @param msg message to print
+   * @param reset whether to restart the stopwatch
+   * @return the elapsed time in milliseconds
+   */
+  public long mark(String msg, boolean reset) {
+    long end = System.nanoTime();
+    long elapsed = (end-start)/1000000;
+    System.out.println(msg + ": " + elapsed + "ms");
+    if(reset)
+      start();
+    return elapsed;
+  }
+  
+  /**
+   * Convenience method that invokes {@link #mark(String, boolean)} with {@code true}
+   * as its second argument.
+   */
+  public long mark(String msg) {
+    return mark(msg, true);
+  }
+}