Improve formatting of compiler output

src/helma/scripting/rhino/debug/Profiler.java

@@ -8,6 +8,8 @@ import org.mozilla.javascript.Scriptable;
 
 import java.util.*;
 
+import helma.util.StringUtils;
+
 public class Profiler implements Debugger {
 
     HashMap frames = new HashMap();
@@ -64,10 +66,16 @@ public class Profiler implements Debugger {
                 return ((ProfilerFrame)o2).runtime - ((ProfilerFrame)o1).runtime;
             }
         });
+        int length = Math.min(100, f.length);
+        int prefixLength = Integer.MAX_VALUE;
+        for (int i = 0; i < length - 1; i++) {
+            prefixLength = Math.min(prefixLength,
+                    StringUtils.getCommonPrefix(f[i].name, f[i+1].name).length());
+        }
         StringBuffer buffer = new StringBuffer("     total  average  calls    path\n");
         buffer.append("==================================================================\n");
-        for (int i = 0; i < Math.min(100, f.length); i++) {
+        for (int i = 0; i < length; i++) {
-            buffer.append(f[i].renderLine(0));
+            buffer.append(f[i].renderLine(prefixLength));
         }
         return buffer.toString();
     }

src/helma/util/StringUtils.java

@@ -84,4 +84,25 @@ public class StringUtils {
         return (String[]) list.toArray(new String[list.size()]);
     }
 
+    /**
+     * Get the largest common prefix of Strings s1 and s2
+     * @param s1 a string
+     * @param s2 another string
+     * @return the largest prefix shared by both strings
+     */
+    public static String getCommonPrefix(String s1, String s2) {
+        if (s1.indexOf(s2) == 0) {
+            return s2;
+        } else if (s2.indexOf(s1) == 0) {
+            return s1;
+        }
+        int length = Math.min(s1.length(), s2.length());
+        for (int i = 0; i < length; i++) {
+            if (s1.charAt(i) != s2.charAt(i)) {
+                return s1.substring(0, i);
+            }
+        }
+        return s1.substring(0, length);
+    }
+
 }