1 /*
   2  * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 
  25 public class TransformUtil {
  26     public static final String BeforePattern = "this-should-be-transformed";
  27     public static final String AfterPattern  = "this-has-been--transformed";
  28     public static final String ParentCheckPattern = "parent-transform-check: ";
  29     public static final String ChildCheckPattern = "child-transform-check: ";
  30 
  31     /**
  32      * @return the number of occurrences of the <code>from</code> string that
  33      * have been replaced.
  34      */
  35     public static int replace(byte buff[], String from, String to) {
  36         if (to.length() != from.length()) {
  37             throw new RuntimeException("bad strings");
  38         }
  39         byte f[] = asciibytes(from);
  40         byte t[] = asciibytes(to);
  41         byte f0 = f[0];
  42 
  43         int numReplaced = 0;
  44         int max = buff.length - f.length;
  45         for (int i = 0; i < max; ) {
  46             if (buff[i] == f0 && replace(buff, f, t, i)) {
  47                 i += f.length;
  48                 numReplaced++;
  49             } else {
  50                 i++;
  51             }
  52         }
  53         return numReplaced;
  54     }
  55 
  56     public static boolean replace(byte buff[], byte f[], byte t[], int i) {
  57         for (int x = 0; x < f.length; x++) {
  58             if (buff[x+i] != f[x]) {
  59                 return false;
  60             }
  61         }
  62         for (int x = 0; x < f.length; x++) {
  63             buff[x+i] = t[x];
  64         }
  65         return true;
  66     }
  67 
  68     static byte[] asciibytes(String s) {
  69         byte b[] = new byte[s.length()];
  70         for (int i = 0; i < b.length; i++) {
  71             b[i] = (byte)s.charAt(i);
  72         }
  73         return b;
  74     }
  75 }