[jboss-dev-forums] [Design of POJO Server] - Re: JBVFS-26 - Optimizing the VFS PathTokenizer

[alesj]

"adrian at jboss.org" wrote : 
  | 1) If StringTokenizer was replaced with an optimized lexer
  | (e.g. like the one used to parse system property references from strings in common-core)
  | then the check for an empty token could be done inline instead of string
  | comparison.
  | 
This is now rewritten into this:

  |    public static String[] getTokens(String path)
  |    {
  |       if (path == null)
  |          throw new IllegalArgumentException("Null path");
  | 
  |       char[] chars = path.toCharArray();
  |       StringBuilder buffer = new StringBuilder();
  |       List<String> list = new ArrayList<String>();
  |       String specialToken = null;
  | 
  |       for (int index=0; index < chars.length; index++)
  |       {
  |          char  ch = chars[index];
  | 
  |          if (ch == '/')
  |          {
  |             if (index > 0)
  |             {
  |                if (buffer.length() == 0 && specialToken == null)
  |                   throw new IllegalArgumentException("A path element is empty: " + path);
  | 
  |                if (specialToken != null)
  |                   list.add(specialToken);
  |                else
  |                   list.add(buffer.toString());
  | 
  |                // reset
  |                buffer.setLength(0);
  |                specialToken = null;
  |             }
  |          }
  |          else if (ch == '.')
  |          {
  |             if (specialToken == null && buffer.length() == 0)
  |                specialToken = CURRENT_PATH;
  |             else if (specialToken == CURRENT_PATH && buffer.length() == 0)
  |                specialToken = REVERSE_PATH;
  |             else
  |                buffer.append(ch);
  |          }
  |          else
  |          {
  |             buffer.append(ch);
  |          }
  |       }
  | 
  |       // add last token
  |       if (specialToken != null)
  |          list.add(specialToken);
  |       else if (buffer.length() > 0)
  |          list.add(buffer.toString());
  | 
  |       return list.toArray(new String[list.size()]);
  |    }
  | 
and we do '==' check on special tokens. ;-)

View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4152637#4152637

Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4152637