Review Request: 7186817 - Remove Windows 95/98/ME Support (original) (raw)

Ulf Zibis Ulf.Zibis at CoSoCo.de
Tue Oct 9 19:31:18 UTC 2012

Hi,

I did not look into the details, but the hint about performance on String.toLower in WindowsNTFileSystem catched my attention. Here is a very fast converter, which may be enough for calculating the hash:

 // Private ASCII-only optimized version
 public static final String toUpper(final String s) {
     boolean allUpper = true;
     char[] ca = null;
     for (int i=0; i<s.length(); i++) {
         int c = s.charAt(i);
         if (c >= 'a' && c <= 'z') {
             if (allUpper) {
                 ca = s.toCharArray();
                 allUpper = false;
             }
             ca[i] -= '\u0020';
         }
     }
     return allUpper ? s : new String(ca);
 }

It also avoids instantiation of new objects, if there is nothing to change. Note: the equivalent toLower algorithm statistically would be little slower on latin characters, but maybe faster on wide spreaded Unicode characters.

-Ulf

Am 09.10.2012 19:46, schrieb Dan Xu:

Hi folks,

Please help review the code change for CR7186817 to remove Windows 95/98/ME support. The webrev has been uploaded to http://cr.openjdk.java.net/~dxu/7186817/webrev/ <http://cr.openjdk.java.net/%7Edxu/7186817/webrev/> The main focus of this clean-up is in IO area. And I also cleaned java/lang/ProcessImplmd.c and java/util/TimeZonemd.c in this transaction. Thanks, -Dan

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