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

Dan Xu dan.xu at oracle.com
Tue Oct 9 20:52:07 UTC 2012

Hi Ulf,

I think it is better to focus on the clean-up for my current transaction. The performance improvement of toUpper() method can be another topic for String class.

Thanks,

-Dan

On 10/09/2012 12:31 PM, Ulf Zibis wrote:

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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