Review Request: 7186817 - Remove Windows 95/98/ME Support

[Dan Xu]

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/ProcessImpl_md.c and java/util/TimeZone_md.c in this 
>> transaction.
>>
>> Thanks,
>>
>> -Dan
>>
>