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
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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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