Hi,
good suggestions, I'll incorporate them.
/Claes
On 2014-07-14 13:08, Andrej Golovnin wrote:
Hi Claes,
in the method Formatter$FormatSpecifier#justify(String) you can
pre-calculate the capacity of the StringBuilder to avoid array
copying, e.g. instead of
2931 StringBuilder sb = new StringBuilder();
use this one:
2931 StringBuilder sb = new StringBuilder(s.length() + sp);
And in the method Formatter$FormatSpecifier#justify(StringBuilder) you
can avoid creation of the StringBuilder object in the line 2956, e.g.
instead of:
2956 StringBuilder tmp = new StringBuilder(sp);
2957 for (int i = 0; i < sp; i++) {
2958 tmp.append(' ');
2959 }
2960 sb.insert(0, tmp);
you can write this:
2956 char[] tmp = new char[sp];
2957 Arrays.fill(tmp, ' ');
2958 sb.insert(0, tmp);
It's not a big improvement but maybe you can change the line
3781 exp.append("0").append(len - 1);
to use the character-based API to append a single character.
Best regards,
Andrej Golovnin
On Mon, Jul 14, 2014 at 12:07 PM, Claes Redestad
<claes.redes...@oracle.com <mailto:claes.redes...@oracle.com>> wrote:
Hi,
please review this patch which optimizes away some allocations
from java.util.Formatter and achieve 1.1-1.3x speedups of micros
targetting String.format. See bug for more details.
webrev: http://cr.openjdk.java.net/~redestad/8050142/webrev.0
<http://cr.openjdk.java.net/%7Eredestad/8050142/webrev.0>
bug: https://bugs.openjdk.java.net/browse/JDK-8050142
Testing: JPRT, jtreg (java/lang/String, java/util/Formatter),
SPECjbb2013 and microbenchmarks
Thanks!
/Claes
