On 03/25/2014 02:07 PM, Jeremy Manson wrote:
Okay. Thanks, Sherman. Here's an updated version.
I've diverged a bit from Peter's version. In this version,
appendExpandedReplacement takes a StringBuilder. The implications is that In
the StringBuilder case, it saves creating a new StringBuilder object. In the
StringBuffer case, it creates a new StringBuilder, but it doesn't have to
acquire and release all of those locks.
Hi Jeremy,
It appears the "optimized" StringBuilder version will cause following test case
failure,
in which the "xyz" will be copied into the result buffer, even when the
replacement
string triggers a IAE.
// Check nothing has been appended into the output buffer if
// the replacement string triggers IllegalArgumentException.
Pattern p = Pattern.compile("(abc)");
Matcher m = p.matcher("abcd");
StringBuilder result = new StringBuilder();
try {
m.appendReplacement(result, ("xyz$g"));
} catch (IllegalArgumentException iae) {
if (result.length() != 0)
System.err.println(" FAILED");
}
We may have to either catch the IAE and reset the sb, or create
a new sb, as the StringBuffer does.
-Sherman
I also noticed a redundant cast to (int), which I removed.
Jeremy
On Fri, Mar 21, 2014 at 7:34 PM, Xueming Shen <xueming.s...@oracle.com
<mailto:xueming.s...@oracle.com>> wrote:
let's add the StringBuilder method(s), if you can provide an updated
version, I can run the rest (since it's
to add new api, there is an internal CCC process need to go through).
-Sherman
On 3/21/14 5:18 PM, Jeremy Manson wrote:
So, this is all a little opaque to me. How do we make the go/no-go
decision on something like this? Everyone who has chimed in seems to think it
is a good idea.
Jeremy
On Thu, Mar 20, 2014 at 10:38 AM, Jeremy Manson <jeremyman...@google.com
<mailto:jeremyman...@google.com>> wrote:
Sherman,
If you had released it then (which you wouldn't have been able to do,
because you would have to wait another two years for Java 7), you would have
found that it improved performance even with C2. It is only
post-escape-analysis that the performance in C2 equalized.
Anyway, I think adding the StringBuilder variant and deferring /
dealing with the Appendable differently is the right approach, FWIW.
Jeremy
On Thu, Mar 20, 2014 at 10:25 AM, Xueming Shen <xueming.s...@oracle.com
<mailto:xueming.s...@oracle.com>> wrote:
2009? I do have something similar back to 2009 :-)
http://cr.openjdk.java.net/~sherman/regex_replace/webrev/
<http://cr.openjdk.java.net/%7Esherman/regex_replace/webrev/>
Then the ball was dropped around the discussion of whether or not
the IOE should be thrown.
But if we are going to/have to have explicit StringBuilder/Buffer
pair
anyway, then we can keep the Appendable version as private for now
and deal with the StringBuilder and Appendable as two separate
issues.
-Sherman
On 03/20/2014 09:52 AM, Jeremy Manson wrote:
That's definitely an improvement - I think that when I wrote
this (circa
2009), I didn't think about Appendable.
I take it my argument convinced someone? :)
Jeremy
On Thu, Mar 20, 2014 at 1:32 AM, Peter Levart<peter.lev...@gmail.com
<mailto:peter.lev...@gmail.com>>wrote:
On 03/19/2014 06:51 PM, Jeremy Manson wrote:
I'm told that the diff didn't make it. I've put it in
a Google drive
folder...
https://drive.google.com/file/d/0B_GaXa6O4K5LY3Y0aHpranM3aEU/
edit?usp=sharing
Jeremy
Hi Jeremy,
Your factoring-out of expandReplacement() method exposed an
opportunity to
further optimize the code. Instead of creating intermediate
StringBuilder
instance for each expandReplacement() call, this method
could append
directly to resulting StringBuffer/StringBuilder, like in
the following:
http://cr.openjdk.java.net/~plevart/jdk9-dev/MatcherWithStringBuilder/
<http://cr.openjdk.java.net/%7Eplevart/jdk9-dev/MatcherWithStringBuilder/>
webrev.01/
Regards, Peter
On Wed, Mar 19, 2014 at 10:41 AM, Jeremy
Manson<jeremyman...@google.com <mailto:jeremyman...@google.com>>
wrote:
Hi folks,
We've had this internally for a while, and I keep
meaning to bring it up
here. The Matcher class has a few public methods
that take
StringBuffers,
and we've found it useful to add similar versions
that take
StringBuilders.
It has two benefits:
- Users don't have to convert from one to the other
when they want to use
the method in question. The symmetry is nice.
- The StringBuilder variants are faster (if lock
optimizations don't kick
in, which happens in the interpreter and the client
compiler). For
interpreted / client-compiled code, we saw
something like a 25% speedup
on
String.replaceAll(), which calls into this code.
Any interest? Diff attached.
Jeremy
