On 04/04/2014 10:08 AM, Xueming Shen wrote:
On 4/3/14 4:43 PM, Jeremy Manson wrote:
Good catch, thanks.

I think we should probably just go with the (equivalent to the) StringBuffer 
variant.  I'm pretty loathe to modify the StringBuilder directly if we are 
going to back that change out.

Do you want me to generate a new patch?

I can/will send out an updated webrev before push.

the latest webrev.

http://cr.openjdk.java.net/~sherman/8039124/webrev

-Sherman


-Sherman


Jeremy


On Thu, Apr 3, 2014 at 2:27 PM, Xueming Shen <xueming.s...@oracle.com 
<mailto:xueming.s...@oracle.com>> wrote:

    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











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