Re: sprintf() of gawk in cvs works very slow under ja_JP.UTF8

[Aharon Robbins]

Hi. Re the below.

Thanks for the report. A patch is attached. It will show up in the CVS
in the next few days.

Arnold
---------------------------
> Date: Sun, 1 Feb 2009 03:12:25 +0900
> From: Hirofumi Saito <address@hidden>
> To: address@hidden
> Subject: sprintf() of gawk in cvs works very slow under ja_JP.UTF8
>
> Hello,
>
> The sprintf() function of latest gawk in CVS is very very slow.
> I've checked the script below.
>
> $ cat test.awk 
> BEGIN {
>     str = "abc";
>     for (i = 1; i <= 10000; i++) {
>         result = sprintf("%s%s", result, str);
>     }
>     print result;
> }
>
> $ time gawk -f test.awk > /dev/null 
> gawk -f test.awk > /dev/null  7.61s user 0.01s system 99% cpu 7.674 total
>
> But under C locale, it works very fast (over 100 times faster!!).
>
> $ time LC_ALL=C gawk -f test.awk > /dev/null
> LC_ALL=C gawk -f test.awk > /dev/null  0.05s user 0.00s system 18% cpu 0.301 
> total
>
> The release version of gawk-3.1.6 works fast under ja_JP.UTF8.
>
> $ time ../gawk-3.1.6/gawk -f test.awk > /dev/null 
> ../gawk-3.1.6/gawk -f test.awk > /dev/null  0.05s user 0.00s system 95% cpu 
> 0.056 total
>
> regards,
>
> Hirofumi Saito.
-------------------------------------
Sat Jan 31 23:14:00 2009  Arnold D. Robbins  <address@hidden>

        * builtin.c (format_tree): For '%s', don't count the multibyte
        characters if we are just copying all the characters. Gives
        big speedup. Thanks to  Hirofumi Saito <address@hidden>
        for reporting the problem.

Index: builtin.c
===================================================================
RCS file: /d/mongo/cvsrep/gawk-stable/builtin.c,v
retrieving revision 1.29
diff -u -r1.29 builtin.c
--- builtin.c   29 Dec 2008 20:44:02 -0000      1.29
+++ builtin.c   31 Jan 2009 21:13:35 -0000
@@ -984,11 +984,13 @@
                                fill = zero_string;
                        parse_next_arg();
                        arg = force_string(arg);
-                       char_count = mbc_char_count(arg->stptr, arg->stlen);
                        if (fw == 0 && ! have_prec)
                                prec = arg->stlen;
-                       else if (! have_prec || prec > char_count)
-                               prec = char_count;
+                       else {
+                               char_count = mbc_char_count(arg->stptr, 
arg->stlen);
+                               if (! have_prec || prec > char_count)
+                                       prec = char_count;
+                       }
                        cp = arg->stptr;
                        goto pr_tail;
                case 'd':