RE: [java-gnome-hackers] String changes

[Jeffrey M. <Jef...@Br...>]

My only concern is that this is a very significant change.
It will not be as simple as just regenerating the generated
code since I have made changes and optimizations to many
of the generated classes.  Still, I think this is the right
thing to do.  Perhaps we should divide this activity up 
between several people to expedite the process.

-Jeff

-----Original Message-----
From: Mark Howard [mailto:mh...@ti...]
Sent: Wednesday, March 19, 2003 4:22 PM
To: jav...@li...
Subject: [java-gnome-hackers] String changes


Hi,
  As discussed at the start of the year, 
  I'd like to make some big changes to the way we handle passing of
strings. The current code has major issues on some (non-Sun) Java
environments (when working with zero length strings) and also does not
take into account charset encoding. 

These changes:
 * use  (*env)->GetStringUTFChars rather than 
        jint str_len = (*env)->GetArrayLength(env, str);
        gchar* str_g = (gchar*)g_malloc(str_len + 1);
        (*env)->GetByteArrayRegion(env, str, 0, str_len, (jbyte*)str_g);
        str_g[str_len] = 0;
 * Also call    (*env)->ReleaseStringUTFChars(env, str, str_g);
   - As far as I can see, the old code is wrong in that it should have
been calling ReleaseByteArrayElements when done 
   - please let me know if you don't agree with this.


The attached files demonstrate the changes I propose. Test.c shows both
the current and proposed methods
They can be executed using 
gcc -c -g -O2 -fPIC Test.c -o Test.o -I/usr/include/gtk-2.0
-I/usr/lib/gtk-2.0/include -I/usr/include/atk-1.0
-I/usr/include/pango-1.0 -I/usr/include/freetype2
-I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include

   gcc   -g -O2 -fPIC -shared -o libTest.so Test.o -Wl,--export-dynamic
-lgtk-x11-2.0 -lgdk-x11-2.0 -latk-1.0 -lgdk_pixbuf-2.0 -lm
-lpangoxft-1.0 -lpangox-1.0 -lpango-1.0 -lgobject-2.0 -lgmodule-2.0 -ldl
-lglib-2.0 -I/usr/include/gtk-2.0 -I/usr/lib/gtk-2.0/include
-I/usr/include/atk-1.0 -I/usr/include/pango-1.0 -I/usr/include/freetype2
-I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -Xlinker
--no-undefined

javac TestClass.java
LD_LIBRARY_PATH=. java TestClass

In my tests, the new code always also has improved performance (Java
1.4.1)

The changes would require regenerating all the generated code and
(hopefully semi-automatically) changing all calls to these.

Any comments?
-- 
  .''`. Mark Howard
 : :' :
 `. `'  http://www.tildemh.com 
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