[jboss-dev] Further profling: Where should I focus?

[Bill Burke]

JarFile is as fast as URLClassLoader:

    public void testJarFile() throws Exception
    {
       URL url = 
Thread.currentThread().getContextClassLoader().getResource("jacorb.jar");
       JarFile jar = new JarFile(new File(url.toURI()));
       JarEntry entry = 
jar.getJarEntry("org/jacorb/orb/portableInterceptor/RequestInterceptorIterator.class");
       System.out.println(entry);

    }

Bill Burke wrote:
> 
> David M. Lloyd wrote:
>> On 01/05/2010 10:40 AM, Bill Burke wrote:
>>> Ales Justin wrote:
>>>> Perhaps this can be solved by custom (+ temp) deployer,
>>>> which would create capabilities from those exports,
>>>> but would just say import-all for imports.
>>>>
>>> No shit shirlock...Especially when thats what is being done now.
>>>
>>> Again, optimizing this algorithm doesn't matter if jars/directories are
>>> being browsed.
>> What do you mean by "browsed"?  If you're going to access any file in a 
>> JAR, you need to scan the (unordered) ZIP directory anyway.  Better to do 
>> it one time and cache it so files can be looked up on an O(1) basis.  And 
>> once you've done that, why not use that data for other purposes?
>>
> 
> A simple test of using ZipInputStream vs. URLClassLoader to find a 
> resource within jacorb.jar.
> 
> ZipInputStream: 256ms.
> URLClassLoader: 5ms.
> 
> URLClasLoader is obviously using some other mechanism to find things.
> 
> 
>     public void testZipStream() throws Exception
>     {
>        URL url = 
> Thread.currentThread().getContextClassLoader().getResource("jacorb.jar");
> 
>        ZipInputStream zis = new ZipInputStream(url.openStream());
> 
>        Map<String, ZipEntry> map = new HashMap<String, ZipEntry>();
>        ZipEntry entry = null;
>        while ((entry = zis.getNextEntry()) != null)
>        {
>           map.put(entry.getName(), entry);
>        }
>     }
> 
>     public void testClassLoader() throws Exception
>     {
>        URL[] urls = 
> {Thread.currentThread().getContextClassLoader().getResource("jacorb.jar")};
> 
>        URLClassLoader cl = new URLClassLoader(urls);
>        URL url = 
> cl.getResource("org/jacorb/orb/portableInterceptor/RequestInterceptorIterator.class");
>        System.out.println(url);
>     }
> 
> 
> --
> Bill Burke
> JBoss, a division of Red Hat
> http://bill.burkecentral.com
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-- 
Bill Burke
JBoss, a division of Red Hat
http://bill.burkecentral.com