Re: [DISCUSS] Containerisms

Mon, 11 Oct 2010 06:39:00 -0700 

 On 10/11/10 3:32, Guillaume Nodet wrote:

What I don't get is why we don't get rid of the existing containerims in
Felix:
   * the reference: and inputstream: url protocol for installing bundles



There is no inputstream: URL for installing bundles. The reference: URL 
is there largely because Equinox has it and it was created specifically 
to match their containerism.



   * the pluggable cache



We could. I'm not aware of anyone using it. But in reality, I'd like to 
find a completely different way to handle the cache. Making it pluggable 
is only good design, since it allows us to change our own implementation 
too.



   * implicit boot delegation



This isn't really a containerism as much as it is trying to faithfully 
implement the spec. It tries to workaround stupid assumptions in the JRE.



I suppose there are some more hidden throughout the code.


Probably, but given this list, it looks like we're doing a pretty good job.


As I said in another message, we look at everything on a case-by-case 
basis. There is no blanket answer, but typically things that break 
abstractions or encapsulation will be frowned upon.



Certainly there are places were we have container-specific behavior, but 
it is often due to leeway in the spec. In other cases, I can almost 
assure you that I discuss them with Tom Watson to make sure we can align 
such areas if possible.


-> richard


On Fri, Oct 8, 2010 at 20:17, Richard S. Hall<[email protected]>  wrote:


  On 10/8/10 14:08, Guillaume Nodet wrote:


On Fri, Oct 8, 2010 at 18:43, Felix Meschberger<[email protected]>
  wrote:

  Hi,

First of all: I agree with Richard in that we should at all cost prevent
containerisms.

Second: I do not really understand what the problem is, that must be
solved with this containerism and which cannot be solved with regular
OSGi API.

  The real problem is to be able to discover resources in the bundle class

space. For example, i want to know all resources in foo/bar/**/*.xml The
OSGi API does not provide any way to do that atm and a lot of libraries
use
  some custom things based on jars / file urls to actually iterate and
discover those resources.

The problem is just about a way to actually do things.  It seems in the
enterprise world (JEE, middleware),  we're more keen on bending the purity
a
bit to the benfit of being able to achieve our goals and we're also more
keen on doing that for third party libraries.

It's true that if you write the whole osgi application from scratch, you
don't really care about supporting third party libraries.  Unfortunately,
people just won't rewrite a third party product they already use just
because they want to play nicely in OSGi.  That's my use case, and it
seems
it doesn't fit well with Felix goals, so I guess i'll have to support a
custom felix version in order to do that or only support equinox.

I think I'll revert my commit as if the plan is to ditch it in the next
felix version, there's really no point in even using such a hack from my
pov.


Which is precisely the point from my perspective. Not only do you want the
hack, but you want it maintained forever. That's precisely what I think we
should avoid.

If you are keen on having your own custom version of Felix, we can always
start a new subproject so you can work on one that you think is better. It
doesn't bother me to have two framework impls...as I've said many times, the
framework is just a subproject like any other. Just create a fork and call
it something completely different so there is no confusion.

->  richard




  Third: For us outsiders of the specification process it is very hard to

understand what insiders are talking of with respect to upcoming
specifications (I only learned 5 minutes ago, that there is a public
draft for 4.3). This issue must probably be solved by OSGi...

Regards
Felix

On 08.10.2010 16:37, Guillaume Nodet wrote:


I was planning to start a discussion around that, so let's do that now.

I'm not convinced we should remove this hack when classpath scanning is
implemented, mostly because even if then ultimately try to solve the
same
problem, they will certainly do it in a different way.  What I mean is


that


AFAIK, the classpath scanning stuff will result in a new api on the


bundle


or bundleContext to iterate through resources, which means that in order


to


support existing libraries, you kinda have to rewrite the whole thing in
order to accomodate those apis (especially if they are written so that


they


work outside of osgi).
I think the hack i've written allows a smoother integration of those
libraries, with the drawback that you know it can break in certain
conditions.

Also, your comment says "Do not make containerisms public."
In that case, it's not really public because the public face of the
Felix
Framework is the OSGi api.
I guess the question comes down to wether we want Felix to remain pure
(without containerisms) or make it easier for people to use it (by


bending


the edges when it makes sense to allow people to deploy their existing
libraries without rewriting the whole thing).
Imho, Felix is not a research prototype, nor supposed to be the
cleaneest
reference implementation of OSGi, so adapting to the users makes sense


imho,


provided that it's done conciensouly by the user by activating a flag or
accessing a non public api (we fall in that case here imho).

Thoughts?

On Fri, Oct 8, 2010 at 16:22,<[email protected]>   wrote:

  Author: rickhall

Date: Fri Oct  8 14:22:39 2010
New Revision: 1005843

URL: http://svn.apache.org/viewvc?rev=1005843&view=rev
Log:
Do not make containerisms public. (FELIX-2645)

Modified:


  
felix/trunk/framework/src/main/java/org/apache/felix/framework/ExtensionManager.java
  felix/trunk/framework/src/main/java/org/apache/felix/framework/ModuleImpl.java
  
felix/trunk/framework/src/main/java/org/apache/felix/framework/URLHandlersBundleURLConnection.java
  
felix/trunk/framework/src/main/java/org/apache/felix/framework/cache/ContentDirectoryContent.java
  
felix/trunk/framework/src/main/java/org/apache/felix/framework/cache/DirectoryContent.java
  
felix/trunk/framework/src/main/java/org/apache/felix/framework/cache/JarContent.java
  
felix/trunk/framework/src/main/java/org/apache/felix/framework/resolver/Content.java
  
felix/trunk/framework/src/main/java/org/apache/felix/framework/resolver/Module.java

Modified:

felix/trunk/framework/src/main/java/org/apache/felix/framework/ExtensionManager.java

URL:



http://svn.apache.org/viewvc/felix/trunk/framework/src/main/java/org/apache/felix/framework/ExtensionManager.java?rev=1005843&r1=1005842&r2=1005843&view=diff


==============================================================================

---

felix/trunk/framework/src/main/java/org/apache/felix/framework/ExtensionManager.java

(original)

+++

felix/trunk/framework/src/main/java/org/apache/felix/framework/ExtensionManager.java

Fri Oct  8 14:22:39 2010

@@ -610,6 +610,7 @@ class ExtensionManager extends URLStream
         return null;
     }

+    // TODO: REMOVE - Remove when class path scanning is implemented.
     public URL getEntryAsURL(String name)
     {
         return null;
@@ -763,6 +764,7 @@ class ExtensionManager extends URLStream
             return
getClass().getClassLoader().getResourceAsStream(urlPath);
         }

+        // TODO: REMOVE - Remove when class path scanning is


implemented.
         public URL getLocalURL(int index, String urlPath)

         {
             return getClass().getClassLoader().getResource(urlPath);

Modified:

felix/trunk/framework/src/main/java/org/apache/felix/framework/ModuleImpl.java

URL:



http://svn.apache.org/viewvc/felix/trunk/framework/src/main/java/org/apache/felix/framework/ModuleImpl.java?rev=1005843&r1=1005842&r2=1005843&view=diff


==============================================================================

---

felix/trunk/framework/src/main/java/org/apache/felix/framework/ModuleImpl.java

(original)

+++

felix/trunk/framework/src/main/java/org/apache/felix/framework/ModuleImpl.java

Fri Oct  8 14:22:39 2010

@@ -1091,6 +1091,7 @@ public class ModuleImpl implements Modul
         return getContentPath()[index - 1].getEntryAsStream(urlPath);
     }

+    // TODO: REMOVE - Remove when class path scanning is implemented.
     public URL getLocalURL(int index, String urlPath)
     {
         if (urlPath.startsWith("/"))

Modified:

felix/trunk/framework/src/main/java/org/apache/felix/framework/URLHandlersBundleURLConnection.java

URL:



http://svn.apache.org/viewvc/felix/trunk/framework/src/main/java/org/apache/felix/framework/URLHandlersBundleURLConnection.java?rev=1005843&r1=1005842&r2=1005843&view=diff


==============================================================================

---

felix/trunk/framework/src/main/java/org/apache/felix/framework/URLHandlersBundleURLConnection.java

(original)

+++

felix/trunk/framework/src/main/java/org/apache/felix/framework/URLHandlersBundleURLConnection.java

Fri Oct  8 14:22:39 2010

@@ -28,7 +28,7 @@ import org.apache.felix.framework.resolv

  import org.apache.felix.framework.util.Util;

-public class URLHandlersBundleURLConnection extends URLConnection
+class URLHandlersBundleURLConnection extends URLConnection
  {
     private Felix m_framework;
     private Module m_targetModule;
@@ -201,7 +201,8 @@ public class URLHandlersBundleURLConnect
      *
      * @return the local URL
      */
-    public URL getLocalURL()
+    // TODO: REMOVE - Remove when class path scanning is implemented.
+    URL getLocalURL()
     {
         if ((m_targetModule == null) || (m_classPathIdx<   0))
         {

Modified:

felix/trunk/framework/src/main/java/org/apache/felix/framework/cache/ContentDirectoryContent.java

URL:



http://svn.apache.org/viewvc/felix/trunk/framework/src/main/java/org/apache/felix/framework/cache/ContentDirectoryContent.java?rev=1005843&r1=1005842&r2=1005843&view=diff


==============================================================================

---

felix/trunk/framework/src/main/java/org/apache/felix/framework/cache/ContentDirectoryContent.java

(original)

+++

felix/trunk/framework/src/main/java/org/apache/felix/framework/cache/ContentDirectoryContent.java

Fri Oct  8 14:22:39 2010

@@ -82,6 +82,7 @@ public class ContentDirectoryContent imp
         return m_content.getEntryAsStream(m_rootPath + name);
     }

+    // TODO: REMOVE - Remove when class path scanning is implemented.
     public URL getEntryAsURL(String name)
     {
         return m_content.getEntryAsURL(m_rootPath + name);

Modified:

felix/trunk/framework/src/main/java/org/apache/felix/framework/cache/DirectoryContent.java

URL:



http://svn.apache.org/viewvc/felix/trunk/framework/src/main/java/org/apache/felix/framework/cache/DirectoryContent.java?rev=1005843&r1=1005842&r2=1005843&view=diff


==============================================================================

---

felix/trunk/framework/src/main/java/org/apache/felix/framework/cache/DirectoryContent.java

(original)

+++

felix/trunk/framework/src/main/java/org/apache/felix/framework/cache/DirectoryContent.java

Fri Oct  8 14:22:39 2010

@@ -133,6 +133,7 @@ public class DirectoryContent implements
         return new FileInputStream(new File(m_dir, name));
     }

+    // TODO: REMOVE - Remove when class path scanning is implemented.
     public URL getEntryAsURL(String name)
     {
         if ((name.length()>   0)&&   (name.charAt(0) == '/'))

Modified:

felix/trunk/framework/src/main/java/org/apache/felix/framework/cache/JarContent.java

URL:



http://svn.apache.org/viewvc/felix/trunk/framework/src/main/java/org/apache/felix/framework/cache/JarContent.java?rev=1005843&r1=1005842&r2=1005843&view=diff


==============================================================================

---

felix/trunk/framework/src/main/java/org/apache/felix/framework/cache/JarContent.java

(original)

+++

felix/trunk/framework/src/main/java/org/apache/felix/framework/cache/JarContent.java

Fri Oct  8 14:22:39 2010

@@ -192,6 +192,7 @@ public class JarContent implements Conte
         return is;
     }

+    // TODO: REMOVE - Remove when class path scanning is implemented.
     public URL getEntryAsURL(String name)
     {
         try

Modified:

felix/trunk/framework/src/main/java/org/apache/felix/framework/resolver/Content.java

URL:



http://svn.apache.org/viewvc/felix/trunk/framework/src/main/java/org/apache/felix/framework/resolver/Content.java?rev=1005843&r1=1005842&r2=1005843&view=diff


==============================================================================

---

felix/trunk/framework/src/main/java/org/apache/felix/framework/resolver/Content.java

(original)

+++

felix/trunk/framework/src/main/java/org/apache/felix/framework/resolver/Content.java

Fri Oct  8 14:22:39 2010

@@ -120,5 +120,6 @@ public interface Content
      * @return A URL using a standard protocol such as file, jar
      *           or null if not possible.
      */
+    // TODO: REMOVE - Remove when class path scanning is implemented.
     URL getEntryAsURL(String name);
  }
\ No newline at end of file

Modified:

felix/trunk/framework/src/main/java/org/apache/felix/framework/resolver/Module.java

URL:



http://svn.apache.org/viewvc/felix/trunk/framework/src/main/java/org/apache/felix/framework/resolver/Module.java?rev=1005843&r1=1005842&r2=1005843&view=diff


==============================================================================

---

felix/trunk/framework/src/main/java/org/apache/felix/framework/resolver/Module.java

(original)

+++

felix/trunk/framework/src/main/java/org/apache/felix/framework/resolver/Module.java

Fri Oct  8 14:22:39 2010

@@ -72,5 +72,6 @@ public interface Module
         throws IOException;
     InputStream getInputStream(int index, String urlPath)
         throws IOException;
+    // TODO: REMOVE - Remove when class path scanning is implemented.
     URL getLocalURL(int index, String urlPath);
  }
\ No newline at end of file






























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