----- Original Message ----- From: "Doğacan Güney" <[EMAIL PROTECTED]> Sent: Friday, June 08, 2007 11:25 PM
> On 6/8/07, Enzo Michelangeli <[EMAIL PROTECTED]> wrote: [...] >> A more serious problem is that an implementation of equals() that returns >> true if the two hashCodes are different violates the specifications of >> Object.hashCode() : >> >> http://java.sun.com/j2se/1.5.0/docs/api/java/lang/Object.html#hashCode() >> "If two objects are equal according to the equals(Object) method, then >> calling the hashCode method on each of the two objects must produce the >> same >> integer result." > > We can just update Configuration.hashCode to calculate hash by summing > hashCode's of all key,value pairs. This should make it equal, > shouldn't it? Sure, in fact it would be much better. I didn't mention it because it affects Hadoop, about the innards of which I know very little, and I was concerned about unforeseen side-effects. In that spirit (think global, act local ;-) ), we could also subclass org.apache.hadoop.conf.Configuration only for use by methods of PluginRepository, and override its hashCode() method instead of touching the original class. > I think so too. When a map task ends and another begins, there will be > no strong references to the configuration object of the previous map > task, so it may be garbage-collected. Nicolas Lichtmaier has a patch > for this to change WeakHashMap to a form of LRU map. > > BTW, this problem has been discussed before (most recently at > http://www.nabble.com/Plugins-initialized-all-the-time ). There even > is an open issue for this - NUTCH-356. I would suggest that we move > our discussion there so that we can all work on this together and fix > this once and for all. I will update the issue with the most recent > discussions. OK, I'll subscribe to nutch-dev as well. Cheers -- Enzo ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Nutch-general mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/nutch-general
