[Trove4j-tracker] [ trove4j-Bugs-3408867 ] TCustomHashMap equals ClassCastException

[SourceForge.net <no...@so...>]

Bugs item #3408867, was opened at 2011-09-13 12:20
Message generated for change (Settings changed) made by robeden
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=424682&aid=3408867&group_id=39235

Please note that this message will contain a full copy of the comment thread,
including the initial issue submission, for this request,
not just the latest update.
Category: Correctness
Group: Next Minor Release
>Status: Closed
Resolution: None
Priority: 5
Private: No
Submitted By: https://www.google.com/accounts ()
Assigned to: Rob Eden (robeden)
Summary: TCustomHashMap equals ClassCastException

Initial Comment:
The following code is a minimal test case that illustrates the problem.

-----


package com.jt.jtp;

import gnu.trove.map.hash.TCustomHashMap;
import gnu.trove.strategy.HashingStrategy;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Random;

public class TroveBug {

    private static byte[] random(int n, Random rnd) {
        byte[] ba = new byte[n];
        for (int i = 0; i < ba.length; i++) {
            ba[i] = (byte)rnd.nextInt();
        }
        return ba;
    }
    
    private static class ByteArrayStrategy implements HashingStrategy<byte[]> { 
        
        // Copied from Arrays.hashCode, but applied only to the first four bytes
        @Override
        public int computeHashCode(byte[] bytes) {
            if (bytes == null) return 0;
            int h = 1;
            for (int i = 0; i < 4; i++) h = 31 * h + bytes[i];
            return h;
        }

        @Override
        public boolean equals(byte[] o1, byte[] o2) {
            return Arrays.equals(o1, o2);
        } 
    }     

    public static void main(String[] args) {
        Random rnd = new Random(1234);
        TCustomHashMap<byte[], Integer> map = new TCustomHashMap<byte[], Integer>(new ByteArrayStrategy());
        List<byte[]> list = new ArrayList<byte[]>();
       
        for (int i = 0; i < 1000; i++) {
            byte[] ba = random(16, rnd);
            list.add(ba);
            map.put(ba, new Integer(i));
        }
        
        for (int i = 0; i < 1000; i++) {
            map.remove(list.get(i));
        }
        
        // Print all nulls!
        for (int i = 0; i < 1000; i++) {
            System.out.println(map.get(list.get(i)));
        }
        
    }
    
    
}


----------------------------------------------------------------------

Comment By: Nobody/Anonymous (nobody)
Date: 2012-08-23 22:44

Message:
Im not that much of a internet reader to be honest but your sites really
nice, keep it up! I'll go ahead and bookmark your website to come back
later on. Many thanks http://www.bestdenalijackets4u.com/

----------------------------------------------------------------------

Comment By: Rob Eden (robeden)
Date: 2011-10-06 21:44

Message:
This bug is being put into "pending" status. It will automatically be
closed in 14 days in no further action is taken. Please make a comment if
you believe the bug to still be relevant.

----------------------------------------------------------------------

Comment By: Rob Eden (robeden)
Date: 2011-10-06 21:44

Message:
I guess I don't see the bug. It should print nulls at the end because the
elements are being removed from the map in the for loop prior to the
println's.

I've added the test TCusomtHashMap.testBug4706479() to test all my
expectations for this case.

----------------------------------------------------------------------

Comment By: Rob Eden (robeden)
Date: 2011-09-13 12:21

Message:
Looking into this...

Associated forum topic:
https://sourceforge.net/projects/trove4j/forums/forum/121845/topic/4706479

----------------------------------------------------------------------

You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=424682&aid=3408867&group_id=39235