[Mulgara-dev] NegativeArraySizeException

[James Leigh]

The latest from trunk plus this patch allows Mulgara to execute the
query and others like it without an exception.

Thanks Alex.

On Thu, 2008-11-06 at 10:08 -0500, Alex Hall wrote:
> James Leigh wrote:
> > Hi Paul et al,
> > 
> > I loaded up 25m of BSBM data and executed a query like the one below.
> > Instead of getting any results, I got this exception. In
> > HybridTuples.java it casts a long into an int. This may account for the
> > int being negative. I have the dataset on another machine and can make
> > it and the exact query available if desired. Paul can you review
> > HybridTuples and DenseLongMatrix and make sure the long/int handling is
> > correct?
> 
> Just taking a quick look here...  When the LeftJoin operation calculates the
> upper bound of its row count, it multiplies a long by a long without checking
> for overflow, which is how I suspect that the negative value is creeping in.  If
> you're building from source, try applying the attached patch and let me know if
> it fixes the problem.
> 
> Regards,
> Alex
> plain text document attachment (LeftJoin.txt)
> Index: C:/Mulgara/trunk/src/jar/tuples/java/org/mulgara/store/tuples/LeftJoin.java
> ===================================================================
> --- C:/Mulgara/trunk/src/jar/tuples/java/org/mulgara/store/tuples/LeftJoin.java	(revision 1373)
> +++ C:/Mulgara/trunk/src/jar/tuples/java/org/mulgara/store/tuples/LeftJoin.java	(working copy)
> @@ -175,7 +175,7 @@
>    public long getRowUpperBound() throws TuplesException {
>      BigInteger rowCount = BigInteger.valueOf(lhs.getRowUpperBound());
>      rowCount = rowCount.multiply(BigInteger.valueOf(rhs.getRowUpperBound()));
> -    return rowCount.longValue();
> +    return rowCount.bitLength() > 63 ? Long.MAX_VALUE : rowCount.longValue();
>    }
>  
> 
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