Bug 191637 Empty cube causes error
Comment removed as requested by the submitter - 2007-06-08 droy
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/olap/data/util/DiskIndex.java
if ( numberOfLevel < 1 || numberOfLevel > 1000 ||Math.pow( degree, numberOfLevel ) < keyCount )
		{
			throw new DataException( ResourceConstants.OLAPFILE_FORMAT_INVALID,
					name );
		}
	}
	private static String getOffsetDocName( String name)
	{
		return name + "_offset";
	}
	
	/**
	 * 
	 * @param keyList
	 * @throws IOException
	 * @throws DataException 
	 */
	private void produce( IDiskArray keyList, boolean isSorted )
			throws IOException, DataException
	{
		createDocumentObject( );
		IndexKey indexKey = (IndexKey) keyList.get( 0 );
		keyDataType = new int[indexKey.getKey().length];
		for ( int i = 0; i < indexKey.getKey().length; i++ )
		{
			keyDataType[i] = DataType.getDataType( ( (IndexKey) keyList.get( 0 ) ).getKey()[i].getClass( ) );
		}
		keyCount = keyList.size( );
		int rootOffsetPos = saveIndexHeader( ) - 6;
		IDiskArray sortedKeyArray = null;