Bug 206861 The data set cache should handle IOException and the cancel request from customer
The data set data will be saved into disk file in the first query and it will be loaded in the later time. The processing of write disk file may be cancelled by customer request or IOException. Using the data from the bad file will cause error.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/executor/cache/SmartCacheHelper.java
getComparator( sortSpec, eventHandler ),
						dataCount,
						this.session,
						stopSign );
				break;
			}
		}
		if ( resultSetCache == null )
		{
			logger.fine( "MemoryCache is used" );
			resultObjects = (IResultObject[]) resultObjectsList.toArray( new IResultObject[0] );
			resultSetCache = new MemoryCache( resultObjects,
					rsMeta,
					getComparator( sortSpec, eventHandler ) );
		}
		odaObject = null;
		resultObjects = null;
		resultObjectsList = null;
		rowResultSet = null;
		long consumedTime = ( System.currentTimeMillis( ) - startTime ) / 1000;
		logger.fine( "Time consumed by cache is: " + consumedTime + " second" );
	}
	
	/**
	 * @param sortSpec
	 * @return Comparator based on specified sortSpec, null indicates there is
	 *         no need to do sorting
	 */
	private static Comparator getComparator( SortSpec sortSpec,
			final IEventHandler eventHandler )