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/disk/DiskDataExport.java
{
	protected ResultObjectUtil resultObjectUtil;
	
	/**
	 * According to the parameter of comparator to generate the instance, which
	 * is disk-based direct output instance or disk-based merge instance.
	 * 
	 * @param infoMap
	 * @param comparator
	 * @param rsMetaData
	 * @return a instance of DataBaseExport
	 */
	static DiskDataExport newInstance( Map infoMap,
			Comparator comparator, IResultClass rsMetaData,
			ResultObjectUtil resultObjectUtil )
	{
		DiskDataExport dbExport;
		if ( comparator != null )