Bug 131011 Support running query based on report document data
Data Engine should support running a query based on data set and expression data stored in a report document. This bugzilla entry serves as a repository for design docs and notes related to this feature.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/document/RDGroupUtil.java
* 0: 	-,0 			0,0 			0,0 
	 * 1: 	-,2 			0,2 			0,2 
	 * 2:	 				1,4 			1,3 
	 * 3: 					1,5 			1,5 
	 * 4: 									2,6 
	 * 5: 									3,7 
	 */
	private List[] groups;
	
	private int leafGroupIdx = 0;
	
	private CacheProvider cacheProvider;
	
	/**
	 * @param inputStream
	 * @param cacheProvider
	 * @throws DataException
	 */
	RDGroupUtil( InputStream inputStream, CacheProvider cacheProvider )
			throws DataException
	{
		try
		{
			int size = IOUtil.readInt( inputStream );
			this.groups = new ArrayList[size];
			for ( int i = 0; i < size; i++ )
			{
				List list = new ArrayList( );
				int asize = IOUtil.readInt( inputStream );
				for ( int j = 0; j < asize; j++ )