Bug 180189 Support in memory data set cache.
Currently, Design-Time Data Cache is stored on disks. By performance tests using ramdisk, we found that caching in physical memory can improve the performance of RunAndRender by 30%.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/api/DataEngineContext.java
*/
	public final static int MODE_UPDATE = 4;
	
	/**
	 * AppContext and Data Set cache count setting decide whether cache is used,
	 * which is default value for data engine context.
	 */
	public final static int CACHE_USE_DEFAULT = 1;
	
	/**
	 * Do not use cache, regardless of data set cache setting
	 */
	public final static int CACHE_USE_DISABLE = 2;
	
	/**
	 * Always use cached data if available, disregard data set cache setting and
	 * AppContext. cachRowCount parameter decides cache count.
	 */
	public final static int CACHE_USE_ALWAYS = 3;
	
	
	private int mode;
	private Scriptable scope;	
	private IDocArchiveReader reader;
	private IDocArchiveWriter writer;
	private ULocale currentLocale;
	
	
	private int cacheOption;
	private int cacheCount;