Bug 188252 [enhancement] remove cube cache when server is shutdown
steps to reproduce: - create a report design using cube and xtab - deploy it to tomcat BIRT viewer - preview it note that one folder named temp29330913 was created under tomcat home folder, there are three files (Customer Cubedata, Customer CubeOat, Customer Cubeobj) within this folder. these won't be removed even after tomcat is shutdown. is it appropriate if these are some kind of cache for the cube data?
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/olap/data/document/FileDocumentManager.java
1024 ) );
	}
	/*
	 * (non-Javadoc)
	 * @see org.eclipse.birt.data.olap.data.document.IDocumentManager#exist(java.lang.String)
	 */
	public boolean exist( String documentObjectName )
	{
		return this.documentObjectMap.get( documentObjectName ) != null;
	}
	/*
	 * (non-Javadoc)
	 * @see org.eclipse.birt.data.olap.data.document.IObjectAllocTable#getNextBlock(int)
	 */
	public int getNextBlock( int blockNo ) throws IOException
	{
		OatFile.seek( blockNo * 4 );
		return OatFile.readInt( );
	}
	/*
	 * (non-Javadoc)
	 * @see org.eclipse.birt.data.olap.data.document.IObjectAllocTable#allocateBlock(int)
	 */
	public int allocateBlock( int blockNo ) throws IOException
	{
		int newBlock = findFreeBlock( );
		OatFile.seek( blockNo * 4 );
		OatFile.writeInt( newBlock );
		return newBlock;
	}