private int getFileID(FSFile file) {
		try {
		    HFSCommonFSFile hfsFile = (HFSCommonFSFile)file;
		    CommonHFSCatalogFile catalogFile = hfsFile.getInternalCatalogFile();
		    CommonHFSCatalogFile.HFSPlusImplementation hfsPlusCatalogFile = (CommonHFSCatalogFile.HFSPlusImplementation)catalogFile;
		    HFSPlusCatalogFile underlying = hfsPlusCatalogFile.getUnderlying();
		    HFSCatalogNodeID fileID = underlying.getFileID();
		    return fileID.toInt();
		}
		catch (Exception e) {
			return -1;
		}
	}
This code will extract the attributes file from the HFS+ file system,
which contains the B-tree for traversing the DECOMPFS files.
GPL/DMG/src/dmg/java/mobiledevices/dmg/hfsplus/AttributesFileParser.java