private static String uriToRelativeFile(String uri) {
        String relative = "uri/" + XXHashFactory.fastestJavaInstance().hash64().hash(ByteBuffer.wrap(Utf8.toBytes(uri)), 0);
        if (uri.endsWith(".json")) {
            relative += ".json";
        } else if (uri.endsWith(".json.lz4")) {
            relative += ".json.lz4";
        } else if (uri.endsWith(".lz4")) {
            relative += ".lz4";
        }
        return relative;
    }
File registry for one application package

@author Tony Vaagenes
configserver/src/main/java/com/yahoo/vespa/config/server/filedistribution/FileDBRegistry.java