public FileReference addFile(File source) throws IOException {
        Long hash = computeHash(source);
        FileReference fileReference = fileReferenceFromHash(hash);

        try (Lock lock = locks.lock(fileReference)) {
            return addFile(source, fileReference, hash);
        }
    }
Global file directory, holding files for file distribution for all deployed applications.
configserver/src/main/java/com/yahoo/vespa/config/server/filedistribution/FileDirectory.java