@Override
    public synchronized FileReference addBlob(String blobName, ByteBuffer blob) {
        String relativePath = blobToRelativeFile(blobName);
        Optional<FileReference> cachedReference = Optional.ofNullable(fileReferenceCache.get(blobName));
        return cachedReference.orElseGet(() -> {
            FileReference newRef = manager.addBlob(blob, Path.fromString(relativePath));
            fileReferenceCache.put(blobName, newRef);
            return newRef;
        });
    }
File registry for one application package

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