private Long computeHash(File file) throws IOException {
        XXHash64 hasher = XXHashFactory.fastestInstance().hash64();
        if (file.isDirectory()) {
            return Files.walk(file.toPath(), 100).map(path -> {
                try {
                    log.log(FINEST, () -> "Calculating hash for '" + path + "'");
                    return hash(path.toFile(), hasher);
                } catch (IOException e) {
                    log.log(WARNING, "Failed getting hash from '" + path + "'");
                    return 0;
                }
            }).mapToLong(Number::longValue).sum();
        } else {
            return hash(file, hasher);
        }
    }
Global file directory, holding files for file distribution for all deployed applications.
configserver/src/main/java/com/yahoo/vespa/config/server/filedistribution/FileDirectory.java