import java.io.InputStream;

class ChecksumHasher implements FileHasher {

    private final HashFunction hashFunction;

    public ChecksumHasher(HashFunction hashFunction) {
        this.hashFunction = hashFunction;
    }

    @Override
    public HashCode hash(File file) {
        try {
            PrimitiveHasher hasher = hashFunction.newPrimitiveHasher();
            byte[] buffer = new byte[4096];
            int len;

  // These can probably be removed sooner or later.
  ;

  private final HashFunction hashFunction;

  private HashFunctionEnum(HashFunction hashFunction) {
    this.hashFunction = hashFunction;
  }

  HashFunction getHashFunction() {
    return hashFunction;
  }

    private TestFile hashFile(TestFile file, HashFunction hashFunction) {
        def hashFile = getHashFile(file, hashFunction)
        def hash = hashFunction.hashFile(file)
        hashFile.text = hash.toZeroPaddedString(hashFunction.hexDigits)
        return hashFile
    }

    private TestFile getHashFile(TestFile file, HashFunction hashFunction) {
        def algorithm = hashFunction.algorithm.toLowerCase(Locale.ROOT).replaceAll('-', '')

                }
            }
        }

        private void publishChecksum(ExternalResourceName destination, File content, HashFunction hashFunction) {
            byte[] checksum = createChecksumFile(content, hashFunction);

  // Helpers + main

  private byte runHashFunction(int reps, HashFunction hashFunction) {
    byte result = 0x01;
    // Trick the JVM to prevent it from using the hash function non-polymorphically
    result ^= Hashing.crc32().hashInt(reps).asBytes()[0];
    result ^= Hashing.adler32().hashInt(reps).asBytes()[0];
    for (int i = 0; i < reps; i++) {
      result ^= hashFunction.hashBytes(testBytes).asBytes()[0];
    }
    return result;

        private final HashFunction hashFunction;

        public GuavaProcessorFactory(HashFunction hashFunction) {
            this.hashFunction = hashFunction;
        }

        @Override
        public HashProcessor create() {
            return new GuavaProcessor(hashFunction.newHasher());
        }
    }

    }

    private static final HashFunction MD5 = MessageDigestHashFunction.of("MD5");

    private static final HashFunction SHA1 = MessageDigestHashFunction.of("SHA-1");

    private static final HashFunction SHA256 = MessageDigestHashFunction.of("SHA-256");

    private static final HashFunction SHA512 = MessageDigestHashFunction.of("SHA-512");

    private static final HashFunction DEFAULT = MD5;

    /**

   * Creates an input stream that hashes using the given {@link HashFunction} and delegates all data
   * read from it to the underlying {@link InputStream}.
   *
   * <p>The {@link InputStream} should not be read from before or after the hand-off.
   */
  public HashingInputStream(HashFunction hashFunction, InputStream in) {
    super(checkNotNull(in));
    this.hasher = checkNotNull(hashFunction.newHasher());
  }

  /**

  // Helpers + main

  private byte runHashFunction(int reps, HashFunction hashFunction) {
    byte result = 0x01;
    // Trick the JVM to prevent it from using the hash function non-polymorphically
    result ^= Hashing.crc32().hashInt(reps).asBytes()[0];
    result ^= Hashing.adler32().hashInt(reps).asBytes()[0];
    for (int i = 0; i < reps; i++) {
      result ^= hashFunction.hashBytes(testBytes).asBytes()[0];
    }
    return result;

 */
public final class HashingOutputStream extends FilterOutputStream {
    private final PrimitiveHasher hasher;

    public HashingOutputStream(HashFunction hashFunction, OutputStream out) {
        super(checkNotNull(out));
        this.hasher = checkNotNull(hashFunction.newPrimitiveHasher());
    }

    @Override
    public void write(int b) throws IOException {
        hasher.putByte((byte) b);
        out.write(b);