// be (optionally) be combined with another if needed (with something like
  // MultiplexingOutputStream).
  public HashingOutputStream(HashFunction hashFunction, OutputStream out) {
    super(checkNotNull(out));
    this.hasher = checkNotNull(hashFunction.newHasher());
  }

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

  @Override

    SHA_256("SHA-256", Hashing.sha256()),
    SHA_384("SHA-384", Hashing.sha384()),
    SHA_512("SHA-512", Hashing.sha512());

    private final String algorithmName;
    private final HashFunction hashFn;

    Algorithm(String algorithmName, HashFunction hashFn) {
      this.algorithmName = algorithmName;
      this.hashFn = hashFn;
    }

    public MessageDigest getMessageDigest() {
      try {

    SHA_256("SHA-256", Hashing.sha256()),
    SHA_384("SHA-384", Hashing.sha384()),
    SHA_512("SHA-512", Hashing.sha512());

    private final String algorithmName;
    private final HashFunction hashFn;

    Algorithm(String algorithmName, HashFunction hashFn) {
      this.algorithmName = algorithmName;
      this.hashFn = hashFn;
    }

    public MessageDigest getMessageDigest() {
      try {

   * 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());
  }

  /**

  // be (optionally) be combined with another if needed (with something like
  // MultiplexingOutputStream).
  public HashingOutputStream(HashFunction hashFunction, OutputStream out) {
    super(checkNotNull(out));
    this.hasher = checkNotNull(hashFunction.newHasher());
  }

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

  @Override

        FileSystem fileSystem,
        FileTimeStampInspector fileTimeStampInspector,
        String name,
        HashFunction hashFunction,
        FileHasherStatistics.Collector statisticsCollector
    ) {
        return new CachingFileHasher(new ChecksumHasher(hashFunction), fileStore, stringInterner, fileTimeStampInspector, name + "-checksums", fileSystem, 1000, statisticsCollector);
    }

    @Override

  // From http://docs.oracle.com/javase/7/docs/technotes/guides/security/StandardNames.html#Mac
  private static final ImmutableTable<String, SecretKey, HashFunction> ALGORITHMS =
      new ImmutableTable.Builder<String, SecretKey, HashFunction>()
          .put("HmacMD5", MD5_KEY, Hashing.hmacMd5(MD5_KEY))
          .put("HmacSHA1", SHA1_KEY, Hashing.hmacSha1(SHA1_KEY))

@ElementTypesAreNonnullByDefault
abstract class AbstractCompositeHashFunction extends AbstractHashFunction {

  @SuppressWarnings("Immutable") // array not modified after creation
  final HashFunction[] functions;

  AbstractCompositeHashFunction(HashFunction... functions) {
    for (HashFunction function : functions) {
      checkNotNull(function);
    }
    this.functions = functions;
  }

  /**

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Skeleton implementation of {@link HashFunction} in terms of {@link #newHasher()}.
 *
 * <p>TODO(lowasser): make public
 */
@Immutable
@ElementTypesAreNonnullByDefault
abstract class AbstractHashFunction implements HashFunction {
  @Override
  public <T extends @Nullable Object> HashCode hashObject(

  //  - For example, the "SHA-1" algorithm might be referred to as "SHA1".
  //  - The algorithm name is not case-sensitive.
  private static final ImmutableMap<String, HashFunction> ALGORITHMS =
      new ImmutableMap.Builder<String, HashFunction>()
          .put("MD5", Hashing.md5())
          .put("SHA", Hashing.sha1()) // Not the official name, but still works