Class HashCode

output/java_guava/1.4.16/HashCode.java:37–444

An immutable hash code of arbitrary bit length. @author Dimitris Andreou @author Kurt Alfred Kluever @since 11.0

@Beta
public abstract class HashCode {
  HashCode() {}

  /**
   * Returns the number of bits in this hash code; a positive multiple of 8.
   */


  public abstract int bits();

  /**
   * Returns the first four bytes of {@linkplain #asBytes() this hashcode's bytes}, converted to an
   * {@code int} value in little-endian order.
   *
   * @throws IllegalStateException if {@code bits() < 32}
   */


  public abstract int asInt();

  /**
   * Returns the first eight bytes of {@linkplain #asBytes() this hashcode's bytes}, converted to a
   * {@code long} value in little-endian order.
   *
   * @throws IllegalStateException if {@code bits() < 64}
   */


  public abstract long asLong();

  /**
   * If this hashcode has enough bits, returns {@code asLong()}, otherwise returns a {@code long}
   * value with {@code asBytes()} as the least-significant bytes and {@code 0x00} as the remaining
   * most-significant bytes.
   *
   * @since 14.0 (since 11.0 as {@code Hashing.padToLong(HashCode)})
   */


  public abstract long padToLong();

  /**
   * Returns the value of this hash code as a byte array. The caller may modify the byte array;
   * changes to it will <i>not</i> be reflected in this {@code HashCode} object or any other arrays
   * returned by this method.
   */
  // TODO(user): consider ByteString here, when that is available


  public abstract byte[] asBytes();

  /**
   * Copies bytes from this hash code into {@code dest}.
   *
   * @param dest the byte array into which the hash code will be written
   * @param offset the start offset in the data
   * @param maxLength the maximum number of bytes to write