Package it.unimi.dsi.sux4j.mph.codec

Interface Codec.Decoder

All Superinterfaces:
Serializable
All Known Implementing Classes:
Codec.Binary.Coder.Decoder, Codec.Gamma.Coder.Decoder, Codec.Huffman.Coder.Decoder, Codec.Unary.Coder.Decoder, Codec.ZeroCodec.Coder.Decoder
Enclosing interface:
Codec
public static interface Codec.Decoder extends Serializable
A decoder: provides a method to turn sequences of bits into symbols.

Note that a decoder can only built using Codec.Coder.getDecoder().

  • Method Summary

    Modifier and Type
    Method
    Description
    long
    decode(long sequence)
    Decodes a sequence of bits.
    default int
    escapedSymbolLength()
    Returns the length in bit of an escaped symbol, or zero if there are no escaped symbols.
    default int
    escapeLength()
    Returns the length of the escape codeword, if it exists, or zero.
    long
    numBits()
    The number of bits used by this decoder.

  • Method Details

    • decode

      long decode(long sequence)
      Decodes a sequence of bits.

      If the first codeword appearing in the sequence is the escape codeword, this method returns −1 and the actual symbol must be retrieved by reading escapedSymbolLength() further bits.

      This method assumes that the first bit of the code is the leftmost bit (i.e., the bit of index Codec.Coder.maxCodewordLength() − 1).

      Parameters:
      sequence - a sequence of bits.
      Returns:
      the symbol associated with the first codeword appearing in the sequence, or −1 if the codeword is an escape.

    • numBits

      long numBits()
      The number of bits used by this decoder.
      Returns:
      the number of bits used by this decoder.

    • escapedSymbolLength

      default int escapedSymbolLength()
      Returns the length in bit of an escaped symbol, or zero if there are no escaped symbols.
      Returns:
      the length in bit of an escaped symbol, or zero if there are no escaped symbols.

    • escapeLength

      default int escapeLength()
      Returns the length of the escape codeword, if it exists, or zero.
      Returns:
      the escape codeword, if it exists, or zero.