Package it.unimi.dsi.sux4j.mph.codec

Interface Codec.Coder

All Known Implementing Classes:
Codec.Binary.Coder, Codec.Gamma.Coder, Codec.Huffman.Coder, Codec.Unary.Coder, Codec.ZeroCodec.Coder
Enclosing interface:
Codec
public static interface Codec.Coder
A coder: provides methods to turn symbols into codewords.

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    codewordLength(long symbol)
    Returns the length of the codeword associated with the given symbol.
    long
    encode(long symbol)
    Returns the codeword associated with a symbol, or −1 if the provided symbol should be escaped.
    default long
    escape()
    Returns the escape codeword, if it exists.
    default int
    escapedSymbolLength()
    Returns the length in bit of an escaped symbol, or zero if there are no escaped symbols.
    Codec.Decoder
    getDecoder()
    Return a decoder associated with this coder.
    int
    maxCodewordLength()
    Returns the maximum length of a codeword (including escaped symbols).

  • Method Details

    • encode

      long encode(long symbol)
      Returns the codeword associated with a symbol, or −1 if the provided symbol should be escaped.

      If a symbol needs to be escaped, it must be encoded using the escape codeword followed by the symbol written in a field of escapedSymbolLength() bits.

      Parameters:
      symbol - a symbol.
      Returns:
      the associated codeword.

    • codewordLength

      int codewordLength(long symbol)
      Returns the length of the codeword associated with the given symbol.

      For escaped symbols, the returned values is the length of the escape codeword plus escapedSymbolLength().

      Parameters:
      symbol - a symbol provided at construction time.
      Returns:
      the length of the codeword associated with the given symbol.

    • maxCodewordLength

      int maxCodewordLength()
      Returns the maximum length of a codeword (including escaped symbols).
      Returns:
      the maximum length of a codeword (including escaped symbols).

    • 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.

    • escape

      default long escape()
      Returns the escape codeword, if it exists.

      Note that the length of the escape codeword can be recovered by subtracting from the length of the codeword of an escaped symbol the length of an escaped symbol.

      Returns:
      the escape codeword, if it exists.

    • getDecoder

      Codec.Decoder getDecoder()
      Return a decoder associated with this coder.
      Returns:
      a decoder associated with this coder.