Class: Zrip::Dictionary

Inherits:
Data
  • Object
show all
Defined in:
lib/zrip/dictionary.rb,
lib/zrip/dictionary.rb

Overview

Immutable Zstandard dictionary value.

Constant Summary collapse

ZDICT_MAGIC = 
"\x37\xA4\x30\xEC".b.freeze
USER_DICT_ID_MIN = 
32_768
USER_DICT_ID_MAX = 
(2**31) - 1
USER_DICT_ID_SIZE = 
USER_DICT_ID_MAX - USER_DICT_ID_MIN + 1

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(bytes:, id: nil) ⇒ Dictionary

Returns a new instance of Dictionary.

Parameters:

  • bytes (String) —

    dictionary bytes

  • id (Integer, nil) (defaults to: nil) —

    optional dictionary ID



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# File 'lib/zrip/dictionary.rb', line 24

def initialize(bytes:, id: nil)
  b = bytes.b
  id ||= if b.byteslice(0, 4) == ZDICT_MAGIC
           b.byteslice(4, 4).unpack1("V")
         else
           raw = Digest::SHA256.digest(b).byteslice(0, 4).unpack1("V")
           USER_DICT_ID_MIN + (raw % USER_DICT_ID_SIZE)
         end
  super(bytes: b.freeze, id: id)
end

Instance Attribute Details

#bytes ⇒ String (readonly)

Returns frozen binary dictionary bytes.

Returns:

  • (String) —

    frozen binary dictionary bytes



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# File 'lib/zrip/dictionary.rb', line 13

Dictionary = Data.define(:bytes, :id)

#id ⇒ Integer (readonly)

Returns dictionary ID.

Returns:

  • (Integer) —

    dictionary ID



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# File 'lib/zrip/dictionary.rb', line 13

Dictionary = Data.define(:bytes, :id)

Instance Method Details

#size ⇒ Integer

Returns dictionary size in bytes.

Returns:

  • (Integer) —

    dictionary size in bytes



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# File 'lib/zrip/dictionary.rb', line 37

def size
  bytes.bytesize
end