Class: Pack::XDelta

Inherits:
Object
  • Object
show all
Defined in:
lib/pack/xdelta.rb

Constant Summary collapse

BLOCK_SIZE = 
16

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(source, index) ⇒ XDelta

Returns a new instance of XDelta.



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# File 'lib/pack/xdelta.rb', line 21

def initialize(source, index)
  @source = source
  @index  = index
end

Class Method Details

.create_index(source) ⇒ Object 



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# File 'lib/pack/xdelta.rb', line 6

def self.create_index(source)
  blocks = source.bytesize / BLOCK_SIZE
  index  = {}

  (0 ... blocks).each do |i|
    offset = i * BLOCK_SIZE
    slice  = source.byteslice(offset, BLOCK_SIZE)

    index[slice] ||= []
    index[slice].push(offset)
  end

  XDelta.new(source, index)
end

Instance Method Details

#compress(target) ⇒ Object 



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# File 'lib/pack/xdelta.rb', line 26

def compress(target)
  @target = target
  @offset = 0
  @insert = []
  @ops    = []

  generate_ops while @offset < @target.bytesize
  flush_insert

  @ops
end