Class: RBzip2::Compressor

Inherits:
Object
  • Object
show all
Includes:
Constants
Defined in:
lib/rbzip2/compressor.rb

Overview

This code is free software you can redistribute it and/or modify it under the terms of the new BSD License.

Copyright © 2011, Sebastian Staudt

Constant Summary

Constants included from Constants

RBzip2::Constants::BASEBLOCKSIZE, RBzip2::Constants::CLEARMASK, RBzip2::Constants::DEPTH_THRESH, RBzip2::Constants::EOF, RBzip2::Constants::GREATER_ICOST, RBzip2::Constants::G_SIZE, RBzip2::Constants::INCS, RBzip2::Constants::LESSER_ICOST, RBzip2::Constants::MAX_ALPHA_SIZE, RBzip2::Constants::MAX_BLOCK_SIZE, RBzip2::Constants::MAX_CODE_LEN, RBzip2::Constants::MAX_SELECTORS, RBzip2::Constants::MIN_BLOCK_SIZE, RBzip2::Constants::NO_RAND_PART_A_STATE, RBzip2::Constants::NO_RAND_PART_B_STATE, RBzip2::Constants::NO_RAND_PART_C_STATE, RBzip2::Constants::NUM_OVERSHOOT_BYTES, RBzip2::Constants::N_GROUPS, RBzip2::Constants::N_ITERS, RBzip2::Constants::QSORT_STACK_SIZE, RBzip2::Constants::RAND_PART_A_STATE, RBzip2::Constants::RAND_PART_B_STATE, RBzip2::Constants::RAND_PART_C_STATE, RBzip2::Constants::RNUMS, RBzip2::Constants::RUNA, RBzip2::Constants::RUNB, RBzip2::Constants::SETMASK, RBzip2::Constants::SMALL_THRESH, RBzip2::Constants::START_BLOCK_STATE, RBzip2::Constants::WORK_FACTOR

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(io, block_size = MAX_BLOCK_SIZE) ⇒ Compressor

Returns a new instance of Compressor.



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# File 'lib/rbzip2/compressor.rb', line 173

def initialize(io, block_size = MAX_BLOCK_SIZE)
  @allowable_block_size = 0
  @block_size           = block_size
  @buff                 = 0
  @combined_crc         = 0
  @crc                  = RBzip2::CRC.new
  @current_char         = -1
  @io                   = io
  @last                 = 0
  @live                 = 0
  @run_length           = 0

  init
end

Instance Attribute Details

#block_size ⇒ Object (readonly)

Returns the value of attribute block_size.



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# File 'lib/rbzip2/compressor.rb', line 171

def block_size
  @block_size
end

Class Method Details

.assign_codes(code, length, min_len, max_len, alpha_size) ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 10

def self.assign_codes(code, length, min_len, max_len, alpha_size)
  vec = 0
  min_len.upto(max_len) do |n|
    alpha_size.times do |i|
      if (length[i] & 0xff) == n
        code[i] = vec
        vec += 1
      end
    end
    vec <<= 1
  end
end

.choose_block_size(input_length) ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 23

def self.choose_block_size(input_length)
  input_length > 0 ? [(input_length / 132000) + 1, 9].min : MAX_BLOCK_SIZE
end

.make_code_lengths(len, freq, data, alpha_size, max_len) ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 27

def self.make_code_lengths(len, freq, data, alpha_size, max_len)
  heap   = data.heap
  weight = data.weight
  parent = data.parent

  weight[0] = 0
  (alpha_size - 1).downto(0) do |i|
    weight[i + 1] = (freq[i] == 0 ? 1 : freq[i]) << 8
  end

  too_long = true
  while too_long
    too_long = false

    n_nodes   = alpha_size
    n_heap    = 0
    heap[0]   = 0
    weight[0] = 0
    parent[0] = -2

    1.upto(alpha_size) do |i|
      parent[i] = -1
      n_heap += 1
      heap[n_heap] = i

      zz = n_heap
      tmp = heap[zz]
      while weight[tmp] < weight[heap[zz >> 1]]
        heap[zz] = heap[zz >> 1]
        zz >>= 1
      end
      heap[zz] = tmp
    end

    while n_heap > 1
      n1 = heap[1]
      heap[1] = heap[n_heap]
      n_heap -= 1

      yy  = 0
      zz  = 1
      tmp = heap[1]

      loop do
        yy = zz << 1

        break if yy > n_heap

        yy += 1 if (yy < n_heap) && (weight[heap[yy + 1]] < weight[heap[yy]])

        break if weight[tmp] < weight[heap[yy]]

        heap[zz] = heap[yy]
        zz = yy
      end

      heap[zz] = tmp

      n2 = heap[1]
      heap[1] = heap[n_heap]
      n_heap -= 1

      yy = 0
      zz = 1
      tmp = heap[1]

      loop do
        yy = zz << 1

        break if yy > n_heap

        yy += 1 if (yy < n_heap) && (weight[heap[yy + 1]] < weight[heap[yy]])

        break if weight[tmp] < weight[heap[yy]]

        heap[zz] = heap[yy]
        zz = yy
      end

      heap[zz] = tmp
      n_nodes += 1
      parent[n1] = parent[n2] = n_nodes

      weight_n1 = weight[n1]
      weight_n2 = weight[n2]
      weight[n_nodes] = ((weight_n1 & 0xffffff00) +
                        (weight_n2 & 0xffffff00)) |
                        (1 + (((weight_n1 & 0x000000ff) >
                        (weight_n2 & 0x000000ff)) ? (weight_n1 & 0x000000ff) :
                        (weight_n2 & 0x000000ff)))

      parent[n_nodes] = -1
      n_heap += 1
      heap[n_heap] = n_nodes

      tmp = 0
      zz = n_heap
      tmp = heap[zz]
      weight_tmp = weight[tmp]
      while weight_tmp < weight[heap[zz >> 1]]
        heap[zz] = heap[zz >> 1]
        zz >>= 1
      end
      heap[zz] = tmp
    end

    1.upto(alpha_size) do |i|
      j = 0
      k = i

      while (parent_k = parent[k]) >= 0
        k = parent_k
        j += 1
      end

      len[i - 1] = j
      too_long = true if j > max_len
    end

    if too_long
      1.upto(alpha_size) do |i|
        j = weight[i] >> 8
        j = 1 + (j >> 1)
        weight[i] = j << 8
      end
    end
  end
end

.med3(a, b, c) ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 156

def self.med3(a, b, c)
  (a < b) ? (b < c ? b : a < c ? c : a) : (b > c ? b : a > c ? c : a)
end

.vswap(fmap, p1, p2, n) ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 160

def self.vswap(fmap, p1, p2, n)
  n += p1
  while p1 < n
    t = fmap[p1]
    fmap[p1] = fmap[p2]
    fmap[p2] = t
    p1 += 1
    p2 += 1
  end
end

Instance Method Details

#block_sort ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 188

def block_sort
  @work_limit = WORK_FACTOR * @last
  @work_done = 0
  @block_randomized = false
  @first_attempt = true
  main_sort

  if @first_attempt && @work_done > @work_limit
    randomize_block
    @work_limit = @work_done = 0
    @first_attempt = false
    main_sort
  end

  fmap = @data.fmap
  @orig_ptr = -1
  (@last + 1).times do |i|
    if fmap[i] == 0
      @orig_ptr = i
      break
    end
  end
end

#close ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 212

def close
  unless @io.nil?
    io_shadow = @io
    finish
    io_shadow.close
  end
end

#end_block ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 220

def end_block
  @block_crc = @crc.final_crc
  @combined_crc = (@combined_crc << 1) | (@combined_crc >> 31)
  @combined_crc ^= @block_crc

  return if @last == -1

  block_sort

  put_byte 0x31
  put_byte 0x41
  put_byte 0x59
  put_byte 0x26
  put_byte 0x53
  put_byte 0x59

  put_int @block_crc

  @block_randomized ? w(1, 1) : w(1, 0)

  move_to_front_code_and_send
end

#end_compression ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 243

def end_compression
  put_byte 0x17
  put_byte 0x72
  put_byte 0x45
  put_byte 0x38
  put_byte 0x50
  put_byte 0x90

  put_int @combined_crc

  finished_with_stream
end

#finish ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 256

def finish
  unless @io.nil?
    begin
      write_run if @run_length > 0
      @current_char = -1
      end_block
      end_compression
    ensure
      @io  = nil
      @data = nil
    end
  end
end

#finished_with_stream ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 270

def finished_with_stream
  while @live > 0
    @io.write((@buff >> 24).chr)
    @buff <<= 8
    @buff &= 0xffffffff
    @live -= 8
  end
end

#flush ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 279

def flush
  @io.flush unless @io.nil?
end

#generate_mtf_values ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 283

def generate_mtf_values
  last_shadow = @last
  data_shadow = @data
  in_use = data_shadow.in_use
  block = data_shadow.block
  fmap = data_shadow.fmap
  sfmap = data_shadow.sfmap
  mtf_freq = data_shadow.mtf_freq
  unseq_to_seq = data_shadow.unseq_to_seq
  yy = data_shadow.generate_mtf_values_yy

  n_in_use_shadow = 0
  256.times do |i|
    if in_use[i]
      unseq_to_seq[i] = n_in_use_shadow
      n_in_use_shadow += 1
    end
  end
  @n_in_use = n_in_use_shadow

  eob = n_in_use_shadow + 1
  eob.times { |i| mtf_freq[i] }

  n_in_use_shadow.times { |i| yy[i] = i }

  wr = 0
  z_pend = 0

  0.upto(last_shadow) do |i|
    ll_i = unseq_to_seq[block[fmap[i]] & 0xff]
    tmp = yy[0]
    j = 0

    while ll_i != tmp
      j += 1
      tmp2 = tmp
      tmp = yy[j]
      yy[j] = tmp2
    end
    yy[0] = tmp

    if j == 0
      z_pend += 1
    else
      if z_pend > 0
        z_pend -= 1
        loop do
          if (z_pend & 1) == 0
            sfmap[wr] = RUNA
            mtf_freq[RUNA] += 1
          else
            sfmap[wr] = RUNB
            mtf_freq[RUNB] += 1
          end
          wr += 1

          break if z_pend < 2

          z_pend = (z_pend - 2) >> 1
        end
        z_pend = 0
      end
      sfmap[wr] = j + 1
      wr += 1
      mtf_freq[j + 1] += 1
    end
  end

  if z_pend > 0
    z_pend -= 1
    loop do
      if (z_pend & 1) == 0
        sfmap[wr] = RUNA
        mtf_freq[RUNA] += 1
      else
        sfmap[wr] = RUNB
        mtf_freq[RUNB] += 1
      end
      wr += 1

      break if z_pend < 2

      z_pend = (z_pend - 2) >> 1
    end
  end

  sfmap[wr] = eob
  mtf_freq[eob] += 1
  @n_mtf = wr + 1
end

#init ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 374

def init
  put_byte 0x42
  put_byte 0x5a

  @data = RBzip2::OutputData.new @block_size

  put_byte 0x68
  put_byte 0x30 + @block_size

  @combined_crc = 0
  init_block
end

#init_block ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 387

def init_block
  @crc.initialize_crc
  @last = -1

  in_use = @data.in_use
  in_use[0, 256] = [false] * 256

  @allowable_block_size = (@block_size * BASEBLOCKSIZE) - 20
end

#main_qsort3(data_shadow, lo_st, hi_st, d_st) ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 518

def main_qsort3(data_shadow, lo_st, hi_st, d_st)
  stack_ll = data_shadow.stack_ll
  stack_hh = data_shadow.stack_hh
  stack_dd = data_shadow.stack_dd
  fmap     = data_shadow.fmap
  block    = data_shadow.block

  stack_ll[0] = lo_st
  stack_hh[0] = hi_st
  stack_dd[0] = d_st

  sp = 1
  while (sp -= 1) >= 0
    lo = stack_ll[sp]
    hi = stack_hh[sp]
    d  = stack_dd[sp]

    if (hi - lo < SMALL_THRESH) || (d > DEPTH_THRESH)
      return if main_simple_sort data_shadow, lo, hi, d
    else
      d1 = d + 1
      med = self.class.med3(block[fmap[lo] + d1], block[fmap[hi] + d1], block[fmap[(lo + hi) >> 1] + d1]) & 0xff

      un_lo = lo
      un_hi = hi
      lt_lo = lo
      gt_hi = hi

      while true
        while un_lo <= un_hi
          n = (block[fmap[un_lo] + d1] & 0xff) - med
          if n == 0
            temp = fmap[un_lo]
            fmap[un_lo] = fmap[lt_lo]
            fmap[lt_lo] = temp
            un_lo += 1
            lt_lo += 1
          elsif n < 0
            un_lo += 1
          else
            break
          end
        end

        while un_lo <= un_hi
          n = (block[fmap[un_hi] + d1] & 0xff) - med
          if n == 0
            temp = fmap[un_hi]
            fmap[un_hi] = fmap[gt_hi]
            fmap[gt_hi] = temp
            un_hi -= 1
            gt_hi -= 1
          elsif n > 0
            un_hi -= 1
          else
            break
          end
        end

        if un_lo <= un_hi
          temp = fmap[un_lo]
          fmap[un_lo] = fmap[un_hi]
          fmap[un_hi] = temp
          un_lo += 1
          un_hi -= 1
        else
          break
        end
      end

      if gt_hi < lt_lo
        stack_ll[sp] = lo
        stack_hh[sp] = hi
        stack_dd[sp] = d1
        sp += 1
      else
        n = ((lt_lo - lo) < (un_lo - lt_lo)) ? (lt_lo - lo) : (un_lo - lt_lo)
        self.class.vswap fmap, lo, un_lo - n, n
        m = ((hi - gt_hi) < (gt_hi - un_hi)) ? (hi - gt_hi) : (gt_hi - un_hi)
        self.class.vswap fmap, un_lo, hi - m + 1, m

        n = lo + un_lo - lt_lo - 1
        m = hi - (gt_hi - un_hi) + 1

        stack_ll[sp] = lo
        stack_hh[sp] = n
        stack_dd[sp] = d
        sp += 1

        stack_ll[sp] = n + 1
        stack_hh[sp] = m - 1
        stack_dd[sp] = d1
        sp += 1

        stack_ll[sp] = m
        stack_hh[sp] = hi
        stack_dd[sp] = d
        sp += 1
      end
    end
  end
end

#main_simple_sort(data_shadow, lo, hi, d) ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 621

def main_simple_sort(data_shadow, lo, hi, d)
  big_n = hi - lo + 1
  return @first_attempt && (@work_done > @work_limit) if big_n < 2

  hp = 0
  while INCS[hp] < big_n
    hp += 1
  end

  fmap = data_shadow.fmap
  quadrant = data_shadow.quadrant
  block = data_shadow.block
  last_shadow = @last
  last_plus_1 = last_shadow + 1
  first_attempt_shadow = @first_attempt
  work_limit_shadow = @work_limit
  work_done_shadow = @work_done

  a = nil
  h = nil
  i1 = nil
  i2 = nil
  j = nil
  mj = nil
  once_runned = nil
  vd = nil
  x = nil

  x_loop = lambda do
    while x > 0
      x -= 4

      if block[i1 + 1] == block[i2 + 1]
        if quadrant[i1] == quadrant[i2]
          if block[i1 + 2] == block[i2 + 2]
            if quadrant[i1 + 1] == quadrant[i2 + 1]
              if block[i1 + 3] == block[i2 + 3]
                if quadrant[i1 + 2] == quadrant[i2 + 2]
                  if block[i1 + 4] == block[i2 + 4]
                    if quadrant[i1 + 3] == quadrant[i2 + 3]
                      i1 -= last_plus_1 if (i1 += 4) >= last_plus_1
                      i2 -= last_plus_1 if (i2 += 4) >= last_plus_1
                      work_done_shadow += 1
                      next
                    elsif quadrant[i1 + 3] > quadrant[i2 + 3]
                      return true
                    else
                      return false
                    end
                  elsif (block[i1 + 4] & 0xff) > (block[i2 + 4] & 0xff)
                    return true
                  else
                    return false
                  end
                elsif quadrant[i1 + 2] > quadrant[i2 + 2]
                  return true
                else
                  return false
                end
              elsif (block[i1 + 3] & 0xff) > (block[i2 + 3] & 0xff)
                return true
              else
                return false
              end
            elsif quadrant[i1 + 1] > quadrant[i2 + 1]
              return true
            else
              return false
            end
          elsif (block[i1 + 2] & 0xff) > (block[i2 + 2] & 0xff)
            return true
          else
            return false
          end
        elsif (quadrant[i1] > quadrant[i2])
          return true
        else
          return false
        end
      elsif (block[i1 + 1] & 0xff) > (block[i2 + 1] & 0xff)
        return true
      else
        return false
      end
    end

    true
  end

  hammer_loop = lambda do
    a = 0

    while true do
      if once_runned
        fmap[j] = a
        break if (j -= h) <= mj
      else
        once_runned = true
      end

      a = fmap[j - h]
      i1 = a + d
      i2 = vd

      if block[i1 + 1] == block[i2 + 1]
        if block[i1 + 2] == block[i2 + 2]
          if block[i1 + 3] == block[i2 + 3]
            if block[i1 + 4] == block[i2 + 4]
              if block[i1 + 5] == block[i2 + 5]
                if block[i1 += 6] == block[i2 += 6]
                  x = last_shadow

                  break unless x_loop.call
                else
                  if (block[i1] & 0xff) > (block[i2] & 0xff)
                    next
                  else
                    break
                  end
                end
              elsif (block[i1 + 5] & 0xff) > (block[i2 + 5] & 0xff)
                next
              else
                break
              end
            elsif (block[i1 + 4] & 0xff) > (block[i2 + 4] & 0xff)
              next
            else
              break
            end
          elsif (block[i1 + 3] & 0xff) > (block[i2 + 3] & 0xff)
            next
          else
            break
          end
        elsif (block[i1 + 2] & 0xff) > (block[i2 + 2] & 0xff)
          next
        else
          break
        end
      elsif (block[i1 + 1] & 0xff) > (block[i2 + 1] & 0xff)
        next
      else
        break
      end
    end
  end

  while (hp -= 1) >= 0
    h = INCS[hp]
    mj = lo + h - 1

    i = lo + h
    while i <= hi
      k = 3
      while i <= hi && (k -= 1) >= 0
        v = fmap[i]
        vd = v + d
        j = i

        once_runned = false

        hammer_loop.call

        fmap[j] = v

        i += 1
      end
    end

    break if first_attempt_shadow && i <= hi && work_done_shadow > work_limit_shadow
  end

  @work_done = work_done_shadow

  first_attempt_shadow && (work_done_shadow > work_limit_shadow)
end

#main_sort ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 397

def main_sort
  data_shadow = @data
  running_order = data_shadow.main_sort_running_order
  copy = data_shadow.main_sort_copy
  big_done = data_shadow.main_sort_big_done
  ftab = data_shadow.ftab
  block = data_shadow.block
  fmap = data_shadow.fmap
  quadrant = data_shadow.quadrant
  last_shadow = @last
  work_limit_shadow = @work_limit
  first_attempt_shadow = @first_attempt

  65537.times { |i| ftab[i] = 0 }

  NUM_OVERSHOOT_BYTES.times do |i|
    block[last_shadow + i + 2] = block[(i % (last_shadow + 1)) + 1]
  end
  (last_shadow + NUM_OVERSHOOT_BYTES).times do |i|
    quadrant[i] = 0
  end
  block[0] = block[last_shadow + 1]

  c1 = block[0] & 0xff
  (last_shadow + 1).times do |i|
    c2 = block[i + 1] & 0xff
    ftab[(c1 << 8) + c2] += 1
    c1 = c2
  end

  1.upto(65536) { |i| ftab[i] += ftab[i - 1] }

  c1 = block[1] & 0xff
  last_shadow.times do |i|
    c2 = block[i + 2] & 0xff
    fmap[ftab[(c1 << 8) + c2] -= 1] = i
    c1 = c2
  end

  fmap[ftab[((block[last_shadow + 1] & 0xff) << 8) + (block[1] & 0xff)] -= 1] = last_shadow

  256.times do |i|
    big_done[i] = false
    running_order[i] = i
  end

  h = 364
  while h != 1
    h /= 3
    h.upto(255) do |i|
      vv = running_order[i]
      a = ftab[(vv + 1) << 8] - ftab[vv << 8]
      b = h - 1
      j = i

      ro = running_order[j - h]
      while ftab[(ro + 1) << 8] - ftab[ro << 8] > a
        running_order[j] = ro
        j -= h
        break if j <= b
        ro = running_order[j - h]
      end

      running_order[j] = vv
    end
  end

  256.times do |i|
    ss = running_order[i]

    256.times do |j|
      sb = (ss << 8) + j
      ftab_sb = ftab[sb]
      if (ftab_sb & SETMASK) != SETMASK
        lo = ftab_sb & CLEARMASK
        hi = (ftab[sb + 1] & CLEARMASK) - 1
        if hi > lo
          main_qsort3 data_shadow, lo, hi, 2
          return if first_attempt_shadow && (@work_done > work_limit_shadow)
        end
        ftab[sb] = ftab_sb | SETMASK
      end
    end

    256.times { |j| copy[j] = ftab[(j << 8) + ss] & CLEARMASK }

    hj = ftab[(ss + 1) << 8] & CLEARMASK
    (ftab[ss << 8] & CLEARMASK).upto(hj - 1) do |j|
      fmap_j = fmap[j]
      c1 = block[fmap_j] & 0xff
      if !big_done[c1]
        fmap[copy[c1]] = (fmap_j == 0) ? last_shadow : (fmap_j - 1)
        copy[c1] += 1
      end
    end

    255.downto(0) { |j| ftab[(j << 8) + ss] |= SETMASK }

    big_done[ss] = true

    if i < 255
      bb_start = ftab[ss << 8] & CLEARMASK
      bb_size = (ftab[(ss + 1) << 8] & CLEARMASK) - bb_start
      shifts = 0

      while (bb_size >> shifts) > 65534
        shifts += 1
      end

      bb_size.times do |j|
        a2update = fmap[bb_start + j]
        q_val = j >> shifts
        quadrant[a2update] = q_val
        if a2update < NUM_OVERSHOOT_BYTES
          quadrant[a2update + last_shadow + 1] = q_val
        end
      end
    end
  end
end

#move_to_front_code_and_send ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 799

def move_to_front_code_and_send
  w 24, @orig_ptr
  generate_mtf_values
  send_mtf_values
end

#put_byte(c) ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 805

def put_byte(c)
  c = c[0].to_i if c.is_a? String
  w 8, c
end

#put_int(u) ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 810

def put_int(u)
  w 8, (u >> 24) & 0xff
  w 8, (u >> 16) & 0xff
  w 8, (u >> 8) & 0xff
  w 8, u & 0xff
end

#randomize_block ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 817

def randomize_block
  in_use      = @data.in_use
  block       = @data.block
  last_shadow = @last

  256.times { |i| in_use[i] = false }

  r_n_to_go = 0
  r_t_pos = 0
  j = 1
  i = 0
  while i <= last_shadow
    i = j

    if r_n_to_go == 0
      r_n_to_go = RNUMS[r_t_pos]
      r_t_pos = 0 if (r_t_pos += 1) == 512
    end

    r_n_to_go -= 1
    block[j] ^= r_n_to_go == 1 ? 1 : 0

    in_use[block[j] & 0xff] = true

    j += 1
  end

  @block_randomized = true
end

#send_mtf_values ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 847

def send_mtf_values
  len = @data.send_mtf_values_len
  alpha_size = @n_in_use + 2

  N_GROUPS.times do |t|
    len_t = len[t]
    alpha_size.times { |v| len_t[v] = GREATER_ICOST }
  end

  n_groups = (@n_mtf < 200) ? 2 : (@n_mtf < 600) ? 3 : (@n_mtf < 1200) ? 4 :
             (@n_mtf < 2400) ? 5 : 6

  send_mtf_values0 n_groups, alpha_size
  n_selectors = send_mtf_values1 n_groups, alpha_size
  send_mtf_values2 n_groups, n_selectors
  send_mtf_values3 n_groups, alpha_size
  send_mtf_values4
  send_mtf_values5 n_groups, n_selectors
  send_mtf_values6 n_groups, alpha_size
  send_mtf_values7
end

#send_mtf_values0(n_groups, alpha_size) ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 869

def send_mtf_values0(n_groups, alpha_size)
  len = @data.send_mtf_values_len
  mtf_freq = @data.mtf_freq

  rem_f = @n_mtf
  gs = 0

  n_groups.downto(1) do |n_part|
    t_freq = rem_f / n_part
    ge = gs - 1
    a_freq = 0

    a = alpha_size - 1
    while a_freq < t_freq && ge < a
      ge += 1
      a_freq += mtf_freq[ge]
    end

    if ge > gs && n_part != n_groups && n_part != 1 &&
       ((n_groups - n_part) & 1) != 0
      ge -= 1
      a_freq -= mtf_freq[ge]
    end

    len_np = len[n_part - 1]
    (alpha_size - 1).downto(0) do |v|
      if v >= gs && v <= ge
        len_np[v] = LESSER_ICOST
      else
        len_np[v] = GREATER_ICOST
      end
    end

    gs = ge +1
    rem_f -= a_freq
  end
end

#send_mtf_values1(n_groups, alpha_size) ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 907

def send_mtf_values1(n_groups, alpha_size)
  data_shadow = @data
  rfreq = data_shadow.send_mtf_values_rfreq
  fave = data_shadow.send_mtf_values_fave
  cost = data_shadow.send_mtf_values_cost
  sfmap = data_shadow.sfmap
  selector = data_shadow.selector
  len = data_shadow.send_mtf_values_len
  len_0 = len[0]
  len_1 = len[1]
  len_2 = len[2]
  len_3 = len[3]
  len_4 = len[4]
  len_5 = len[5]
  n_mtf_shadow = @n_mtf
  n_selectors = 0

  N_ITERS.times do
    (n_groups - 1).downto(0) do |t|
      fave[t] = 0
      rfreqt = rfreq[t]
      (alpha_size - 1).downto(0) { |i| rfreqt[i] = 0 }
    end

    n_selectors = 0

    gs = 0
    while gs < @n_mtf
      ge = [gs + G_SIZE - 1, n_mtf_shadow - 1].min

      if n_groups == N_GROUPS
        cost0 = 0
        cost1 = 0
        cost2 = 0
        cost3 = 0
        cost4 = 0
        cost5 = 0

        gs.upto(ge) do |i|
          icv = sfmap[i]
          cost0 += len_0[icv] & 0xff
          cost1 += len_1[icv] & 0xff
          cost2 += len_2[icv] & 0xff
          cost3 += len_3[icv] & 0xff
          cost4 += len_4[icv] & 0xff
          cost5 += len_5[icv] & 0xff
        end

        cost[0] = cost0
        cost[1] = cost1
        cost[2] = cost2
        cost[3] = cost3
        cost[4] = cost4
        cost[5] = cost5
      else
        (n_groups - 1).downto(0) { |t| cost[t] = 0 }

        gs.upto(ge) do |i|
          icv = sfmap[i]
          (n_groups - 1).downto(0) { |t| cost[t] += len[t][icv] & 0xff }
        end
      end

      bt = -1
      bc = 999999999
      (n_groups - 1).downto(0) do |t|
        cost_t = cost[t]
        if cost_t < bc
          bc = cost_t
          bt = t
        end
      end

      fave[bt] += 1
      selector[n_selectors] = bt
      n_selectors += 1

      rfreq_bt = rfreq[bt]
      gs.upto(ge) { |i| rfreq_bt[sfmap[i]] += 1 }

      gs = ge + 1
    end

    n_groups.times do |t|
      self.class.make_code_lengths len[t], rfreq[t], @data, alpha_size, 20
    end
  end

  n_selectors
end

#send_mtf_values2(n_groups, n_selectors) ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 998

def send_mtf_values2(n_groups, n_selectors)
  data_shadow = @data
  pos = data_shadow.send_mtf_values2_pos

  n_groups.times { |i| pos[i] = i }

  n_selectors.times do |i|
    ll_i = data_shadow.selector[i]
    tmp = pos[0]
    j = 0

    while ll_i != tmp
      j += 1
      tmp2 = tmp
      tmp = pos[j]
      pos[j] = tmp2
    end

    pos[0] = tmp
    data_shadow.selector_mtf[i] = j
  end
end

#send_mtf_values3(n_groups, alpha_size) ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 1021

def send_mtf_values3(n_groups, alpha_size)
  code = @data.send_mtf_values_code
  len = @data.send_mtf_values_len

  n_groups.times do |t|
    min_len = 32
    max_len = 0
    len_t = len[t]
    (alpha_size - 1).downto(0) do |i|
      l = len_t[i] & 0xff
      max_len = l if l > max_len
      min_len = l if l < min_len
    end

    self.class.assign_codes code[t], len[t], min_len, max_len, alpha_size
  end
end

#send_mtf_values4 ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 1039

def send_mtf_values4
  in_use = @data.in_use
  in_use_16 = @data.send_mtf_values4_in_use_16

  15.downto(0) do |i|
    in_use_16[i] = false
    i16 = i * 16
    15.downto(0) do |j|
      in_use_16[i] = true if in_use[i16 + j]
    end
  end

  16.times { |i| w 1, (in_use_16[i] ? 1 : 0) }

  io_shadow   = @io
  live_shadow = @live
  buff_shadow = @buff

  16.times do |i|
    if in_use_16[i]
      i16 = i * 16
      16.times do |j|
        while live_shadow >= 8
          io_shadow.write(((buff_shadow >> 24) & 0xffffffff).chr)
          buff_shadow <<= 8
          buff_shadow &= 0xffffffff
          live_shadow -= 8
        end
        buff_shadow |= 1 << (32 - live_shadow - 1) if in_use[i16 + j]
        live_shadow += 1
      end
    end
  end

  @buff = buff_shadow
  @live = live_shadow
end

#send_mtf_values5(n_groups, n_selectors) ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 1077

def send_mtf_values5(n_groups, n_selectors)
  w 3, n_groups
  w 15, n_selectors

  io_shadow   = @io
  selector_mtf = @data.selector_mtf

  live_shadow = @live
  buff_shadow = @buff

  n_selectors.times do |i|
    hj = selector_mtf[i] & 0xff
    hj.times do
      while live_shadow >= 8
        io_shadow.write(((buff_shadow >> 24) & 0xffffffff).chr)
        buff_shadow <<= 8
        buff_shadow &= 0xffffffff
        live_shadow -= 8
      end
      buff_shadow |= 1 << (32 - live_shadow - 1)
      live_shadow += 1
    end

    while live_shadow >= 8
      io_shadow.write(((buff_shadow >> 24) & 0xffffffff).chr)
      buff_shadow <<= 8
      buff_shadow &= 0xffffffff
      live_shadow -= 8
    end
    live_shadow += 1
  end

  @buff = buff_shadow
  @live = live_shadow
end

#send_mtf_values6(n_groups, alpha_size) ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 1113

def send_mtf_values6(n_groups, alpha_size)
  len = @data.send_mtf_values_len
  io_shadow = @io

  live_shadow = @live
  buff_shadow = @buff

  n_groups.times do |t|
    len_t = len[t]
    curr = len_t[0] & 0xff

    while live_shadow >= 8
      io_shadow.write(((buff_shadow >> 24) & 0xffffffff).chr)
      buff_shadow <<= 8
      buff_shadow &= 0xffffffff
      live_shadow -= 8
    end
    buff_shadow |= curr << (32 - live_shadow - 5)
    live_shadow += 5

    alpha_size.times do |i|
      lti = len_t[i] & 0xff
      while curr < lti
        while live_shadow >= 8
          io_shadow.write(((buff_shadow >> 24) & 0xffffffff).chr)
          buff_shadow <<= 8
          buff_shadow &= 0xffffffff
          live_shadow -= 8
        end
        buff_shadow |= 2 << (32 - live_shadow - 2)
        live_shadow += 2

        curr += 1
      end

      while curr > lti
        while live_shadow >= 8
          io_shadow.write(((buff_shadow >> 24) & 0xffffffff).chr)
          buff_shadow <<= 8
          buff_shadow &= 0xffffffff
          live_shadow -= 8
        end
        buff_shadow |= 3 << (32 - live_shadow - 2)
        live_shadow += 2

        curr -= 1
      end

      while live_shadow >= 8
        io_shadow.write(((buff_shadow >> 24) & 0xffffffff).chr)
        buff_shadow <<= 8
        buff_shadow &= 0xffffffff
        live_shadow -= 8
      end
      live_shadow += 1
    end
  end

  @buff = buff_shadow
  @live = live_shadow
end

#send_mtf_values7 ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 1175

def send_mtf_values7
  data_shadow = @data
  len = data_shadow.send_mtf_values_len
  code = data_shadow.send_mtf_values_code
  io_shadow = @io
  selector = data_shadow.selector
  sfmap = data_shadow.sfmap
  n_mtf_shadow = @n_mtf

  sel_ctr = 0

  live_shadow = @live
  buff_shadow = @buff

  gs = 0
  while gs < n_mtf_shadow
    ge = [gs + G_SIZE - 1, n_mtf_shadow - 1].min
    selector_sel_ctr = selector[sel_ctr] & 0xff
    code_sel_ctr = code[selector_sel_ctr]
    len_sel_ctr = len[selector_sel_ctr]

    while gs <= ge
      sfmap_i = sfmap[gs]

      while live_shadow >= 8
        io_shadow.write(((buff_shadow >> 24) & 0xffffffff).chr)
        buff_shadow <<= 8
        buff_shadow &= 0xffffffff
        live_shadow -= 8
      end
      n = len_sel_ctr[sfmap_i] & 0xff
      buff_shadow |= code_sel_ctr[sfmap_i] << (32 - live_shadow - n)
      live_shadow += n

      gs += 1
    end

    gs = ge + 1
    sel_ctr += 1
  end

  @buff = buff_shadow
  @live = live_shadow
end

#w(n, v) ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 1220

def w(n, v)
  io_shadow = @io
  live_shadow = @live
  buff_shadow = @buff

  while live_shadow >= 8
    io_shadow.write(((buff_shadow >> 24) & 0xffffffff).chr)
    buff_shadow <<= 8
    buff_shadow &= 0xffffffff
    live_shadow -= 8
  end

  @buff = buff_shadow | (v << (32 - live_shadow - n))
  @live = live_shadow + n
end

#write(bytes) ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 1236

def write(bytes)
  raise 'stream closed' if @io.nil?

  bytes.each_byte { |b| write0 b }
end

#write0(b) ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 1242

def write0(b)
  if @current_char != -1
    b &= 0xff
    if @current_char == b
      @run_length += 1
      if @run_length > 254
        write_run
        @current_char = -1
        @run_length = 0
      end
    else
      write_run
      @run_length = 1
      @current_char = b
    end
  else
    @current_char = b & 0xff
    @run_length += 1
  end
end

#write_run ⇒ Object 



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# File 'lib/rbzip2/compressor.rb', line 1263

def write_run
  last_shadow = @last

  if last_shadow < @allowable_block_size
    current_char_shadow = @current_char
    data_shadow = @data
    data_shadow.in_use[current_char_shadow] = true
    ch = current_char_shadow

    run_length_shadow = @run_length
    @crc.update_crc current_char_shadow, run_length_shadow

    case run_length_shadow
      when 1
        data_shadow.block[last_shadow + 2] = ch
        @last = last_shadow + 1

      when 2
        data_shadow.block[last_shadow + 2] = ch
        data_shadow.block[last_shadow + 3] = ch
        @last = last_shadow + 2

      when 3
        block = data_shadow.block
        block[last_shadow + 2] = ch
        block[last_shadow + 3] = ch
        block[last_shadow + 4] = ch
        @last = last_shadow + 3

      else
        run_length_shadow -= 4
        data_shadow.in_use[run_length_shadow] = true
        block = data_shadow.block
        block[last_shadow + 2] = ch
        block[last_shadow + 3] = ch
        block[last_shadow + 4] = ch
        block[last_shadow + 5] = ch
        block[last_shadow + 6] = run_length_shadow
        @last = last_shadow + 5
    end
  else
    end_block
    init_block
    write_run
  end
end