Class: Zlib::ZStream

Inherits:
Object
  • Object
show all
Defined in:
lib/pr/zlib/zstream.rb

Direct Known Subclasses

Deflate, Inflate

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#buf ⇒ Object

Returns the value of attribute buf.



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# File 'lib/pr/zlib/zstream.rb', line 7

def buf
  @buf
end

#flags ⇒ Object

Returns the value of attribute flags.



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# File 'lib/pr/zlib/zstream.rb', line 7

def flags
  @flags
end

#func ⇒ Object

Returns the value of attribute func.



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# File 'lib/pr/zlib/zstream.rb', line 7

def func
  @func
end

#input ⇒ Object

Returns the value of attribute input.



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# File 'lib/pr/zlib/zstream.rb', line 7

def input
  @input
end

#stream ⇒ Object

Returns the value of attribute stream.



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# File 'lib/pr/zlib/zstream.rb', line 7

def stream
  @stream
end

Instance Method Details

#raise_zlib_error(err, msg) ⇒ Object 



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# File 'lib/pr/zlib/zstream.rb', line 9

def raise_zlib_error(err, msg)
  msg = zError(err) if msg.nil? || msg == ''

  case err
    when Z_STREAM_END
      raise StreamEnd, msg
    when Z_NEED_DICT
      raise NeedDict, msg
    when Z_STREAM_ERROR
      raise StreamError, msg
    when Z_DATA_ERROR
      raise DataError, msg
    when Z_BUF_ERROR
      raise BufError, msg
    when Z_VERSION_ERROR
      raise VersionError, msg
    when Z_MEM_ERROR
      raise MemError, msg
    when Z_ERRNO
      raise SystemCallError, msg
    else
      raise Error, 'unknown zlib error #errend: #msgend'
  end
end

#zstream_append_buffer(src, len) ⇒ Object 



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# File 'lib/pr/zlib/zstream.rb', line 58

def zstream_append_buffer(src, len)
  if @buf.nil?
    @buf = Bytef.new(src[0, len], len)
    @stream.next_out = Bytef.new(@buf)
    @stream.avail_out = 0
    return
  end
  if @buf.length < @buf.offset + len
    @buf.buffer << (0.chr * (@buf.offset + len - @buf.length))
    @stream.avail_out = 0
  else
    if @stream.avail_out >= len
      @stream.avail_out -= len
    else
      @stream.avail_out = 0
    end
  end
  @buf.buffer[@buf.offset, len] = src[0, len]
  @buf += len
  @stream.next_out = Bytef.new(@buf, @buf.offset)
end

#zstream_append_input(src, len) ⇒ Object 



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# File 'lib/pr/zlib/zstream.rb', line 123

def zstream_append_input(src, len)
  return if len <= 0
  src = src.current if src.class != String
  if @input.nil?
    @input = src[0, len]
  else
    @input << src[0, len]
  end
end

#zstream_buffer_ungetc(c) ⇒ Object 



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# File 'lib/pr/zlib/zstream.rb', line 111

def zstream_buffer_ungetc(c)
  if @buf.nil? || (@buf.length - @buf.offset).zero?
    zstream_expand_buffer()
  end
  @buf.buffer[0, 0] = c.chr
  @buf += 1
  if @stream.avail_out > 0
    @stream.next_out += 1
    @stream.avail_out -= 1
  end
end

#zstream_detach_buffer ⇒ Object 



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# File 'lib/pr/zlib/zstream.rb', line 80

def zstream_detach_buffer
  if @buf.nil?
    dst = ''
  else
    dst = @buf.buffer[0, @buf.offset]
  end

  @buf = Bytef.new(0.chr * ZSTREAM_INITIAL_BUFSIZE)
  @stream.next_out = Bytef.new(@buf)
  @stream.avail_out = ZSTREAM_INITIAL_BUFSIZE
  @buf_filled = 0

  dst
end

#zstream_detach_input ⇒ Object 



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# File 'lib/pr/zlib/zstream.rb', line 152

def zstream_detach_input
  if @input.nil?
    dst = ''
  else
    dst = @input
  end
  @input = nil
  dst
end

#zstream_discard_input(len) ⇒ Object 



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# File 'lib/pr/zlib/zstream.rb', line 133

def zstream_discard_input(len)
  if @input.nil? || @input.length <= len
    @input = nil
  else
    @input[0, len] = ''
  end
end

#zstream_end ⇒ Object 



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# File 'lib/pr/zlib/zstream.rb', line 175

def zstream_end
  if !ZSTREAM_IS_READY()
    warn('attempt to close uninitialized zstream; ignored.')
    return nil
  end
  if (@flags & ZSTREAM_FLAG_IN_STREAM).nonzero?
    warn('attempt to close unfinished zstream; reset forced.')
    zstream_reset()
  end

  zstream_reset_input()
  err = send(@func.end, @stream)
  if err != Z_OK
    raise_zlib_error(err, @stream.msg)
  end
  @flags = 0
  nil
end

#zstream_expand_buffer ⇒ Object 



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# File 'lib/pr/zlib/zstream.rb', line 34

def zstream_expand_buffer
  if @buf.nil?
    @buf = Bytef.new(0.chr * ZSTREAM_INITIAL_BUFSIZE)
    @stream.next_out = Bytef.new(@buf)
    @stream.avail_out = ZSTREAM_INITIAL_BUFSIZE
    return
  end

  if @buf.length - @buf.offset >= ZSTREAM_AVAIL_OUT_STEP_MAX
    @stream.avail_out = ZSTREAM_AVAIL_OUT_STEP_MAX
  else
    inc = @buf.offset / 2
    if inc < ZSTREAM_AVAIL_OUT_STEP_MIN
      inc = ZSTREAM_AVAIL_OUT_STEP_MIN
    end
    if @buf.length < @buf.offset + inc
      @buf.buffer << 0.chr * (@buf.offset + inc - @buf.length)
    end
    @stream.avail_out = (inc < ZSTREAM_AVAIL_OUT_STEP_MAX) ?
        inc : ZSTREAM_AVAIL_OUT_STEP_MAX
  end
  @stream.next_out = Bytef.new(@buf, @buf.offset)
end

#zstream_init(func) ⇒ Object 



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# File 'lib/pr/zlib/zstream.rb', line 227

def zstream_init(func)
  @flags = 0
  @buf = nil
  @input = nil
  @stream = Z_stream.new
  @stream.msg = ''
  @stream.next_in = nil
  @stream.avail_in = 0
  @stream.next_out = nil
  @stream.avail_out = 0
  @func = func
end

#ZSTREAM_IS_CLOSING ⇒ Object 



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# File 'lib/pr/zlib/zstream.rb', line 298

def ZSTREAM_IS_CLOSING
  !(@flags & ZSTREAM_FLAG_CLOSING).zero?
end

#ZSTREAM_IS_FINISHED ⇒ Object 



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# File 'lib/pr/zlib/zstream.rb', line 294

def ZSTREAM_IS_FINISHED
  !(@flags & ZSTREAM_FLAG_FINISHED).zero?
end

#ZSTREAM_IS_READY ⇒ Object 



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# File 'lib/pr/zlib/zstream.rb', line 290

def ZSTREAM_IS_READY
  !(@flags & ZSTREAM_FLAG_READY).zero?
end

#zstream_passthrough_input ⇒ Object 



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# File 'lib/pr/zlib/zstream.rb', line 145

def zstream_passthrough_input
  if @input
    zstream_append_buffer(@input, @input.length)
    @input = nil
  end
end

#ZSTREAM_READY ⇒ Object 



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# File 'lib/pr/zlib/zstream.rb', line 286

def ZSTREAM_READY
  (@flags |= ZSTREAM_FLAG_READY)
end

#zstream_reset ⇒ Object 



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# File 'lib/pr/zlib/zstream.rb', line 162

def zstream_reset
  err = send(@func.reset, @stream)
  if err != Z_OK
    raise_zlib_error(err, @stream.msg)
  end
  @flags = ZSTREAM_FLAG_READY
  @buf = nil
  @buf_filled = 0
  @stream.next_out = 0
  @stream.avail_out = 0
  zstream_reset_input()
end

#zstream_reset_input ⇒ Object 



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# File 'lib/pr/zlib/zstream.rb', line 141

def zstream_reset_input
  @input = nil
end

#zstream_run(src, len, flush) ⇒ Object 



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# File 'lib/pr/zlib/zstream.rb', line 240

def zstream_run(src, len, flush)
  if @input.nil? && len == 0
    @stream.next_in = ''
    @stream.avail_in = 0
  else
    zstream_append_input(src, len)
    @stream.next_in = Bytef.new(@input)
    @stream.avail_in = @input.length
  end
  if @stream.avail_out.zero?
    zstream_expand_buffer()
  end

  loop do
    n = @stream.avail_out
    err = send(@func.run, @stream, flush)
    @buf += n - @stream.avail_out
    if err == Z_STREAM_END
      @flags &= ~ZSTREAM_FLAG_IN_STREAM
      @flags |= ZSTREAM_FLAG_FINISHED
      break
    end
    if err != Z_OK
      if flush != Z_FINISH && err == Z_BUF_ERROR && @stream.avail_out > 0
        @flags |= ZSTREAM_FLAG_IN_STREAM
        break
      end
      @input = nil
      if @stream.avail_in > 0
        zstream_append_input(@stream.next_in, @stream.avail_in)
      end
      raise_zlib_error(err, @stream.msg)
    end
    if @stream.avail_out > 0
      @flags |= ZSTREAM_FLAG_IN_STREAM
      break
    end
    zstream_expand_buffer()
  end

  @input = nil
  if @stream.avail_in > 0
    zstream_append_input(@stream.next_in, @stream.avail_in)
  end
end

#zstream_shift_buffer(len) ⇒ Object 



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# File 'lib/pr/zlib/zstream.rb', line 95

def zstream_shift_buffer(len)
  if @buf.offset <= len
    return zstream_detach_buffer()
  end

  dst = @buf.buffer[0, len]
  @buf -= len
  @buf.buffer[0, @buf.offset] = @buf.buffer[len, @buf.offset]
  @stream.next_out = Bytef.new(@buf, @buf.offset)
  @stream.avail_out = @buf.length - @buf.offset
  if @stream.avail_out > ZSTREAM_AVAIL_OUT_STEP_MAX
    @stream.avail_out = ZSTREAM_AVAIL_OUT_STEP_MAX
  end
  dst
end

#zstream_sync(src, len) ⇒ Object 



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# File 'lib/pr/zlib/zstream.rb', line 194

def zstream_sync(src, len)
  if @input
    @stream.next_in = Bytef.new(@input)
    @stream.avail_in = @input.length
    err = inflateSync(@stream)
    if err == Z_OK
      zstream_discard_input(@input.length - @stream.avail_in)
      zstream_append_input(src, len)
      return true
    end
    zstream_reset_input()
    if err != Z_DATA_ERROR
      @stream.next_in.buffer[0, @stream.avail_in]
      raise_zlib_error(err, @stream.msg)
    end
  end

  return false if len <= 0

  @stream.next_in = src
  @stream.avail_in = len
  err = inflateSync(@stream)
  if err == Z_OK
    zstream_append_input(@stream.next_in, @stream.avail_in)
    return true
  end
  if err != Z_DATA_ERROR
    @stream.next_in.buffer[0, @stream.avail_in]
    raise_zlib_error(err, @stream.msg)
  end
  false
end