Class: Omnizip::Formats::XzImpl::StreamEncoder

Inherits:
Object
  • Object
show all
Includes:
Omnizip::Formats::XzConst
Defined in:
lib/omnizip/formats/xz_impl/stream_encoder.rb

Overview

XZ Stream encoder Orchestrates the complete XZ stream creation Based on XZ Utils stream_encoder.c

Constant Summary

Constants included from Omnizip::Formats::XzConst

Omnizip::Formats::XzConst::BACKWARD_SIZE_MAX, Omnizip::Formats::XzConst::BACKWARD_SIZE_MIN, Omnizip::Formats::XzConst::BLOCK_HEADER_SIZE_MAX, Omnizip::Formats::XzConst::BLOCK_HEADER_SIZE_MIN, Omnizip::Formats::XzConst::CHECK_CRC32, Omnizip::Formats::XzConst::CHECK_CRC64, Omnizip::Formats::XzConst::CHECK_NONE, Omnizip::Formats::XzConst::CHECK_SHA256, Omnizip::Formats::XzConst::FILTERS_MAX, Omnizip::Formats::XzConst::FILTER_LZMA2, Omnizip::Formats::XzConst::FOOTER_MAGIC, Omnizip::Formats::XzConst::INDEX_INDICATOR, Omnizip::Formats::XzConst::MAGIC, Omnizip::Formats::XzConst::STREAM_FLAGS_SIZE, Omnizip::Formats::XzConst::STREAM_FOOTER_SIZE, Omnizip::Formats::XzConst::STREAM_HEADER_SIZE, Omnizip::Formats::XzConst::VLI_BYTES_MAX, Omnizip::Formats::XzConst::VLI_UNKNOWN

Instance Method Summary collapse

Constructor Details

#initialize(check_type: CHECK_CRC64, dict_size: 64 * 1024 * 1024) ⇒ StreamEncoder

Returns a new instance of StreamEncoder.



14
15
16
17
18
 
# File 'lib/omnizip/formats/xz_impl/stream_encoder.rb', line 14

def initialize(check_type: CHECK_CRC64, dict_size: 64 * 1024 * 1024)
  @check_type = check_type
  @dict_size = dict_size
  @index = IndexEncoder.new
end

Instance Method Details

#encode(input) ⇒ String

Encode data into XZ format

Parameters:

  • input (String, IO) —

    Input data to compress

Returns:

  • (String) —

    XZ-formatted compressed data



23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
 
# File 'lib/omnizip/formats/xz_impl/stream_encoder.rb', line 23

def encode(input)
  output = StringIO.new
  output.set_encoding(Encoding::BINARY)

  # Read input data
  input_data = Omnizip::IO::Source.for(input).read
  input_data = input_data.dup.force_encoding(Encoding::BINARY)

  # 1. Write Stream Header
  header = StreamHeader.new(check_type: @check_type)
  output.write(header.encode)

  # 2. Encode and write Block(s)
  encode_blocks(input_data, output)

  # 3. Write Index
  index_data = @index.encode
  output.write(index_data)

  # 4. Write Stream Footer
  footer = StreamFooter.new(
    check_type: @check_type,
    backward_size: @index.size,
  )
  output.write(footer.encode)

  output.string
end