Class: Zippo::ZipFileWriter

Inherits:
Object
  • Object
show all
Defined in:
lib/zippo/zip_file_writer.rb

Overview

ZipFileWriter writes the contents of a ZipDirectory to a Zip file.

Instance Method Summary collapse

Constructor Details

#initialize(directory, filename) ⇒ ZipFileWriter

Returns a new instance of ZipFileWriter.

Parameters:

  • directory (ZipDirectory) —

    the ZipDirectory to write

  • filename (String) —

    the filename to write to



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# File 'lib/zippo/zip_file_writer.rb', line 6

def initialize(directory, filename)
  @directory = directory
  @filename = filename
end

Instance Method Details

#write ⇒ Object

Writes the directory to the file.



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# File 'lib/zippo/zip_file_writer.rb', line 12

def write
  File.open(@filename, 'wb:ASCII-8BIT') do |io|
    packer = LocalFileHeader::Packer.new io
    headers = []
    @directory.each do |member|
      header = CdFileHeader.default
      header.compression_method = 8 # XXX configurable
      # XXX hack fix for maintaining method in zipped data copies
      if member.is_a? ZipMember
        header.compression_method = member.compression_method
      end
      header.name = member.name
      header.extra_field = "" # XXX extra field unimplemented
      header_size = header.file_name_length + header.extra_field_length + 30

      # record header position so we can write it later
      header.local_file_header_offset = io.pos

      # move to after the header
      io.seek header_size, IO::SEEK_CUR

      # write the compressed data
      header.compressed_size, header.uncompressed_size, header.crc32 =
        member.write_to io, header.compression_method

      # write the completed header, returning to the current position
      io.seek header.local_file_header_offset
      # packer.pack LocalFileHeader.from header.convert_to LocalHileHeader
      packer.pack header.convert_to LocalFileHeader
      io.seek header.compressed_size, IO::SEEK_CUR
      headers << header
    end

    eocdr = EndCdRecord.default
    eocdr.cd_offset = io.pos
    packer = CdFileHeader::Packer.new io
    headers.each do |header|
      packer.pack header
    end
    eocdr.cd_size = io.pos - eocdr.cd_offset
    eocdr.records = eocdr.total_records = headers.size
    EndCdRecord::Packer.new(io).pack eocdr
  end
end