Class: Zippo::CentralDirectoryReader

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

Overview

Reads the zip central directory from an IO stream.

Instance Method Summary collapse

Constructor Details

#initialize(io) ⇒ CentralDirectoryReader

Returns a new instance of CentralDirectoryReader.



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# File 'lib/zippo/central_directory_reader.rb', line 7

def initialize(io)
  @io = io
end

Instance Method Details

#cd_file_headers ⇒ Object 



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# File 'lib/zippo/central_directory_reader.rb', line 15

def cd_file_headers
  @cd_file_headers ||= CentralDirectoryEntriesUnpacker.new(@io, end_of_cd_record.cd_size, end_of_cd_record.cd_offset).unpack
end

#end_of_cd_record ⇒ Object 



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# File 'lib/zippo/central_directory_reader.rb', line 11

def end_of_cd_record
  @end_of_cd_record ||= EndCdRecord::Unpacker.new(read_from end_of_cd_record_position).unpack
end

#end_of_cd_record_position ⇒ Object 



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# File 'lib/zippo/central_directory_reader.rb', line 19

def end_of_cd_record_position
  # XXX implement optimised scanning at -22 position
  [44, 22].each do |pos|
    next if pos > @io.size
    return @io.size - pos if (read 4, -pos) == EndCdRecord::PACKED_SIGNATURE
  end

  scan_from = @io.size - EndCdRecord::MAX_COMMENT_LENGTH
  scan_from = 0 if scan_from < 0
  scan_from + (read_from(scan_from).rindex(EndCdRecord::PACKED_SIGNATURE) or fail "End of Central Directory Record not found")
end