Class: ZipTricks::FileReader::ZipEntry

Inherits:
Object
  • Object
show all
Defined in:
lib/zip_tricks/file_reader.rb

Overview

Represents a file within the ZIP archive being read. This is different from the Entry object used in Streamer for ZIP writing, since during writing more data can be kept in memory for immediate use.

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#comment ⇒ String

Returns the file comment.

Returns:

  • (String) —

    the file comment



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# File 'lib/zip_tricks/file_reader.rb', line 133

def comment
  @comment
end

#compressed_size ⇒ Fixnum

Returns size of compressed file data in the ZIP.

Returns:

  • (Fixnum) —

    size of compressed file data in the ZIP



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# File 'lib/zip_tricks/file_reader.rb', line 111

def compressed_size
  @compressed_size
end

#crc32 ⇒ Fixnum

Returns the CRC32 checksum of this file.

Returns:

  • (Fixnum) —

    the CRC32 checksum of this file



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# File 'lib/zip_tricks/file_reader.rb', line 108

def crc32
  @crc32
end

#disk_number_start ⇒ Fixnum

Returns disk number where this file starts.

Returns:

  • (Fixnum) —

    disk number where this file starts



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# File 'lib/zip_tricks/file_reader.rb', line 120

def disk_number_start
  @disk_number_start
end

#dos_date ⇒ Fixnum

Returns the bit-packed DOS date.

Returns:

  • (Fixnum) —

    the bit-packed DOS date



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# File 'lib/zip_tricks/file_reader.rb', line 105

def dos_date
  @dos_date
end

#dos_time ⇒ Fixnum

Returns the bit-packed DOS time.

Returns:

  • (Fixnum) —

    the bit-packed DOS time



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# File 'lib/zip_tricks/file_reader.rb', line 102

def dos_time
  @dos_time
end

#external_attrs ⇒ Fixnum

Returns external attributes of the file.

Returns:

  • (Fixnum) —

    external attributes of the file



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# File 'lib/zip_tricks/file_reader.rb', line 126

def external_attrs
  @external_attrs
end

#filename ⇒ String

Returns the filename.

Returns:

  • (String) —

    the filename



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# File 'lib/zip_tricks/file_reader.rb', line 117

def filename
  @filename
end

#gp_flags ⇒ Fixnum

Returns bit-packed general purpose flags.

Returns:

  • (Fixnum) —

    bit-packed general purpose flags



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# File 'lib/zip_tricks/file_reader.rb', line 96

def gp_flags
  @gp_flags
end

#internal_attrs ⇒ Fixnum

Returns internal attributes of the file.

Returns:

  • (Fixnum) —

    internal attributes of the file



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# File 'lib/zip_tricks/file_reader.rb', line 123

def internal_attrs
  @internal_attrs
end

#local_file_header_offset ⇒ Fixnum

Returns at what offset the local file header starts in your original IO object.

Returns:

  • (Fixnum) —

    at what offset the local file header starts in your original IO object



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# File 'lib/zip_tricks/file_reader.rb', line 130

def local_file_header_offset
  @local_file_header_offset
end

#made_by ⇒ Fixnum

Returns bit-packed version signature of the program that made the archive.

Returns:

  • (Fixnum) —

    bit-packed version signature of the program that made the archive



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# File 'lib/zip_tricks/file_reader.rb', line 90

def made_by
  @made_by
end

#storage_mode ⇒ Fixnum

Returns Storage mode (0 for stored, 8 for deflate).

Returns:

  • (Fixnum) —

    Storage mode (0 for stored, 8 for deflate)



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# File 'lib/zip_tricks/file_reader.rb', line 99

def storage_mode
  @storage_mode
end

#uncompressed_size ⇒ Fixnum

Returns size of the file once uncompressed.

Returns:

  • (Fixnum) —

    size of the file once uncompressed



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# File 'lib/zip_tricks/file_reader.rb', line 114

def uncompressed_size
  @uncompressed_size
end

#version_needed_to_extract ⇒ Fixnum

Returns ZIP version support needed to extract this file.

Returns:

  • (Fixnum) —

    ZIP version support needed to extract this file



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# File 'lib/zip_tricks/file_reader.rb', line 93

def version_needed_to_extract
  @version_needed_to_extract
end

Instance Method Details

#compressed_data_offset ⇒ Fixnum

Returns at what offset you should start reading for the compressed data in your original IO object.

Returns:

  • (Fixnum) —

    at what offset you should start reading for the compressed data in your original IO object



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# File 'lib/zip_tricks/file_reader.rb', line 156

def compressed_data_offset
  @compressed_data_offset || raise(LocalHeaderPending)
end

#compressed_data_offset=(offset) ⇒ Object

Sets the offset at which the compressed data for this file starts in the ZIP. By default, the value will be set by the Reader for you. If you use delayed reading, you need to set it by using the get_compressed_data_offset on the Reader:

entry.compressed_data_offset = reader.get_compressed_data_offset(io: file,
       local_file_header_offset: entry.local_header_offset)



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# File 'lib/zip_tricks/file_reader.rb', line 178

def compressed_data_offset=(offset)
  @compressed_data_offset = offset.to_i
end

#extractor_from(from_io) ⇒ #extract(n_bytes), #eof?

Returns a reader for the actual compressed data of the entry.

reader = entry.extractor_from(source_file) outfile << reader.extract(512 * 1024) until reader.eof?

Returns:

  • (#extract(n_bytes), #eof?) —

    the reader for the data



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# File 'lib/zip_tricks/file_reader.rb', line 141

def extractor_from(from_io)
  from_io.seek(compressed_data_offset, IO::SEEK_SET)
  case storage_mode
  when 8
    InflatingReader.new(from_io, compressed_size)
  when 0
    StoredReader.new(from_io, compressed_size)
  else
    raise UnsupportedFeature, 'Unsupported storage mode for reading - %<storage_mode>d' %
                              {storage_mode: storage_mode}
  end
end

#known_offset? ⇒ Boolean

Tells whether the compressed data offset is already known for this entry

Returns:

  • (Boolean) 


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# File 'lib/zip_tricks/file_reader.rb', line 162

def known_offset?
  !@compressed_data_offset.nil?
end

#uses_data_descriptor? ⇒ Boolean

Tells whether the entry uses a data descriptor (this is defined by bit 3 in the GP flags).

Returns:

  • (Boolean) 


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# File 'lib/zip_tricks/file_reader.rb', line 168

def uses_data_descriptor?
  (gp_flags & 0x0008) == 0x0008
end