Class: Zip::OutputStream

Inherits:
Object
  • Object
show all
Includes:
IOExtras::AbstractOutputStream
Defined in:
lib/zip/output_stream.rb

Overview

ZipOutputStream is the basic class for writing zip files. It is possible to create a ZipOutputStream object directly, passing the zip file name to the constructor, but more often than not the ZipOutputStream will be obtained from a ZipFile (perhaps using the ZipFileSystem interface) object for a particular entry in the zip archive.

A ZipOutputStream inherits IOExtras::AbstractOutputStream in order to provide an IO-like interface for writing to a single zip entry. Beyond methods for mimicking an IO-object it contains the method put_next_entry that closes the current entry and creates a new.

Please refer to ZipInputStream for example code.

java.util.zip.ZipOutputStream is the original inspiration for this class.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from IOExtras::AbstractOutputStream

#print, #printf, #putc, #puts, #write

Methods included from IOExtras::FakeIO

#kind_of?

Constructor Details

#initialize(file_name, stream = false) ⇒ OutputStream

Opens the indicated zip file. If a file with that name already exists it will be overwritten.



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# File 'lib/zip/output_stream.rb', line 27

def initialize(file_name, stream=false)
  super()
  @file_name = file_name
  @output_stream = if stream
                     iostream = @file_name.dup
                     iostream.reopen
                     iostream.rewind
                     iostream
                   else
                     ::File.new(@file_name, "wb")
                   end
  @entry_set = ::Zip::EntrySet.new
  @compressor = ::Zip::NullCompressor.instance
  @closed = false
  @current_entry = nil
  @comment = nil
end

Instance Attribute Details

#comment ⇒ Object

Returns the value of attribute comment.



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# File 'lib/zip/output_stream.rb', line 23

def comment
  @comment
end

Class Method Details

.open(file_name) ⇒ Object 



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# File 'lib/zip/output_stream.rb', line 49

def open(file_name)
  return new(file_name) unless block_given?
  zos = new(file_name)
  yield zos
ensure
  zos.close if zos
end

.write_buffer(io = ::StringIO.new('')) {|zos| ... } ⇒ Object

Same as #open but writes to a filestream instead

Yields:

  • (zos) 


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# File 'lib/zip/output_stream.rb', line 58

def write_buffer(io = ::StringIO.new(''))
  zos = new(io, true)
  yield zos
  zos.close_buffer
end

Instance Method Details

#<<(data) ⇒ Object

Modeled after IO.<<



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# File 'lib/zip/output_stream.rb', line 175

def << (data)
  @compressor << data
  self
end

#close ⇒ Object

Closes the stream and writes the central directory to the zip file



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# File 'lib/zip/output_stream.rb', line 66

def close
  return if @closed
  finalize_current_entry
  update_local_headers
  write_central_directory
  @output_stream.close
  @closed = true
end

#close_buffer ⇒ Object

Closes the stream and writes the central directory to the zip file



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# File 'lib/zip/output_stream.rb', line 76

def close_buffer
  return @output_stream if @closed
  finalize_current_entry
  update_local_headers
  write_central_directory
  @closed = true
  @output_stream
end

#copy_raw_entry(entry) ⇒ Object

Raises:



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# File 'lib/zip/output_stream.rb', line 103

def copy_raw_entry(entry)
  entry = entry.dup
  raise Error, "zip stream is closed" if @closed
  raise Error, "entry is not a ZipEntry" unless entry.is_a?(Entry)
  finalize_current_entry
  @entry_set << entry
  src_pos = entry.local_header_offset
  entry.write_local_entry(@output_stream)
  @compressor = NullCompressor.instance
  entry.get_raw_input_stream do |is|
    is.seek(src_pos, IO::SEEK_SET)
    ::Zip::Entry.read_local_entry(is)
    IOExtras.copy_stream_n(@output_stream, is, entry.compressed_size)
  end
  @compressor = NullCompressor.instance
  @current_entry = nil
end

#put_next_entry(entry_name, comment = nil, extra = nil, compression_method = Entry::DEFLATED, level = Zip.default_compression) ⇒ Object

Closes the current entry and opens a new for writing. entry can be a ZipEntry object or a string.

Raises:



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# File 'lib/zip/output_stream.rb', line 87

def put_next_entry(entry_name, comment = nil, extra = nil, compression_method = Entry::DEFLATED, level = Zip.default_compression)
  raise Error, "zip stream is closed" if @closed
  if entry_name.kind_of?(Entry)
    new_entry = entry_name
  else
    new_entry = Entry.new(@file_name, entry_name.to_s)
  end
  new_entry.comment = comment unless comment.nil?
  unless extra.nil?
    new_entry.extra = ExtraField === extra ? extra : ExtraField.new(extra.to_s)
  end
  new_entry.compression_method = compression_method unless compression_method.nil?
  init_next_entry(new_entry, level)
  @current_entry = new_entry
end