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Class: Rack::RewindableInput

Relationships & Source Files
Namespace Children
Classes:
Middleware
Inherits: Object
Defined in: lib/rack/rewindable_input.rb

Overview

Class which can make any IO object rewindable, including non-rewindable ones. It does this by buffering the data into a tempfile, which is rewindable.

Don’t forget to call #close when you’re done. This frees up temporary resources that RewindableInput uses, though it does not close the original IO object.

Class Method Summary

Instance Attribute Summary

Instance Method Summary

Constructor Details

.new(io) ⇒ RewindableInput

[ GitHub ] 

  


# File 'lib/rack/rewindable_input.rb', line 32



def initialize(io)
  @io = io
  @rewindable_io = nil
  @unlinked = false
end


  







Instance Attribute Details



  

    #filesystem_has_posix_semantics?  ⇒ Boolean  (readonly, private)
  

  [ GitHub ]


  

  


# File 'lib/rack/rewindable_input.rb', line 112



def filesystem_has_posix_semantics?
  RUBY_PLATFORM !~ /(mswin|mingw|cygwin|java)/
end


  







Instance Method Details



  

    #close  
  



  

    

Closes this RewindableInput object without closing the originally wrapped IO object. Cleans up any temporary resources that this RewindableInput has created.



This method may be called multiple times. It does nothing on subsequent calls.


  



  [ GitHub ]


  

  


# File 'lib/rack/rewindable_input.rb', line 68



def close
  if @rewindable_io
    if @unlinked
      @rewindable_io.close
    else
      @rewindable_io.close!
    end
    @rewindable_io = nil
  end
end


  








  

    #each(&block)  
  

  [ GitHub ]


  

  


# File 'lib/rack/rewindable_input.rb', line 48



def each(&block)
  make_rewindable unless @rewindable_io
  @rewindable_io.each(&block)
end


  








  

    #gets  
  

  [ GitHub ]


  

  


# File 'lib/rack/rewindable_input.rb', line 38



def gets
  make_rewindable unless @rewindable_io
  @rewindable_io.gets
end


  








  

    #make_rewindable   (private)
  

  [ GitHub ]


  

  


# File 'lib/rack/rewindable_input.rb', line 81



def make_rewindable
  # Buffer all data into a tempfile. Since this tempfile is private to this
  # RewindableInput object, we chmod it so that nobody else can read or write
  # it. On POSIX filesystems we also unlink the file so that it doesn't
  # even have a file entry on the filesystem anymore, though we can still
  # access it because we have the file handle open.
  @rewindable_io = Tempfile.new('RackRewindableInput')
  @rewindable_io.chmod(0000)
  @rewindable_io.set_encoding(Encoding::BINARY)
  @rewindable_io.binmode
  # :nocov:
  if filesystem_has_posix_semantics?
    raise 'Unlink failed. IO closed.' if @rewindable_io.closed?
    @unlinked = true
  end
  # :nocov:

  buffer = "".dup
  while @io.read(1024 * 4, buffer)
    entire_buffer_written_out = false
    while !entire_buffer_written_out
      written = @rewindable_io.write(buffer)
      entire_buffer_written_out = written == buffer.bytesize
      if !entire_buffer_written_out
        buffer.slice!(0 .. written - 1)
      end
    end
  end
  @rewindable_io.rewind
end


  








  

    #read(*args)  
  

  [ GitHub ]


  

  


# File 'lib/rack/rewindable_input.rb', line 43



def read(*args)
  make_rewindable unless @rewindable_io
  @rewindable_io.read(*args)
end


  








  

    #rewind  
  

  [ GitHub ]


  

  


# File 'lib/rack/rewindable_input.rb', line 53



def rewind
  make_rewindable unless @rewindable_io
  @rewindable_io.rewind
end


  








  

    #size  
  

  [ GitHub ]


  

  


# File 'lib/rack/rewindable_input.rb', line 58



def size
  make_rewindable unless @rewindable_io
  @rewindable_io.size
end