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.
rack.input is required to be rewindable, so if your input stream IO is non-rewindable by nature (e.g. a pipe or a socket) then you can wrap it in an object of this class to easily make it 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.
# File lib/rack/rewindable_input.rb, line 15 def initialize(io) @io = io @rewindable_io = nil @unlinked = false end
Closes this RewindableInput object without closing the originally wrapped IO oject. Cleans up any temporary resources that this RewindableInput has created.
This method may be called multiple times. It does nothing on subsequent calls.
# File lib/rack/rewindable_input.rb, line 46 def close if @rewindable_io if @unlinked @rewindable_io.close else @rewindable_io.close! end @rewindable_io = nil end end
# File lib/rack/rewindable_input.rb, line 31 def each(&block) make_rewindable unless @rewindable_io @rewindable_io.each(&block) end
# File lib/rack/rewindable_input.rb, line 21 def gets make_rewindable unless @rewindable_io @rewindable_io.gets end
# File lib/rack/rewindable_input.rb, line 26 def read(*args) make_rewindable unless @rewindable_io @rewindable_io.read(*args) end
# File lib/rack/rewindable_input.rb, line 36 def rewind make_rewindable unless @rewindable_io @rewindable_io.rewind end
# File lib/rack/rewindable_input.rb, line 99 def filesystem_has_posix_semantics? RUBY_PLATFORM !~ /(mswin|mingw|cygwin|java)/ end
# File lib/rack/rewindable_input.rb, line 68 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) if @rewindable_io.respond_to?(:set_encoding) @rewindable_io.binmode if filesystem_has_posix_semantics? # Use ::File.unlink as 1.9.1 Tempfile has a bug where unlink closes the file! ::File.unlink @rewindable_io.path raise 'Unlink failed. IO closed.' if @rewindable_io.closed? @unlinked = true end buffer = "" 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 == Rack::Utils.bytesize(buffer) if !entire_buffer_written_out buffer.slice!(0 .. written - 1) end end end @rewindable_io.rewind end