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/phusion_passenger/utils/rewindable_input.rb, line 18 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/phusion_passenger/utils/rewindable_input.rb, line 54 def close if @rewindable_io if @unlinked @rewindable_io.close else @rewindable_io.close! end @rewindable_io = nil end end
# File lib/phusion_passenger/utils/rewindable_input.rb, line 34 def each(&block) make_rewindable unless @rewindable_io @rewindable_io.each(&block) end
# File lib/phusion_passenger/utils/rewindable_input.rb, line 24 def gets make_rewindable unless @rewindable_io @rewindable_io.gets end
# File lib/phusion_passenger/utils/rewindable_input.rb, line 29 def read(*args) make_rewindable unless @rewindable_io @rewindable_io.read(*args) end
# File lib/phusion_passenger/utils/rewindable_input.rb, line 39 def rewind make_rewindable unless @rewindable_io @rewindable_io.rewind end
# File lib/phusion_passenger/utils/rewindable_input.rb, line 44 def size make_rewindable unless @rewindable_io @rewindable_io.size end
# File lib/phusion_passenger/utils/rewindable_input.rb, line 109 def filesystem_has_posix_semantics? RUBY_PLATFORM !~ /(mswin|mingw|cygwin|java)/ end
# File lib/phusion_passenger/utils/rewindable_input.rb, line 80 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? && !tempfile_unlink_contains_bug? @rewindable_io.unlink @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 == buffer.size if !entire_buffer_written_out buffer.slice!(0 .. written - 1) end end end @rewindable_io.rewind end
# File lib/phusion_passenger/utils/rewindable_input.rb, line 113 def tempfile_unlink_contains_bug? # The tempfile library as included in Ruby 1.9.1-p152 and later # contains a bug: unlinking an open Tempfile object also closes # it, which breaks our expected POSIX semantics. This problem # has been fixed in Ruby 1.9.2, but the Ruby team chose not to # include the bug fix in later versions of the 1.9.1 series. ruby_engine = defined?(RUBY_ENGINE) ? RUBY_ENGINE : "ruby" ruby_engine == "ruby" && RUBY_VERSION == "1.9.1" && RUBY_PATCHLEVEL >= 152 end