+module ActionController
+ class RewindableInput
+ class RewindableIO < ActiveSupport::BasicObject
+ def initialize(io)
+ @io = io
+ @rewindable = io.is_a?(::StringIO)
+ end
+
+ def method_missing(method, *args, &block)
+ unless @rewindable
+ @io = ::StringIO.new(@io.read)
+ @rewindable = true
+ end
+
+ @io.__send__(method, *args, &block)
+ end
+ end
+
+ def initialize(app)
+ @app = app
+ end
+
+ def call(env)
+ env['rack.input'] = RewindableIO.new(env['rack.input'])
+ @app.call(env)
+ end
+ end
+end