require 'rack/utils' module Rack # Middleware that applies chunked transfer encoding to response bodies # when the response does not include a Content-Length header. class Chunked include Rack::Utils # A body wrapper that emits chunked responses class Body TERM = "\r\n" TAIL = "0#{TERM}#{TERM}" include Rack::Utils def initialize(body) @body = body end def each term = TERM @body.each do |chunk| size = bytesize(chunk) next if size == 0 chunk = chunk.dup.force_encoding(Encoding::BINARY) if chunk.respond_to?(:force_encoding) yield [size.to_s(16), term, chunk, term].join end yield TAIL end def close @body.close if @body.respond_to?(:close) end end def initialize(app) @app = app end def call(env) status, headers, body = @app.call(env) headers = HeaderHash.new(headers) if env['HTTP_VERSION'] == 'HTTP/1.0' || STATUS_WITH_NO_ENTITY_BODY.include?(status) || headers['Content-Length'] || headers['Transfer-Encoding'] [status, headers, body] else headers.delete('Content-Length') headers['Transfer-Encoding'] = 'chunked' [status, headers, Body.new(body)] end end end end