Class: Mongrel::HttpResponse

Inherits:
Object
  • Object
show all
Defined in:
lib/mongrel.rb

Overview

Writes and controls your response to the client using the HTTP/1.1 specification. You use it by simply doing:

response.start(200) do |head,out|
  head['Content-Type'] = 'text/plain'
  out.write("hello\n")
end

The parameter to start is the response code–which Mongrel will translate for you based on HTTP_STATUS_CODES. The head parameter is how you write custom headers. The out parameter is where you write your body. The default status code for HttpResponse.start is 200 so the above example is redundant.

As you can see, it’s just like using a Hash and as you do this it writes the proper header to the output on the fly. You can even intermix specifying headers and writing content. The HttpResponse class with write the things in the proper order once the HttpResponse.block is ended.

You may also work the HttpResponse object directly using the various attributes available for the raw socket, body, header, and status codes. If you do this you’re on your own. A design decision was made to force the client to not pipeline requests. HTTP/1.1 pipelining really kills the performance due to how it has to be handled and how unclear the standard is. To fix this the HttpResponse gives a “Connection: close” header which forces the client to close right away. The bonus for this is that it gives a pretty nice speed boost to most clients since they can close their connection immediately.

One additional caveat is that you don’t have to specify the Content-length header as the HttpResponse will write this for you based on the out length.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(socket) ⇒ HttpResponse

Returns a new instance of HttpResponse.



263
264
265
266
267
268
269
270
271
272
 
# File 'lib/mongrel.rb', line 263

def initialize(socket)
  @socket = socket
  @body = StringIO.new
  @status = 404
  @header = HeaderOut.new(StringIO.new)
  @header[Const::DATE] = Time.now.httpdate
  @body_sent = false
  @header_sent = false
  @status_sent = false
end

Instance Attribute Details

#body ⇒ Object (readonly)

Returns the value of attribute body.



255
256
257
 
# File 'lib/mongrel.rb', line 255

def body
  @body
end

#body_sent ⇒ Object (readonly)

Returns the value of attribute body_sent.



259
260
261
 
# File 'lib/mongrel.rb', line 259

def body_sent
  @body_sent
end

#header ⇒ Object (readonly)

Returns the value of attribute header.



256
257
258
 
# File 'lib/mongrel.rb', line 256

def header
  @header
end

#header_sent ⇒ Object (readonly)

Returns the value of attribute header_sent.



260
261
262
 
# File 'lib/mongrel.rb', line 260

def header_sent
  @header_sent
end

#socket ⇒ Object (readonly)

Returns the value of attribute socket.



254
255
256
 
# File 'lib/mongrel.rb', line 254

def socket
  @socket
end

#status ⇒ Object

Returns the value of attribute status.



257
258
259
 
# File 'lib/mongrel.rb', line 257

def status
  @status
end

#status_sent ⇒ Object (readonly)

Returns the value of attribute status_sent.



261
262
263
 
# File 'lib/mongrel.rb', line 261

def status_sent
  @status_sent
end

Instance Method Details

#done ⇒ Object 



339
340
341
 
# File 'lib/mongrel.rb', line 339

def done
  (@status_sent and @header_sent and @body_sent)
end

#finished ⇒ Object

This takes whatever has been done to header and body and then writes it in the proper format to make an HTTP/1.1 response.



333
334
335
336
337
 
# File 'lib/mongrel.rb', line 333

def finished
  send_status
  send_header
  send_body
end

#reset ⇒ Object

Primarily used in exception handling to reset the response output in order to write an alternative response. It will abort with an exception if you have already sent the header or the body. This is pretty catastrophic actually.



291
292
293
294
295
296
297
298
299
300
 
# File 'lib/mongrel.rb', line 291

def reset
  if @body_sent
    raise "You have already sent the request body."
  elsif @header_sent
    raise "You have already sent the request headers."
  else
    @header.out.rewind
    @body.rewind
  end
end

#send_body ⇒ Object 



318
319
320
321
322
323
324
325
 
# File 'lib/mongrel.rb', line 318

def send_body
  if not @body_sent
    @body.rewind
    # connection: close is also added to ensure that the client does not pipeline.
    @socket.write(@body.read)
    @body_sent = true
  end
end

#send_header ⇒ Object 



310
311
312
313
314
315
316
 
# File 'lib/mongrel.rb', line 310

def send_header
  if not @header_sent
    @header.out.rewind
    @socket.write(@header.out.read + Const::LINE_END)
    @header_sent = true
  end
end

#send_status(content_length = nil) ⇒ Object 



302
303
304
305
306
307
308
 
# File 'lib/mongrel.rb', line 302

def send_status(content_length=nil)
  if not @status_sent
	content_length ||= @body.length
    @socket.write(Const::STATUS_FORMAT % [status, HTTP_STATUS_CODES[@status], content_length])
    @status_sent = true
  end
end

#start(status = 200, finalize = false) {|@header, @body| ... } ⇒ Object

Receives a block passing it the header and body for you to work with. When the block is finished it writes everything you’ve done to the socket in the proper order. This lets you intermix header and body content as needed. Handlers are able to modify pretty much any part of the request in the chain, and can stop further processing by simple passing “finalize=true” to the start method. By default all handlers run and then mongrel finalizes the request when they’re all done.

Yields:



282
283
284
285
286
 
# File 'lib/mongrel.rb', line 282

def start(status=200, finalize=false)
  @status = status.to_i
  yield @header, @body
  finished if finalize
end

#write(data) ⇒ Object 



327
328
329
 
# File 'lib/mongrel.rb', line 327

def write(data)
  @socket.write(data)
end