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.



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

def initialize(socket)
  @socket = socket
  @body = StringIO.new
  @status = 404
  @header = HeaderOut.new(StringIO.new)
end

Instance Attribute Details

#body ⇒ Object (readonly)

Returns the value of attribute body.



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

def body
  @body
end

#header ⇒ Object (readonly)

Returns the value of attribute header.



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

def header
  @header
end

#socket ⇒ Object (readonly)

Returns the value of attribute socket.



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# File 'lib/mongrel.rb', line 253

def socket
  @socket
end

#status ⇒ Object

Returns the value of attribute status.



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

def status
  @status
end

Instance Method Details

#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.



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# File 'lib/mongrel.rb', line 302

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.



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# File 'lib/mongrel.rb', line 278

def reset
  @header.out.rewind
  @body.rewind
end

#send_body ⇒ Object 



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# File 'lib/mongrel.rb', line 294

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

#send_header ⇒ Object 



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# File 'lib/mongrel.rb', line 288

def send_header
  @header.out.rewind
  @socket.write(@header.out.read)
  @socket.write("\r\n")
end

#send_status ⇒ Object 



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# File 'lib/mongrel.rb', line 283

def send_status
  status = "HTTP/1.1 #{@status} #{HTTP_STATUS_CODES[@status]}\r\nContent-Length: #{@body.length}\r\nConnection: close\r\n"
  @socket.write(status)
end

#start(status = 200) {|@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.

Yields:



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# File 'lib/mongrel.rb', line 270

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