Class: Thin::Connection

Inherits:
EventMachine::Connection
  • Object
show all
Includes:
Logging
Defined in:
lib/thin/connection.rb

Overview

Connection between the server and client. This class is instanciated by EventMachine on each new connection that is opened.

Direct Known Subclasses

SwiftiplyConnection, UnixConnection

Constant Summary collapse

AsyncResponse =

This is a template async response. N.B. Can’t use string for body on 1.9

[-1, {}, []].freeze
EMPTY_BODY = 
[].freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Logging

debug=, debug?, level, level=, #log, log_debug, #log_debug, log_error, #log_error, #log_info, log_info, log_msg, #silent, #silent=, silent=, silent?, #trace, trace, trace=, trace?, trace_msg

Instance Attribute Details

#app ⇒ Object

Rack application (adapter) served by this connection.



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# File 'lib/thin/connection.rb', line 16

def app
  @app
end

#backend ⇒ Object

Backend to the server



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# File 'lib/thin/connection.rb', line 19

def backend
  @backend
end

#request ⇒ Object

Current request served by the connection



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# File 'lib/thin/connection.rb', line 22

def request
  @request
end

#response ⇒ Object

Next response sent through the connection



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# File 'lib/thin/connection.rb', line 25

def response
  @response
end

#threaded=(value) ⇒ Object (writeonly)

Calling the application in a threaded allowing concurrent processing of requests.



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# File 'lib/thin/connection.rb', line 29

def threaded=(value)
  @threaded = value
end

Instance Method Details

#can_persist! ⇒ Object

Allows this connection to be persistent.



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# File 'lib/thin/connection.rb', line 168

def can_persist!
  @can_persist = true
end

#can_persist? ⇒ Boolean

Return true if this connection is allowed to stay open and be persistent.

Returns:

  • (Boolean) 


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# File 'lib/thin/connection.rb', line 173

def can_persist?
  @can_persist
end

#close_request_response ⇒ Object 



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# File 'lib/thin/connection.rb', line 135

def close_request_response
  @request.async_close.succeed if @request.async_close
  @request.close  rescue nil
  @response.close rescue nil
end

#idle? ⇒ Boolean

Return true if the connection is open but is not processing any user requests

Returns:

  • (Boolean) 


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# File 'lib/thin/connection.rb', line 185

def idle?
  @idle
end

#persistent? ⇒ Boolean

Return true if the connection must be left open and ready to be reused for another request.

Returns:

  • (Boolean) 


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# File 'lib/thin/connection.rb', line 179

def persistent?
  @can_persist && @response.persistent?
end

#post_init ⇒ Object

Get the connection ready to process a request.



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# File 'lib/thin/connection.rb', line 32

def post_init
  @request  = Request.new
  @response = Response.new
end

#post_process(result) ⇒ Object 



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# File 'lib/thin/connection.rb', line 91

def post_process(result)
  return unless result
  result = result.to_a

  # Status code -1 indicates that we're going to respond later (async).
  return if result.first == AsyncResponse.first

  @response.status, @response.headers, @response.body = *result

  log_error("Rack application returned nil body. " \
            "Probably you wanted it to be an empty string?") if @response.body.nil?

  # HEAD requests should not return a body.
  @response.body = EMPTY_BODY if @request.head?

  # Make the response persistent if requested by the client
  @response.persistent! if @request.persistent?

  # Send the response
  @response.each do |chunk|
    trace chunk
    send_data chunk
  end

rescue Exception => e
  unexpected_error(e)
  # Close connection since we can't handle response gracefully
  close_connection
ensure
  # If the body is being deferred, then terminate afterward.
  if @response.body.respond_to?(:callback) && @response.body.respond_to?(:errback)
    @response.body.callback { terminate_request }
    @response.body.errback  { terminate_request }
  else
    # Don't terminate the response if we're going async.
    terminate_request unless result && result.first == AsyncResponse.first
  end
end

#pre_process ⇒ Object 



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# File 'lib/thin/connection.rb', line 59

def pre_process
  # Add client info to the request env
  @request.remote_address = remote_address

  # Connection may be closed unless the App#call response was a [-1, ...]
  # It should be noted that connection objects will linger until this
  # callback is no longer referenced, so be tidy!
  @request.async_callback = method(:post_process)

  if @backend.ssl?
    @request.env["rack.url_scheme"] = "https"

    if cert = get_peer_cert
      @request.env['rack.peer_cert'] = cert
    end
  end

  # When we're under a non-async framework like rails, we can still spawn
  # off async responses using the callback info, so there's little point
  # in removing this.
  response = AsyncResponse
  catch(:async) do
    # Process the request calling the Rack adapter
    response = @app.call(@request.env)
  end
  response
rescue Exception => e
  unexpected_error(e)
  # Pass through error response
  can_persist? && @request.persistent? ? Response::PERSISTENT_ERROR : Response::ERROR
end

#process ⇒ Object

Called when all data was received and the request is ready to be processed.



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# File 'lib/thin/connection.rb', line 49

def process
  if threaded?
    @request.threaded = true
    EventMachine.defer(method(:pre_process), method(:post_process))
  else
    @request.threaded = false
    post_process(pre_process)
  end
end

#receive_data(data) ⇒ Object

Called when data is received from the client.



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# File 'lib/thin/connection.rb', line 38

def receive_data(data)
  @idle = false
  trace data
  process if @request.parse(data)
rescue InvalidRequest => e
  log_error("Invalid request", e)
  post_process Response::BAD_REQUEST
end

#remote_address ⇒ Object

IP Address of the remote client.



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# File 'lib/thin/connection.rb', line 197

def remote_address
  socket_address
rescue Exception => e
  log_error('Could not infer remote address', e)
  nil
end

#terminate_request ⇒ Object

Does request and response cleanup (closes open IO streams and deletes created temporary files). Re-initializes response and request if client supports persistent connection.



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# File 'lib/thin/connection.rb', line 145

def terminate_request
  unless persistent?
    close_connection_after_writing rescue nil
    close_request_response
  else
    close_request_response
    # Connection become idle but it's still open
    @idle = true
    # Prepare the connection for another request if the client
    # supports HTTP pipelining (persistent connection).
    post_init
  end
end

#threaded? ⇒ Boolean

true if app.call will be called inside a thread. You can set all requests as threaded setting Connection#threaded=true or on a per-request case returning true in app.deferred?.

Returns:

  • (Boolean) 


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# File 'lib/thin/connection.rb', line 192

def threaded?
  @threaded || (@app.respond_to?(:deferred?) && @app.deferred?(@request.env))
end

#unbind ⇒ Object

Called when the connection is unbinded from the socket and can no longer be used to process requests.



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# File 'lib/thin/connection.rb', line 161

def unbind
  @request.async_close.succeed if @request.async_close
  @response.body.fail if @response.body.respond_to?(:fail)
  @backend.connection_finished(self)
end

#unexpected_error(e) ⇒ Object

Logs information about an unexpected exceptional condition



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# File 'lib/thin/connection.rb', line 131

def unexpected_error(e)
  log_error("Unexpected error while processing request", e)
end