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

CONTENT_LENGTH = 
'Content-Length'.freeze
TRANSFER_ENCODING = 
'Transfer-Encoding'.freeze
CHUNKED_REGEXP = 
/\bchunked\b/i.freeze
AsyncResponse =

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

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Logging

#debug, debug, debug?, #log, log, #log_error, log_error, #silent, #silent=, silent?, #trace, trace, trace?

Instance Attribute Details

#app ⇒ Object

Rack application (adapter) served by this connection.



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# File 'lib/thin/connection.rb', line 18

def app
  @app
end

#backend ⇒ Object

Backend to the server



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# File 'lib/thin/connection.rb', line 21

def backend
  @backend
end

#request ⇒ Object

Current request served by the connection



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# File 'lib/thin/connection.rb', line 24

def request
  @request
end

#response ⇒ Object

Next response sent through the connection



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# File 'lib/thin/connection.rb', line 27

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 31

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 159

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 164

def can_persist?
  @can_persist
end

#close_request_response ⇒ Object 



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# File 'lib/thin/connection.rb', line 128

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

#handle_error ⇒ Object

Logs catched exception and closes the connection.



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# File 'lib/thin/connection.rb', line 122

def handle_error
  log "!! Unexpected error while processing request: #{$!.message}"
  log_error
  close_connection rescue nil
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 170

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 34

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

#post_process(result) ⇒ Object 



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# File 'lib/thin/connection.rb', line 85

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

  # Set the Content-Length header if possible
  set_content_length(result) if need_content_length?(result)
  
  @response.status, @response.headers, @response.body = *result

  log "!! Rack application returned nil body. Probably you wanted it to be an empty string?" if @response.body.nil?

  # 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
  handle_error
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 61

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)
  
  # 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
  handle_error
  terminate_request
  nil # Signal to post_process that the request could not be processed
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 51

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 40

def receive_data(data)
  trace { data }
  process if @request.parse(data)
rescue InvalidRequest => e
  log "!! Invalid request"
  log_error e
  close_connection
end

#remote_address ⇒ Object

IP Address of the remote client.



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# File 'lib/thin/connection.rb', line 182

def remote_address
  @request.forwarded_for || socket_address
rescue Exception
  log_error
  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 138

def terminate_request
  unless persistent?
    close_connection_after_writing rescue nil
    close_request_response
  else
    close_request_response
    # 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 177

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 152

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