Class: HTTPX::Connection

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Includes:
Callbacks, Loggable
Defined in:
lib/httpx/connection.rb

Overview

The Connection can be watched for IO events.

It contains the io object to read/write from, and knows what to do when it can.

It defers connecting until absolutely necessary. Connection should be triggered from the IO selector (until then, any request will be queued).

A connection boots up its parser after connection is established. All pending requests will be redirected there after connection.

A connection can be prevented from closing by the parser, that is, if there are pending requests. This will signal that the connection was prematurely closed, due to a possible number of conditions:

  • Remote peer closed the connection (“Connection: close”);

  • Remote peer doesn’t support pipelining;

A connection may also route requests for a different host for which the io was connected to, provided that the IP is the same and the port and scheme as well. This will allow to share the same socket to send HTTP/2 requests to different hosts.

Defined Under Namespace

Classes: HTTP1, HTTP2

Constant Summary

Constants included from Loggable

Loggable::COLORS, Loggable::USE_DEBUG_LOG

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Callbacks

#callbacks_for?, #emit, #on, #once

Methods included from Loggable

#log, #log_exception, #log_redact, #log_redact_body, #log_redact_headers

Constructor Details

#initialize(uri, options) ⇒ Connection

Returns a new instance of Connection.



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# File 'lib/httpx/connection.rb', line 47

def initialize(uri, options)
  @current_session = @current_selector = @max_concurrent_requests =
                       @parser = @sibling = @coalesced_connection = @altsvc_connection =
                                              @ping_timer = @family = @io = @ssl_session =
                                                                        @timeout = @connected_at = @response_received_at = nil

  @exhausted = @cloned = @main_sibling = false

  @options = Options.new(options)
  @type = initialize_type(uri, @options)
  @origins = [uri.origin]
  @origin = Utils.to_uri(uri.origin)
  @window_size = @options.window_size
  @read_buffer = Buffer.new(@options.buffer_size)
  @write_buffer = Buffer.new(@options.buffer_size)
  @pending = []
  @inflight = 0
  @keep_alive_timeout = @options.timeout[:keep_alive_timeout]
  @no_more_requests_counter = 0

  if @options.io
    # if there's an already open IO, get its
    # peer address, and force-initiate the parser
    transition(:already_open)
    @io = build_socket
    parser
  else
    transition(:idle)
  end
  self.addresses = @options.addresses if @options.addresses
end

Instance Attribute Details

#current_selector=(value) ⇒ Object (writeonly)

Sets the attribute current_selector

Parameters:

  • value —

    the value to set the attribute current_selector to.



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# File 'lib/httpx/connection.rb', line 41

def current_selector=(value)
  @current_selector = value
end

#current_session ⇒ Object

Returns the value of attribute current_session.



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# File 'lib/httpx/connection.rb', line 43

def current_session
  @current_session
end

#family ⇒ Object

Returns the value of attribute family.



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# File 'lib/httpx/connection.rb', line 43

def family
  @family
end

#io ⇒ Object (readonly)

Returns the value of attribute io.



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# File 'lib/httpx/connection.rb', line 39

def io
  @io
end

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/httpx/connection.rb', line 39

def options
  @options
end

#origin ⇒ Object (readonly)

Returns the value of attribute origin.



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# File 'lib/httpx/connection.rb', line 39

def origin
  @origin
end

#origins ⇒ Object (readonly)

Returns the value of attribute origins.



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# File 'lib/httpx/connection.rb', line 39

def origins
  @origins
end

#pending ⇒ Object (readonly)

Returns the value of attribute pending.



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# File 'lib/httpx/connection.rb', line 39

def pending
  @pending
end

#sibling=(connection) ⇒ Object 



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# File 'lib/httpx/connection.rb', line 395

def sibling=(connection)
  @sibling = connection

  return unless connection

  @main_sibling = connection.sibling.nil?

  return unless @main_sibling

  connection.sibling = self
end

#state ⇒ Object (readonly)

Returns the value of attribute state.



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# File 'lib/httpx/connection.rb', line 39

def state
  @state
end

#type ⇒ Object (readonly)

Returns the value of attribute type.



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# File 'lib/httpx/connection.rb', line 39

def type
  @type
end

Instance Method Details

#addresses ⇒ Object 



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# File 'lib/httpx/connection.rb', line 93

def addresses
  @io && @io.addresses
end

#addresses=(addrs) ⇒ Object

this is a semi-private method, to be used by the resolver to initiate the io object.



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

def addresses=(addrs)
  if @io
    @io.add_addresses(addrs)
  else
    @io = build_socket(addrs)
  end
end

#addresses? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/httpx/connection.rb', line 97

def addresses?
  @io && @io.addresses?
end

#call ⇒ Object 



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# File 'lib/httpx/connection.rb', line 215

def call
  case @state
  when :idle
    connect

    # when opening the tcp or ssl socket fails
    return if @state == :closed

    consume
  when :closed
    return if @pending.empty?

    # there are pending requests to send, restart the state machine.
    idling

    # @fiber-switch-guard
    # fiber may have switch after ensuring that @io is closed.
    return unless @state == :idle

    call
  when :closing
    consume
    transition(:closed)

    # @fiber-switch-guard
    # fiber may have switch while closing @io.
    return if @state == :closed &&
              # only remain here if there are pending requests.
              @pending.empty?

    call
  when :open
    consume
  end
  nil
rescue IOError => e
  @write_buffer.clear
  on_io_error(e)
rescue StandardError => e
  @write_buffer.clear
  on_error(e)
rescue Exception => e # rubocop:disable Lint/RescueException
  force_close(true)
  raise e
end

#close ⇒ Object 



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# File 'lib/httpx/connection.rb', line 261

def close
  transition(:active) if @state == :inactive

  @parser.close if @parser
end

#coalescable?(connection) ⇒ Boolean

coalescable connections need to be mergeable! but internally, #mergeable? is called before #coalescable?

Returns:

  • (Boolean) 


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# File 'lib/httpx/connection.rb', line 138

def coalescable?(connection)
  if @io.protocol == "h2" &&
     @origin.scheme == "https" &&
     connection.origin.scheme == "https" &&
     @io.can_verify_peer?
    @io.verify_hostname(connection.origin.host)
  else
    @origin == connection.origin
  end
end

#coalesce!(connection) ⇒ Object

coalesces self into connection.



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# File 'lib/httpx/connection.rb', line 125

def coalesce!(connection)
  @coalesced_connection = connection

  close_sibling
  connection.merge(self)
end

#coalesced? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/httpx/connection.rb', line 132

def coalesced?
  @coalesced_connection
end

#connecting? ⇒ Boolean

Returns:

  • (Boolean) 


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

def connecting?
  @state == :idle
end

#deactivate ⇒ Object 



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# File 'lib/httpx/connection.rb', line 381

def deactivate
  transition(:inactive)
end

#disconnect ⇒ Object

disconnects from the current session it’s attached to



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# File 'lib/httpx/connection.rb', line 416

def disconnect
  return if @exhausted # it'll reset

  return unless (current_session = @current_session) && (current_selector = @current_selector)

  @current_session = @current_selector = nil

  current_session.deselect_connection(self, current_selector, @cloned)
end

#force_close(delete_pending = false) ⇒ Object

bypasses state machine rules while setting the connection in the :closed state.



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# File 'lib/httpx/connection.rb', line 286

def force_close(delete_pending = false)
  force_purge
  return unless @state == :closed

  if delete_pending
    @pending.clear
  elsif (parser = @parser)
    enqueue_pending_requests_from_parser(parser)
  end

  return unless @pending.empty?

  disconnect
  emit(:force_closed, delete_pending)
end

#force_reset(cloned = false) ⇒ Object

bypasses the state machine to force closing of connections still connecting. only used for Happy Eyeballs v2.



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# File 'lib/httpx/connection.rb', line 304

def force_reset(cloned = false)
  @state = :closing
  @cloned = cloned
  transition(:closed)
end

#handle_connect_error(error) ⇒ Object 



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# File 'lib/httpx/connection.rb', line 407

def handle_connect_error(error)
  return on_error(error) unless @sibling && @sibling.connecting?

  @sibling.merge(self)

  force_reset(true)
end

#handle_socket_timeout(interval) ⇒ Object 



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# File 'lib/httpx/connection.rb', line 389

def handle_socket_timeout(interval)
  error = OperationTimeoutError.new(interval, "timed out while waiting on select")
  error.set_backtrace(caller)
  on_error(error)
end

#idling ⇒ Object 



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# File 'lib/httpx/connection.rb', line 364

def idling
  purge_after_closed

  return unless @state == :closed

  @write_buffer.clear
  transition(:idle)
  return unless @parser

  enqueue_pending_requests_from_parser(parser)
  @parser = nil
end

#inflight? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/httpx/connection.rb', line 186

def inflight?
  @parser && (
    # parser may be dealing with other requests (possibly started from a different fiber)
    !@parser.empty? ||
    # connection may be doing connection termination handshake
    !@write_buffer.empty?
  )
end

#inspect ⇒ Object

:nocov:



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# File 'lib/httpx/connection.rb', line 460

def inspect
  "#<#{self.class}:#{object_id} " \
    "@origin=#{@origin} " \
    "@state=#{@state} " \
    "@pending=#{@pending.size} " \
    "@io=#{@io}>"
end

#interests ⇒ Object 



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# File 'lib/httpx/connection.rb', line 195

def interests
  # connecting
  if connecting?
    connect

    return @io.interests if connecting?
  end

  return @parser.interests if @parser

  nil
rescue StandardError => e
  on_error(e)
  nil
end

#io_connected? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/httpx/connection.rb', line 176

def io_connected?
  return @coalesced_connection.io_connected? if @coalesced_connection

  @io && @io.state == :connected
end

#match?(uri, options) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/httpx/connection.rb', line 101

def match?(uri, options)
  return false if !used? && (@state == :closing || @state == :closed)

  @origins.include?(uri.origin) &&
    # if there is more than one origin to match, it means that this connection
    # was the result of coalescing. To prevent blind trust in the case where the
    # origin came from an ORIGIN frame, we're going to verify the hostname with the
    # SSL certificate
    (@origins.size == 1 || @origin == uri.origin || (@io.is_a?(SSL) && @io.verify_hostname(uri.host))) &&
    @options.connection_options_match?(options)
end

#merge(connection) ⇒ Object 



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# File 'lib/httpx/connection.rb', line 149

def merge(connection)
  @origins |= connection.instance_variable_get(:@origins)
  if @ssl_session.nil? && connection.ssl_session
    @ssl_session = connection.ssl_session
    @io.session_new_cb do |sess|
      @ssl_session = sess
    end if @io
  end
  connection.purge_pending do |req|
    req.transition(:idle)
    send(req)
  end
end

#mergeable?(connection) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/httpx/connection.rb', line 113

def mergeable?(connection)
  return false if @state == :closing || @state == :closed || !@io

  return false unless connection.addresses

  (
    (open? && @origin == connection.origin) ||
    !(@io.addresses & (connection.addresses || [])).empty?
  ) && @options.connection_options_match?(connection.options)
end

#on_connect_error(e) ⇒ Object 



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# File 'lib/httpx/connection.rb', line 426

def on_connect_error(e)
  # connect errors, exit gracefully
  error = ConnectionError.new(e.message)
  error.set_backtrace(e.backtrace)
  handle_connect_error(error) if connecting?
  force_close
end

#on_error(error, request = nil) ⇒ Object 



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# File 'lib/httpx/connection.rb', line 439

def on_error(error, request = nil)
  if error.is_a?(OperationTimeoutError)

    # inactive connections do not contribute to the select loop, therefore
    # they should not fail due to such errors.
    return if @state == :inactive

    if @timeout
      @timeout -= error.timeout
      return unless @timeout <= 0

      @timeout = nil
    end

    error = error.to_connection_error if connecting?
  end
  handle_error(error, request)
  reset
end

#on_io_error(e) ⇒ Object 



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# File 'lib/httpx/connection.rb', line 434

def on_io_error(e)
  on_error(e)
  force_close(true)
end

#open? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/httpx/connection.rb', line 385

def open?
  @state == :open || @state == :inactive
end

#peer ⇒ Object 



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# File 'lib/httpx/connection.rb', line 79

def peer
  @origin
end

#purge_pending(&block) ⇒ Object 



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# File 'lib/httpx/connection.rb', line 163

def purge_pending(&block)
  pendings = []
  if @parser
    pending = @parser.pending
    @inflight -= pending.size
    pendings << pending
  end
  pendings << @pending
  pendings.each do |pending|
    pending.reject!(&block)
  end
end

#reset ⇒ Object 



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# File 'lib/httpx/connection.rb', line 310

def reset
  return if @state == :closing || @state == :closed

  # do not reset a connection which may have restarted back to :idle, such when the parser resets
  # (example: HTTP/1 parser disabling pipelining)
  return if @state == :idle && @pending.any?

  parser = @parser

  if parser && parser.respond_to?(:max_concurrent_requests)
    # if connection being reset has at some downgraded the number of concurrent
    # requests, such as in the case where an attempt to use HTTP/1 pipelining failed,
    # keep that information around.
    @max_concurrent_requests = parser.max_concurrent_requests
  end

  transition(:closing)

  transition(:closed)
end

#send(request) ⇒ Object 



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# File 'lib/httpx/connection.rb', line 331

def send(request)
  return @coalesced_connection.send(request) if @coalesced_connection

  if @parser && !@write_buffer.full?
    if @response_received_at && @keep_alive_timeout &&
       Utils.elapsed_time(@response_received_at) > @keep_alive_timeout
      # when pushing a request into an existing connection, we have to check whether there
      # is the possibility that the connection might have extended the keep alive timeout.
      # for such cases, we want to ping for availability before deciding to shovel requests.
      log(level: 3) { "keep alive timeout expired, pinging connection..." }
      @pending << request
      transition(:active) if @state == :inactive
      request.ping!
      ping(request)
      return
    end

    send_request_to_parser(request)
  else
    @pending << request
  end
end

#terminate ⇒ Object 



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# File 'lib/httpx/connection.rb', line 267

def terminate
  case @state
  when :idle
    purge_after_closed

    # @fiber-switch-guard
    if @io.can_disconnect? && @pending.empty?
      disconnect
      return
    end
  when :closed
    @connected_at = nil
  end

  close
end

#timeout ⇒ Object 



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# File 'lib/httpx/connection.rb', line 354

def timeout
  return if @state == :closed || @state == :inactive

  return @timeout if @timeout

  return @options.timeout[:connect_timeout] if @state == :idle

  @options.timeout[:operation_timeout]
end

#to_io ⇒ Object 



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# File 'lib/httpx/connection.rb', line 211

def to_io
  @io.to_io
end

#used? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/httpx/connection.rb', line 377

def used?
  @connected_at
end