Class: HTTPX::Connection

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Includes:
Callbacks, Loggable, Registry
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 collapse

BUFFER_SIZE = 
1 << 14

Constants included from Loggable

Loggable::COLORS

Constants included from Registry

Registry::Error

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Callbacks

#emit, #on, #once

Methods included from Loggable

#log, #log_exception

Methods included from Registry

extended, included

Constructor Details

#initialize(type, uri, options) ⇒ Connection

Returns a new instance of Connection.



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# File 'lib/httpx/connection.rb', line 51

def initialize(type, uri, options)
  @type = type
  @origins = [uri.origin]
  @origin = URI(uri.origin)
  @options = Options.new(options)
  @window_size = @options.window_size
  @read_buffer = Buffer.new(BUFFER_SIZE)
  @write_buffer = Buffer.new(BUFFER_SIZE)
  @pending = []
  on(:error, &method(:on_error))
  if @options.io
    # if there's an already open IO, get its
    # peer address, and force-initiate the parser
    transition(:already_open)
    @io = IO.registry(@type).new(@origin, nil, @options)
    parser
  else
    transition(:idle)
  end

  @inflight = 0
  @keep_alive_timeout = options.timeout.keep_alive_timeout
  @keep_alive_timer = nil
end

Instance Attribute Details

#options ⇒ Object (readonly)

Returns the value of attribute options.



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

def options
  @options
end

#origin ⇒ Object (readonly)

Returns the value of attribute origin.



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

def origin
  @origin
end

#pending ⇒ Object (readonly)

Returns the value of attribute pending.



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

def pending
  @pending
end

#state ⇒ Object (readonly)

Returns the value of attribute state.



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

def state
  @state
end

#timers=(value) ⇒ Object (writeonly)

Sets the attribute timers

Parameters:

  • value —

    the value to set the attribute timers to.



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

def timers=(value)
  @timers = value
end

Instance Method Details

#addresses ⇒ Object 



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# File 'lib/httpx/connection.rb', line 82

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 78

def addresses=(addrs)
  @io ||= IO.registry(@type).new(@origin, addrs, @options) # rubocop:disable Naming/MemoizedInstanceVariableName
end

#call ⇒ Object 



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

def call
  case @state
  when :closed
    return
  when :closing
    consume
    transition(:closed)
    emit(:close)
  when :open
    consume
  end
  nil
end

#close ⇒ Object 



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

def close
  @parser.close if @parser
  return unless @keep_alive_timer

  @keep_alive_timer.cancel
  remove_instance_variable(:@keep_alive_timer)
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 113

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

#connecting? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/httpx/connection.rb', line 169

def connecting?
  @state == :idle
end

#create_idle ⇒ Object 



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# File 'lib/httpx/connection.rb', line 123

def create_idle
  self.class.new(@type, @origin, @options)
end

#inflight? ⇒ Boolean

Returns:

  • (Boolean) 


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

def inflight?
  @parser && !@parser.empty? && !@write_buffer.empty?
end

#interests ⇒ Object 



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# File 'lib/httpx/connection.rb', line 177

def interests
  # connecting
  if connecting?
    connect

    return @io.interests if connecting?
  end

  # if the write buffer is full, we drain it
  return :w if @write_buffer.full?

  return @parser.interests if @parser

  nil
end

#match?(uri, options) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/httpx/connection.rb', line 86

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

  return false if exhausted?

  (
    (
      @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 && @io.verify_hostname(uri.host)))
    ) || match_altsvcs?(uri)
  ) && @options == options
end

#match_altsvcs?(uri) ⇒ Boolean

checks if this is connection is an alternative service of uri

Returns:

  • (Boolean) 


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

def match_altsvcs?(uri)
  @origins.any? { |origin| uri.altsvc_match?(origin) } ||
    AltSvc.cached_altsvc(@origin).any? do |altsvc|
      origin = altsvc["origin"]
      origin.altsvc_match?(uri.origin)
    end
end

#merge(connection) ⇒ Object 



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# File 'lib/httpx/connection.rb', line 127

def merge(connection)
  @origins += connection.instance_variable_get(:@origins)
  connection.purge_pending do |req|
    send(req)
  end
end

#mergeable?(connection) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/httpx/connection.rb', line 103

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

  return false if exhausted?

  !(@io.addresses & connection.addresses).empty? && @options == connection.options
end

#purge_pending ⇒ Object 



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

def purge_pending
  pendings = []
  if @parser
    @inflight -= @parser.pending.size
    pendings << @parser.pending
  end
  pendings << @pending
  pendings.each do |pending|
    pending.reject! do |request|
      yield request
    end
  end
end

#reset ⇒ Object 



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# File 'lib/httpx/connection.rb', line 219

def reset
  transition(:closing)
  transition(:closed)
  emit(:close)
end

#send(request) ⇒ Object 



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# File 'lib/httpx/connection.rb', line 225

def send(request)
  if @parser && !@write_buffer.full?
    request.headers["alt-used"] = @origin.authority if match_altsvcs?(request.uri)
    if @keep_alive_timer
      # 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.
      if @keep_alive_timer.fires_in.negative?
        @pending << request
        parser.ping
        return
      end

      @keep_alive_timer.pause
    end
    @inflight += 1
    parser.send(request)
  else
    @pending << request
  end
end

#timeout ⇒ Object 



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# File 'lib/httpx/connection.rb', line 247

def timeout
  return @timeout if defined?(@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 193

def to_io
  @io.to_io
end

#unmerge(connection) ⇒ Object 



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# File 'lib/httpx/connection.rb', line 134

def unmerge(connection)
  @origins -= connection.instance_variable_get(:@origins)
  purge_pending do |request|
    request.uri.origin == connection.origin && begin
      request.transition(:idle)
      connection.send(request)
      true
    end
  end
end