Module: HTTPX::AltSvc

Defined in:
lib/httpx/altsvc.rb

Defined Under Namespace

Modules: ConnectionMixin

Class Method Summary collapse

Class Method Details

.cached_altsvc(origin) ⇒ Object 



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# File 'lib/httpx/altsvc.rb', line 64

def cached_altsvc(origin)
  now = Utils.now
  @altsvc_mutex.synchronize do
    lookup(origin, now)
  end
end

.cached_altsvc_set(origin, entry) ⇒ Object 



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# File 'lib/httpx/altsvc.rb', line 71

def cached_altsvc_set(origin, entry)
  now = Utils.now
  @altsvc_mutex.synchronize do
    return if @altsvcs[origin].any? { |altsvc| altsvc["origin"] == entry["origin"] }

    entry["TTL"] = Integer(entry["ma"]) + now if entry.key?("ma")
    @altsvcs[origin] << entry
    entry
  end
end

.emit(request, response) ⇒ Object 



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# File 'lib/httpx/altsvc.rb', line 91

def emit(request, response)
  return unless response.respond_to?(:headers)
  # Alt-Svc
  return unless response.headers.key?("alt-svc")

  origin = request.origin
  host = request.uri.host

  altsvc = response.headers["alt-svc"]

  # https://datatracker.ietf.org/doc/html/rfc7838#section-3
  # A field value containing the special value "clear" indicates that the
  # origin requests all alternatives for that origin to be invalidated
  # (including those specified in the same response, in case of an
  # invalid reply containing both "clear" and alternative services).
  if altsvc == "clear"
    @altsvc_mutex.synchronize do
      @altsvcs[origin].clear
    end

    return
  end

  parse(altsvc) do |alt_origin, alt_params|
    alt_origin.host ||= host
    yield(alt_origin, origin, alt_params)
  end
end

.lookup(origin, ttl) ⇒ Object 



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

def lookup(origin, ttl)
  return [] unless @altsvcs.key?(origin)

  @altsvcs[origin] = @altsvcs[origin].select do |entry|
    !entry.key?("TTL") || entry["TTL"] > ttl
  end
  @altsvcs[origin].reject { |entry| entry["noop"] }
end

.parse(altsvc) ⇒ Object 



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# File 'lib/httpx/altsvc.rb', line 120

def parse(altsvc)
  return enum_for(__method__, altsvc) unless block_given?

  scanner = StringScanner.new(altsvc)
  until scanner.eos?
    alt_service = scanner.scan(/[^=]+=("[^"]+"|[^;,]+)/)

    alt_params = []
    loop do
      alt_param = scanner.scan(/[^=]+=("[^"]+"|[^;,]+)/)
      alt_params << alt_param.strip if alt_param
      scanner.skip(/;/)
      break if scanner.eos? || scanner.scan(/ *, */)
    end
    alt_params = Hash[alt_params.map { |field| field.split("=", 2) }]

    alt_proto, alt_authority = alt_service.split("=", 2)
    alt_origin = parse_altsvc_origin(alt_proto, alt_authority)
    return unless alt_origin

    yield(alt_origin, alt_params.merge("proto" => alt_proto))
  end
end

.parse_altsvc_origin(alt_proto, alt_origin) ⇒ Object 



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# File 'lib/httpx/altsvc.rb', line 153

def parse_altsvc_origin(alt_proto, alt_origin)
  alt_scheme = parse_altsvc_scheme(alt_proto)

  return unless alt_scheme

  alt_origin = alt_origin[1..-2] if alt_origin.start_with?("\"") && alt_origin.end_with?("\"")

  URI.parse("#{alt_scheme}://#{alt_origin}")
end

.parse_altsvc_scheme(alt_proto) ⇒ Object 



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# File 'lib/httpx/altsvc.rb', line 144

def parse_altsvc_scheme(alt_proto)
  case alt_proto
  when "h2c"
    "http"
  when "h2"
    "https"
  end
end