client.rb in httpx-0.3.0

- old
+ new

@@ -45,11 +45,10 @@
     end
 
     def on_promise(_, stream)
       log(level: 2, label: "#{stream.id}: ") { "refusing stream!" }
       stream.refuse
-      # TODO: policy for handling promises
     end
 
     def fetch_response(request)
       @responses.delete(request)
     end
@@ -64,15 +63,47 @@
       channel.on(:promise, &method(:on_promise))
       channel.on(:uncoalesce) do |uncoalesced_uri|
         other_channel = build_channel(uncoalesced_uri, options)
         channel.unmerge(other_channel)
       end
+      channel.on(:altsvc) do |alt_origin, origin, alt_params|
+        build_altsvc_channel(channel, alt_origin, origin, alt_params, options)
+      end
     end
 
     def build_channel(uri, options)
       channel = @connection.build_channel(uri, **options)
       set_channel_callbacks(channel, options)
       channel
+    end
+
+    def build_altsvc_channel(existing_channel, alt_origin, origin, alt_params, options)
+      altsvc = AltSvc.cached_altsvc_set(origin, alt_params.merge("origin" => alt_origin))
+
+      # altsvc already exists, somehow it wasn't advertised, probably noop
+      return unless altsvc
+
+      channel = @connection.find_channel(alt_origin) || build_channel(alt_origin, options)
+      # advertised altsvc is the same origin being used, ignore
+      return if channel == existing_channel
+
+      log(level: 1) { "#{origin} alt-svc: #{alt_origin}" }
+
+      # get uninitialized requests
+      # incidentally, all requests will be re-routed to the first
+      # advertised alt-svc, which incidentally follows the spec.
+      existing_channel.purge_pending do |request, args|
+        is_idle = request.origin == origin &&
+                  request.state == :idle &&
+                  !request.headers.key?("alt-used")
+        if is_idle
+          log(level: 1) { "#{origin} alt-svc: sending #{request.uri} to #{alt_origin}" }
+          channel.send(request, args)
+        end
+        is_idle
+      end
+    rescue UnsupportedSchemeError
+      altsvc["noop"] = true
     end
 
     def __build_reqs(*args, **options)
       requests = case args.size
                  when 1