Adding embedded PuSH server

app/workers/pubsubhubbub/confirmation_worker.rb

@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+class Pubsubhubbub::ConfirmationWorker
+  include Sidekiq::Worker
+  include RoutingHelper
+
+  def perform(subscription_id, mode, secret = nil, lease_seconds = nil)
+    subscription = Subscription.find(subscription_id)
+    challenge    = SecureRandom.hex
+
+    subscription.secret        = secret
+    subscription.lease_seconds = lease_seconds
+
+    response = HTTP.headers(user_agent: 'Mastodon/PubSubHubbub')
+                   .timeout(:per_operation, write: 20, connect: 20, read: 50)
+                   .get(subscription.callback_url, params: {
+                          'hub.topic' => account_url(subscription.account, format: :atom),
+                          'hub.mode'          => mode,
+                          'hub.challenge'     => challenge,
+                          'hub.lease_seconds' => subscription.lease_seconds,
+                        })
+
+    if mode == 'subscribe' && response.body.to_s == challenge
+      subscription.save!
+    elsif (mode == 'unsubscribe' && response.body.to_s == challenge) || !subscription.confirmed?
+      subscription.destroy!
+    end
+  end
+end

app/workers/pubsubhubbub/delivery_worker.rb

@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+class Pubsubhubbub::DeliveryWorker
+  include Sidekiq::Worker
+  include RoutingHelper
+
+  def perform(subscription_id, payload)
+    subscription = Subscription.find(subscription_id)
+    headers      = {}
+
+    headers['User-Agent']      = 'Mastodon/PubSubHubbub'
+    headers['Link']            = LinkHeader.new([[api_push_url, [%w(rel hub)]], [account_url(subscription.account, format: :atom), [%w(rel self)]]]).to_s
+    headers['X-Hub-Signature'] = signature(subscription.secret, payload) unless subscription.secret.blank?
+
+    response = HTTP.timeout(:per_operation, write: 50, connect: 20, read: 50)
+                   .headers(headers)
+                   .post(subscription.callback_url, body: payload)
+
+    raise "Delivery failed for #{subscription.callback_url}: HTTP #{response.code}" unless response.code > 199 && response.code < 300
+  end
+
+  private
+
+  def signature(secret, payload)
+    hmac = OpenSSL::HMAC.hexdigest(OpenSSL::Digest.new('sha1'), secret, payload)
+    "sha1=#{hmac}"
+  end
+end

app/workers/pubsubhubbub/distribution_worker.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+class Pubsubhubbub::DistributionWorker
+  include Sidekiq::Worker
+
+  def perform(stream_entry_id)
+    stream_entry = StreamEntry.find(stream_entry_id)
+    account      = stream_entry.account
+    payload      = AccountsController.render(:show, assigns: { account: account, entries: [stream_entry] }, formats: [:atom])
+
+    Subscription.where(account: account).active.select('id').find_each do |subscription|
+      Pubsubhubbub::DeliveryWorker.perform_async(subscription.id, payload)
+    end
+  end
+end

app/workers/thread_resolve_worker.rb

@@ -7,9 +7,9 @@ class ThreadResolveWorker
     child_status  = Status.find(child_status_id)
     parent_status = FetchRemoteStatusService.new.call(parent_url)
 
-    unless parent_status.nil?
-      child_status.thread = parent_status
-      child_status.save!
-    end
+    return if parent_status.nil?
+
+    child_status.thread = parent_status
+    child_status.save!
   end
 end