Fix performance of follow import (mastodon#13836)

app/helpers/webfinger_helper.rb

@@ -1,5 +1,16 @@
 # frozen_string_literal: true
 
+# Monkey-patch on monkey-patch.
+# Because it conflicts with the request.rb patch.
+class HTTP::Timeout::PerOperationOriginal < HTTP::Timeout::PerOperation
+  def connect(socket_class, host, port, nodelay = false)
+    ::Timeout.timeout(@connect_timeout, HTTP::TimeoutError) do
+      @socket = socket_class.open(host, port)
+      @socket.setsockopt(Socket::IPPROTO_TCP, Socket::TCP_NODELAY, 1) if nodelay
+    end
+  end
+end
+
 module WebfingerHelper
   def webfinger!(uri)
     hidden_service_uri = /\.(onion|i2p)(:\d+)?$/.match(uri)
@@ -12,6 +23,14 @@ def webfinger!(uri)
       headers: {
         'User-Agent': Mastodon::Version.user_agent,
       },
+
+      timeout_class: HTTP::Timeout::PerOperationOriginal,
+
+      timeout_options: {
+        write_timeout: 10,
+        connect_timeout: 5,
+        read_timeout: 10,
+      },
     }
 
     Goldfinger::Client.new(uri, opts.merge(Rails.configuration.x.http_client_proxy)).finger

app/services/import_service.rb

@@ -81,7 +81,9 @@ def import_relationships!(action, undo_action, overwrite_scope, limit, extra_fie
       end
     end
 
-    Import::RelationshipWorker.push_bulk(items) do |acct, extra|
+    head_items = items.uniq { |acct, _| acct.split('@')[1] }
+    tail_items = items - head_items
+    Import::RelationshipWorker.push_bulk(head_items + tail_items) do |acct, extra|
       [@account.id, acct, action, extra]
     end
   end

app/services/resolve_account_service.rb

@@ -112,6 +112,8 @@ def process_account!
   end
 
   def webfinger_update_due?
+    return false if @options[:check_delivery_availability] && !DeliveryFailureTracker.available?(@domain)
+
     @account.nil? || ((!@options[:skip_webfinger] || @account.ostatus?) && @account.possibly_stale?)
   end
 

app/workers/import/relationship_worker.rb

@@ -7,7 +7,8 @@ class Import::RelationshipWorker
 
   def perform(account_id, target_account_uri, relationship, options = {})
     from_account   = Account.find(account_id)
-    target_account = ResolveAccountService.new.call(target_account_uri)
+    target_domain  = domain(target_account_uri)
+    target_account = stoplight_wrap_request(target_domain) { ResolveAccountService.new.call(target_account_uri, { check_delivery_availability: true }) }
     options.symbolize_keys!
 
     return if target_account.nil?
@@ -29,4 +30,22 @@ def perform(account_id, target_account_uri, relationship, options = {})
   rescue ActiveRecord::RecordNotFound
     true
   end
+
+  def domain(uri)
+    domain = uri.is_a?(Account) ? uri.domain : uri.split('@')[1]
+    TagManager.instance.local_domain?(domain) ? nil : TagManager.instance.normalize_domain(domain)
+  end
+
+  def stoplight_wrap_request(domain, &block)
+    if domain.present?
+      Stoplight("source:#{domain}", &block)
+        .with_fallback { nil }
+        .with_threshold(1)
+        .with_cool_off_time(5.minutes.seconds)
+        .with_error_handler { |error, handle| error.is_a?(HTTP::Error) || error.is_a?(OpenSSL::SSL::SSLError) ? handle.call(error) : raise(error) }
+        .run
+    else
+      block.call
+    end
+  end
 end