Fix #24 - Thread resolving for remote statuses

This is a big one, so let me enumerate:

Accounts as well as stream entry pages now contain Link headers that
reference the Atom feed and Webfinger URL for the former and Atom entry
for the latter. So you only need to HEAD those resources to get that
information, no need to download and parse HTML <link>s.

ProcessFeedService will now queue ThreadResolveWorker for each remote
status that it cannot find otherwise. Furthermore, entries are now
processed in reverse order (from bottom to top) in case a newer entry
references a chronologically previous one.

ThreadResolveWorker uses FetchRemoteStatusService to obtain a status
and attach the child status it was queued for to it.

FetchRemoteStatusService looks up the URL, first with a HEAD, tests
if it's an Atom feed, in which case it processes it directly. Next
for Link headers to the Atom feed, in which case that is fetched
and processed. Lastly if it's HTML, it is checked for <link>s to the Atom
feed, and if such is found, that is fetched and processed. The account for
the status is derived from author/name attribute in the XML and the hostname
in the URL (domain). FollowRemoteAccountService and ProcessFeedService
are used.

This means that potentially threads are resolved recursively until a dead-end
is encountered, however it is performed asynchronously over background jobs,
so it should be ok.

diff --git a/Gemfile b/Gemfile
index 2e3d9b814cf845b1155495f6699c50e25fc2aba7..7b8b9f0f34ed1050d356ffe494130a354dec6d81 100644 (file)
--- a/Gemfile
+++ b/Gemfile
@@ -21,6 +21,7 @@ gem 'paperclip-av-transcoder'
 gem 'http'
 gem 'addressable'
 gem 'nokogiri'
+gem 'link_header'
 gem 'ostatus2'
 gem 'goldfinger'
 gem 'devise'

diff --git a/Gemfile.lock b/Gemfile.lock
index 6a567adec00133e2619bf50c5494f93db883f159..485a4687a22210ae5ca4aceabce95dfc6d8c379c 100644 (file)
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -149,6 +149,7 @@ GEM
     letter_opener (1.4.1)
       launchy (~> 2.2)
     libv8 (3.16.14.15)
+    link_header (0.0.8)
     lograge (0.4.1)
       actionpack (>= 4, < 5.1)
       activesupport (>= 4, < 5.1)
@@ -368,6 +369,7 @@ DEPENDENCIES
   jbuilder (~> 2.0)
   jquery-rails
   letter_opener
+  link_header
   lograge
   nokogiri
   oj

diff --git a/app/controllers/accounts_controller.rb b/app/controllers/accounts_controller.rb
index 2d4c2dd9a56b2fe7bc364288cfc6fddc3a9f6099..bfdc5b6d91ab1a18f0219c57d672dcbbaac87d66 100644 (file)
--- a/app/controllers/accounts_controller.rb
+++ b/app/controllers/accounts_controller.rb
@@ -2,7 +2,7 @@ class AccountsController < ApplicationController
   layout 'public'
 
   before_action :set_account
-  before_action :set_webfinger_header
+  before_action :set_link_headers
 
   def show
     respond_to do |format|
@@ -39,8 +39,11 @@ class AccountsController < ApplicationController
     @account = Account.find_local!(params[:username])
   end
 
-  def set_webfinger_header
-    response.headers['Link'] = "<#{webfinger_account_url}>; rel=\"lrdd\"; type=\"application/xrd+xml\""
+  def set_link_headers
+    response.headers['Link'] = LinkHeader.new([
+      [webfinger_account_url, [['rel', 'lrdd'], ['type', 'application/xrd+xml']]],
+      [account_url(@account, format: 'atom'), [['rel', 'alternate'], ['type', 'application/atom+xml']]]
+    ])
   end
 
   def webfinger_account_url

diff --git a/app/controllers/stream_entries_controller.rb b/app/controllers/stream_entries_controller.rb
index c26149627954a134c04aa1f3307d95d1093b496b..e25e7f5edb3d0500d2d4baf1fda5018dd22094e8 100644 (file)
--- a/app/controllers/stream_entries_controller.rb
+++ b/app/controllers/stream_entries_controller.rb
@@ -3,6 +3,7 @@ class StreamEntriesController < ApplicationController
 
   before_action :set_account
   before_action :set_stream_entry
+  before_action :set_link_headers
 
   def show
     @type = @stream_entry.activity_type.downcase
@@ -33,6 +34,12 @@ class StreamEntriesController < ApplicationController
     @account = Account.find_local!(params[:account_username])
   end
 
+  def set_link_headers
+    response.headers['Link'] = LinkHeader.new([
+      [account_stream_entry_url(@account, @stream_entry, format: 'atom'), [['rel', 'alternate'], ['type', 'application/atom+xml']]]
+    ])
+  end
+
   def set_stream_entry
     @stream_entry = @account.stream_entries.find(params[:id])
   end

diff --git a/app/services/fetch_remote_status_service.rb b/app/services/fetch_remote_status_service.rb
new file mode 100644 (file)
index 0000000..c872cb3
--- /dev/null
+++ b/app/services/fetch_remote_status_service.rb
@@ -0,0 +1,71 @@
+class FetchRemoteStatusService < BaseService
+  def call(url)
+    response = http_client.head(url)
+
+    Rails.logger.debug "Remote status HEAD request returned code #{response.code}"
+    return nil if response.code != 200
+
+    if response.mime_type == 'application/atom+xml'
+      return process_atom(url, fetch(url))
+    elsif !response['Link'].blank?
+      return process_headers(response)
+    else
+      return process_html(fetch(url))
+    end
+  end
+
+  private
+
+  def process_atom(url, body)
+    Rails.logger.debug "Processing Atom for remote status"
+
+    xml     = Nokogiri::XML(body)
+    account = extract_author(url, xml)
+
+    return nil if account.nil?
+
+    statuses = ProcessFeedService.new.(body, account)
+
+    return statuses.first
+  end
+
+  def process_html(body)
+    Rails.logger.debug "Processing HTML for remote status"
+
+    page = Nokogiri::HTML(body)
+    alternate_link = page.xpath('//link[@rel="alternate"]').find { |link| link['type'] == 'application/atom+xml' }
+
+    return nil if alternate_link.nil?
+    return process_atom(alternate_link['href'], fetch(alternate_link['href']))
+  end
+
+  def process_headers(response)
+    Rails.logger.debug "Processing link header for remote status"
+
+    link_header    = LinkHeader.parse(response['Link'])
+    alternate_link = link_header.find_link(['rel', 'alternate'], ['type', 'application/atom+xml'])
+
+    return nil if alternate_link.nil?
+    return process_atom(alternate_link.href, fetch(alternate_link.href))
+  end
+
+  def extract_author(url, xml)
+    url_parts = Addressable::URI.parse(url)
+    username  = xml.at_xpath('//xmlns:author/xmlns:name').try(:content)
+    domain    = url_parts.host
+
+    return nil if username.nil?
+
+    Rails.logger.debug "Going to webfinger #{username}@#{domain}"
+
+    return FollowRemoteAccountService.new.("#{username}@#{domain}")
+  end
+
+  def fetch(url)
+    http_client.get(url).to_s
+  end
+
+  def http_client
+    HTTP.timeout(:per_operation, write: 20, connect: 20, read: 50)
+  end
+end

diff --git a/app/services/follow_remote_account_service.rb b/app/services/follow_remote_account_service.rb
index f3a384ecca3a7e48071eb8b9767ec7f106bfce38..ef3949e3682045d073a7f2826f62f090a42e1bc6 100644 (file)
--- a/app/services/follow_remote_account_service.rb
+++ b/app/services/follow_remote_account_service.rb
@@ -72,7 +72,7 @@ class FollowRemoteAccountService < BaseService
   end
 
   def http_client
-    HTTP
+    HTTP.timeout(:per_operation, write: 20, connect: 20, read: 50)
   end
 end
 

diff --git a/app/services/process_feed_service.rb b/app/services/process_feed_service.rb
index a692054947a00727122212fa3af2f04062431739..49834f5c16c1fe03838ed22fcb9835086f0675ba 100644 (file)
--- a/app/services/process_feed_service.rb
+++ b/app/services/process_feed_service.rb
@@ -2,10 +2,11 @@ class ProcessFeedService < BaseService
   # Create local statuses from an Atom feed
   # @param [String] body Atom feed
   # @param [Account] account Account this feed belongs to
+  # @return [Enumerable] created statuses
   def call(body, account)
     xml = Nokogiri::XML(body)
     update_remote_profile_service.(xml.at_xpath('/xmlns:feed/xmlns:author'), account) unless xml.at_xpath('/xmlns:feed').nil?
-    xml.xpath('//xmlns:entry').each { |entry| process_entry(account, entry) }
+    xml.xpath('//xmlns:entry').reverse_each.map { |entry| process_entry(account, entry) }.compact
   end
 
   private
@@ -45,6 +46,8 @@ class ProcessFeedService < BaseService
 
       DistributionWorker.perform_async(status.id)
     end
+
+    return status
   end
 
   def record_remote_mentions(status, links)
@@ -103,6 +106,10 @@ class ProcessFeedService < BaseService
   def add_reply!(entry, status)
     status.thread = find_original_status(entry, thread_id(entry))
     status.save!
+
+    if status.thread.nil? && !thread_href(entry).nil?
+      ThreadResolveWorker.perform_async(status.id, thread_href(entry))
+    end
   end
 
   def delete_post!(status)
@@ -131,6 +138,13 @@ class ProcessFeedService < BaseService
 
     status = Status.new(account: account, uri: target_id(xml), text: target_content(xml), url: target_url(xml), created_at: published(xml), updated_at: updated(xml))
     status.thread = find_original_status(xml, thread_id(xml))
+    status.save
+
+    if status.saved? && status.thread.nil? && !thread_href(xml).nil?
+      ThreadResolveWorker.perform_async(status.id, thread_href(xml))
+    end
+
+    status
   rescue Goldfinger::Error, HTTP::Error
     nil
   end
@@ -153,6 +167,12 @@ class ProcessFeedService < BaseService
     nil
   end
 
+  def thread_href(xml)
+    xml.at_xpath('./thr:in-reply-to').attribute('href').value
+  rescue
+    nil
+  end
+
   def target_id(xml)
     xml.at_xpath('.//activity:object/xmlns:id').content
   rescue

diff --git a/app/workers/thread_resolve_worker.rb b/app/workers/thread_resolve_worker.rb
new file mode 100644 (file)
index 0000000..ccc5638
--- /dev/null
+++ b/app/workers/thread_resolve_worker.rb
@@ -0,0 +1,13 @@
+class ThreadResolveWorker
+  include Sidekiq::Worker
+
+  def perform(child_status_id, parent_url)
+    child_status  = Status.find(child_status_id)
+    parent_status = FetchRemoteStatusService.new.(parent_url)
+
+    unless parent_status.nil?
+      child_status.thread = parent_status
+      child_status.save!
+    end
+  end
+end

diff --git a/spec/controllers/api/subscriptions_controller_spec.rb b/spec/controllers/api/subscriptions_controller_spec.rb
index ad0d0bc05548cef069fd2e5ee6ab0304b4347902..e0ae8d48ea3d429eb4f2dd0f21ab94bd0cf405c2 100644 (file)
--- a/spec/controllers/api/subscriptions_controller_spec.rb
+++ b/spec/controllers/api/subscriptions_controller_spec.rb
@@ -24,6 +24,14 @@ RSpec.describe Api::SubscriptionsController, type: :controller do
 
     before do
       stub_request(:get, "https://quitter.no/avatar/7477-300-20160211190340.png").to_return(request_fixture('avatar.txt'))
+      stub_request(:head, "https://quitter.no/notice/1269244").to_return(status: 404)
+      stub_request(:head, "https://quitter.no/notice/1265331").to_return(status: 404)
+      stub_request(:head, "https://community.highlandarrow.com/notice/54411").to_return(status: 404)
+      stub_request(:head, "https://community.highlandarrow.com/notice/53857").to_return(status: 404)
+      stub_request(:head, "https://community.highlandarrow.com/notice/51852").to_return(status: 404)
+      stub_request(:head, "https://social.umeahackerspace.se/notice/424348").to_return(status: 404)
+      stub_request(:head, "https://community.highlandarrow.com/notice/50467").to_return(status: 404)
+      stub_request(:head, "https://quitter.no/notice/1243309").to_return(status: 404)
 
       request.env['HTTP_X_HUB_SIGNATURE'] = "sha1=#{OpenSSL::HMAC.hexdigest('sha1', 'abc', feed)}"
       request.env['RAW_POST_DATA'] = feed