Separate PuSH subscriptions from following, add mastodon:push:refresh task,

respect hub.lease_seconds (fix #46)

app/controllers/api/subscriptions_controller.rb

@@ -4,6 +4,7 @@ class Api::SubscriptionsController < ApiController
 
   def show
     if @account.subscription(api_subscription_url(@account.id)).valid?(params['hub.topic'], params['hub.verify_token'])
+      @account.update(subscription_expires_at: Time.now + (params['hub.lease_seconds'].to_i).seconds)
       render plain: HTMLEntities.new.encode(params['hub.challenge']), status: 200
     else
       head 404

app/models/account.rb

@@ -38,6 +38,12 @@ class Account < ApplicationRecord
 
   has_many :media_attachments, dependent: :destroy
 
+  scope :remote, -> { where.not(domain: nil) }
+  scope :local, -> { where(domain: nil) }
+  scope :without_followers, -> { where('(select count(f.id) from follows as f where f.target_account_id = accounts.id) = 0') }
+  scope :with_followers, -> { where('(select count(f.id) from follows as f where f.target_account_id = accounts.id) > 0') }
+  scope :expiring, -> (time) { where(subscription_expires_at: nil).or(where('subscription_expires_at < ?', time)).remote.with_followers }
+
   def follow!(other_account)
     self.active_relationships.where(target_account: other_account).first_or_create!(target_account: other_account)
   end

app/services/follow_remote_account_service.rb

@@ -3,22 +3,18 @@ class FollowRemoteAccountService < BaseService
   # When creating, look up the user's webfinger and fetch all
   # important information from their feed
   # @param [String] uri User URI in the form of username@domain
-  # @param [Boolean] subscribe Whether to initiate a PubSubHubbub subscription
   # @return [Account]
-  def call(uri, subscribe = true)
+  def call(uri)
     username, domain = uri.split('@')
 
     return Account.find_local(username) if domain == Rails.configuration.x.local_domain || domain.nil?
 
     account = Account.find_remote(username, domain)
 
-    if account.nil?
+    return account unless account.nil?
+
     Rails.logger.debug "Creating new remote account for #{uri}"
     account = Account.new(username: username, domain: domain)
-    elsif account.subscribed?
-      Rails.logger.debug "Already subscribed to remote account #{uri}"
-      return account
-    end
 
     data = Goldfinger.finger("acct:#{uri}")
 
@@ -45,16 +41,6 @@ class FollowRemoteAccountService < BaseService
     get_profile(feed, account)
     account.save!
 
-    if subscribe
-      account.secret       = SecureRandom.hex
-      account.verify_token = SecureRandom.hex
-
-      subscription = account.subscription(api_subscription_url(account.id))
-      subscription.subscribe
-
-      account.save!
-    end
-
     return account
   end
 
@@ -90,8 +76,3 @@ class FollowRemoteAccountService < BaseService
   end
 end
 
-class NoAuthorFeedError < StandardError
-end
-
-class NoHubError < StandardError
-end

app/services/follow_service.rb

@@ -12,6 +12,7 @@ class FollowService < BaseService
     if target_account.local?
       NotificationMailer.follow(target_account, source_account).deliver_later
     else
+      subscribe_service.(target_account)
       NotificationWorker.perform_async(follow.stream_entry.id, target_account.id)
     end
 
@@ -40,4 +41,8 @@ class FollowService < BaseService
   def follow_remote_account_service
     @follow_remote_account_service ||= FollowRemoteAccountService.new
   end
+
+  def subscribe_service
+    @subscribe_service ||= SubscribeService.new
+  end
 end

app/services/process_feed_service.rb

@@ -106,7 +106,7 @@ class ProcessFeedService < BaseService
   end
 
   def delete_post!(status)
-    RemoveStatusService.new.(status)
+    remove_status_service.(status)
   end
 
   def find_original_status(_xml, id)
@@ -126,7 +126,7 @@ class ProcessFeedService < BaseService
     account  = Account.find_by(username: username, domain: domain)
 
     if account.nil?
-      account = follow_remote_account_service.("#{username}@#{domain}", false)
+      account = follow_remote_account_service.("#{username}@#{domain}")
     end
 
     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))
@@ -196,4 +196,8 @@ class ProcessFeedService < BaseService
   def update_remote_profile_service
     @update_remote_profile_service ||= UpdateRemoteProfileService.new
   end
+
+  def remove_status_service
+    @remove_status_service ||= RemoveStatusService.new
+  end
 end

app/services/process_interaction_service.rb

@@ -14,7 +14,7 @@ class ProcessInteractionService < BaseService
     account  = Account.find_by(username: username, domain: domain)
 
     if account.nil?
-      account = follow_remote_account_service.("#{username}@#{domain}", false)
+      account = follow_remote_account_service.("#{username}@#{domain}")
     end
 
     if salmon.verify(envelope, account.keypair)
@@ -71,7 +71,7 @@ class ProcessInteractionService < BaseService
     return if status.nil?
 
     if account.id == status.account_id
-      RemoveStatusService.new.(status)
+      remove_status_service.(status)
     end
   end
 
@@ -108,4 +108,8 @@ class ProcessInteractionService < BaseService
   def update_remote_profile_service
     @update_remote_profile_service ||= UpdateRemoteProfileService.new
   end
+
+  def remove_status_service
+    @remove_status_service ||= RemoveStatusService.new
+  end
 end

app/services/subscribe_service.rb

@@ -0,0 +1,20 @@
+class SubscribeService < BaseService
+  def call(account)
+    account.secret       = SecureRandom.hex
+    account.verify_token = SecureRandom.hex
+
+    subscription = account.subscription(api_subscription_url(account.id))
+    response = subscription.subscribe
+
+    unless response.successful?
+      account.secret       = ''
+      account.verify_token = ''
+
+      Rails.logger.debug "PuSH subscription request for #{account.acct} failed: #{response.message}"
+    end
+
+    account.save!
+  rescue HTTP::Error, OpenSSL::SSL::SSLError
+    Rails.logger.debug "PuSH subscription request for #{account.acct} could not be made due to HTTP or SSL error"
+  end
+end

db/migrate/20160919221059_add_subscription_expires_at_to_accounts.rb

@@ -0,0 +1,5 @@
+class AddSubscriptionExpiresAtToAccounts < ActiveRecord::Migration[5.0]
+  def change
+    add_column :accounts, :subscription_expires_at, :datetime, null: true, default: nil
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20160905150353) do
+ActiveRecord::Schema.define(version: 20160919221059) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -40,6 +40,7 @@ ActiveRecord::Schema.define(version: 20160905150353) do
     t.integer  "header_file_size"
     t.datetime "header_updated_at"
     t.string   "avatar_remote_url"
+    t.datetime "subscription_expires_at"
     t.index ["username", "domain"], name: "index_accounts_on_username_and_domain", unique: true, using: :btree
   end
 

lib/tasks/mastodon.rake

@@ -11,9 +11,16 @@ namespace :mastodon do
   namespace :push do
     desc 'Unsubscribes from PuSH updates of feeds nobody follows locally'
     task clear: :environment do
-      Account.where('(select count(f.id) from follows as f where f.target_account_id = accounts.id) = 0').where.not(domain: nil).find_each do |a|
+      Account.remote.without_followers.find_each do |a|
         a.subscription('').unsubscribe
-        a.update!(verify_token: '', secret: '')
+        a.update!(verify_token: '', secret: '', subscription_expires_at: nil)
+      end
+    end
+
+    desc 'Re-subscribes to soon expiring PuSH subscriptions'
+    task refresh: :environment do
+      Account.expiring(1.day.from_now).find_each do |a|
+        SubscribeService.new.(a)
       end
     end
   end