Add triggers for updating feeds

src/invidious.cr

@@ -2845,8 +2845,9 @@ post "/feed/webhook/:token" do |env|
         premiere_timestamp: video.premiere_timestamp,
       )
 
-      PG_DB.exec("UPDATE users SET notifications = notifications || $1 \
-      WHERE updated < $2 AND $3 = ANY(subscriptions) AND $1 <> ALL(notifications)", video.id, video.published, video.ucid)
+      users = PG_DB.query_all("UPDATE users SET notifications = notifications || $1 \
+        WHERE updated < $2 AND $3 = ANY(subscriptions) AND $1 <> ALL(notifications) RETURNING email",
+        video.id, video.published, video.ucid, as: String)
 
       video_array = video.to_a
       args = arg_array(video_array)
@@ -2855,6 +2856,14 @@ post "/feed/webhook/:token" do |env|
         ON CONFLICT (id) DO UPDATE SET title = $2, published = $3, \
         updated = $4, ucid = $5, author = $6, length_seconds = $7, \
         live_now = $8, premiere_timestamp = $9", video_array)
+
+      users.each do |user|
+        payload = {
+          "email"  => user,
+          "action" => "refresh",
+        }.to_json
+        PG_DB.exec("NOTIFY feeds, E'#{payload}'")
+      end
     end
   end
 

src/invidious/channels.cr

@@ -178,18 +178,27 @@ def fetch_channel(ucid, db, pull_all_videos = true, locale = nil)
       premiere_timestamp: premiere_timestamp
     )
 
-    db.exec("UPDATE users SET notifications = notifications || $1 \
-        WHERE updated < $2 AND $3 = ANY(subscriptions) AND $1 <> ALL(notifications)", video.id, video.published, ucid)
+    users = db.query_all("UPDATE users SET notifications = notifications || $1 \
+      WHERE updated < $2 AND $3 = ANY(subscriptions) AND $1 <> ALL(notifications) RETURNING email",
+      video.id, video.published, ucid, as: String)
 
     video_array = video.to_a
     args = arg_array(video_array)
 
-    # We don't include the 'premire_timestamp' here because channel pages don't include them,
+    # We don't include the 'premiere_timestamp' here because channel pages don't include them,
     # meaning the above timestamp is always null
     db.exec("INSERT INTO channel_videos VALUES (#{args}) \
       ON CONFLICT (id) DO UPDATE SET title = $2, published = $3, \
       updated = $4, ucid = $5, author = $6, length_seconds = $7, \
       live_now = $8", video_array)
+
+    users.each do |user|
+      payload = {
+        "email"  => user,
+        "action" => "refresh",
+      }.to_json
+      PG_DB.exec("NOTIFY feeds, E'#{payload}'")
+    end
   end
 
   if pull_all_videos
@@ -233,10 +242,12 @@ def fetch_channel(ucid, db, pull_all_videos = true, locale = nil)
       videos.each do |video|
         ids << video.id
 
-        # FIXME: Red videos don't provide published date, so the best we can do is ignore them
+        # We are notified of Red videos elsewhere (PubSub), which includes a correct published date,
+        # so since they don't provide a published date here we can safely ignore them.
         if Time.now - video.published > 1.minute
-          db.exec("UPDATE users SET notifications = notifications || $1 \
-          WHERE updated < $2 AND $3 = ANY(subscriptions) AND $1 <> ALL(notifications)", video.id, video.published, video.ucid)
+          users = db.query_all("UPDATE users SET notifications = notifications || $1 \
+            WHERE updated < $2 AND $3 = ANY(subscriptions) AND $1 <> ALL(notifications) RETURNING email",
+            video.id, video.published, video.ucid, as: String)
 
           video_array = video.to_a
           args = arg_array(video_array)
@@ -245,6 +256,15 @@ def fetch_channel(ucid, db, pull_all_videos = true, locale = nil)
           db.exec("INSERT INTO channel_videos VALUES (#{args}) \
             ON CONFLICT (id) DO UPDATE SET title = $2, updated = $4, \
             ucid = $5, author = $6, length_seconds = $7, live_now = $8", video_array)
+
+          # Update all users affected by insert
+          users.each do |user|
+            payload = {
+              "email"  => user,
+              "action" => "refresh",
+            }.to_json
+            PG_DB.exec("NOTIFY feeds, E'#{payload}'")
+          end
         end
       end
 

src/invidious/helpers/jobs.cr

@@ -45,6 +45,29 @@ end
 def refresh_feeds(db, logger, max_threads = 1)
   max_channel = Channel(Int32).new
 
+  # TODO: Make this config option, similar to use_pubsub
+  # Spawn thread to handle feed events
+  if max_threads > 0
+    spawn do
+      PG.connect_listen(PG_URL, "feeds") do |event|
+        spawn do
+          feed = JSON.parse(event.payload)
+          email = feed["email"].as_s
+          action = feed["action"].as_s
+
+          view_name = "subscriptions_#{sha256(email)}"
+
+          case action
+          when "refresh"
+            db.exec("REFRESH MATERIALIZED VIEW #{view_name}")
+          end
+        end
+
+        Fiber.yield
+      end
+    end
+  end
+
   spawn do
     max_threads = max_channel.receive
     active_threads = 0