Use materialized views for subscription feeds

src/invidious/helpers/helpers.cr

@@ -15,6 +15,7 @@ class Config
     hmac_key:     String?,
     full_refresh: Bool,
     geo_bypass:   Bool,
+    update_feeds: Bool,
   })
 end
 

src/invidious/helpers/utils.cr

@@ -238,3 +238,9 @@ def write_var_int(value : Int)
 
   return bytes
 end
+
+def sha256(text)
+  digest = OpenSSL::Digest.new("SHA256")
+  digest << text
+  return digest.hexdigest
+end

src/invidious/jobs.cr

@@ -104,6 +104,17 @@ def refresh_videos(db)
   end
 end
 
+def update_feeds(db)
+  loop do
+    users = db.query_all("SELECT email FROM users", as: String)
+
+    users.each do |email|
+      view_name = "subscriptions_#{sha256(email)[0..7]}"
+      db.exec("REFRESH MATERIALIZED VIEW #{view_name}")
+    end
+  end
+end
+
 def pull_top_videos(config, db)
   if config.dl_api_key
     DetectLanguage.configure do |dl_config|