Merge pull request code-dot-org#832 from code-dot-org/l2-redis

use redis as an L2 cache for the Script.script_cache stuff

Author: laurelfan

aws/build.rake

@@ -158,6 +158,9 @@ $websites = build_task('websites', [deploy_dir('rebuild'), BLOCKLY_COMMIT_TASK])
     RakeUtils.system 'rake', 'build'
 
     if rack_env?(:production) && CDO.daemon
+      HipChat.log "Putting <b>dashboard</b> scripts in redis..."
+      RakeUtils.rake 'seed:script_cache_to_redis'
+
       thread_count = 1 + (CDO.app_servers.keys.count / 10)
       threaded_each CDO.app_servers.keys, thread_count do |name|
         upgrade_frontend name, CDO.app_servers[name]

dashboard/app/models/script.rb

@@ -73,15 +73,34 @@ def starting_level
     candidate_level
   end
 
-  def self.script_cache
-    @@script_cache ||= {}.tap do |cache|
+  def self.redis
+    @@redis ||= CDO.level_sources_redis_url ? Redis.connect(url:CDO.level_sources_redis_url) : Hash.new
+  end
+
+  def self.script_cache_from_redis
+    if marshalled = self.redis['script-cache']
+      Script.connection # rails doesn't load the mysql libraries unless you ask it to, this confuses Marshal
+      Marshal.load marshalled
+    end
+  end
+
+  def self.script_cache_to_redis
+    redis['script-cache'] = Marshal.dump(script_cache_from_db)
+  end
+
+  def self.script_cache_from_db
+    {}.tap do |cache|
       [twenty_hour_script, frozen_script, hoc_script, flappy_script, playlab_script].each do |script|
         cache[script.name] = script
         cache[script.id.to_s] = script
       end
     end
   end
 
+  def self.script_cache
+    @@script_cache ||= script_cache_from_redis || script_cache_from_db
+  end
+
   def self.get_from_cache(id)
     if self.script_cache[id.to_s]
       self.script_cache[id.to_s]

dashboard/lib/tasks/seed.rake

@@ -295,4 +295,8 @@ namespace :seed do
 
   task all: [:videos, :concepts, :scripts, :trophies, :prize_providers, :callouts, STANFORD_HINTS_IMPORTED, :secret_words, :secret_pictures]
   task incremental: [:videos, :concepts, :scripts_incremental, :trophies, :prize_providers, :callouts, STANFORD_HINTS_IMPORTED, :secret_words, :secret_pictures]
+
+  task script_cache_to_redis: :environment do
+    Script.script_cache_to_redis
+  end
 end

dashboard/test/models/script_test.rb

@@ -208,4 +208,13 @@ def setup
       artist.get_script_level_by_stage_and_position(11, 1)
     end
   end
+
+  test 'gets script cache from redis (or fake redis)' do
+    Script.script_cache_to_redis # in test this is just a hash
+
+    Script.connection.disconnect!     # we don't need no stinkin db
+
+    assert_equal 'Flappy', Script.get_from_cache('flappy').script_levels[3].level.game.name
+    assert_equal 'anna', Script.get_from_cache('frozen').script_levels[5].level.skin
+  end
 end