Add a fast unlock computing implementation

Author: nygrenh

Gemfile

@@ -17,6 +17,7 @@ gem 'newrelic_rpm', '~> 4.8', '>= 4.8.0.341'
 gem 'paperclip', '~> 5.0'
 gem 'pdfkit', '~> 0.8.2'
 gem 'pg', '~> 0.19.0'
+gem 'activerecord-import', '~> 0.28.1'
 gem 'rack-cors'
 gem 'rake'
 gem 'responders', '~> 2.0'

Gemfile.lock

@@ -30,6 +30,8 @@ GEM
       activemodel (= 4.2.10)
       activesupport (= 4.2.10)
       arel (~> 6.0)
+    activerecord-import (0.28.1)
+      activerecord (>= 3.2)
     activerecord-session_store (1.0.0)
       actionpack (>= 4.0, < 5.1)
       activerecord (>= 4.0, < 5.1)
@@ -367,6 +369,7 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
+  activerecord-import (~> 0.28.1)
   activerecord-session_store (~> 1.0.0)
   andand
   bootstrap (~> 4.0.0.beta2.1)

app/models/unlock.rb

@@ -65,4 +65,26 @@ def self.refresh_unlocks_impl(course, user, user_unlocks_by_exercise_name)
         end
       end
     end
+
+    def self.fast_refresh_unlocks_impl(course, user, user_unlocks_by_exercise_name)
+      # We can share the calculation between the exercises that have the same condition
+      new_unlocks = []
+      course.exercises.enabled.group_by { |o| o.unlock_spec }.each do |_spec, exercises|
+        exercise = exercises.first
+        existing = user_unlocks_by_exercise_name[exercise.name]
+        exists = !!existing
+        may_exist = exercise.requires_unlock? && exercise.unlock_spec_obj.permits_unlock_for?(user)
+        next unless !exists && may_exist && !exercise.requires_explicit_unlock?
+
+        exercises.select { |e| !user_unlocks_by_exercise_name[e.name] }.each do |exercise|
+          new_unlocks << Unlock.new(
+            user: user,
+            course: course,
+            exercise: exercise,
+            valid_after: exercise.unlock_spec_obj.valid_after
+          )
+        end
+      end
+      Unlock.import new_unlocks
+    end
 end

script/background_daemon

@@ -21,7 +21,7 @@ Daemons.run_proc('background_daemon', dir_mode: :normal, dir: pid_dir, log_dir:
   require root_dir + '/config/environment'
   Rails.logger = Logger.new(Rails.root.join('log', 'background_daemon.log'))
   Rails.logger.auto_flushing = true if Rails.logger.respond_to? :auto_flushing=
-  ActiveRecord::Base.connection_config[:pool] = 20
+  ActiveRecord::Base.connection_config[:pool] = 25
 
   # Tasks may be longrunning so we want each one in a thread so one task won't
   # block other ones.