lib/popcorn/pop_tasks.nit

   1 # This file is part of NIT ( http://www.nitlanguage.org ).
   2 #
   3 # Copyright 2016 Alexandre Terrasa <alexandre@moz-code.org>
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License");
   6 # you may not use this file except in compliance with the License.
   7 # You may obtain a copy of the License at
   8 #
   9 #     http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 # See the License for the specific language governing permissions and
  15 # limitations under the License.
  16
  17 # Popcorn threaded tasks
  18 #
  19 # Tasks allow you to execute code in another thread than the app listening loop.
  20 # Useful when you want to run some tasks periodically.
  21 #
  22 # Let's say you want to purge the `downloads/` directory of your app every hour:
  23 #
  24 # ~~~nitish
  25 # class PurgeTask
  26 #       super PopTask
  27 #
  28 #       var dir: String
  29 #
  30 #       redef fun main do
  31 #               loop
  32 #                       dir.rmdir
  33 #                       3600.sleep
  34 #               end
  35 #       end
  36 # end
  37 #
  38 # var app = new App
  39 #
  40 # # Register a new task
  41 # app.register_task(new PurgeTask("downloads/"))
  42 #
  43 # # Add your handlers
  44 # # app.use('/', new MyHandler)
  45 #
  46 # # Run the tasks
  47 # app.run_tasks
  48 #
  49 # # Start the app
  50 # app.listen("0.0.0.0", 3000)
  51 # ~~~
  52 module pop_tasks
  53
  54 import pop_handlers
  55 import pthreads
  56
  57 # An abstract Popcorn task
  58 #
  59 # Redefine the `main` method to do something
  60 #
  61 # TODO provide a CRON-like syntax like SpringBoot?
  62 abstract class PopTask
  63         super Thread
  64
  65         redef fun main do return null
  66 end
  67
  68 redef class App
  69
  70         # Tasks to run
  71         var tasks = new Array[PopTask]
  72
  73         # Register a new task in `self`
  74         fun register_task(task: PopTask) do tasks.add task
  75
  76         # Run all registered tasks
  77         fun run_tasks do for task in tasks do task.start
  78 end