Added background scheduler and scheduled thumbnail generation job

cps.py

@@ -43,7 +43,6 @@ from cps.gdrive import gdrive
 from cps.editbooks import editbook
 from cps.remotelogin import remotelogin
 from cps.error_handler import init_errorhandler
-from cps.thumbnails import generate_thumbnails
 
 try:
     from cps.kobo import kobo, get_kobo_activated
@@ -79,9 +78,6 @@ def main():
         app.register_blueprint(kobo_auth)
     if oauth_available:
         app.register_blueprint(oauth)
-
-    generate_thumbnails()
-
     success = web_server.start()
     sys.exit(0 if success else 1)
 

cps/__init__.py

@@ -36,6 +36,8 @@ from flask_principal import Principal
 from . import config_sql, logger, cache_buster, cli, ub, db
 from .reverseproxy import ReverseProxied
 from .server import WebServer
+from .services.background_scheduler import BackgroundScheduler
+from .tasks.thumbnail import TaskThumbnail
 
 
 mimetypes.init()
@@ -115,8 +117,13 @@ def create_app():
                                            config.config_goodreads_api_secret,
                                            config.config_use_goodreads)
 
+    scheduler = BackgroundScheduler()
+    # Generate 100 book cover thumbnails every 5 minutes
+    scheduler.add_task(user=None, task=lambda: TaskThumbnail(config=config, limit=100), trigger='interval', minutes=5)
+
     return app
 
+
 @babel.localeselector
 def get_locale():
     # if a user is logged in, use the locale from the user settings

cps/services/background_scheduler.py

@@ -0,0 +1,52 @@
+# -*- coding: utf-8 -*-
+
+#   This file is part of the Calibre-Web (https://github.com/janeczku/calibre-web)
+#     Copyright (C) 2020 mmonkey
+#
+#   This program is free software: you can redistribute it and/or modify
+#   it under the terms of the GNU General Public License as published by
+#   the Free Software Foundation, either version 3 of the License, or
+#   (at your option) any later version.
+#
+#   This program is distributed in the hope that it will be useful,
+#   but WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#   GNU General Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License
+#   along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+from __future__ import division, print_function, unicode_literals
+import atexit
+
+from .. import logger
+from .worker import WorkerThread
+from apscheduler.schedulers.background import BackgroundScheduler as BScheduler
+
+
+class BackgroundScheduler:
+    _instance = None
+
+    def __new__(cls):
+        if cls._instance is None:
+            cls._instance = super(BackgroundScheduler, cls).__new__(cls)
+
+            scheduler = BScheduler()
+            atexit.register(lambda: scheduler.shutdown())
+
+            cls.log = logger.create()
+            cls.scheduler = scheduler
+            cls.scheduler.start()
+
+        return cls._instance
+
+    def add(self, func, trigger, **trigger_args):
+        self.scheduler.add_job(func=func, trigger=trigger, **trigger_args)
+
+    def add_task(self, user, task, trigger, **trigger_args):
+        def scheduled_task():
+            worker_task = task()
+            self.log.info('Running scheduled task in background: ' + worker_task.name + ': ' + worker_task.message)
+            WorkerThread.add(user, worker_task)
+
+        self.add(func=scheduled_task, trigger=trigger, **trigger_args)

cps/tasks/thumbnail.py

@@ -19,7 +19,7 @@
 from __future__ import division, print_function, unicode_literals
 import os
 
-from cps import config, db, gdriveutils, logger, ub
+from cps import db, logger, ub
 from cps.constants import CACHE_DIR as _CACHE_DIR
 from cps.services.worker import CalibreTask
 from datetime import datetime, timedelta
@@ -36,8 +36,9 @@ THUMBNAIL_RESOLUTION_2X = 2.0
 
 
 class TaskThumbnail(CalibreTask):
-    def __init__(self, limit=100, task_message=u'Generating cover thumbnails'):
+    def __init__(self, config, limit=100, task_message=u'Generating cover thumbnails'):
         super(TaskThumbnail, self).__init__(task_message)
+        self.config = config
         self.limit = limit
         self.log = logger.create()
         self.app_db_session = ub.get_new_session_instance()
@@ -47,9 +48,6 @@ class TaskThumbnail(CalibreTask):
         if self.worker_db.session and use_IM:
             thumbnails = self.get_thumbnail_book_ids()
             thumbnail_book_ids = list(map(lambda t: t.book_id, thumbnails))
-            self.log.info(','.join([str(elem) for elem in thumbnail_book_ids]))
-            self.log.info(len(thumbnail_book_ids))
-
             books_without_thumbnails = self.get_books_without_thumbnails(thumbnail_book_ids)
 
             count = len(books_without_thumbnails)
@@ -116,10 +114,10 @@ class TaskThumbnail(CalibreTask):
 
     def generate_book_thumbnail(self, book, thumbnail):
         if book and thumbnail:
-            if config.config_use_google_drive:
+            if self.config.config_use_google_drive:
                 self.log.info('google drive thumbnail')
             else:
-                book_cover_filepath = os.path.join(config.config_calibre_dir, book.path, 'cover.jpg')
+                book_cover_filepath = os.path.join(self.config.config_calibre_dir, book.path, 'cover.jpg')
                 if os.path.isfile(book_cover_filepath):
                     with Image(filename=book_cover_filepath) as img:
                         height = self.get_thumbnail_height(thumbnail)

cps/thumbnails.py

@@ -57,7 +57,3 @@ def cover_thumbnail_exists_for_book(book):
             return thumbnail_path and os.path.isfile(thumbnail_path)
 
     return False
-
-
-def generate_thumbnails():
-    WorkerThread.add(None, TaskThumbnail())

requirements.txt

@@ -1,3 +1,4 @@
+APScheduler==3.6.3
 Babel>=1.3, <2.9
 Flask-Babel>=0.11.1,<2.1.0
 Flask-Login>=0.3.2,<0.5.1