From 508f49df18cef291ec576c96407444f1738b3e90 Mon Sep 17 00:00:00 2001
From: blitzmann <holmes.ryan.90@gmail.com>
Date: Sun, 23 Aug 2020 23:00:23 -0400
Subject: [PATCH] Remove completed tasks and sort the tasks by date added when
 calling `.tasks`

---
 cps/helper.py          |  2 +-
 cps/services/worker.py | 51 ++++++++++++++++++++++--------------------
 2 files changed, 28 insertions(+), 25 deletions(-)

diff --git a/cps/helper.py b/cps/helper.py
index e3a0e5b1..2b2a0adb 100644
--- a/cps/helper.py
+++ b/cps/helper.py
@@ -723,7 +723,7 @@ def format_runtime(runtime):
 # helper function to apply localize status information in tasklist entries
 def render_task_status(tasklist):
     renderedtasklist = list()
-    for user, task in tasklist:
+    for user, added, task in tasklist:
         if user == current_user.nickname or current_user.role_admin():
             ret = {}
             if task.start_time:
diff --git a/cps/services/worker.py b/cps/services/worker.py
index e4ccf988..bb3e3b07 100644
--- a/cps/services/worker.py
+++ b/cps/services/worker.py
@@ -1,16 +1,18 @@
 
 from __future__ import division, print_function, unicode_literals
 import threading
+import abc
+import uuid
 
 try:
     import queue
 except ImportError:
     import Queue as queue
 from datetime import datetime
+from collections import namedtuple
 
 from cps import calibre_db
 from cps import logger
-import abc
 
 log = logger.create()
 
@@ -20,6 +22,11 @@ STAT_FAIL = 1
 STAT_STARTED = 2
 STAT_FINISH_SUCCESS = 3
 
+# Only retain this many tasks in dequeued list
+TASK_CLEANUP_TRIGGER = 20
+
+QueuedTask = namedtuple('QueuedTask', 'user, added, task')
+
 
 def _get_main_thread():
     for t in threading.enumerate():
@@ -51,10 +58,7 @@ class WorkerThread(threading.Thread):
     def __init__(self):
         threading.Thread.__init__(self)
 
-        self.finished = list()
-
-        self.db_queue = queue.Queue()
-        calibre_db.add_queue(self.db_queue)
+        self.dequeued = list()
 
         self.doLock = threading.Lock()
         self.queue = ImprovedQueue()
@@ -64,43 +68,41 @@ class WorkerThread(threading.Thread):
     @classmethod
     def add(cls, user, task):
         ins = cls.getInstance()
-        ins.queue.put((user, task))
+        ins.queue.put(QueuedTask(
+            user=user,
+            added=datetime.now(),
+            task=task,
+        ))
 
     @property
     def tasks(self):
         with self.doLock:
-            tasks = list(self.queue.to_list()) + self.finished
-        return tasks  # todo: order by data added
+            tasks = list(self.queue.to_list()) + self.dequeued
+        return sorted(tasks, key=lambda x: x.added)
 
     # Main thread loop starting the different tasks
     def run(self):
         main_thread = _get_main_thread()
         while main_thread.is_alive():
-            user, item = self.queue.get()
+            item = self.queue.get()
 
             # add to list so that in-progress tasks show up
             with self.doLock:
-                self.finished.append((user, item))
+                # Remove completed tasks if needed
+                if len(self.dequeued) > TASK_CLEANUP_TRIGGER:
+                    # sort first (just to be certain), then lob off the extra
+                    self.dequeued = sorted(self.dequeued, key=lambda x: x.added)[-1 * TASK_CLEANUP_TRIGGER:]
+                self.dequeued.append(item)
+
+            user, added, task = item
 
             # sometimes tasks (like Upload) don't actually have work to do and are created as already finished
-            if item.stat is STAT_WAITING:
+            if task.stat is STAT_WAITING:
                 # CalibreTask.start() should wrap all exceptions in it's own error handling
-                item.start(self)
+                task.start(self)
 
             self.queue.task_done()
 
-    def _delete_completed_tasks(self):
-        raise NotImplementedError()
-        # for index, task in reversed(list(enumerate(self.UIqueue))):
-        #     if task['progress'] == "100 %":
-        #         # delete tasks
-        #         self.queue.pop(index)
-        #         self.UIqueue.pop(index)
-        #         # if we are deleting entries before the current index, adjust the index
-        #         if index <= self.current and self.current:
-        #             self.current -= 1
-        # self.last = len(self.queue)
-
 class CalibreTask:
     __metaclass__ = abc.ABCMeta
 
@@ -111,6 +113,7 @@ class CalibreTask:
         self.start_time = None
         self.end_time = None
         self.message = message
+        self.id = uuid.uuid4()
 
     @abc.abstractmethod
     def run(self, worker_thread):