added a task scheduler for recurring tasks

src/documents/tasks.py

@@ -0,0 +1,57 @@
+import logging
+
+from django.conf import settings
+from django_q.tasks import async_task, result
+from whoosh.writing import AsyncWriter
+
+from documents import index
+from documents.classifier import DocumentClassifier, \
+    IncompatibleClassifierVersionError
+from documents.mail import MailFetcher
+from documents.models import Document
+
+
+def consume_mail():
+    MailFetcher().pull()
+
+
+def index_optimize():
+    index.open_index().optimize()
+
+
+def index_reindex():
+    documents = Document.objects.all()
+
+    ix = index.open_index(recreate=True)
+
+    with AsyncWriter(ix) as writer:
+        for document in documents:
+            index.update_document(writer, document)
+
+
+def train_classifier():
+    classifier = DocumentClassifier()
+
+    try:
+        # load the classifier, since we might not have to train it again.
+        classifier.reload()
+    except (FileNotFoundError, IncompatibleClassifierVersionError):
+        # This is what we're going to fix here.
+        pass
+
+    try:
+        if classifier.train():
+            logging.getLogger(__name__).info(
+                "Saving updated classifier model to {}...".format(
+                    settings.MODEL_FILE)
+            )
+            classifier.save_classifier()
+        else:
+            logging.getLogger(__name__).debug(
+                "Training data unchanged."
+            )
+
+    except Exception as e:
+        logging.getLogger(__name__).error(
+            "Classifier error: " + str(e)
+        )