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mayan-edms/apps/ocr/tasks.py

58 lines
2.3 KiB
Python

from datetime import timedelta, datetime
import platform
import time
import random
from django.db.models import Q
from celery.decorators import task, periodic_task
from ocr.api import do_document_ocr
from ocr.literals import QUEUEDOCUMENT_STATE_PENDING, \
QUEUEDOCUMENT_STATE_PROCESSING, DOCUMENTQUEUE_STATE_ACTIVE, \
QUEUEDOCUMENT_STATE_ERROR
from ocr.models import QueueDocument, DocumentQueue
from ocr.conf.settings import NODE_CONCURRENT_EXECUTION
from ocr.conf.settings import REPLICATION_DELAY
@task
def task_process_queue_document(queue_document_id):
queue_document = QueueDocument.objects.get(id=queue_document_id)
if queue_document.state == QUEUEDOCUMENT_STATE_PROCESSING:
#Recheck to avoid race condition
return
queue_document.state = QUEUEDOCUMENT_STATE_PROCESSING
queue_document.node_name = platform.node()
queue_document.save()
try:
do_document_ocr(queue_document.document)
queue_document.delete()
except Exception, e:
queue_document.state = QUEUEDOCUMENT_STATE_ERROR
queue_document.result = e
queue_document.save()
@periodic_task(run_every=timedelta(seconds=15))
def task_process_document_queues():
#Introduce random 0 < t < 1 second delay to further reduce the
#chance of a race condition
time.sleep(random.random())
q_pending = Q(state=QUEUEDOCUMENT_STATE_PENDING)
q_delayed = Q(delay=True)
q_delay_interval = Q(datetime_submitted__lt=datetime.now() - timedelta(seconds=REPLICATION_DELAY))
for document_queue in DocumentQueue.objects.filter(state=DOCUMENTQUEUE_STATE_ACTIVE):
if QueueDocument.objects.filter(
state=QUEUEDOCUMENT_STATE_PROCESSING).filter(
node_name=platform.node()).count() < NODE_CONCURRENT_EXECUTION:
try:
oldest_queued_document_qs = document_queue.queuedocument_set.filter(
(q_pending & ~q_delayed) | (q_pending & q_delayed & q_delay_interval))
if oldest_queued_document_qs:
oldest_queued_document = oldest_queued_document_qs.order_by('datetime_submitted')[0]
task_process_queue_document.delay(oldest_queued_document.id)
except Exception, e:
print 'DocumentQueueWatcher exception: %s' % e