Files
mayan-edms/mayan/apps/ocr/tasks.py
2014-06-20 19:59:33 -04:00

77 lines
2.9 KiB
Python

from __future__ import absolute_import
from datetime import timedelta, datetime
import logging
import platform
from django.db.models import Q
from job_processor.api import process_job
from lock_manager import Lock, LockError
from .api import do_document_ocr
from .conf.settings import (NODE_CONCURRENT_EXECUTION, REPLICATION_DELAY,
QUEUE_PROCESSING_INTERVAL)
from .literals import (QUEUEDOCUMENT_STATE_PENDING,
QUEUEDOCUMENT_STATE_PROCESSING, DOCUMENTQUEUE_STATE_ACTIVE,
QUEUEDOCUMENT_STATE_ERROR)
from .models import QueueDocument, DocumentQueue
LOCK_EXPIRE = 60 * 10 # Lock expires in 10 minutes
# TODO: Tie LOCK_EXPIRATION with hard task timeout
logger = logging.getLogger(__name__)
def task_process_queue_document(queue_document_id):
lock_id = u'task_proc_queue_doc-%d' % queue_document_id
try:
logger.debug('trying to acquire lock: %s' % lock_id)
lock = Lock.acquire_lock(lock_id, LOCK_EXPIRE)
logger.debug('acquired lock: %s' % lock_id)
queue_document = QueueDocument.objects.get(pk=queue_document_id)
queue_document.state = QUEUEDOCUMENT_STATE_PROCESSING
queue_document.node_name = platform.node()
queue_document.save()
try:
do_document_ocr(queue_document)
queue_document.delete()
except Exception, e:
queue_document.state = QUEUEDOCUMENT_STATE_ERROR
queue_document.result = e
queue_document.save()
lock.release()
except LockError:
logger.debug('unable to obtain lock')
pass
def task_process_document_queues():
logger.debug('executed')
# TODO: reset_orphans()
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):
current_local_processing_count = QueueDocument.objects.filter(
state=QUEUEDOCUMENT_STATE_PROCESSING).filter(
node_name=platform.node()).count()
if current_local_processing_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]
process_job(task_process_queue_document, oldest_queued_document.pk)
except Exception, e:
logger.error('unhandled exception: %s' % e)
finally:
# Don't process anymore from this queryset, might be stale
break
else:
logger.debug('already processing maximum')
else:
logger.debug('nothing to process')