58 lines
1.6 KiB
Python
58 lines
1.6 KiB
Python
from datetime import datetime, timedelta
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from database import QueueItem
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class WorkQueue(object):
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def __init__(self, queue_name):
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self.queue_name = queue_name
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def put(self, message, available_after=0):
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"""
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Put an item, if it shouldn't be processed for some number of seconds,
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specify that amount as available_after.
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"""
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params = {
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'queue_name': self.queue_name,
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'body': message,
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}
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if available_after:
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available_date = datetime.now() + timedelta(seconds=available_after)
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params['available_after'] = available_date
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QueueItem.create(**params)
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def get(self, processing_time=300):
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"""
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Get an available item and mark it as unavailable for the default of five
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minutes.
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"""
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now = datetime.now()
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available_or_expired = (QueueItem.available == True |
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QueueItem.processing_expires <= now)
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# TODO the query and the update should be atomic, but for now we only
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# have one worker.
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avail = QueueItem.select().where(QueueItem.queue_name == self.queue_name,
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QueueItem.available_after <= now,
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available_or_expired)
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found = list(avail.limit(1).order_by(QueueItem.available_after))
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if found:
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item = found[0]
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item.available = False
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item.processing_expires = now + timedelta(seconds=processing_time)
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item.save()
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return item
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return None
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def complete(self, completed_item):
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completed_item.delete_instance()
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image_diff_queue = WorkQueue('imagediff')
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