model.py 文件源码

def _increment_atomic_counter(key):
    try:
        entry = _db.config.find_one_and_update(
            {'_id': key},
            {
                '$setOnInsert': {'_id': key},
                '$inc': {'value': 1},
            },
            upsert=True,
            return_document=pymongo.collection.ReturnDocument.AFTER)
    except pymongo.errors.DuplicateKeyError:
        entry = _db.config.find_one_and_update(
            {'_id': key},
            {'$inc': {'value': 1}},
            return_document=pymongo.collection.ReturnDocument.AFTER)
    return entry['value']