def get(instance_type):
nowtime = datetime.datetime.now(pytz.utc)
cached = None
if instance_type in SpotPriceCache.CACHE:
cached = SpotPriceCache.CACHE[instance_type]
if (cached['time'] - nowtime).total_seconds() < SpotPriceCache.SPOT_PRICE_REFETCH_SECS:
cached = None
if cached is None:
newprices = Cluster.get_spot_price(instance_type)
cached = {
'time': nowtime,
'prices': newprices
}
SpotPriceCache.CACHE[instance_type] = cached
return cached['prices']