Caching

The LatestValueCache caches the latest value in a receiver.

It provides a way to look up the latest value in a stream whenever required, as long as there has been one value received.

LatestValueCache takes a Receiver as an argument and stores the latest value received by that receiver. As soon as a value is received, its has_value method returns True, and its get method returns the latest value received. The get method will raise an exception if called before any messages have been received from the receiver.

Example:

from frequenz.channels import Broadcast, LatestValueCache

channel = Broadcast[int](name="lvc_test")

cache = LatestValueCache(channel.new_receiver())
sender = channel.new_sender()

assert not cache.has_value()

await sender.send(5)

assert cache.has_value()
assert cache.get() == 5