Summary & Motivation

This creates a new StateBackedComponent class that takes advantage of the new StateStore object.

Subclasses of StateBackedComponent will implement two methods:

build_defs_from_state: given a path to a state file, they will return a Definitions object. two things to note here:

• this is a filepath, not an in-memory object. this helps for potential cases like dbt where we just need to forward the path to some other tool rather than paying the cost of reading it all into memory.
• this is an optional filepath. this gives the user control over what happens in the case that no state currently exists. in our current system / integrations, we always automatically invoke the "rebuild state" functionality when there is no existing state, but this is likely not the right thing to do in the new world where we expect to be able to deploy an initial version of our code before any state has been stored and not have that lock up the code server for minutes as it rebuilds that initial state.

write_state_to_path: the user code is given a path in which to write some state. The reason that the path is passed into this method is so that the framework can control the lifecycle of this path (i.e. making sure it gets cleaned up after we upload it).

How I Tested These Changes

Changelog

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