* feat: add support for generating tipset CIDs
(cherry-picked from feat/nv18-fevm)
* feat: fvm: add support for looking up past tipset CIDs
We do this by adding yet another "getter" to the VM that resolves an
epoch into a TipSetKey.
Co-authored-by: Kevin Li <ychiaoli18@users.noreply.github.com>
The next FVM version will only support nv15+.
This change also disables the FVM before nv15, even if enabled through
the environment variable. This allows "catching up" from before nv15.
This paves the way for better object lifetime management.
Concretely, it makes it possible to:
- have different stores backing chain and state data.
- having the same datastore library, but using different parameters.
- attach different caching layers/policies to each class of data, e.g.
sizing caches differently.
- specifying different retention policies for chain and state data.
This separation is important because:
- access patterns/frequency of chain and state data are different.
- state is derivable from chain, so one could never expunge the chain
store, and only retain state objects reachable from the last finality
in the state store.
_Always_ (almost) use the tipset's parent state, instead of computing.
Exceptions:
* MinerGetBaseInfo. Fixing this would break things so we need to be
careful (although we could bump the API version, fix it, then fix the call
sites).
* StateReplay. This is replaying a message on top of the given tipset.
* GasEstimateGasLimit. This executes the message on-top-of the tipset's
computed state (unlike call which executes it on the tipset's parent state).
* Having this method and Call apply the message at different heights is really
weird.
Method numbers never change anyways. At worst, we'll deprecate old methods and
have to explicitly import them from the correct actors version to use them.
If miner is found in current state, just return nil base info as miner
cannot mine if he is not found in the lookback.
Signed-off-by: Jakub Sztandera <kubuxu@protocol.ai>
