The `begin_construction` function now accepts an optional argument
`proto_header`. This is to be used by a new RPC that ease forging the
shell header of a block (i.e. it will compute the fitness and, in a
near future, the hash of the resulting context).
This prepares the context to the inclusion the hash of the context in
the block header. By "looking" into the resulting context of a block,
we are now know able to determine whether:
- no testnet is currently associated to the branch;
- a testnet must be forked after the block;
- a previously forked testnet is running.
The minimal header now (classically) contains the root of a Merkle tree,
wrapping a list of lists of operations. Currently, the validator only
accept a single list of operations, but the 3+pass validator will
requires at least two lists.
Intead of providing a `fitness` function, an economic protocol should
now call `Context.set_fitness`.
This simplify the shell's code and avoid complexity on protocol
change. Previously the fitness of a context produced by the old protocol
had to be read by the new protocol. Now, the shell read the context
without requesting the help of the economic protocol.
This refactors `src/node/shell/state.ml` in order to trace the source of
blocks and operations. This prepares the node for the three-pass
validator.
In the procces, it adds an in-memory overlay for blocks and operations.
