This implements the necessary state machine for taking a wallet in some
arbitrary synchronization status, and fully scanning (the remainder of)
the chain.
Closeszcash/librustzcash#1169.
In the event that the pool to which change should be sent cannot
automatically be determined based upon the inputs and outputs of a
transaction, it is up to the caller to specify where change should
be sent.
This change makes it easier for third parties to make use of the Unified
key infrastructure without incurring a dependency upon the rest of the
`zcash_client_backend` interfaces.
We plan to also introduce a similar flag to gate access to Sapling
functionality. Since introduction of Orchard functionality is still
nascent, it's the correct time to introduce this isolation, before
there's more functionality that needs to be isolated in this fashion.
In preparation for out-of-order range-based scanning, it is necessary
to ensure that the size of the Sapling note commitment tree is carried
along through the scan process and that stored blocks are always
persisted with the updated note commitment tree size.
The change selection algorithm has the most useful information for
determining whether or not a note is dust, so this adds a new error case
to `ChangeError` that allows the change selection to report the presence
of input notes without economic value back to its caller.
This adds a fee calculation strategy abstraction that can be used to
dynamically compute fees so that the total fees required may be taken
taken into account during note selection, and also removes automatic
change creation from the transaction builder.
Change outputs must now be directly created by the caller by the caller.
This is a necessary prerequisite for permitting fees to adjust based
upon the contents of the transaction being constructed.
The initial implementation of the fee strategy simply uses the current
default fee.
In the interest of making the library usable for both
testnet and mainnet without recompilation, static resolution
of network parameters has been replaced with a parameter passed
to the relevant functions. This also moves addres prefix constants
into the network parameters.
Kris Nuttycombe
Jack Grigg
Kris Nuttycombe
Jack Grigg
Kris Nuttycombe