There are cases where we wish to return informaiton that is relevant to
a specific shielded protocol and `Transparent` is an invalid case. This
is a minor preparatory refactoring that makes this distinction
expressible.
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.
Memos may be absent for both sent and received notes in cases where only
compact block information has been used to populate the wallet database.
This fixes a potential crash in the case that we attempt to decode a
SQLite `NULL` as a byte array. It does, however, introduce a slight
semantic confusion that will need to be considered in the case of future
updates where a note may not have an associated memo; at present, the
only reason we might not have the memo is that we might not have
retrieved the full transaction information from the chain, but in the
future there might be other possible reasons for this absence.
Fixes#384
This is in preparation for extraction into the `incrementalmerkletree`
crate, which is not Sapling-specific and therefore cannot hard-code
the depths of these data structures.
This better reflects the semantics of wallet behavior. Also, this
adds a `zcash_client_backend::WalletRead::get_min_unspent_height`
method that replaces the deprecated & removed (and misleadingly
named) `get_rewind_height` method.
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 set of abstractions that allow wallets to provide
independent strategies for fee estimation and note selection, and
implementations of these strategies that perform these operations in the
same fashion as the existing `spend` and `shield_transparent_funds`
functions.
This required a somewhat hefty rework of the error handling in
zcash_client_backend. It fixes an issue with the error types whereby
callees needed to have a bit too much information about the error
types produced by their callers.
Reflect the updated note selection and error handling in zcash_client_sqlite.
Previously, `shield_transparent_funds` was only shielding funds
associated with the legacy default transparent address. This meant
that transparent funds sent to unified addresses could not reliably
be shielded, as a unified address will frequently be constructed
using a diversifier index greater than zero.
This modifies the `get_transparent_receivers` method to return address
metadata containing the account ID and diversifier index used to derive
each address along with the receiver.
These traits introduce a problem, in that constraints on a method cannot
be conditionally required based upon the presence or absence of a
feature flag. Instead, we make the methods previously introduced by
the removed traits present in all cases on the `WalletRead` and
`WalletWrite` traits, but ensure that their implementations return
an error if the caller attempts to use them in a wallet that has not
been configured with support for transparent inputs functionality.
The currently deprecated implementations of `insert_sent_utxo`,
`insert_sent_note`, `put_sent_utxo` and `put_sent_note` all store to the
same `sent_notes` table internally. Since there's no immediate plan to
change this arrangement, it's better to have a single pair of internal
`insert_sent_output` and `put_sent_output` methods instead.
This updates the data access API to provide diversified address
functionality. In order to support this change, the addresses table
is updated to store diversifier index information in big-endian order
to allow sorting by diversifier index, and account initialization
is updated to store the diversifier index accordingly. The currently
unreleased `addresses_table` migration is updated to reflect this
change.
This fixes a bug in the logic ported from the Android SDK: it was
possible to remove a transaction in the middle of a chain, which would
cause a long-spent note to become unspent and cause the wallet balance
to be over-counted. We now restrict transaction removal to unmined
transactions, which is sufficient for the Android SDK use cases.
This is to replace the database mutations in the Android SDK. It is
placed behind an `unstable` feature flag until we are satisfied that it
is suitable as a general-purpose API (or replace it).
This is a breaking change to the database format. We don't have support
for migrations yet, so existing wallets won't work after this commit
until zcash/librustzcash#489 is done.
Add retrieval of transparent UTXOs to WalletRead
Co-authored-by: Kris Nuttycombe <kris@electriccoin.co>
Co-authored-by: Kevin Gorham <anothergmale@gmail.com>
`create_spend_to_address` was originally written only for sending to
Sapling addresses. It was later amended to support sending to
transparent addresses, but the assumption about there being a Sapling
output was not removed. This was not an issue for most transactions
because there would be change, but in the case of a z->t transaction
with no change, `create_spend_to_address` would reliably panic.
This commit fixes the bug by setting the output index for transparent
recipients to 0. The `output_index` field of `SentTransaction` is also
documented to correctly reflect its dependency on the type of
`recipient_address`.
The MemoBytes struct is a minimal wrapper around the memo bytes, and only
imposes the existence of null-padding for shorter memos. The only error
case is attempting to construct a memo that is too long. MemoBytes is
guaranteed to be round-trip encodable (modulo null padding).
The Memo enum implements the additional memo rules defined in ZIP 302,
interpreting the contents of a memo (for example, parsing it as text).
Also move dependency on params out of wallet read/write methods.
The result is cleaner because these parameters are only required
for backend-specific encoding and decoding operations.
Kris Nuttycombe
Kris Nuttycombe
Francisco Gindre
Jack Grigg
Kris Nuttycombe
Kevin Gorham
Jack Grigg