`rusqlite` includes a mechanism for creating prepared statements that
automatically caches them and reuses the caches when possible. This
means that it's unnecessary for us to do our own caching, and also
offers a minor performance improvement in that we don't need to eagerly
prepare statements that we may not execute in the lifetime of a given
`WalletDb` object. It also improves code locality, because the prepared
statements are now adjacent in the code to the parameter assignment
blocks that correspond to those statements.
This also updates a number of `put_x` methods to use sqlite upsert
functionality via the `ON CONFLICT` clause, instead of having to perform
separate inserts and updates.
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.
This change also settles on `account_value_delta` as the name of the
column in `v_transactions` that describes the transaction's effect on
the value of the associated account.
The remaining uses of `assert!(matches!(...))` are all in cases where
for some reason the `assert_matches` macro interferes with correct
type inference.
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.
The legacy transparent address is never added to the `addresses` table,
but we still need to be able to receive UTXOs sent to that address. So,
we add a special case for when a UTXO matches that legacy address, and
set the account ID to 0 manually.
Due to how the wallets retrieved unspent transparent outputs from the
light wallet server, the account associated with a particular UTXO may
not be known by the light wallet. Instead of requiring the caller to
perform a separate lookup and match the address of the received UTXO
with a known account, it's simpler to perform this lookup internally at
the time of insertion or update.
In order to make this operation more efficient, the `addresses_table`
migration is modified to add a column to cache the transparent receiver
so that it may be used in the joins in the UTXO insert and update
operations.
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 replaces the current wallet initialization code with a migration
that brings the database up to the state produced by release 0.3.0.
A subsequent commit will add migrations that correctly produce the
database state as of zcash/librustzcash@602270cb1f.
Fixes#369
Per ZIP 316, the Sapling FVK Encoding only includes `(ak, nk, ovk, dk)`
which is a subset of the Sapling `ExtendedFullViewingKey`. We therefore
need to use `DiversifiableFullViewingKey` inside `UnifiedFullViewingKey`
in order to make it parseable from the UFVK string encoding.
`zcash_client_sqlite::wallet::get_extended_full_viewing_keys` has been
removed as a consequence of this change: we can no longer reconstruct
the correct `ExtendedFullViewingKey` from the `UnifiedFullViewingKey`.
The account number is not stored in the ZIP 316 UFVK encoding, and in
general won't necessarily be known (e.g. if a UFVK is being imported
into a wallet).
`zcash_client_sqlite::wallet::init::init_accounts_table` reverts to its
previous behaviour of requiring the provided `&[UnifiedFullViewingKey]`
to be indexed by account number.
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.
Kris Nuttycombe
Kris Nuttycombe
Jack Grigg
Francisco Gindre
Kris Nuttycombe
Kevin Gorham