Instead of calling `put_block` for each block scanned,
`scan_cached_blocks` will now defer the block writes until the scan of a
batch is complete and will perform the block writes and note commitment
tree updates all within a single transaction.
This should ordinarily be fine in terms of memory consumption, because
the block data being saved is pruned to only that spend an output
information that is related to transactions in the wallet, which will
normally be sparse enough that the block range size that is appropriate
for a given platform to run within a batch scanner adequately bounds the
memory consumption of this pruned representation.
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.
Local chain validation will be performed internal to
`scan_cached_blocks`, and as handling of chain reorgs will need to
change to support out-of-order scanning, the `validate_chain` method
will be superfluous. It is removed in advance of other changes in order
to avoid updating it to reflect the forthcoming changes.
We move thes fields out into a separate BlockMetadata struct to ensure
that future additions to block metadata are structurally separated from
future additions to block data.
`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.
Fixes#384
(cherry picked from commit d99b4d4d6e)
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 removes the `CommitmentTree`, `IncrementalWitness`, and
`MerklePath` types in favor of equivalent versions available
from the `incrementalmerkletree` crate.
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.
This removes the path-based dependencies on the `zcash_note_encryption`
crate in favor of using versioned dependencies locally. This better
reflects the future state in which `zcash_note_encryption` is factored
out of the workspace and maintained in a separate repository.
The `halo2_proofs/multicore` flag must be disabled when running wasm
builds; this ensures that we do not accidentally include it as a
transitive dependency when building with `--no-default-features`.
This change makes it possible for wallets using the
`zcash_client_backend::data_api::wallet` module to perform transaction
preparation, including input selection and fee calculation, as an
independent step prior to creating proofs and signatures. This can be
used to improve user experience by making it possible to report the
proposed effects of the transaction to the wallet user (including
privacy implications) prior to authorizing the transaction.
Previously, if a caller wanted to use a block source to perform
scanning from the first available block, they would have to guess
at the block height to start from. Changing this to an optional
argument makes this explicit.
This allows callers to validate smaller intervals of the given
`BlockSourceT` shortening processing times of the function call at the
expense of obtaining a partial result on a given section of interest of
the block source.
`params: &ParamsT` has been removed from the arguments since they were
only needed to fall back to `sapling_activation_height` when `None` as
passed as the `validate_from` argument. Passing `None` as validation
start point on a pre-populated `block_source` would result in an error
`ChainError::block_height_discontinuity(sapling_activation_height - 1, current_height)`
With this new API callers must specify a concrete `validate_from`
argument and assume that `validate_chain` will not take any default
fallbacks to chain `ParamsT`.
The addition of a `limit` to the chain validation function changes the
meaning of its successful output, being now a `BlockHeight, BlockHash)`
tuple indicating the block height and block hash up to which the chain
as been validated on its continuity of heights and hashes. Callers
providing a `limit` aregument are responsible of subsequent calls to
`validate_chain()` to complete validating the remaining blocks stored on
the `block_source`.
Closeszcash/librustzcash#705
The MSRVs of the component crates are left as-is, partly because our
dependencies don't require us to bump them, and partly because those
crates have no pending changes and are relatively stable. We also plan
to split the component crates out into a separate repository, where it
will be easier to have a separate MSRV.
Closeszcash/librustzcash#759.
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.
Kris Nuttycombe
Kris Nuttycombe
Nate Wilcox
Jack Grigg
Daira Emma Hopwood
Hazel OHearn
Francisco Gindre
Dimitris Apostolou
Sean Bowe