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feat(params): Add method new_single_descriptor
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The change descriptor is made optional, making this an effective
reversion of bitcoindevkit#1390 and enables creating wallets with a single
descriptor.
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@ValuedMammal
ValuedMammal committed Aug 1, 2024
1 parent 785371e commit dcb4f70
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Showing 3 changed files with 186 additions and 78 deletions.
188 changes: 114 additions & 74 deletions crates/wallet/src/wallet/mod.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -347,20 +347,22 @@ impl Wallet {
let (descriptor, mut descriptor_keymap) = (params.descriptor)(&secp, network)?;
descriptor_keymap.extend(params.descriptor_keymap);

let (change_descriptor, mut change_descriptor_keymap) =
(params.change_descriptor)(&secp, network)?;
change_descriptor_keymap.extend(params.change_descriptor_keymap);

let signers = Arc::new(SignersContainer::build(
descriptor_keymap,
&descriptor,
&secp,
));
let change_signers = Arc::new(SignersContainer::build(
change_descriptor_keymap,
&change_descriptor,
&secp,
));

let (change_descriptor, change_signers) = match params.change_descriptor {
Some(desc_fn) => {
let (descriptor, mut keymap) = desc_fn(&secp, network)?;
keymap.extend(params.change_descriptor_keymap);
let change_signers = Arc::new(SignersContainer::build(keymap, &descriptor, &secp));
(Some(descriptor), change_signers)
}
None => (None, Arc::new(SignersContainer::new())),
};

let index = create_indexer(descriptor, change_descriptor, params.lookahead)?;

let descriptor = index.get_descriptor(KeychainKind::External).cloned();
Expand Down Expand Up @@ -457,10 +459,33 @@ impl Wallet {
check_wallet_descriptor(&descriptor).map_err(LoadError::Descriptor)?;

let mut change_descriptor_keymap = params.change_descriptor_keymap;
let change_descriptor = changeset
.change_descriptor
.ok_or(LoadError::MissingDescriptor(KeychainKind::Internal))?;
check_wallet_descriptor(&change_descriptor).map_err(LoadError::Descriptor)?;

let (change_descriptor, change_signers) = match changeset.change_descriptor {
Some(change_descriptor) => {
check_wallet_descriptor(&change_descriptor).map_err(LoadError::Descriptor)?;
// check params match loaded
if let Some(exp_change_descriptor) = params.check_change_descriptor {
let (exp_change_descriptor, keymap) =
(exp_change_descriptor)(&secp, network).map_err(LoadError::Descriptor)?;
change_descriptor_keymap.extend(keymap);

if change_descriptor.descriptor_id() != exp_change_descriptor.descriptor_id() {
return Err(LoadError::Mismatch(LoadMismatch::Descriptor {
keychain: KeychainKind::Internal,
loaded: change_descriptor,
expected: exp_change_descriptor,
}));
}
}
let change_signers = Arc::new(SignersContainer::build(
change_descriptor_keymap,
&change_descriptor,
&secp,
));
(Some(change_descriptor), change_signers)
}
None => (None, Arc::new(SignersContainer::new())),
};

// checks
if let Some(exp_network) = params.check_network {
Expand Down Expand Up @@ -492,30 +517,12 @@ impl Wallet {
}));
}
}
if let Some(exp_change_descriptor) = params.check_change_descriptor {
let (exp_change_descriptor, keymap) =
(exp_change_descriptor)(&secp, network).map_err(LoadError::Descriptor)?;
change_descriptor_keymap.extend(keymap);

if change_descriptor.descriptor_id() != exp_change_descriptor.descriptor_id() {
return Err(LoadError::Mismatch(LoadMismatch::Descriptor {
keychain: KeychainKind::Internal,
loaded: change_descriptor,
expected: exp_change_descriptor,
}));
}
}

let signers = Arc::new(SignersContainer::build(
descriptor_keymap,
&descriptor,
&secp,
));
let change_signers = Arc::new(SignersContainer::build(
change_descriptor_keymap,
&change_descriptor,
&secp,
));
let index = create_indexer(descriptor, change_descriptor, params.lookahead)
.map_err(LoadError::Descriptor)?;

Expand Down Expand Up @@ -550,7 +557,7 @@ impl Wallet {
///
/// For non-wildcard descriptors this returns the same address at every provided index.
///
/// # Panics
/// # Panics (TODO: document panics for address methods)
///
/// This panics when the caller requests for an address of derivation index greater than the
/// [BIP32](https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki) max index.
Expand Down Expand Up @@ -785,7 +792,13 @@ impl Wallet {
self.indexed_graph
.index
.unbounded_spk_iter(keychain)
.expect("keychain must exist")
.unwrap_or_else(|| {
// Given an empty keychain just create a dummy `SpkIterator` with
// a range that will always return None.
let (desc, _) = <ExtendedDescriptor>::parse_descriptor(self.secp_ctx(), "wsh(0)")
.expect("valid descriptor");
bdk_chain::SpkIterator::new_with_range(desc, 1..)
})
}

/// Returns the utxo owned by this wallet corresponding to `outpoint` if it exists in the
Expand Down Expand Up @@ -1053,17 +1066,18 @@ impl Wallet {
}

/// Set the keymap for a given keychain.
///
/// Note this is a no-op if the given keychain is not assigned to a descriptor
/// because we won't know the context (segwit, taproot, etc) in which to create
/// signatures.
pub fn set_keymap(&mut self, keychain: KeychainKind, keymap: KeyMap) {
let wallet_signers = match keychain {
KeychainKind::External => Arc::make_mut(&mut self.signers),
KeychainKind::Internal => Arc::make_mut(&mut self.change_signers),
};
let descriptor = self
.indexed_graph
.index
.get_descriptor(keychain)
.expect("keychain must exist");
*wallet_signers = SignersContainer::build(keymap, descriptor, &self.secp);
if let Some(descriptor) = self.indexed_graph.index.get_descriptor(keychain) {
*wallet_signers = SignersContainer::build(keymap, descriptor, &self.secp)
}
}

/// Set the keymap for each keychain.
Expand Down Expand Up @@ -1143,14 +1157,19 @@ impl Wallet {
) -> Result<Psbt, CreateTxError> {
let keychains: BTreeMap<_, _> = self.indexed_graph.index.keychains().collect();
let external_descriptor = keychains.get(&KeychainKind::External).expect("must exist");
let internal_descriptor = keychains.get(&KeychainKind::Internal).expect("must exist");
let internal_descriptor = keychains.get(&KeychainKind::Internal);

let external_policy = external_descriptor
.extract_policy(&self.signers, BuildSatisfaction::None, &self.secp)?
.unwrap();
let internal_policy = internal_descriptor
.extract_policy(&self.change_signers, BuildSatisfaction::None, &self.secp)?
.unwrap();
.map(|desc| {
Ok::<_, CreateTxError>(
desc.extract_policy(&self.change_signers, BuildSatisfaction::None, &self.secp)?
.unwrap(),
)
})
.transpose()?;

// The policy allows spending external outputs, but it requires a policy path that hasn't been
// provided
Expand All @@ -1163,29 +1182,38 @@ impl Wallet {
));
};
// Same for the internal_policy path
if params.change_policy != tx_builder::ChangeSpendPolicy::ChangeForbidden
&& internal_policy.requires_path()
&& params.internal_policy_path.is_none()
{
return Err(CreateTxError::SpendingPolicyRequired(
KeychainKind::Internal,
));
};
if let Some(internal_policy) = &internal_policy {
if params.change_policy != tx_builder::ChangeSpendPolicy::ChangeForbidden
&& internal_policy.requires_path()
&& params.internal_policy_path.is_none()
{
return Err(CreateTxError::SpendingPolicyRequired(
KeychainKind::Internal,
));
};
}

let external_requirements = external_policy.get_condition(
params
.external_policy_path
.as_ref()
.unwrap_or(&BTreeMap::new()),
)?;
let internal_requirements = internal_policy.get_condition(
params
.internal_policy_path
.as_ref()
.unwrap_or(&BTreeMap::new()),
)?;
let internal_requirements = internal_policy
.map(|policy| {
Ok::<_, CreateTxError>(
policy.get_condition(
params
.internal_policy_path
.as_ref()
.unwrap_or(&BTreeMap::new()),
)?,
)
})
.transpose()?;

let requirements = external_requirements.merge(&internal_requirements)?;
let requirements =
external_requirements.merge(&internal_requirements.unwrap_or_default())?;

let version = match params.version {
Some(tx_builder::Version(0)) => return Err(CreateTxError::Version0),
Expand Down Expand Up @@ -1351,7 +1379,11 @@ impl Wallet {
let drain_script = match params.drain_to {
Some(ref drain_recipient) => drain_recipient.clone(),
None => {
let change_keychain = KeychainKind::Internal;
let change_keychain = if self.is_single_descriptor_wallet() {
KeychainKind::External
} else {
KeychainKind::Internal
};
let ((index, spk), index_changeset) = self
.indexed_graph
.index
Expand Down Expand Up @@ -1852,8 +1884,8 @@ impl Wallet {
self.indexed_graph
.index
.next_index(keychain)
.expect("keychain must exist")
.0
.map(|(i, _)| i)
.unwrap_or_default()
}

/// Informs the wallet that you no longer intend to broadcast a tx that was built from it.
Expand Down Expand Up @@ -1977,7 +2009,8 @@ impl Wallet {

let mut i = 0;
may_spend.retain(|u| {
let retain = change_policy.is_satisfied_by(&u.0)
let retain = (self.is_single_descriptor_wallet()
|| change_policy.is_satisfied_by(&u.0))
&& !unspendable.contains(&u.0.outpoint)
&& satisfies_confirmed[i];
i += 1;
Expand Down Expand Up @@ -2310,6 +2343,11 @@ impl Wallet {
.batch_insert_relevant_unconfirmed(unconfirmed_txs);
self.stage.merge(indexed_graph_changeset.into());
}

/// Returns `true` if this wallet only has a single descriptor.
fn is_single_descriptor_wallet(&self) -> bool {
self.keychains().count() == 1
}
}

/// Methods to construct sync/full-scan requests for spk-based chain sources.
Expand Down Expand Up @@ -2391,7 +2429,7 @@ fn new_local_utxo(

fn create_indexer(
descriptor: ExtendedDescriptor,
change_descriptor: ExtendedDescriptor,
change_descriptor: Option<ExtendedDescriptor>,
lookahead: u32,
) -> Result<KeychainTxOutIndex<KeychainKind>, DescriptorError> {
let mut indexer = KeychainTxOutIndex::<KeychainKind>::new(lookahead);
Expand All @@ -2404,19 +2442,21 @@ fn create_indexer(

// let (descriptor, keymap) = change_descriptor;
// let change_signers = Arc::new(SignersContainer::build(keymap, &descriptor, secp));
assert!(indexer
.insert_descriptor(KeychainKind::Internal, change_descriptor)
.map_err(|e| {
use bdk_chain::indexer::keychain_txout::InsertDescriptorError;
match e {
InsertDescriptorError::DescriptorAlreadyAssigned { .. } => {
crate::descriptor::error::Error::ExternalAndInternalAreTheSame
}
InsertDescriptorError::KeychainAlreadyAssigned { .. } => {
unreachable!("this is the first time we're assigning internal")
if let Some(change_descriptor) = change_descriptor {
assert!(indexer
.insert_descriptor(KeychainKind::Internal, change_descriptor)
.map_err(|e| {
use bdk_chain::indexer::keychain_txout::InsertDescriptorError;
match e {
InsertDescriptorError::DescriptorAlreadyAssigned { .. } => {
crate::descriptor::error::Error::ExternalAndInternalAreTheSame
}
InsertDescriptorError::KeychainAlreadyAssigned { .. } => {
unreachable!("this is the first time we're assigning internal")
}
}
}
})?);
})?);
}

Ok(indexer)
}
Expand Down
24 changes: 20 additions & 4 deletions crates/wallet/src/wallet/params.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -32,22 +32,38 @@ where
pub struct CreateParams {
pub(crate) descriptor: DescriptorToExtract,
pub(crate) descriptor_keymap: KeyMap,
pub(crate) change_descriptor: DescriptorToExtract,
pub(crate) change_descriptor: Option<DescriptorToExtract>,
pub(crate) change_descriptor_keymap: KeyMap,
pub(crate) network: Network,
pub(crate) genesis_hash: Option<BlockHash>,
pub(crate) lookahead: u32,
}

impl CreateParams {
/// Construct parameters with provided `descriptor`, `change_descriptor` and `network`.
/// Construct parameters with provided `descriptor`.
pub fn new_single_descriptor<D: IntoWalletDescriptor + 'static>(descriptor: D) -> Self {
Self {
descriptor: make_descriptor_to_extract(descriptor),
descriptor_keymap: KeyMap::default(),
change_descriptor: None,
change_descriptor_keymap: KeyMap::default(),
network: Network::Bitcoin,
genesis_hash: None,
lookahead: DEFAULT_LOOKAHEAD,
}
}

/// Construct parameters with provided `descriptor` and `change_descriptor`.
///
/// Default values: `network` = [`Network::Bitcoin`], `genesis_hash` = `None`,
/// `lookahead` = [`DEFAULT_LOOKAHEAD`]
///
/// Default values: `genesis_hash` = `None`, `lookahead` = [`DEFAULT_LOOKAHEAD`]
/// To build a single descriptor wallet use [`CreateParams::new_single_descriptor`].
pub fn new<D: IntoWalletDescriptor + 'static>(descriptor: D, change_descriptor: D) -> Self {
Self {
descriptor: make_descriptor_to_extract(descriptor),
descriptor_keymap: KeyMap::default(),
change_descriptor: make_descriptor_to_extract(change_descriptor),
change_descriptor: Some(make_descriptor_to_extract(change_descriptor)),
change_descriptor_keymap: KeyMap::default(),
network: Network::Bitcoin,
genesis_hash: None,
Expand Down
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