zcash_client_backend::data_api::wallet::input_selection

Trait InputSelector

pub trait InputSelector {
    type Error;
    type InputSource: InputSource;

    // Required method
    fn propose_transaction<ParamsT, ChangeT>(
        &self,
        params: &ParamsT,
        wallet_db: &Self::InputSource,
        target_height: TargetHeight,
        anchor_height: BlockHeight,
        confirmations_policy: ConfirmationsPolicy,
        account: <Self::InputSource as InputSource>::AccountId,
        transaction_request: TransactionRequest,
        change_strategy: &ChangeT,
    ) -> Result<Proposal<<ChangeT as ChangeStrategy>::FeeRule, <Self::InputSource as InputSource>::NoteRef>, InputSelectorError<<Self::InputSource as InputSource>::Error, Self::Error, ChangeT::Error, <Self::InputSource as InputSource>::NoteRef>>
       where ParamsT: Parameters,
             ChangeT: ChangeStrategy<MetaSource = Self::InputSource>;
}

Expand description

A strategy for selecting transaction inputs and proposing transaction outputs.

Proposals should include only economically useful inputs, as determined by Self::FeeRule; that is, do not return inputs that cause fees to increase by an amount greater than the value of the input.

Required Associated Types§

Source

type Error

The type of errors that may be generated in input selection

Source

The type of data source that the input selector expects to access to obtain input notes. This associated type permits input selectors that may use specialized knowledge of the internals of a particular backing data store, if the generic API of InputSource does not provide sufficiently fine-grained operations for a particular backing store to optimally perform input selection.

Required Methods§

Source

fn propose_transaction<ParamsT, ChangeT>( &self, params: &ParamsT, wallet_db: &Self::InputSource, target_height: TargetHeight, anchor_height: BlockHeight, confirmations_policy: ConfirmationsPolicy, account: <Self::InputSource as InputSource>::AccountId, transaction_request: TransactionRequest, change_strategy: &ChangeT, ) -> Result<Proposal<<ChangeT as ChangeStrategy>::FeeRule, <Self::InputSource as InputSource>::NoteRef>, InputSelectorError<<Self::InputSource as InputSource>::Error, Self::Error, ChangeT::Error, <Self::InputSource as InputSource>::NoteRef>>
where ParamsT: Parameters, ChangeT: ChangeStrategy<MetaSource = Self::InputSource>,

Performs input selection and returns a proposal for transaction construction including change and fee outputs.

Implementations of this method should return inputs sufficient to satisfy the given transaction request using a best-effort strategy to preserve user privacy, as follows:

If it is possible to satisfy the specified transaction request by creating a fully-shielded transaction without requiring value to cross pool boundaries, return the inputs necessary to construct such a transaction; otherwise
If it is possible to satisfy the transaction request by creating a fully-shielded transaction with some amounts crossing between shielded pools, return the inputs necessary.

If insufficient funds are available to satisfy the required outputs for the shielding request, this operation must fail and return InputSelectorError::InsufficientFunds.