Implement check and execute for LQT votes (#5033)

Closes #5032.

The check and execute logic for the action handler is still missing the
nullifier check, but there's an obvious insertion point for adding that
logic.

Testing deferred.

crates/core/component/funding/Cargo.toml

@@ -14,6 +14,7 @@ component = [
     "penumbra-sdk-proto/cnidarium",
     "penumbra-sdk-community-pool/component",
     "penumbra-sdk-distributions/component",
+    "penumbra-sdk-governance/component",
     "penumbra-sdk-sct/component",
     "penumbra-sdk-shielded-pool/component",
     "penumbra-sdk-stake/component",

crates/core/component/funding/src/action_handler/liquidity_tournament/mod.rs

@@ -1,15 +1,25 @@
-use anyhow::Context as _;
+use anyhow::{anyhow, Context as _};
 use async_trait::async_trait;
-use cnidarium::StateWrite;
-use penumbra_sdk_asset::asset::Denom;
+use cnidarium::{StateRead, StateWrite};
+use cnidarium_component::ActionHandler;
+use penumbra_sdk_asset::{asset::Denom, Value};
+use penumbra_sdk_governance::StateReadExt as _;
+use penumbra_sdk_num::Amount;
 use penumbra_sdk_proof_params::DELEGATOR_VOTE_PROOF_VERIFICATION_KEY;
-use penumbra_sdk_txhash::TransactionContext;
+use penumbra_sdk_sct::component::clock::EpochRead as _;
+use penumbra_sdk_sct::epoch::Epoch;
+use penumbra_sdk_stake::component::validator_handler::ValidatorDataRead as _;
+use penumbra_sdk_tct::Position;
+use penumbra_sdk_txhash::{TransactionContext, TransactionId};
 
+use crate::component::liquidity_tournament::{
+    nullifier::{NullifierRead as _, NullifierWrite as _},
+    votes::StateWriteExt as _,
+};
 use crate::liquidity_tournament::{
     proof::LiquidityTournamentVoteProofPublic, ActionLiquidityTournamentVote,
     LiquidityTournamentVoteBody, LIQUIDITY_TOURNAMENT_VOTE_DENOM_MAX_BYTES,
 };
-use cnidarium_component::ActionHandler;
 
 fn is_valid_denom(denom: &Denom) -> anyhow::Result<()> {
     anyhow::ensure!(
@@ -26,6 +36,37 @@ fn is_valid_denom(denom: &Denom) -> anyhow::Result<()> {
     Ok(())
 }
 
+// Check that the start position is early enough to vote in the current epoch.
+async fn start_position_good_for_epoch(epoch: Epoch, start: Position) -> anyhow::Result<()> {
+    anyhow::ensure!(
+        epoch.index > u64::from(start.epoch()),
+        "position {start:?} is not before epoch {epoch:?}"
+    );
+    Ok(())
+}
+
+/// Fetch the unbonded equivalent of some purported delegation token.
+///
+/// Will fail if (either):
+///  - the token is not for a known validator,
+///  - the validator does not have any rate data.
+async fn unbonded_amount(state: impl StateRead, value: Value) -> anyhow::Result<Amount> {
+    let validator = state.validator_by_delegation_asset(value.asset_id).await?;
+    let rate = state
+        .get_validator_rate(&validator)
+        .await?
+        .ok_or_else(|| anyhow!("{} has no rate data", &validator))?;
+    Ok(rate.unbonded_amount(value.amount))
+}
+
+// This isolates the logic for how we should handle out of bounds amounts.
+fn voting_power(amount: Amount) -> u64 {
+    amount
+        .value()
+        .try_into()
+        .expect("someone acquired {amount:?} > u64::MAX worth of delegation tokens!")
+}
+
 #[async_trait]
 impl ActionHandler for ActionLiquidityTournamentVote {
     type CheckStatelessContext = TransactionContext;
@@ -70,7 +111,37 @@ impl ActionHandler for ActionLiquidityTournamentVote {
         Ok(())
     }
 
-    async fn check_and_execute<S: StateWrite>(&self, _state: S) -> anyhow::Result<()> {
-        todo!()
+    async fn check_and_execute<S: StateWrite>(&self, mut state: S) -> anyhow::Result<()> {
+        // 1. Check that the start position can vote in this round.
+        let current_epoch = state
+            .get_current_epoch()
+            .await
+            .expect("failed to fetch current epoch");
+        start_position_good_for_epoch(current_epoch, self.body.start_position).await?;
+        // 2. We can tally, as long as the nullifier hasn't been used yet (this round).
+        let nullifier = self.body.nullifier;
+        let nullifier_exists = state.get_lqt_spent_nullifier(nullifier).await.is_some();
+        anyhow::ensure!(
+            !nullifier_exists,
+            "nullifier {} already voted in epoch {}",
+            self.body.nullifier,
+            current_epoch.index
+        );
+        state.put_lqt_spent_nullifier(current_epoch.index, nullifier, TransactionId([0u8; 32]));
+        // 3. Ok, actually tally.
+        let power = voting_power(unbonded_amount(&state, self.body.value).await?);
+        let incentivized = self
+            .body
+            .incentivized_id()
+            .ok_or_else(|| anyhow!("{:?} is not a base denom", self.body.incentivized))?;
+        state
+            .tally(
+                current_epoch.index,
+                incentivized,
+                power,
+                &self.body.rewards_recipient,
+            )
+            .await?;
+        Ok(())
     }
 }

crates/core/component/funding/src/component/liquidity_tournament/mod.rs

@@ -1 +1,2 @@
 pub mod nullifier;
+pub mod votes;

crates/core/component/funding/src/component/liquidity_tournament/nullifier/mod.rs

@@ -6,7 +6,6 @@ use cnidarium::{StateRead, StateWrite};
 use penumbra_sdk_proto::{StateReadProto, StateWriteProto};
 use penumbra_sdk_sct::{component::clock::EpochRead, Nullifier};
 
-#[allow(dead_code)]
 #[async_trait]
 pub trait NullifierRead: StateRead {
     /// Returns the `TransactionId` if the nullifier has been spent; otherwise, returns None.
@@ -34,7 +33,6 @@ pub trait NullifierRead: StateRead {
 
 impl<T: StateRead + ?Sized> NullifierRead for T {}
 
-#[allow(dead_code)]
 #[async_trait]
 pub trait NullifierWrite: StateWrite {
     /// Sets the LQT nullifier in the NV storage.

crates/core/component/funding/src/component/liquidity_tournament/votes/mod.rs

@@ -0,0 +1,26 @@
+use async_trait::async_trait;
+use cnidarium::StateWrite;
+use penumbra_sdk_asset::asset;
+use penumbra_sdk_keys::Address;
+
+use crate::component::state_key;
+
+#[async_trait]
+pub trait StateWriteExt: StateWrite {
+    // Keeping this as returning a result to not have to touch other code if it changes to return an error.
+    async fn tally(
+        &mut self,
+        epoch: u64,
+        asset: asset::Id,
+        power: u64,
+        voter: &Address,
+    ) -> anyhow::Result<()> {
+        self.nonverifiable_put_raw(
+            state_key::lqt::v1::votes::receipt(epoch, asset, power, voter).to_vec(),
+            Vec::default(),
+        );
+        Ok(())
+    }
+}
+
+impl<T: StateWrite + ?Sized> StateWriteExt for T {}

crates/core/component/funding/src/component/state_key.rs

@@ -12,5 +12,59 @@ pub mod lqt {
                 format!("funding/lqt/v1/nullifier/{epoch_index:020}/lookup/{nullifier}")
             }
         }
+
+        pub mod votes {
+            use penumbra_sdk_asset::asset;
+            use penumbra_sdk_keys::{address::ADDRESS_LEN_BYTES, Address};
+
+            const PART0: &'static str = "funding/lqt/v1/votes/";
+            const EPOCH_LEN: usize = 20;
+            const PART1: &'static str = "/by_asset/";
+            const PREFIX_LEN: usize = PART0.len() + EPOCH_LEN + PART1.len();
+
+            /// A prefix for accessing the votes in a given epoch, c.f. [`power_asset_address`];
+            pub(crate) fn prefix(epoch_index: u64) -> [u8; PREFIX_LEN] {
+                let mut bytes = [0u8; PREFIX_LEN];
+
+                let rest = &mut bytes;
+                let (bytes_part0, rest) = rest.split_at_mut(PART0.len());
+                let (bytes_epoch_index, bytes_part1) = rest.split_at_mut(EPOCH_LEN);
+
+                bytes_part0.copy_from_slice(PART0.as_bytes());
+                bytes_epoch_index
+                    .copy_from_slice(format!("{epoch_index:0w$}", w = EPOCH_LEN).as_bytes());
+                bytes_part1.copy_from_slice(PART1.as_bytes());
+
+                bytes
+            }
+
+            const ASSET_LEN: usize = 32;
+            const POWER_LEN: usize = 8;
+            const RECEIPT_LEN: usize = PREFIX_LEN + ASSET_LEN + POWER_LEN + ADDRESS_LEN_BYTES;
+
+            /// When present, indicates that an address voted for a particular asset, with a given power.
+            ///
+            /// To get the values ordered by descending voting power, use [`prefix`];
+            pub(crate) fn receipt(
+                epoch_index: u64,
+                asset: asset::Id,
+                power: u64,
+                voter: &Address,
+            ) -> [u8; RECEIPT_LEN] {
+                let mut bytes = [0u8; RECEIPT_LEN];
+
+                let rest = &mut bytes;
+                let (bytes_prefix, rest) = rest.split_at_mut(PREFIX_LEN);
+                let (bytes_asset, rest) = rest.split_at_mut(ASSET_LEN);
+                let (bytes_power, bytes_voter) = rest.split_at_mut(POWER_LEN);
+
+                bytes_prefix.copy_from_slice(&prefix(epoch_index));
+                bytes_asset.copy_from_slice(&asset.to_bytes());
+                bytes_power.copy_from_slice(&((!power).to_be_bytes()));
+                bytes_voter.copy_from_slice(&voter.to_vec());
+
+                bytes
+            }
+        }
     }
 }

crates/core/component/funding/src/liquidity_tournament/action/mod.rs

@@ -1,6 +1,9 @@
 use anyhow::{anyhow, Context};
 use decaf377_rdsa::{Signature, SpendAuth, VerificationKey};
-use penumbra_sdk_asset::{asset::Denom, balance, Value};
+use penumbra_sdk_asset::{
+    asset::{self, Denom, REGISTRY},
+    balance, Value,
+};
 use penumbra_sdk_keys::Address;
 use penumbra_sdk_proto::{core::component::funding::v1 as pb, DomainType};
 use penumbra_sdk_sct::Nullifier;
@@ -34,6 +37,17 @@ pub struct LiquidityTournamentVoteBody {
     pub rk: VerificationKey<SpendAuth>,
 }
 
+impl LiquidityTournamentVoteBody {
+    /// Get the asset id that should be incentivized.
+    ///
+    /// This will return None if the denom is not a base denom.
+    pub fn incentivized_id(&self) -> Option<asset::Id> {
+        REGISTRY
+            .parse_denom(&self.incentivized.denom)
+            .map(|x| x.id())
+    }
+}
+
 impl DomainType for LiquidityTournamentVoteBody {
     type Proto = pb::LiquidityTournamentVoteBody;
 }