Shielded Inflation rewards

.changelog/unreleased/features/714-pos-inflation-rewards.md

@@ -0,0 +1,6 @@
+- Introduce infrastructure for PoS inflation and rewards. Includes inflation
+  using the PD controller mechanism and rewards based on validator block voting
+  behavior. Rewards are tracked and effectively distributed using the F1 fee
+  mechanism. In this PR, rewards are calculated and stored, but they are not
+  yet applied to voting powers or considered when unbonding and withdrawing.
+  ([#714](https://github.com/anoma/namada/pull/714))

apps/src/lib/config/genesis.rs

@@ -15,6 +15,7 @@ use namada::types::key::dkg_session_keys::DkgPublicKey;
 use namada::types::key::*;
 use namada::types::time::{DateTimeUtc, DurationSecs};
 use namada::types::token::Denomination;
+use namada::types::uint::I256;
 use namada::types::{storage, token};
 
 /// Genesis configuration file format
@@ -38,6 +39,7 @@ pub mod genesis_config {
     use namada::types::key::*;
     use namada::types::time::Rfc3339String;
     use namada::types::token::Denomination;
+    use namada::types::uint::I256;
     use namada::types::{storage, token};
     use serde::{Deserialize, Serialize};
     use thiserror::Error;
@@ -210,6 +212,9 @@ pub mod genesis_config {
         // Initial balances held by accounts defined elsewhere.
         // XXX: u64 doesn't work with toml-rs!
         pub balances: Option<HashMap<String, token::Amount>>,
+        // Token parameters
+        // XXX: u64 doesn't work with toml-rs!
+        pub parameters: Option<token::parameters::Parameters>,
     }
 
     #[derive(Clone, Debug, Deserialize, Serialize)]
@@ -392,6 +397,9 @@ pub mod genesis_config {
         let token_vp_config = wasm.get(token_vp_name).unwrap();
 
         TokenAccount {
+            last_locked_ratio: Dec::zero(),
+            last_inflation: I256::zero(),
+            parameters: config.parameters.as_ref().unwrap().to_owned(),
             address: Address::decode(config.address.as_ref().unwrap()).unwrap(),
             denom: config.denom,
             vp_code_path: token_vp_config.filename.to_owned(),
@@ -806,6 +814,13 @@ pub struct TokenAccount {
     /// Accounts' balances of this token
     #[derivative(PartialOrd = "ignore", Ord = "ignore")]
     pub balances: HashMap<Address, token::Amount>,
+    // please put the last inflation amount here.
+    /// Token parameters
+    pub parameters: token::parameters::Parameters,
+    /// Token inflation from the last epoch (read + write for every epoch)
+    pub last_inflation: I256,
+    /// Token shielded ratio from the last epoch (read + write for every epoch)
+    pub last_locked_ratio: Dec,
 }
 
 #[derive(
@@ -881,9 +896,7 @@ pub fn genesis(
 }
 #[cfg(any(test, feature = "dev"))]
 pub fn genesis(num_validators: u64) -> Genesis {
-    use namada::types::address::{
-        self, apfel, btc, dot, eth, kartoffel, nam, schnitzel,
-    };
+    use namada::types::address::{self};
 
     use crate::wallet;
 
@@ -1027,28 +1040,17 @@ pub fn genesis(num_validators: u64) -> Genesis {
         balances.insert((&validator.account_key).into(), default_key_tokens);
     }
 
-    /// Deprecated function, soon to be deleted. Generates default tokens
-    fn tokens() -> HashMap<Address, (&'static str, Denomination)> {
-        vec![
-            (nam(), ("NAM", 6.into())),
-            (btc(), ("BTC", 8.into())),
-            (eth(), ("ETH", 18.into())),
-            (dot(), ("DOT", 10.into())),
-            (schnitzel(), ("Schnitzel", 6.into())),
-            (apfel(), ("Apfel", 6.into())),
-            (kartoffel(), ("Kartoffel", 6.into())),
-        ]
-        .into_iter()
-        .collect()
-    }
-    let token_accounts = tokens()
+    let token_accounts = address::tokens()
         .into_iter()
         .map(|(address, (_, denom))| TokenAccount {
             address,
             denom,
             vp_code_path: vp_token_path.into(),
             vp_sha256: Default::default(),
             balances: balances.clone(),
+            parameters: token::parameters::Parameters::default(),
+            last_inflation: I256::zero(),
+            last_locked_ratio: Dec::zero(),
         })
         .collect();
     Genesis {

apps/src/lib/node/ledger/shell/finalize_block.rs

@@ -945,7 +945,6 @@ mod test_finalize_block {
     use crate::node::ledger::shims::abcipp_shim_types::shim::request::{
         FinalizeBlock, ProcessedTx,
     };
-
     /// Check that if a wrapper tx was rejected by [`process_proposal`],
     /// check that the correct event is returned. Check that it does
     /// not appear in the queue of txs to be decrypted

apps/src/lib/node/ledger/shell/init_chain.rs

@@ -277,8 +277,20 @@ where
             vp_code_path,
             vp_sha256,
             balances,
+            parameters,
+            last_inflation,
+            last_locked_ratio,
         } in genesis.token_accounts
         {
+            // Init token parameters and last inflation and caching rates
+            parameters.init_storage(&address, &mut self.wl_storage);
+            self.wl_storage
+                .write(&token::last_inflation(&address), last_inflation)
+                .unwrap();
+            self.wl_storage
+                .write(&token::last_locked_ratio(&address), last_locked_ratio)
+                .unwrap();
+
             // associate a token with its denomination.
             write_denom(
                 &mut self.wl_storage,
@@ -313,10 +325,19 @@ where
                 .write_bytes(&Key::validity_predicate(&address), vp_code_hash)
                 .unwrap();
 
+            let mut total_balance_for_token = token::Amount::default();
             for (owner, amount) in balances {
+                total_balance_for_token += amount;
                 credit_tokens(&mut self.wl_storage, &address, &owner, amount)
                     .unwrap();
             }
+            // Write the total amount of tokens for the ratio
+            self.wl_storage
+                .write(
+                    &token::total_supply_key(&address),
+                    total_balance_for_token,
+                )
+                .unwrap();
         }
 
         // Initialize genesis validator accounts

apps/src/lib/node/ledger/shell/mod.rs

@@ -1002,6 +1002,7 @@ mod test_utils {
     use namada::ledger::storage::mockdb::MockDB;
     use namada::ledger::storage::{update_allowed_conversions, Sha256Hasher};
     use namada::proto::{Code, Data};
+    use namada::types::address::init_token_storage;
     use namada::types::chain::ChainId;
     use namada::types::hash::Hash;
     use namada::types::key::*;
@@ -1235,6 +1236,7 @@ mod test_utils {
             .storage
             .begin_block(BlockHash::default(), BlockHeight(1))
             .expect("begin_block failed");
+        init_token_storage(&mut shell.wl_storage, 60);
         let keypair = gen_keypair();
         // enqueue a wrapper tx
         let mut wrapper = Tx::new(TxType::Wrapper(Box::new(WrapperTx::new(

apps/src/lib/node/ledger/storage/mod.rs

@@ -58,6 +58,7 @@ mod tests {
         types, update_allowed_conversions, WlStorage,
     };
     use namada::ledger::storage_api::{self, StorageWrite};
+    use namada::types::address::init_token_storage;
     use namada::types::chain::ChainId;
     use namada::types::hash::Hash;
     use namada::types::storage::{BlockHash, BlockHeight, Key};
@@ -143,6 +144,7 @@ mod tests {
         storage.block.pred_epochs.new_epoch(BlockHeight(100), 1000);
         // make wl_storage to update conversion for a new epoch
         let mut wl_storage = WlStorage::new(WriteLog::default(), storage);
+        init_token_storage(&mut wl_storage, 60);
         update_allowed_conversions(&mut wl_storage)
             .expect("update conversions failed");
         wl_storage.commit_block().expect("commit failed");

shared/src/ledger/inflation.rs → core/src/ledger/inflation.rs

@@ -2,8 +2,9 @@
 //! proof-of-stake, providing liquity to shielded asset pools, and public goods
 //! funding.
 
-use namada_core::types::dec::Dec;
-
+use crate::ledger::storage_api::{self, StorageRead, StorageWrite};
+use crate::types::address::Address;
+use crate::types::dec::Dec;
 use crate::types::token;
 
 /// The domains of inflation
@@ -47,6 +48,32 @@ pub struct RewardsController {
 }
 
 impl RewardsController {
+    /// Initialize a new PD controller
+    #[allow(clippy::too_many_arguments)]
+    pub fn new(
+        locked_tokens: token::Amount,
+        total_tokens: token::Amount,
+        locked_ratio_target: Dec,
+        locked_ratio_last: Dec,
+        max_reward_rate: Dec,
+        last_inflation_amount: token::Amount,
+        p_gain_nom: Dec,
+        d_gain_nom: Dec,
+        epochs_per_year: u64,
+    ) -> Self {
+        Self {
+            locked_tokens,
+            total_tokens,
+            locked_ratio_target,
+            locked_ratio_last,
+            max_reward_rate,
+            last_inflation_amount,
+            p_gain_nom,
+            d_gain_nom,
+            epochs_per_year,
+        }
+    }
+
     /// Calculate a new rewards rate
     pub fn run(self) -> ValsToUpdate {
         let Self {
@@ -95,3 +122,31 @@ impl RewardsController {
         }
     }
 }
+
+/// Function that allows the protocol to mint some number of tokens of a desired
+/// type to a destination address TODO: think of error cases that must be
+/// handled.
+pub fn mint_tokens<S>(
+    storage: &mut S,
+    target: &Address,
+    token: &Address,
+    amount: token::Amount,
+) -> storage_api::Result<()>
+where
+    S: StorageWrite + StorageRead,
+{
+    let dest_key = token::balance_key(token, target);
+    let mut dest_bal: token::Amount =
+        storage.read(&dest_key)?.unwrap_or_default();
+    dest_bal.receive(&amount);
+    storage.write(&dest_key, dest_bal)?;
+
+    // Update the total supply of the tokens in storage
+    let mut total_tokens: token::Amount = storage
+        .read(&token::total_supply_key(token))?
+        .unwrap_or_default();
+    total_tokens.receive(&amount);
+    storage.write(&token::total_supply_key(token), total_tokens)?;
+
+    Ok(())
+}

core/src/ledger/mod.rs

@@ -4,6 +4,7 @@ pub mod gas;
 pub mod governance;
 #[cfg(any(feature = "abciplus", feature = "abcipp"))]
 pub mod ibc;
+pub mod inflation;
 pub mod parameters;
 pub mod replay_protection;
 pub mod slash_fund;