Refactor handling of previous PoS inflation data

.changelog/unreleased/improvements/2559-remove-pos-inflation-from-params.md

@@ -0,0 +1,3 @@
+- Remove last staked ratio and pos inflation amount from
+  Parameters and initialize them in pos genesis initialization.
+  ([\#2559](https://github.com/anoma/namada/pull/2559))

crates/apps/src/lib/config/genesis.rs

@@ -310,10 +310,6 @@ pub struct Parameters {
     pub epochs_per_year: u64,
     /// Maximum amount of signatures per transaction
     pub max_signatures_per_transaction: u8,
-    /// PoS staked ratio (read + write for every epoch)
-    pub staked_ratio: Dec,
-    /// PoS inflation amount from the last epoch (read + write for every epoch)
-    pub pos_inflation_amount: token::Amount,
     /// Fee unshielding gas limit
     pub fee_unshielding_gas_limit: u64,
     /// Fee unshielding descriptions limit

crates/apps/src/lib/config/genesis/chain.rs

@@ -9,7 +9,6 @@ use namada::core::address::{
     Address, EstablishedAddress, EstablishedAddressGen,
 };
 use namada::core::chain::{ChainId, ChainIdPrefix};
-use namada::core::dec::Dec;
 use namada::core::hash::Hash;
 use namada::core::key::{common, RefTo};
 use namada::core::time::{DateTimeUtc, DurationNanos, Rfc3339String};
@@ -321,8 +320,6 @@ impl Finalized {
                 .into();
         let vp_allowlist = vp_allowlist.unwrap_or_default();
         let tx_allowlist = tx_allowlist.unwrap_or_default();
-        let staked_ratio = Dec::zero();
-        let pos_inflation_amount = 0;
 
         namada::ledger::parameters::Parameters {
             max_tx_bytes,
@@ -332,8 +329,6 @@ impl Finalized {
             tx_allowlist,
             implicit_vp_code_hash,
             epochs_per_year,
-            staked_ratio,
-            pos_inflation_amount: Amount::native_whole(pos_inflation_amount),
             max_proposal_bytes,
             max_signatures_per_transaction,
             fee_unshielding_gas_limit,

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

@@ -1993,8 +1993,6 @@ mod test_utils {
             implicit_vp_code_hash: Default::default(),
             epochs_per_year: 365,
             max_signatures_per_transaction: 10,
-            staked_ratio: Default::default(),
-            pos_inflation_amount: Default::default(),
             fee_unshielding_gas_limit: 0,
             fee_unshielding_descriptions_limit: 0,
             minimum_gas_price: Default::default(),

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

@@ -167,8 +167,6 @@ mod tests {
             implicit_vp_code_hash: Default::default(),
             epochs_per_year: 365,
             max_signatures_per_transaction: 10,
-            staked_ratio: Default::default(),
-            pos_inflation_amount: Default::default(),
             fee_unshielding_gas_limit: 0,
             fee_unshielding_descriptions_limit: 0,
             minimum_gas_price: Default::default(),

crates/core/src/parameters.rs

@@ -8,7 +8,6 @@ use namada_migrations::*;
 
 use super::address::Address;
 use super::chain::ProposalBytes;
-use super::dec::Dec;
 use super::hash::Hash;
 use super::time::DurationSecs;
 use super::token;
@@ -49,10 +48,6 @@ pub struct Parameters {
     pub epochs_per_year: u64,
     /// Maximum number of signature per transaction
     pub max_signatures_per_transaction: u8,
-    /// PoS staked ratio (read + write for every epoch)
-    pub staked_ratio: Dec,
-    /// PoS inflation amount from the last epoch (read + write for every epoch)
-    pub pos_inflation_amount: token::Amount,
     /// Fee unshielding gas limit
     pub fee_unshielding_gas_limit: u64,
     /// Fee unshielding descriptions limit

crates/parameters/src/lib.rs

@@ -5,7 +5,6 @@ use std::collections::BTreeMap;
 
 use namada_core::address::{Address, InternalAddress};
 use namada_core::chain::ProposalBytes;
-use namada_core::dec::Dec;
 use namada_core::hash::Hash;
 pub use namada_core::parameters::*;
 use namada_core::storage::Key;
@@ -59,8 +58,6 @@ where
         implicit_vp_code_hash,
         epochs_per_year,
         max_signatures_per_transaction,
-        staked_ratio,
-        pos_inflation_amount,
         minimum_gas_price,
         fee_unshielding_gas_limit,
         fee_unshielding_descriptions_limit,
@@ -138,12 +135,6 @@ where
         max_signatures_per_transaction,
     )?;
 
-    let staked_ratio_key = storage::get_staked_ratio_key();
-    storage.write(&staked_ratio_key, staked_ratio)?;
-
-    let pos_inflation_key = storage::get_pos_inflation_amount_key();
-    storage.write(&pos_inflation_key, pos_inflation_amount)?;
-
     let gas_cost_key = storage::get_gas_cost_key();
     storage.write(&gas_cost_key, minimum_gas_price)?;
 
@@ -238,32 +229,6 @@ where
     storage.write(&key, value)
 }
 
-/// Update the PoS staked ratio parameter in storage. Returns the parameters and
-/// gas cost.
-pub fn update_staked_ratio_parameter<S>(
-    storage: &mut S,
-    value: &Dec,
-) -> namada_storage::Result<()>
-where
-    S: StorageRead + StorageWrite,
-{
-    let key = storage::get_staked_ratio_key();
-    storage.write(&key, value)
-}
-
-/// Update the PoS inflation rate parameter in storage. Returns the parameters
-/// and gas cost.
-pub fn update_pos_inflation_amount_parameter<S>(
-    storage: &mut S,
-    value: &u64,
-) -> namada_storage::Result<()>
-where
-    S: StorageRead + StorageWrite,
-{
-    let key = storage::get_pos_inflation_amount_key();
-    storage.write(&key, value)
-}
-
 /// Update the implicit VP parameter in storage. Return the gas cost.
 pub fn update_implicit_vp<S>(
     storage: &mut S,
@@ -409,20 +374,6 @@ where
         .ok_or(ReadError::ParametersMissing)
         .into_storage_result()?;
 
-    // read staked ratio
-    let staked_ratio_key = storage::get_staked_ratio_key();
-    let value = storage.read(&staked_ratio_key)?;
-    let staked_ratio = value
-        .ok_or(ReadError::ParametersMissing)
-        .into_storage_result()?;
-
-    // read PoS inflation rate
-    let pos_inflation_key = storage::get_pos_inflation_amount_key();
-    let value = storage.read(&pos_inflation_key)?;
-    let pos_inflation_amount = value
-        .ok_or(ReadError::ParametersMissing)
-        .into_storage_result()?;
-
     // read gas cost
     let gas_cost_key = storage::get_gas_cost_key();
     let value = storage.read(&gas_cost_key)?;
@@ -448,8 +399,6 @@ where
         implicit_vp_code_hash: Some(implicit_vp_code_hash),
         epochs_per_year,
         max_signatures_per_transaction,
-        staked_ratio,
-        pos_inflation_amount,
         minimum_gas_price,
         fee_unshielding_gas_limit,
         fee_unshielding_descriptions_limit,

crates/parameters/src/storage.rs

@@ -25,11 +25,6 @@ struct Keys {
     /// Sub-lkey for storing the Ethereum address of the bridge contract.
     bridge_contract_address: &'static str,
     // ========================================
-    // PoS parameters
-    // ========================================
-    pos_inflation_amount: &'static str,
-    staked_ratio: &'static str,
-    // ========================================
     // Core parameters
     // ========================================
     epoch_duration: &'static str,
@@ -95,16 +90,6 @@ pub fn is_epochs_per_year_key(key: &Key) -> bool {
     is_epochs_per_year_key_at_addr(key, &ADDRESS)
 }
 
-/// Returns if the key is the staked ratio key.
-pub fn is_staked_ratio_key(key: &Key) -> bool {
-    is_staked_ratio_key_at_addr(key, &ADDRESS)
-}
-
-/// Returns if the key is the PoS reward rate key.
-pub fn is_pos_inflation_amount_key(key: &Key) -> bool {
-    is_pos_inflation_amount_key_at_addr(key, &ADDRESS)
-}
-
 /// Returns if the key is the max proposal bytes key.
 pub fn is_max_proposal_bytes_key(key: &Key) -> bool {
     is_max_proposal_bytes_key_at_addr(key, &ADDRESS)
@@ -155,16 +140,6 @@ pub fn get_epochs_per_year_key() -> Key {
     get_epochs_per_year_key_at_addr(ADDRESS)
 }
 
-/// Storage key used for staked ratio parameter.
-pub fn get_staked_ratio_key() -> Key {
-    get_staked_ratio_key_at_addr(ADDRESS)
-}
-
-/// Storage key used for the inflation amount parameter.
-pub fn get_pos_inflation_amount_key() -> Key {
-    get_pos_inflation_amount_key_at_addr(ADDRESS)
-}
-
 /// Storage key used for the max proposal bytes.
 pub fn get_max_proposal_bytes_key() -> Key {
     get_max_proposal_bytes_key_at_addr(ADDRESS)

crates/proof_of_stake/src/lib.rs

@@ -67,8 +67,10 @@ use crate::storage::{
     validator_rewards_products_handle, validator_set_positions_handle,
     validator_slashes_handle, validator_state_handle,
     validator_total_redelegated_bonded_handle,
-    validator_total_redelegated_unbonded_handle, write_last_reward_claim_epoch,
-    write_pos_params, write_validator_address_raw_hash, write_validator_avatar,
+    validator_total_redelegated_unbonded_handle,
+    write_last_pos_inflation_amount, write_last_reward_claim_epoch,
+    write_last_staked_ratio, write_pos_params,
+    write_validator_address_raw_hash, write_validator_avatar,
     write_validator_description, write_validator_discord_handle,
     write_validator_email, write_validator_max_commission_rate_change,
     write_validator_metadata, write_validator_website,
@@ -113,6 +115,11 @@ where
     tracing::debug!("Initializing PoS genesis");
     write_pos_params(storage, params)?;
 
+    // Initialize values for PoS inflation
+    write_last_staked_ratio(storage, Dec::zero())?;
+    write_last_pos_inflation_amount(storage, token::Amount::zero())?;
+
+    // Initialize validator set data
     consensus_validator_set_handle().init(storage, current_epoch)?;
     below_capacity_validator_set_handle().init(storage, current_epoch)?;
     validator_set_positions_handle().init(storage, current_epoch)?;

crates/proof_of_stake/src/rewards.rs

@@ -14,9 +14,11 @@ use thiserror::Error;
 
 use crate::storage::{
     consensus_validator_set_handle, get_last_reward_claim_epoch,
-    read_pos_params, read_total_stake, read_validator_stake,
-    rewards_accumulator_handle, validator_commission_rate_handle,
-    validator_rewards_products_handle, validator_state_handle,
+    read_last_pos_inflation_amount, read_last_staked_ratio, read_pos_params,
+    read_total_stake, read_validator_stake, rewards_accumulator_handle,
+    validator_commission_rate_handle, validator_rewards_products_handle,
+    validator_state_handle, write_last_pos_inflation_amount,
+    write_last_staked_ratio,
 };
 use crate::token::storage_key::minted_balance_key;
 use crate::token::{credit_tokens, inflation};
@@ -309,26 +311,26 @@ where
     // Read from Parameters storage
     let epochs_per_year: u64 = storage
         .read(&params_storage::get_epochs_per_year_key())?
-        .expect("Epochs per year should exist in storage");
-    let pos_last_staked_ratio: Dec = storage
-        .read(&params_storage::get_staked_ratio_key())?
-        .expect("PoS staked ratio should exist in storage");
-    let pos_last_inflation_amount: token::Amount = storage
-        .read(&params_storage::get_pos_inflation_amount_key())?
-        .expect("PoS inflation amount should exist in storage");
+        .expect("Epochs per year should exist in parameters storage");
 
-    // Read from PoS storage
-    let params = read_pos_params(storage)?;
     let staking_token = staking_token_address(storage);
-    let pos_p_gain_nom = params.rewards_gain_p;
-    let pos_d_gain_nom = params.rewards_gain_d;
-
     let total_tokens: token::Amount = storage
         .read(&minted_balance_key(&staking_token))?
         .expect("Total NAM balance should exist in storage");
+
+    // Read from PoS storage
+    let params = read_pos_params(storage)?;
     let pos_locked_supply = read_total_stake(storage, &params, last_epoch)?;
+
+    let pos_last_staked_ratio = read_last_staked_ratio(storage)?
+        .expect("Last staked ratio should exist in PoS storage");
+    let pos_last_inflation_amount = read_last_pos_inflation_amount(storage)?
+        .expect("Last inflation amount should exist in PoS storage");
+
     let pos_locked_ratio_target = params.target_staked_ratio;
     let pos_max_inflation_rate = params.max_inflation_rate;
+    let pos_p_gain_nom = params.rewards_gain_p;
+    let pos_d_gain_nom = params.rewards_gain_d;
 
     // Run rewards PD controller
     let pos_controller = inflation::PosRewardsController {
@@ -365,9 +367,8 @@ where
 
     // Write new rewards parameters that will be used for the inflation of
     // the current new epoch
-    storage
-        .write(&params_storage::get_pos_inflation_amount_key(), inflation)?;
-    storage.write(&params_storage::get_staked_ratio_key(), locked_ratio)?;
+    write_last_staked_ratio(storage, locked_ratio)?;
+    write_last_pos_inflation_amount(storage, inflation)?;
 
     Ok(())
 }

crates/proof_of_stake/src/storage.rs

@@ -387,6 +387,52 @@ where
     storage.write(&key, address)
 }
 
+/// Read last epoch's staked ratio.
+pub fn read_last_staked_ratio<S>(
+    storage: &S,
+) -> namada_storage::Result<Option<Dec>>
+where
+    S: StorageRead,
+{
+    let key = storage_key::last_staked_ratio_key();
+    storage.read(&key)
+}
+
+/// Write last epoch's staked ratio.
+pub fn write_last_staked_ratio<S>(
+    storage: &mut S,
+    ratio: Dec,
+) -> namada_storage::Result<()>
+where
+    S: StorageRead + StorageWrite,
+{
+    let key = storage_key::last_staked_ratio_key();
+    storage.write(&key, ratio)
+}
+
+/// Read last epoch's PoS inflation amount.
+pub fn read_last_pos_inflation_amount<S>(
+    storage: &S,
+) -> namada_storage::Result<Option<token::Amount>>
+where
+    S: StorageRead,
+{
+    let key = storage_key::last_pos_inflation_amount_key();
+    storage.read(&key)
+}
+
+/// Write last epoch's pos inflation amount.
+pub fn write_last_pos_inflation_amount<S>(
+    storage: &mut S,
+    inflation: token::Amount,
+) -> namada_storage::Result<()>
+where
+    S: StorageRead + StorageWrite,
+{
+    let key = storage_key::last_pos_inflation_amount_key();
+    storage.write(&key, inflation)
+}
+
 /// Read PoS validator's delta value.
 pub fn read_validator_deltas_value<S>(
     storage: &S,

crates/proof_of_stake/src/storage_key.rs

@@ -58,6 +58,8 @@ const VALIDATOR_AVATAR_KEY: &str = "avatar";
 const LIVENESS_PREFIX: &str = "liveness";
 const LIVENESS_MISSED_VOTES: &str = "missed_votes";
 const LIVENESS_MISSED_VOTES_SUM: &str = "sum_missed_votes";
+const LAST_STAKED_RATIO_KEY: &str = "last_staked_ratio";
+const LAST_POS_INFLATION_AMOUNT_KEY: &str = "last_inflation_amount";
 
 /// Is the given key a PoS storage key?
 pub fn is_pos_key(key: &Key) -> bool {
@@ -1044,3 +1046,17 @@ pub fn liveness_sum_missed_votes_key() -> Key {
         .push(&LIVENESS_MISSED_VOTES_SUM.to_owned())
         .expect("Cannot obtain a storage key")
 }
+
+/// Storage key for the last epoch's staked ratio.
+pub fn last_staked_ratio_key() -> Key {
+    Key::from(ADDRESS.to_db_key())
+        .push(&LAST_STAKED_RATIO_KEY.to_owned())
+        .expect("Cannot obtain a storage key")
+}
+
+/// Storage key for the last epoch's PoS inflation amount.
+pub fn last_pos_inflation_amount_key() -> Key {
+    Key::from(ADDRESS.to_db_key())
+        .push(&LAST_POS_INFLATION_AMOUNT_KEY.to_owned())
+        .expect("Cannot obtain a storage key")
+}

crates/shielded_token/src/conversion.rs

@@ -583,8 +583,6 @@ mod tests {
             implicit_vp_code_hash: Default::default(),
             epochs_per_year: 365,
             max_signatures_per_transaction: 10,
-            staked_ratio: Default::default(),
-            pos_inflation_amount: Default::default(),
             fee_unshielding_gas_limit: 0,
             fee_unshielding_descriptions_limit: 0,
             minimum_gas_price: Default::default(),