Gas-optimization: remove unnecessary main.* calls

CHANGELOG.md

@@ -1,5 +1,27 @@
 # Changelog
 
+# 3.2.0
+
+This release gives new RTokens being deployed the option to enable a variable target basket, or to be "reweightable". An RToken that is not reweightable cannot have its target basket changed in terms of quantities of target units.
+
+### Upgrade Steps
+
+Upgrade BasketHandler and Distributor
+
+Call `Distributor.cacheComponents()` if this is the first upgrade to a >=3.0.0 token.
+
+### Core Protocol Contracts
+
+New governance param added to `DeploymentParams`: `reweightable`
+
+- `BasketHandler` [+1 slot]
+  - Add concept of a reweightable basket: a basket that can have its target amounts (once grouped by target unit) changed
+  - Add immutable-after-init `reweightable` bool
+- `Deployer`
+  - New boolean field `reweightable` added to `IDeployer.DeploymentParams`
+- `Distributor`
+  - Minor gas-optimization
+
 # 3.1.0 - Unreleased
 
 ### Upgrade Steps -- Required

common/configuration.ts

@@ -592,6 +592,7 @@ export interface IConfig {
   unstakingDelay: BigNumber
   withdrawalLeak: BigNumber
   warmupPeriod: BigNumber
+  reweightable: boolean
   tradingDelay: BigNumber
   batchAuctionLength: BigNumber
   dutchAuctionLength: BigNumber

contracts/interfaces/IBasketHandler.sol

@@ -49,7 +49,11 @@ interface IBasketHandler is IComponent {
     event BasketStatusChanged(CollateralStatus oldStatus, CollateralStatus newStatus);
 
     // Initialization
-    function init(IMain main_, uint48 warmupPeriod_) external;
+    function init(
+        IMain main_,
+        uint48 warmupPeriod_,
+        bool reweightable_
+    ) external;
 
     /// Set the prime basket
     /// @param erc20s The collateral tokens for the new prime basket

contracts/interfaces/IDeployer.sol

@@ -38,6 +38,7 @@ struct DeploymentParams {
     //
     // === BasketHandler ===
     uint48 warmupPeriod; // {s} how long to wait until issuance/trading after regaining SOUND
+    bool reweightable; // whether the basket can change in value
     //
     // === BackingManager ===
     uint48 tradingDelay; // {s} how long to wait until starting auctions after switching basket

contracts/p0/BasketHandler.sol

@@ -116,7 +116,7 @@ contract BasketHandlerP0 is ComponentP0, IBasketHandler {
     uint192 public constant MAX_TARGET_AMT = 1e3 * FIX_ONE; // {target/BU} max basket weight
 
     // config is the basket configuration, from which basket will be computed in a basket-switch
-    // event. config is only modified by governance through setPrimeBakset and setBackupConfig
+    // event. config is only modified by governance through setPrimeBasket and setBackupConfig
     BasketConfig private config;
 
     // basket, disabled, nonce, and timestamp are only ever set by `_switchBasket()`
@@ -148,6 +148,9 @@ contract BasketHandlerP0 is ComponentP0, IBasketHandler {
     // A history of baskets by basket nonce; includes current basket
     mapping(uint48 => Basket) private basketHistory;
 
+    // Whether the total weights of the target basket can be changed
+    bool public reweightable; // immutable after init
+
     // ==== Invariants ====
     // basket is a valid Basket:
     //   basket.erc20s is a valid collateral array and basket.erc20s == keys(basket.refAmts)
@@ -158,10 +161,15 @@ contract BasketHandlerP0 is ComponentP0, IBasketHandler {
     // if basket.erc20s is empty then disabled == true
 
     // BasketHandler.init() just leaves the BasketHandler state zeroed
-    function init(IMain main_, uint48 warmupPeriod_) external initializer {
+    function init(
+        IMain main_,
+        uint48 warmupPeriod_,
+        bool reweightable_
+    ) external initializer {
         __Component_init(main_);
 
         setWarmupPeriod(warmupPeriod_);
+        reweightable = reweightable_; // immutable thereafter
 
         // Set last status to DISABLED (default)
         lastStatus = CollateralStatus.DISABLED;
@@ -245,7 +253,9 @@ contract BasketHandlerP0 is ComponentP0, IBasketHandler {
         requireValidCollArray(erc20s);
 
         // If this isn't initial setup, require targets remain constant
-        if (config.erc20s.length > 0) requireConstantConfigTargets(erc20s, targetAmts);
+        if (!reweightable && config.erc20s.length > 0) {
+            requireConstantConfigTargets(erc20s, targetAmts);
+        }
 
         // Clean up previous basket config
         for (uint256 i = 0; i < config.erc20s.length; ++i) {

contracts/p0/Deployer.sol

@@ -95,7 +95,7 @@ contract DeployerP0 is IDeployer, Versioned {
         );
 
         // Init Basket Handler
-        main.basketHandler().init(main, params.warmupPeriod);
+        main.basketHandler().init(main, params.warmupPeriod, params.reweightable);
 
         // Init Revenue Traders
         main.rsrTrader().init(main, rsr, params.maxTradeSlippage, params.minTradeVolume);

contracts/p1/BasketHandler.sol

@@ -79,6 +79,12 @@ contract BasketHandlerP1 is ComponentP1, IBasketHandler {
     // Effectively local variable of `requireConstantConfigTargets()`
     EnumerableMap.Bytes32ToUintMap private _targetAmts; // targetName -> {target/BU}
 
+    // ===
+    // Added in 3.2.0
+
+    // Whether the total weights of the target basket can be changed
+    bool public reweightable; // immutable after init
+
     // ===
 
     // ==== Invariants ====
@@ -91,7 +97,11 @@ contract BasketHandlerP1 is ComponentP1, IBasketHandler {
     // if basket.erc20s is empty then disabled == true
 
     // BasketHandler.init() just leaves the BasketHandler state zeroed
-    function init(IMain main_, uint48 warmupPeriod_) external initializer {
+    function init(
+        IMain main_,
+        uint48 warmupPeriod_,
+        bool reweightable_
+    ) external initializer {
         __Component_init(main_);
 
         assetRegistry = main_.assetRegistry();
@@ -101,6 +111,7 @@ contract BasketHandlerP1 is ComponentP1, IBasketHandler {
         stRSR = main_.stRSR();
 
         setWarmupPeriod(warmupPeriod_);
+        reweightable = reweightable_; // immutable thereafter
 
         // Set last status to DISABLED (default)
         lastStatus = CollateralStatus.DISABLED;
@@ -174,16 +185,16 @@ contract BasketHandlerP1 is ComponentP1, IBasketHandler {
     //   config'.erc20s = erc20s
     //   config'.targetAmts[erc20s[i]] = targetAmts[i], for i from 0 to erc20s.length-1
     //   config'.targetNames[e] = assetRegistry.toColl(e).targetName, for e in erc20s
-    function setPrimeBasket(IERC20[] calldata erc20s, uint192[] calldata targetAmts)
-        external
-        governance
-    {
+    function setPrimeBasket(IERC20[] calldata erc20s, uint192[] calldata targetAmts) external {
+        requireGovernanceOnly();
         require(erc20s.length > 0, "empty basket");
         require(erc20s.length == targetAmts.length, "len mismatch");
         requireValidCollArray(erc20s);
 
         // If this isn't initial setup, require targets remain constant
-        if (config.erc20s.length > 0) requireConstantConfigTargets(erc20s, targetAmts);
+        if (!reweightable && config.erc20s.length > 0) {
+            requireConstantConfigTargets(erc20s, targetAmts);
+        }
 
         // Clean up previous basket config
         for (uint256 i = 0; i < config.erc20s.length; ++i) {
@@ -224,7 +235,8 @@ contract BasketHandlerP1 is ComponentP1, IBasketHandler {
         bytes32 targetName,
         uint256 max,
         IERC20[] calldata erc20s
-    ) external governance {
+    ) external {
+        requireGovernanceOnly();
         requireValidCollArray(erc20s);
         BackupConfig storage conf = config.backups[targetName];
         conf.max = max;
@@ -507,14 +519,19 @@ contract BasketHandlerP1 is ComponentP1, IBasketHandler {
     // === Governance Setters ===
 
     /// @custom:governance
-    function setWarmupPeriod(uint48 val) public governance {
+    function setWarmupPeriod(uint48 val) public {
+        requireGovernanceOnly();
         require(val >= MIN_WARMUP_PERIOD && val <= MAX_WARMUP_PERIOD, "invalid warmupPeriod");
         emit WarmupPeriodSet(warmupPeriod, val);
         warmupPeriod = val;
     }
 
     // === Private ===
 
+    // contract-size-saver
+    // solhint-disable-next-line no-empty-blocks
+    function requireGovernanceOnly() private governance {}
+
     /// Select and save the next basket, based on the BasketConfig and Collateral statuses
     function _switchBasket() private {
         // Mark basket disabled. Pause most protocol functions unless there is a next basket
@@ -673,5 +690,5 @@ contract BasketHandlerP1 is ComponentP1, IBasketHandler {
      * variables without shifting down storage in the inheritance chain.
      * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
      */
-    uint256[37] private __gap;
+    uint256[36] private __gap;
 }

contracts/p1/Deployer.sol

@@ -183,7 +183,7 @@ contract DeployerP1 is IDeployer, Versioned {
         );
 
         // Init Basket Handler
-        components.basketHandler.init(main, params.warmupPeriod);
+        components.basketHandler.init(main, params.warmupPeriod, params.reweightable);
 
         // Init Revenue Traders
         components.rsrTrader.init(main, rsr, params.maxTradeSlippage, params.minTradeVolume);

contracts/p1/Distributor.sol

@@ -35,8 +35,8 @@ contract DistributorP1 is ComponentP1, IDistributor {
 
     IERC20 private rsr;
     IERC20 private rToken;
-    address private furnace;
-    address private stRSR;
+    IFurnace private furnace;
+    IStRSR private stRSR;
     address private rTokenTrader;
     address private rsrTrader;
 
@@ -108,8 +108,8 @@ contract DistributorP1 is ComponentP1, IDistributor {
         Transfer[] memory transfers = new Transfer[](destinations.length());
         uint256 numTransfers;
 
-        address furnaceAddr = furnace; // gas-saver
-        address stRSRAddr = stRSR; // gas-saver
+        address furnaceAddr = address(furnace); // gas-saver
+        address stRSRAddr = address(stRSR); // gas-saver
 
         bool accountRewards = false;
 
@@ -144,9 +144,9 @@ contract DistributorP1 is ComponentP1, IDistributor {
         // Perform reward accounting
         if (accountRewards) {
             if (isRSR) {
-                main.stRSR().payoutRewards();
+                stRSR.payoutRewards();
             } else {
-                main.furnace().melt();
+                furnace.melt();
             }
         }
     }
@@ -176,7 +176,7 @@ contract DistributorP1 is ComponentP1, IDistributor {
     function _setDistribution(address dest, RevenueShare memory share) internal {
         require(dest != address(0), "dest cannot be zero");
         require(
-            dest != furnace && dest != stRSR,
+            dest != address(furnace) && dest != address(stRSR),
             "destination can not be furnace or strsr directly"
         );
         if (dest == FURNACE) require(share.rsrDist == 0, "Furnace must get 0% of RSR");
@@ -205,8 +205,8 @@ contract DistributorP1 is ComponentP1, IDistributor {
     function cacheComponents() public {
         rsr = main.rsr();
         rToken = IERC20(address(main.rToken()));
-        furnace = address(main.furnace());
-        stRSR = address(main.stRSR());
+        furnace = main.furnace();
+        stRSR = main.stRSR();
         rTokenTrader = address(main.rTokenTrader());
         rsrTrader = address(main.rsrTrader());
     }

contracts/plugins/assets/VersionedAsset.sol

@@ -4,7 +4,7 @@ pragma solidity 0.8.19;
 import "../../interfaces/IVersioned.sol";
 
 // This value should be updated on each release
-string constant ASSET_VERSION = "3.1.0";
+string constant ASSET_VERSION = "3.2.0";
 
 /**
  * @title VersionedAsset