feat(protocol): reenable time as basefee calculation input

packages/protocol/contract_layout.md

@@ -35,10 +35,10 @@
 | __gap           | uint256[49]                 | 202  | 0      | 1568  | contracts/L2/TaikoL2.sol:TaikoL2 |
 | l2Hashes        | mapping(uint256 => bytes32) | 251  | 0      | 32    | contracts/L2/TaikoL2.sol:TaikoL2 |
 | publicInputHash | bytes32                     | 252  | 0      | 32    | contracts/L2/TaikoL2.sol:TaikoL2 |
-| gasExcess       | uint64                      | 253  | 0      | 8     | contracts/L2/TaikoL2.sol:TaikoL2 |
+| parentGasExcess | uint64                      | 253  | 0      | 8     | contracts/L2/TaikoL2.sol:TaikoL2 |
 | lastSyncedBlock | uint64                      | 253  | 8      | 8     | contracts/L2/TaikoL2.sol:TaikoL2 |
-| __deprecated1   | uint64                      | 253  | 16     | 8     | contracts/L2/TaikoL2.sol:TaikoL2 |
-| __deprecated2   | uint64                      | 253  | 24     | 8     | contracts/L2/TaikoL2.sol:TaikoL2 |
+| parentTimestamp | uint64                      | 253  | 16     | 8     | contracts/L2/TaikoL2.sol:TaikoL2 |
+| parentGasTarget | uint64                      | 253  | 24     | 8     | contracts/L2/TaikoL2.sol:TaikoL2 |
 | l1ChainId       | uint64                      | 254  | 0      | 8     | contracts/L2/TaikoL2.sol:TaikoL2 |
 | __gap           | uint256[46]                 | 255  | 0      | 1472  | contracts/L2/TaikoL2.sol:TaikoL2 |
 

packages/protocol/contracts/L1/TaikoData.sol

@@ -41,7 +41,7 @@ library TaikoData {
         // ---------------------------------------------------------------------
         uint8 basefeeAdjustmentQuotient;
         uint8 basefeeSharingPctg;
-        uint32 blockGasIssuance;
+        uint32 gasIssuancePerSecond;
         // ---------------------------------------------------------------------
         // Group 6: Others
         // ---------------------------------------------------------------------
@@ -126,7 +126,7 @@ library TaikoData {
         uint8 blobIndex;
         uint8 basefeeAdjustmentQuotient;
         uint8 basefeeSharingPctg;
-        uint32 blockGasIssuance;
+        uint32 gasIssuancePerSecond;
     }
 
     /// @dev Struct representing transition to be proven.

packages/protocol/contracts/L1/TaikoL1.sol

@@ -290,18 +290,9 @@ contract TaikoL1 is EssentialContract, ITaikoL1, TaikoEvents {
 
     /// @inheritdoc ITaikoL1
     function getConfig() public pure virtual override returns (TaikoData.Config memory) {
-        // All hard-coded configurations:
-        // - treasury: the actual TaikoL2 address.
-        // - anchorGasLimit: 250_000 (based on internal devnet, its ~220_000
-        // after 256 L2 blocks)
         return TaikoData.Config({
             chainId: LibNetwork.TAIKO_MAINNET,
-            // If we have 1 block per 12 seconds, then each day there will be 86400/12=7200 blocks.
-            // We therefore use 7200 as the base unit to configure blockMaxProposals and
-            // blockRingBufferSize.
             blockMaxProposals: 324_000, // = 7200 * 45
-            // We give 7200 * 5 = 36000 slots for verifeid blocks in case third party apps will use
-            // their data.
             blockRingBufferSize: 360_000, // = 7200 * 50
             maxBlocksToVerify: 16,
             blockMaxGasLimit: 240_000_000,
@@ -310,7 +301,7 @@ contract TaikoL1 is EssentialContract, ITaikoL1, TaikoEvents {
             maxAnchorHeightOffset: 64,
             basefeeAdjustmentQuotient: 8,
             basefeeSharingPctg: 75,
-            blockGasIssuance: 20_000_000,
+            gasIssuancePerSecond: 5_000_000,
             ontakeForkHeight: 374_400 // = 7200 * 52
          });
     }

packages/protocol/contracts/L1/libs/LibData.sol

@@ -78,7 +78,7 @@ library LibData {
             blobIndex: 0,
             basefeeAdjustmentQuotient: 0,
             basefeeSharingPctg: 0,
-            blockGasIssuance: 0
+            gasIssuancePerSecond: 0
         });
     }
 }

packages/protocol/contracts/L1/libs/LibProposing.sol

@@ -176,7 +176,7 @@ library LibProposing {
                 blobIndex: local.params.blobIndex,
                 basefeeAdjustmentQuotient: _config.basefeeAdjustmentQuotient,
                 basefeeSharingPctg: _config.basefeeSharingPctg,
-                blockGasIssuance: _config.blockGasIssuance
+                gasIssuancePerSecond: _config.gasIssuancePerSecond
             });
         }
 

packages/protocol/contracts/L2/Lib1559Math.sol

@@ -17,8 +17,7 @@ library Lib1559Math {
     error EIP1559_INVALID_PARAMS();
 
     function calc1559BaseFee(
-        uint32 _gasTarget,
-        uint8 _adjustmentQuotient,
+        uint256 _gasTarget,
         uint64 _gasExcess,
         uint64 _gasIssuance,
         uint32 _parentGasUsed
@@ -37,42 +36,52 @@ library Lib1559Math {
         // bonding curve, regardless the actual amount of gas used by this
         // block, however, this block's gas used will affect the next
         // block's base fee.
-        basefee_ = basefee(gasExcess_, uint256(_adjustmentQuotient) * _gasTarget);
-
-        // Always make sure basefee is nonzero, this is required by the node.
-        if (basefee_ == 0) basefee_ = 1;
+        basefee_ = basefee(gasExcess_, _gasTarget);
     }
 
-    /// @dev eth_qty(excess_gas_issued) / (TARGET * ADJUSTMENT_QUOTIENT)
-    /// @param _gasExcess The gas excess value
-    /// @param _adjustmentFactor The product of gasTarget and adjustmentQuotient
-    function basefee(
-        uint256 _gasExcess,
-        uint256 _adjustmentFactor
+    /// @dev Returns the new gas excess that will keep the basefee the same.
+    /// `_newGasTarget * ln(_newGasTarget / _target) + _gasExcess * _newGasTarget / _target`
+    function adjustExcess(
+        uint64 _gasExcess,
+        uint64 _gasTarget,
+        uint64 _newGasTarget
     )
         internal
         pure
-        returns (uint256)
+        returns (uint64)
     {
-        if (_adjustmentFactor == 0) {
-            revert EIP1559_INVALID_PARAMS();
+        if (_gasTarget == 0) {
+            return _newGasTarget;
         }
-        return _ethQty(_gasExcess, _adjustmentFactor) / FixedPointMathLib.WAD;
+
+        uint256 f = FixedPointMathLib.WAD;
+        uint256 ratio = f * _newGasTarget / _gasTarget;
+        if (ratio > uint256(type(int256).max)) revert EIP1559_INVALID_PARAMS();
+
+        int256 lnRatio = FixedPointMathLib.lnWad(int256(ratio)); // may be negative
+
+        uint256 newGasExcess;
+        assembly {
+            newGasExcess := sdiv(add(mul(lnRatio, _newGasTarget), mul(ratio, _gasExcess)), f)
+        }
+
+        return uint64(newGasExcess.min(type(uint64).max));
     }
 
-    /// @dev exp(gas_qty / TARGET / ADJUSTMENT_QUOTIENT)
-    function _ethQty(
-        uint256 _gasExcess,
-        uint256 _adjustmentFactor
-    )
-        private
-        pure
-        returns (uint256)
-    {
-        uint256 input = _gasExcess * FixedPointMathLib.WAD / _adjustmentFactor;
+    /// @dev exp(_gasExcess / _gasTarget) / _gasTarget
+    function basefee(uint256 _gasExcess, uint256 _gasTarget) internal pure returns (uint256) {
+        uint256 fee = ethQty(_gasExcess, _gasTarget) / _gasTarget;
+        return fee == 0 ? 1 : fee;
+    }
+
+    /// @dev exp(_gasExcess / _gasTarget)
+    function ethQty(uint256 _gasExcess, uint256 _gasTarget) internal pure returns (uint256) {
+        if (_gasTarget == 0) revert EIP1559_INVALID_PARAMS();
+
+        uint256 input = FixedPointMathLib.WAD * _gasExcess / _gasTarget;
         if (input > MAX_EXP_INPUT) {
             input = MAX_EXP_INPUT;
         }
-        return uint256(FixedPointMathLib.expWad(int256(input)));
+        return uint256(FixedPointMathLib.expWad(int256(input))) / FixedPointMathLib.WAD;
     }
 }