update checkpoint struct

src/contracts/interfaces/IEigenPod.sol

@@ -102,9 +102,14 @@ interface IEigenPod {
         bytes32 beaconBlockRoot;
         uint24 proofsRemaining;
         uint64 podBalanceGwei;
-        int128 balanceDeltasGwei;
+        // this used to be an int128 before the slashing release
+        // now it is an int64. (2^63 - 1) gwei * 1e-9 eth/gwei = 9_223_372_036.85 eth = 9 billion eth
+        int64 balanceDeltasGwei;
+        uint64 beaconChainBalanceBeforeGwei;
+    }
+
+    struct ExtendedCheckpoint {
         uint128 beaconChainBalanceBefore;
-        uint128 beaconChainBalanceAfter;
     }
 
     /**

src/contracts/pods/EigenPod.sol

@@ -189,14 +189,15 @@ contract EigenPod is Initializable, ReentrancyGuardUpgradeable, EigenPodPausingC
             // If the proof shows the validator has a balance of 0, they are marked `WITHDRAWN`.
             // The assumption is that if this is the case, any withdrawn ETH was already in
             // the pod when `startCheckpoint` was originally called.
-            (int128 balanceDeltaGwei, uint64 exitedBalanceGwei) = _verifyCheckpointProof({
+            (uint64 prevBalanceGwei, int64 balanceDeltaGwei, uint64 exitedBalanceGwei) = _verifyCheckpointProof({
                 validatorInfo: validatorInfo,
                 checkpointTimestamp: checkpointTimestamp,
                 balanceContainerRoot: balanceContainerProof.balanceContainerRoot,
                 proof: proof
             });
 
             checkpoint.proofsRemaining--;
+            checkpoint.beaconChainBalanceBeforeGwei += prevBalanceGwei;
             checkpoint.balanceDeltasGwei += balanceDeltaGwei;
             exitedBalancesGwei += exitedBalanceGwei;
 
@@ -260,6 +261,10 @@ contract EigenPod is Initializable, ReentrancyGuardUpgradeable, EigenPodPausingC
             );
         }
 
+        if (currentCheckpointTimestamp != 0) {
+            _currentCheckpoint.beaconChainBalanceBeforeGwei += uint64(totalAmountToBeRestakedWei / GWEI_TO_WEI);
+        }
+
         // Update the EigenPodManager on this pod's new balance
         eigenPodManager.recordBeaconChainETHBalanceUpdate(podOwner, int256(totalAmountToBeRestakedWei), 0); // no decrease
     }
@@ -493,8 +498,6 @@ contract EigenPod is Initializable, ReentrancyGuardUpgradeable, EigenPodPausingC
         uint64 lastCheckpointedAt = lastCheckpointTimestamp;
         if (currentCheckpointTimestamp != 0) {
             lastCheckpointedAt = currentCheckpointTimestamp;
-            _currentCheckpoint.beaconChainBalanceBefore += uint128(restakedBalanceGwei);
-            _currentCheckpoint.beaconChainBalanceAfter += uint128(restakedBalanceGwei);
         }
 
         // Proofs complete - create the validator in state
@@ -515,11 +518,11 @@ contract EigenPod is Initializable, ReentrancyGuardUpgradeable, EigenPodPausingC
         uint64 checkpointTimestamp,
         bytes32 balanceContainerRoot,
         BeaconChainProofs.BalanceProof calldata proof
-    ) internal returns (int128 balanceDeltaGwei, uint64 exitedBalanceGwei) {
+    ) internal returns (uint64 prevBalanceGwei, int64 balanceDeltaGwei, uint64 exitedBalanceGwei) {
         uint40 validatorIndex = uint40(validatorInfo.validatorIndex);
 
         // Verify validator balance against `balanceContainerRoot`
-        uint64 prevBalanceGwei = validatorInfo.restakedBalanceGwei;
+        prevBalanceGwei = validatorInfo.restakedBalanceGwei;
         uint64 newBalanceGwei = BeaconChainProofs.verifyValidatorBalance({
             balanceContainerRoot: balanceContainerRoot,
             validatorIndex: validatorIndex,
@@ -534,10 +537,6 @@ contract EigenPod is Initializable, ReentrancyGuardUpgradeable, EigenPodPausingC
                 previousAmountGwei: prevBalanceGwei
             });
 
-            // Update the checkpoint values
-            _currentCheckpoint.beaconChainBalanceBefore += uint128(prevBalanceGwei);
-            _currentCheckpoint.beaconChainBalanceAfter += uint128(newBalanceGwei);
-
             emit ValidatorBalanceUpdated(validatorIndex, checkpointTimestamp, newBalanceGwei);
         }
 
@@ -550,12 +549,12 @@ contract EigenPod is Initializable, ReentrancyGuardUpgradeable, EigenPodPausingC
             validatorInfo.status = VALIDATOR_STATUS.WITHDRAWN;
             // If we reach this point, `balanceDeltaGwei` should always be negative,
             // so this should be a safe conversion
-            exitedBalanceGwei = uint64(uint128(-balanceDeltaGwei));
+            exitedBalanceGwei = uint64(-balanceDeltaGwei);
 
             emit ValidatorWithdrawn(checkpointTimestamp, validatorIndex);
         }
 
-        return (balanceDeltaGwei, exitedBalanceGwei);
+        return (prevBalanceGwei, balanceDeltaGwei, exitedBalanceGwei);
     }
 
     /**
@@ -607,8 +606,7 @@ contract EigenPod is Initializable, ReentrancyGuardUpgradeable, EigenPodPausingC
             proofsRemaining: uint24(activeValidatorCount),
             podBalanceGwei: podBalanceGwei,
             balanceDeltasGwei: 0,
-            beaconChainBalanceBefore: 0,
-            beaconChainBalanceAfter: 0
+            beaconChainBalanceBeforeGwei: 0
         });
 
         // Place checkpoint in storage. If `proofsRemaining` is 0, the checkpoint
@@ -646,8 +644,8 @@ contract EigenPod is Initializable, ReentrancyGuardUpgradeable, EigenPodPausingC
             // Calculate the slashing proportion
             uint64 proportionOfOldBalance = 0;
             if (totalShareDeltaWei < 0) {
-                uint256 totalBefore = withdrawableRestakedExecutionLayerGwei + checkpoint.beaconChainBalanceBefore;
-                proportionOfOldBalance = uint64((totalBefore + uint256(-totalShareDeltaWei)) * WAD / totalBefore);
+                uint256 totalRestakedBeforeWei = (withdrawableRestakedExecutionLayerGwei + checkpoint.beaconChainBalanceBeforeGwei) * GWEI_TO_WEI;
+                proportionOfOldBalance = uint64((totalRestakedBeforeWei + uint256(-totalShareDeltaWei)) * WAD / totalRestakedBeforeWei);
             }
 
             // Update pod owner's shares
@@ -675,8 +673,8 @@ contract EigenPod is Initializable, ReentrancyGuardUpgradeable, EigenPodPausingC
     }
 
     /// @dev Calculates the delta between two Gwei amounts and returns as an int256
-    function _calcBalanceDelta(uint64 newAmountGwei, uint64 previousAmountGwei) internal pure returns (int128) {
-        return int128(uint128(newAmountGwei)) - int128(uint128(previousAmountGwei));
+    function _calcBalanceDelta(uint64 newAmountGwei, uint64 previousAmountGwei) internal pure returns (int64) {
+        return int64(newAmountGwei) - int64(previousAmountGwei);
     }
 
     /**

src/contracts/pods/EigenPodStorage.sol

@@ -68,18 +68,21 @@ abstract contract EigenPodStorage is IEigenPod {
     mapping(uint64 => uint64) public checkpointBalanceExitedGwei;
 
     /// @notice The current checkpoint, if there is one active
-    Checkpoint internal _currentCheckpoint; // TODO: this storage is fucked need split structs
+    Checkpoint internal _currentCheckpoint; 
 
     /// @notice An address with permissions to call `startCheckpoint` and `verifyWithdrawalCredentials`, set
     /// by the podOwner. This role exists to allow a podOwner to designate a hot wallet that can call
     /// these methods, allowing the podOwner to remain a cold wallet that is only used to manage funds.
     /// @dev If this address is NOT set, only the podOwner can call `startCheckpoint` and `verifyWithdrawalCredentials`
     address public proofSubmitter;
 
+    /// @notice The total balance of the pod before the current checkpoint
+    uint128 public beaconChainBalanceBeforeCurrentCheckpoint;
+
     /**
      * @dev This empty reserved space is put in place to allow future versions to add new
      * variables without shifting down storage in the inheritance chain.
      * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
      */
-    uint256[35] private __gap; // Reduced the gap size by 1 to accommodate the new variable
+    uint256[35] private __gap;
 }