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OpenZeppelin · Jan 2, 2025 · ecd1107 · ecd1107
1 parent 2f15d8b
commit ecd1107
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Showing 5 changed files with 25 additions and 8 deletions.
diff --git a/src/base/BaseCustomAccounting.sol b/src/base/BaseCustomAccounting.sol
@@ -39,36 +39,47 @@ abstract contract BaseCustomAccounting is BaseHook {
         override
         returns (bytes4, BeforeSwapDelta, uint24)
     {
+        // Determine if the swap is exact input or exact output
         bool exactInput = params.amountSpecified < 0;
+
+        // Determine which currency is specified and which is unspecified
         (Currency specified, Currency unspecified) =
             (params.zeroForOne == exactInput) ? (key.currency0, key.currency1) : (key.currency1, key.currency0);
 
+        // Get the positive specified amount
         uint256 specifiedAmount = exactInput ? uint256(-params.amountSpecified) : uint256(params.amountSpecified);
+
+        // Get the amount of the unspecified currency to be taken or settled
         uint256 unspecifiedAmount = _getAmount(
             specifiedAmount,
             exactInput ? specified : unspecified,
             exactInput ? unspecified : specified,
             params.zeroForOne,
             exactInput
         );
+
+        // New delta must be returned, so store in memory
         BeforeSwapDelta returnDelta;
+
         if (exactInput) {
             specified.take(poolManager, address(this), specifiedAmount, true);
             unspecified.settle(poolManager, address(this), unspecifiedAmount, true);
 
+            // On exact input, amount0 is specified and amount1 is unspecified.
             returnDelta = toBeforeSwapDelta(specifiedAmount.toInt128(), -unspecifiedAmount.toInt128());
         } else {
             unspecified.take(poolManager, address(this), unspecifiedAmount, true);
             specified.settle(poolManager, address(this), specifiedAmount, true);
 
+            // On exact output, amount1 is specified and amount0 is unspecified.
             returnDelta = toBeforeSwapDelta(-specifiedAmount.toInt128(), unspecifiedAmount.toInt128());
         }
 
-        return (BaseHook.beforeSwap.selector, returnDelta, 0);
+        return (this.beforeSwap.selector, returnDelta, 0);
     }
 
     /**
-     * @dev Calculate the amount of tokens to be take or settle.
+     * @dev Calculate the amount of tokens to take or send (settle).
      */
     function _getAmount(uint256 amountIn, Currency input, Currency output, bool zeroForOne, bool exactInput)
         internal

diff --git a/src/base/BaseNoOp.sol b/src/base/BaseNoOp.sol
@@ -41,9 +41,9 @@ abstract contract BaseNoOp is BaseHook {
             uint256 amountTaken = uint256(-params.amountSpecified);
             Currency input = params.zeroForOne ? key.currency0 : key.currency1;
             poolManager.mint(address(this), input.toId(), amountTaken);
-            return (BaseHook.beforeSwap.selector, toBeforeSwapDelta(amountTaken.toInt128(), 0), 0);
+            return (this.beforeSwap.selector, toBeforeSwapDelta(amountTaken.toInt128(), 0), 0);
         } else {
-            return (BaseHook.beforeSwap.selector, BeforeSwapDeltaLibrary.ZERO_DELTA, 0);
+            return (this.beforeSwap.selector, BeforeSwapDeltaLibrary.ZERO_DELTA, 0);
         }
     }
 

diff --git a/src/fee/BaseDynamicFee.sol b/src/fee/BaseDynamicFee.sol
@@ -38,7 +38,7 @@ abstract contract BaseDynamicFee is BaseHook {
         returns (bytes4)
     {
         poolManager.updateDynamicLPFee(key, _getFee(key));
-        return BaseHook.afterInitialize.selector;
+        return this.afterInitialize.selector;
     }
 
     /**

diff --git a/src/fee/BaseOverrideFee.sol b/src/fee/BaseOverrideFee.sol
@@ -42,7 +42,7 @@ abstract contract BaseOverrideFee is BaseHook {
         bytes calldata hookData
     ) internal virtual override returns (bytes4, BeforeSwapDelta, uint24) {
         uint24 fee = _getFee(sender, key, params, hookData);
-        return (BaseHook.beforeSwap.selector, BeforeSwapDeltaLibrary.ZERO_DELTA, fee | LPFeeLibrary.OVERRIDE_FEE_FLAG);
+        return (this.beforeSwap.selector, BeforeSwapDeltaLibrary.ZERO_DELTA, fee | LPFeeLibrary.OVERRIDE_FEE_FLAG);
     }
 
     /**

diff --git a/src/fee/DynamicAfterFee.sol b/src/fee/DynamicAfterFee.sol
@@ -44,24 +44,30 @@ abstract contract DynamicAfterFee is BaseHook {
         BalanceDelta delta,
         bytes calldata
     ) internal virtual override returns (bytes4, int128) {
+        // Only apply target delta for exact-input swaps
         if (params.amountSpecified < 0) {
             PoolId poolId = key.toId();
             BalanceDelta targetDelta = _targetDeltas[poolId];
             int128 feeAmount = 0;
 
+            // Skip empty/undefined target delta
             if (BalanceDelta.unwrap(targetDelta) != 0) {
                 // Reset storage target delta to 0 and use one stored in memory
                 _targetDeltas[poolId] = BalanceDelta.wrap(0);
 
                 if (delta.amount0() == targetDelta.amount0() && delta.amount1() > targetDelta.amount1()) {
                     feeAmount = delta.amount1() - targetDelta.amount1();
+
+                    // feeAmount is positive and int128, so we can safely cast to uint128 given that uint128
+                    // has a larger maximum value.
                     poolManager.donate(key, 0, uint256(uint128(feeAmount)), "");
                 }
 
-                // Apply target delta to only exact-input swaps
                 if (delta.amount1() == targetDelta.amount1() && delta.amount0() > targetDelta.amount0()) {
                     feeAmount = delta.amount0() - targetDelta.amount0();
-                    // feeAmount is positive and int128, so we can safely cast to uint128 and then to uint256
+
+                    // feeAmount is positive and int128, so we can safely cast to uint128 given that uint128
+                    // has a larger maximum value.
                     poolManager.donate(key, uint256(uint128(feeAmount)), 0, "");
                 }
             }