pancakeswap · ChefMist · May 31, 2024
diff --git a/.forge-snapshots/BinHookTest#testBurnSucceedsWithHook.snap b/.forge-snapshots/BinHookTest#testBurnSucceedsWithHook.snap
@@ -1 +1 @@
-180732
+180720
diff --git a/.forge-snapshots/BinHookTest#testDonateSucceedsWithHook.snap b/.forge-snapshots/BinHookTest#testDonateSucceedsWithHook.snap
@@ -1 +1 @@
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diff --git a/.forge-snapshots/BinHookTest#testInitializeSucceedsWithHook.snap b/.forge-snapshots/BinHookTest#testInitializeSucceedsWithHook.snap
@@ -1 +1 @@
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diff --git a/.forge-snapshots/BinHookTest#testMintSucceedsWithHook.snap b/.forge-snapshots/BinHookTest#testMintSucceedsWithHook.snap
@@ -1 +1 @@
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diff --git a/.forge-snapshots/BinPoolManagerTest#testBurnNativeCurrency.snap b/.forge-snapshots/BinPoolManagerTest#testBurnNativeCurrency.snap
@@ -1 +1 @@
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diff --git a/.forge-snapshots/BinPoolManagerTest#testExtLoadPoolActiveId.snap b/.forge-snapshots/BinPoolManagerTest#testExtLoadPoolActiveId.snap
@@ -1 +1 @@
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diff --git a/.forge-snapshots/BinPoolManagerTest#testFuzzUpdateDynamicLPFee.snap b/.forge-snapshots/BinPoolManagerTest#testFuzzUpdateDynamicLPFee.snap
@@ -1 +1 @@
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diff --git a/.forge-snapshots/BinPoolManagerTest#testFuzz_SetMaxBinStep.snap b/.forge-snapshots/BinPoolManagerTest#testFuzz_SetMaxBinStep.snap
@@ -1 +1 @@
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diff --git a/.forge-snapshots/BinPoolManagerTest#testGasBurnHalfBin.snap b/.forge-snapshots/BinPoolManagerTest#testGasBurnHalfBin.snap
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diff --git a/.forge-snapshots/BinPoolManagerTest#testGasBurnNineBins.snap b/.forge-snapshots/BinPoolManagerTest#testGasBurnNineBins.snap
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diff --git a/.forge-snapshots/BinPoolManagerTest#testGasBurnOneBin.snap b/.forge-snapshots/BinPoolManagerTest#testGasBurnOneBin.snap
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diff --git a/.forge-snapshots/BinPoolManagerTest#testGasDonate.snap b/.forge-snapshots/BinPoolManagerTest#testGasDonate.snap
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diff --git a/.forge-snapshots/BinPoolManagerTest#testGasMintNneBins-1.snap b/.forge-snapshots/BinPoolManagerTest#testGasMintNneBins-1.snap
@@ -1 +1 @@
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diff --git a/.forge-snapshots/BinPoolManagerTest#testGasMintNneBins-2.snap b/.forge-snapshots/BinPoolManagerTest#testGasMintNneBins-2.snap
@@ -1 +1 @@
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diff --git a/.forge-snapshots/BinPoolManagerTest#testGasMintOneBin-1.snap b/.forge-snapshots/BinPoolManagerTest#testGasMintOneBin-1.snap
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diff --git a/.forge-snapshots/BinPoolManagerTest#testGasMintOneBin-2.snap b/.forge-snapshots/BinPoolManagerTest#testGasMintOneBin-2.snap
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diff --git a/.forge-snapshots/BinPoolManagerTest#testGasSwapMultipleBins.snap b/.forge-snapshots/BinPoolManagerTest#testGasSwapMultipleBins.snap
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diff --git a/.forge-snapshots/BinPoolManagerTest#testGasSwapOverBigBinIdGate.snap b/.forge-snapshots/BinPoolManagerTest#testGasSwapOverBigBinIdGate.snap
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diff --git a/.forge-snapshots/BinPoolManagerTest#testGasSwapSingleBin.snap b/.forge-snapshots/BinPoolManagerTest#testGasSwapSingleBin.snap
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diff --git a/.forge-snapshots/BinPoolManagerTest#testMintNativeCurrency.snap b/.forge-snapshots/BinPoolManagerTest#testMintNativeCurrency.snap
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diff --git a/.forge-snapshots/BinPoolManagerTest#testSetProtocolFee.snap b/.forge-snapshots/BinPoolManagerTest#testSetProtocolFee.snap
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diff --git a/.forge-snapshots/BitMathTest#leastSignificantBitMaxUint128.snap b/.forge-snapshots/BitMathTest#leastSignificantBitMaxUint128.snap
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diff --git a/.forge-snapshots/BitMathTest#leastSignificantBitMaxUint256.snap b/.forge-snapshots/BitMathTest#leastSignificantBitMaxUint256.snap
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diff --git a/.forge-snapshots/BitMathTest#leastSignificantBitSmallNumber.snap b/.forge-snapshots/BitMathTest#leastSignificantBitSmallNumber.snap
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diff --git a/.forge-snapshots/CLPoolManagerTest#addLiquidity_fromEmpty.snap b/.forge-snapshots/CLPoolManagerTest#addLiquidity_fromEmpty.snap
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diff --git a/.forge-snapshots/CLPoolManagerTest#addLiquidity_fromNonEmpty.snap b/.forge-snapshots/CLPoolManagerTest#addLiquidity_fromNonEmpty.snap
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diff --git a/.forge-snapshots/CLPoolManagerTest#addLiquidity_nativeToken.snap b/.forge-snapshots/CLPoolManagerTest#addLiquidity_nativeToken.snap
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diff --git a/.forge-snapshots/CLPoolManagerTest#donateBothTokens.snap b/.forge-snapshots/CLPoolManagerTest#donateBothTokens.snap
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diff --git a/.forge-snapshots/CLPoolManagerTest#gasDonateOneToken.snap b/.forge-snapshots/CLPoolManagerTest#gasDonateOneToken.snap
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diff --git a/.forge-snapshots/CLPoolManagerTest#swap_againstLiquidity.snap b/.forge-snapshots/CLPoolManagerTest#swap_againstLiquidity.snap
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diff --git a/.forge-snapshots/CLPoolManagerTest#swap_leaveSurplusTokenInVault.snap b/.forge-snapshots/CLPoolManagerTest#swap_leaveSurplusTokenInVault.snap
@@ -1 +1 @@
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diff --git a/.forge-snapshots/CLPoolManagerTest#swap_runOutOfLiquidity.snap b/.forge-snapshots/CLPoolManagerTest#swap_runOutOfLiquidity.snap
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diff --git a/.forge-snapshots/CLPoolManagerTest#testFuzzUpdateDynamicLPFee.snap b/.forge-snapshots/CLPoolManagerTest#testFuzzUpdateDynamicLPFee.snap
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diff --git a/.forge-snapshots/ExtsloadTest#extsloadInBatch.snap b/.forge-snapshots/ExtsloadTest#extsloadInBatch.snap
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diff --git a/.forge-snapshots/ExtsloadTest#testExtsloadNSlot.snap b/.forge-snapshots/ExtsloadTest#testExtsloadNSlot.snap
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diff --git a/.forge-snapshots/VaultTest#Vault.snap b/.forge-snapshots/VaultTest#Vault.snap
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diff --git a/.forge-snapshots/VaultTest#collectFee.snap b/.forge-snapshots/VaultTest#collectFee.snap
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diff --git a/.forge-snapshots/VaultTest#lockSettledWhenAddLiquidity.snap b/.forge-snapshots/VaultTest#lockSettledWhenAddLiquidity.snap
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diff --git a/.forge-snapshots/VaultTest#lockSettledWhenFlashloan.snap b/.forge-snapshots/VaultTest#lockSettledWhenFlashloan.snap
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diff --git a/.forge-snapshots/VaultTest#lockSettledWhenMultiHopSwap.snap b/.forge-snapshots/VaultTest#lockSettledWhenMultiHopSwap.snap
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diff --git a/.forge-snapshots/VaultTest#lockSettledWhenSwap.snap b/.forge-snapshots/VaultTest#lockSettledWhenSwap.snap
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diff --git a/.forge-snapshots/VaultTest#registerPoolManager.snap b/.forge-snapshots/VaultTest#registerPoolManager.snap
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diff --git a/.forge-snapshots/VaultTest#testLock_NoOp.snap b/.forge-snapshots/VaultTest#testLock_NoOp.snap
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diff --git a/src/Extsload.sol b/src/Extsload.sol
@@ -18,6 +18,25 @@ abstract contract Extsload is IExtsload {
         }
     }
 
+    /// @inheritdoc IExtsload
+    function extsload(bytes32 startSlot, uint256 nSlots) external view returns (bytes memory) {
+        assembly ("memory-safe") {
+            // The abi offset of dynamic array in the returndata is 32.
+            mstore(0, 0x20)
+            // A left bit-shift of 5 is equivalent to multiplying by 32 but costs less gas.
+            mstore(0x20, shl(5, nSlots))
+            let end := add(0x40, shl(5, nSlots))
+            for { let memptr := 0x40 } 1 {} {
+                mstore(memptr, sload(startSlot))
+                memptr := add(memptr, 0x20)
+                startSlot := add(startSlot, 1)
+                if iszero(lt(memptr, end)) { break }
+            }
+            // The end offset is also the length of the returndata.
+            return(0, end)
+        }
+    }
+
     /// @inheritdoc IExtsload
     function extsload(bytes32[] calldata slots) external view returns (bytes32[] memory) {
         // since the function is external and enters a new call context and exits right

diff --git a/src/Exttload.sol b/src/Exttload.sol
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+// Copyright (C) 2024 PancakeSwap
+pragma solidity ^0.8.24;
+
+import {IExttload} from "./interfaces/IExttload.sol";
+
+/// @notice Enables public transient storage access for efficient state retrieval by external contracts.
+/// https://eips.ethereum.org/EIPS/eip-2330#rationale
+abstract contract Exttload is IExttload {
+    /// @inheritdoc IExttload
+    function exttload(bytes32 slot) external view returns (bytes32) {
+        assembly ("memory-safe") {
+            mstore(0, tload(slot))
+            return(0, 0x20)
+        }
+    }
+
+    /// @inheritdoc IExttload
+    function exttload(bytes32[] calldata slots) external view returns (bytes32[] memory) {
+        // since the function is external and enters a new call context and exits right
+        // after execution, Solidity's memory management convention can be disregarded
+        // and a direct slice of memory can be returned
+        assembly ("memory-safe") {
+            // Copy the abi offset of dynamic array and the length of the array to memory.
+            calldatacopy(0, 0x04, 0x40)
+            // A left bit-shift of 5 is equivalent to multiplying by 32 but costs less gas.
+            let end := add(0x40, shl(5, slots.length))
+            let calldataptr := slots.offset
+            // Return values will start at 64 while calldata offset is 68.
+            for { let memptr := 0x40 } 1 {} {
+                mstore(memptr, tload(calldataload(calldataptr)))
+                memptr := add(memptr, 0x20)
+                calldataptr := add(calldataptr, 0x20)
+                if iszero(lt(memptr, end)) { break }
+            }
+            // The end offset is also the length of the returndata.
+            return(0, end)
+        }
+    }
+}
diff --git a/src/Vault.sol b/src/Vault.sol
@@ -14,8 +14,9 @@ import {ILockCallback} from "./interfaces/ILockCallback.sol";
 import {SafeCast} from "./libraries/SafeCast.sol";
 import {VaultReserves} from "./libraries/VaultReserves.sol";
 import {VaultToken} from "./VaultToken.sol";
+import {Exttload} from "./Exttload.sol";
 
-contract Vault is IVault, VaultToken, Ownable {
+contract Vault is IVault, VaultToken, Ownable, Exttload {
     using SafeCast for *;
     using PoolIdLibrary for PoolKey;
     using CurrencyLibrary for Currency;

diff --git a/src/interfaces/IExtsload.sol b/src/interfaces/IExtsload.sol
@@ -7,6 +7,12 @@ interface IExtsload {
     /// @return value The value of the slot as bytes32
     function extsload(bytes32 slot) external view returns (bytes32 value);
 
+    /// @notice Called by external contracts to access granular pool state
+    /// @param slot Key of slot to start sloading from
+    /// @param nSlots Number of slots to load into return value
+    /// @return value The value of the sload-ed slots concatenated as dynamic bytes
+    function extsload(bytes32 slot, uint256 nSlots) external view returns (bytes memory value);
+
     /// @notice Called by external contracts to access sparse pool state
     /// @param slots List of slots to SLOAD from.
     /// @return values List of loaded values.

diff --git a/src/interfaces/IExttload.sol b/src/interfaces/IExttload.sol
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.24;
+
+interface IExttload {
+    /// @notice Called by external contracts to access transient storage of the contract
+    /// @param slot Key of slot to tload
+    /// @return value The value of the slot as bytes32
+    function exttload(bytes32 slot) external view returns (bytes32 value);
+
+    /// @notice Called by external contracts to access sparse transient pool state
+    /// @param slots List of slots to tload
+    /// @return values List of loaded values
+    function exttload(bytes32[] calldata slots) external view returns (bytes32[] memory values);
+}
diff --git a/src/interfaces/IVault.sol b/src/interfaces/IVault.sol
@@ -7,8 +7,9 @@ import {PoolKey} from "../types/PoolKey.sol";
 import {BalanceDelta} from "../types/BalanceDelta.sol";
 import {IPoolManager} from "./IPoolManager.sol";
 import {IVaultToken} from "./IVaultToken.sol";
+import {IExttload} from "./IExttload.sol";
 
-interface IVault is IVaultToken {
+interface IVault is IVaultToken, IExttload {
     event PoolManagerRegistered(address indexed poolManager);
 
     /// @notice Thrown when a function is not called by a pool manager

diff --git a/test/Extsload.t.sol b/test/Extsload.t.sol
@@ -45,6 +45,23 @@ contract ExtsloadTest is Test, GasSnapshot {
         assertEq(abi.encode(slot3), abi.encode(address(0xabcd)));
     }
 
+    function testExtsloadNSlot() public {
+        snapStart("ExtsloadTest#testExtsloadNSlot");
+        bytes memory data = poolManager.extsload(bytes32(uint256(0x00)), 4);
+        snapEnd();
+
+        address owner;
+        address protocolFeeController;
+        assembly {
+            owner := mload(add(data, 32))
+            // slot 0x01 and 0x02 are mapping so skip for now
+            protocolFeeController := mload(add(data, 128))
+        }
+
+        assertEq(owner, address(this));
+        assertEq(protocolFeeController, address(0xabcd));
+    }
+
     function testExtsloadInBatch() public {
         bytes32[] memory slots = new bytes32[](2);
         slots[0] = 0x00;