use transient storage for the current hook addr

.forge-snapshots/before swap hook, already cached dynamic fee.snap

@@ -1 +1 @@
-188685
+186984

.forge-snapshots/cached dynamic fee, no hooks.snap

@@ -1 +1 @@
-142201
+142310

.forge-snapshots/donate gas with 1 token.snap

@@ -1 +1 @@
-134065
+132186

.forge-snapshots/donate gas with 2 tokens.snap

@@ -1 +1 @@
-182638
+180759

.forge-snapshots/mint with empty hook.snap

@@ -1 +1 @@
-335320
+313472

.forge-snapshots/mint with native token.snap

@@ -1 +1 @@
-198076
+196197

.forge-snapshots/mint.snap

@@ -1 +1 @@
-198018
+196139

.forge-snapshots/poolManager bytecode size.snap

@@ -1 +1 @@
-25133
+25374

.forge-snapshots/simple swap with native.snap

@@ -1 +1 @@
-193042
+191151

.forge-snapshots/simple swap.snap

@@ -1 +1 @@
-201609
+199718

.forge-snapshots/swap against liquidity with native token.snap

@@ -1 +1 @@
-121638
+121747

.forge-snapshots/swap against liquidity.snap

@@ -1 +1 @@
-109127
+109236

.forge-snapshots/swap burn claim for input.snap

@@ -1 +1 @@
-128197
+128306

.forge-snapshots/swap mint output as claim.snap

@@ -1 +1 @@
-211778
+209887

.forge-snapshots/swap with dynamic fee.snap

@@ -1 +1 @@
-187925
+186224

.forge-snapshots/swap with hooks.snap

@@ -1 +1 @@
-109106
+109215

.forge-snapshots/update dynamic fee in before swap.snap

@@ -1 +1 @@
-194515
+192814

foundry.toml

@@ -6,7 +6,7 @@ fs_permissions = [{ access = "read-write", path = ".forge-snapshots/"}, { access
 cancun = true
 
 [profile.default.fuzz]
-runs = 1000
+runs = 100
 seed = "0x4444"
 
 [profile.ci.fuzz]

src/PoolManager.sol

@@ -21,6 +21,7 @@ import {Claims} from "./Claims.sol";
 import {PoolId, PoolIdLibrary} from "./types/PoolId.sol";
 import {BalanceDelta} from "./types/BalanceDelta.sol";
 import {Lockers} from "./libraries/Lockers.sol";
+import {CurrentHookAddress} from "./libraries/CurrentHookAddress.sol";
 
 /// @notice Holds the state for all pools
 contract PoolManager is IPoolManager, Fees, NoDelegateCall, Claims {
@@ -179,7 +180,7 @@ contract PoolManager is IPoolManager, Fees, NoDelegateCall, Claims {
         // todo fix stack too deep :/
         address locker = Lockers.getCurrentLocker();
         if (msg.sender != locker) {
-            if (msg.sender != currentHook || !Hooks.shouldAccessLock(IHooks(currentHook))) {
+            if (msg.sender != CurrentHookAddress.get() || !Hooks.shouldAccessLock(IHooks(CurrentHookAddress.get()))) {
                 revert LockedBy(locker);
             }
         }
@@ -192,7 +193,7 @@ contract PoolManager is IPoolManager, Fees, NoDelegateCall, Claims {
         IPoolManager.ModifyPositionParams memory params,
         bytes calldata hookData
     ) external override noDelegateCall onlyByLocker returns (BalanceDelta delta) {
-        _setCurrentHook(address(key.hooks));
+        CurrentHookAddress.set(address(key.hooks));
 
         if (key.hooks.shouldCallBeforeModifyPosition()) {
             if (
@@ -252,7 +253,7 @@ contract PoolManager is IPoolManager, Fees, NoDelegateCall, Claims {
         onlyByLocker
         returns (BalanceDelta delta)
     {
-        _setCurrentHook(address(key.hooks));
+        CurrentHookAddress.set(address(key.hooks));
 
         if (key.hooks.shouldCallBeforeSwap()) {
             if (key.hooks.beforeSwap(msg.sender, key, params, hookData) != IHooks.beforeSwap.selector) {
@@ -306,7 +307,7 @@ contract PoolManager is IPoolManager, Fees, NoDelegateCall, Claims {
         onlyByLocker
         returns (BalanceDelta delta)
     {
-        _setCurrentHook(address(key.hooks));
+        CurrentHookAddress.set(address(key.hooks));
 
         if (key.hooks.shouldCallBeforeDonate()) {
             if (key.hooks.beforeDonate(msg.sender, key, amount0, amount1, hookData) != IHooks.beforeDonate.selector) {
@@ -406,11 +407,6 @@ contract PoolManager is IPoolManager, Fees, NoDelegateCall, Claims {
         return Lockers.nonzeroDeltaCount();
     }
 
-    // TODO: Use transient storage
-    function _setCurrentHook(address hookAddr) internal {
-        if (currentHook != hookAddr) currentHook = hookAddr;
-    }
-
     /// @notice receive native tokens for native pools
     receive() external payable {}
 }

src/libraries/CurrentHookAddress.sol

@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+// TODO: Remove this library once the `transient` keyword is supported in solidity.
+library CurrentHookAddress {
+    uint256 constant HOOK_ADDRESS_SLOT = uint256(keccak256("HookAddress")) - 1;
+
+    function get() internal view returns (address _address) {
+        uint256 slot = HOOK_ADDRESS_SLOT;
+        assembly {
+            _address := tload(slot)
+        }
+    }
+
+    function set(address _address) internal {
+        if (_address != get()) {
+            uint256 slot = HOOK_ADDRESS_SLOT;
+            assembly {
+                tstore(slot, _address)
+            }
+        }
+    }
+}

src/test/AccessLockHook.sol

@@ -9,8 +9,6 @@ import {CurrencyLibrary, Currency} from "../types/Currency.sol";
 import {Hooks} from "../libraries/Hooks.sol";
 import {TickMath} from "../libraries/TickMath.sol";
 
-import "forge-std/console2.sol";
-
 contract AccessLockHook is BaseTestHooks {
     using CurrencyLibrary for Currency;
 
@@ -67,8 +65,6 @@ contract AccessLockHook is BaseTestHooks {
         if (action == LockAction.Mint) {
             manager.mint(key.currency1, address(this), amount);
         } else if (action == LockAction.Take) {
-            console2.log("TAKE");
-            console2.log(key.currency1.balanceOf(address(manager)));
             manager.take(key.currency1, address(this), amount);
         } else if (action == LockAction.Donate) {
             manager.donate(key, amount, amount, new bytes(0));

test/AccessLock.t.sol

@@ -18,8 +18,6 @@ import {BalanceDelta} from "../src/types/BalanceDelta.sol";
 import {Pool} from "../src/libraries/Pool.sol";
 import {TickMath} from "../src/libraries/TickMath.sol";
 
-import "forge-std/console2.sol";
-
 contract AccessLockTest is Test, Deployers {
     using Pool for Pool.State;
     using CurrencyLibrary for Currency;

test/CurrentHookAddress.t.sol

@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.20;
+
+import {Test} from "forge-std/Test.sol";
+import {CurrentHookAddress} from "../src/libraries/CurrentHookAddress.sol";
+
+contract CurrentHookAddressTest is Test {
+    function test_get_currentHookAddress() public {
+        assertEq(CurrentHookAddress.get(), address(0));
+    }
+
+    function test_set_currentHookAddress() public {
+        CurrentHookAddress.set(address(1));
+        assertEq(CurrentHookAddress.get(), address(1));
+    }
+
+    function test_set_currentHookAddressTwice() public {
+        CurrentHookAddress.set(address(1));
+        CurrentHookAddress.set(address(2));
+
+        assertEq(CurrentHookAddress.get(), address(2));
+    }
+}