写入任意插槽

写入任意插槽

Solidity 存储就像一个长度为 2^256 的数组。数组中的每个槽可以存储 32 个字节。

声明的顺序和状态变量的类型定义了它将使用哪些槽。

然而，使用汇编，您可以写入任何插槽。

Solidity storage is like an array of length 2^256. Each slot in the array can store 32 bytes.

Order of declaration and the type of state variables define which slots it will use.

However using assembly, you can write to any slot.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

library StorageSlot {
    // Wrap address in a struct so that it can be passed around as a storage pointer
    struct AddressSlot {
        address value;
    }

    function getAddressSlot(
        bytes32 slot
    ) internal pure returns (AddressSlot storage pointer) {
        assembly {
            // Get the pointer to AddressSlot stored at slot
            pointer.slot := slot
        }
    }
}

contract TestSlot {
    bytes32 public constant TEST_SLOT = keccak256("TEST_SLOT");

    function write(address _addr) external {
        StorageSlot.AddressSlot storage data = StorageSlot.getAddressSlot(TEST_SLOT);
        data.value = _addr;
    }

    function get() external view returns (address) {
        StorageSlot.AddressSlot storage data = StorageSlot.getAddressSlot(TEST_SLOT);
        return data.value;
    }
}