in remix -> "Storage" -> what is the meaning of this top level key?

Question

what is the meaning of this key?

it's not a memory address of value - this is thisobject.key

---

contract code (but it doesn't matter)

// SPDX-License-Identifier: GPL-3.0

pragma solidity >=0.5.12;

struct Xx { int256 x; }


contract Storage {
    mapping(uint256 => bool) public mappingName;
    Xx yy;
    bool mybool;
    
    constructor () {
        mybool = true;
        mybool = false;
        mappingName[1] = true;
        mappingName[4] = true;

        mappingName[3] = false;
        yy = Xx(0x01);
    }
    
    /**
     * @dev Store value in variable
     */
    function store() public returns (bool) {
        bytes32 asdf;
        assembly {
            asdf := sload(0x3f9553dc324cd1fd24b54243720c42e18e5c20165bc5e523e42b440a8654abd1)
            asdf := sload(0xada5013122d395ba3c54772283fb069b10426056ef8ca54750cb9bb552a59e7d)
            asdf := sload(0x8c5463c4917005f6f56c5b404257d4579d1c38c101ead4559bdf4510fcfa0ebd)
            asdf := sload(0x52d75039926638d3c558b2bdefb945d5be8dae29dedd1c313212a4d472d9fde5)
        }
       mappingName[1] = false;
       delete mappingName[4];

       return mappingName[1];
        
    }
}

---

EDIT

in code it is called innerkey

https://github.com/ethereum/remix-project/blob/6e896f3676a01fbb332adf6cf1873008640a49b8/libs/remix-ui/debugger-ui/src/lib/vm-debugger/dropdown-panel.tsx#L210

which is a key of calldata object

not this https://github.com/ethereum/remix-project/blob/6e896f3676a01fbb332adf6cf1873008640a49b8/libs/remix-ui/debugger-ui/src/types/index.ts#L21

but this https://github.com/ethereum/remix-project/blob/6e896f3676a01fbb332adf6cf1873008640a49b8/libs/remix-ui/debugger-ui/src/reducers/calldata.ts#L7

Answer 1

It appears that the top level key is the keccak256 hash of the key value under it. For example below are the storage values displayed in Remix debugger in a dummy contract I wrote. The keccak256(000...0001) = 0xb10e...cf6, keccak256(e5585...4994) = 0xc5f7...3e6d etc.

This is shown this way because of how the account storage data structure Trie encodes into the trie a mapping from the Keccak256-bit hash of the 256-bit integer keys to the RLP-encoded 256-bit integer values. See "storageRoot" explantion in the image at https://i.sstatic.net/afWDt.jpg and for more information see - https://medium.com/shyft-network/understanding-trie-databases-in-ethereum-9f03d2c3325d

{
    "0xb10e2d527612073b26eecdfd717e6a320cf44b4afac2b0732d9fcbe2b7fa0cf6": {
        "key": "0x0000000000000000000000000000000000000000000000000000000000000001",
        "value": "0x07855b46a623a8ecabac76ed697aa4e13631e3b6718c8a0d342860c13c30d2fc"
    },
    "0xc5f7bd2ffa69640fdb902c1e99f6e20c5315b1da99817a0ff0bf40db3d863e6d": {
        "key": "0xe5585f670120da72037ceaaf17a48de28247bb09935fce827f7b42f44cfe4994",
        "value": "0x00000000000000000000000000000000000000000000000000000000000000a1"
    },
    "0x5907fe8790797888d8e2f8ed99b17c95ed9a74b233ef6370039da40c7ba33ab9": {
        "key": "0xc5f7bd2ffa69640fdb902c1e99f6e20c5315b1da99817a0ff0bf40db3d863e6d",
        "value": "0x68656c6c6f68656c6c6f68656c6c6f68656c6c6f68656c6c6f68656c6c6f6865"
    },
    "0xc60576cc8d9783786e09d7eeb7af374ff4cadcff85940ac057b23705362bb5a7": {
        "key": "0xc5f7bd2ffa69640fdb902c1e99f6e20c5315b1da99817a0ff0bf40db3d863e6e",
        "value": "0x6c6c6f68656c6c6f68656c6c6f68656c6c6f68656c6c6f68656c6c6f68656c6c"
    },
    "0x4fa43ab19b07248b845176509abfef01aaf15f03ccafa4eb387319661c08ec63": {
        "key": "0xc5f7bd2ffa69640fdb902c1e99f6e20c5315b1da99817a0ff0bf40db3d863e6f",
        "value": "0x6f68656c6c6f68656c6c6f68656c6c6f00000000000000000000000000000000"
    }
}