What's the position of Metadata.CKB_RELATED_INFO_KEY?

[yangby-cryptape]

Question

I want to get the proof of Metadata.CKB_RELATED_INFO_KEY through eth_getProof.

What's the position (or storage keys) of it?

axon/core/executor/src/system_contract/metadata/store.rs

Line 24 in 3dbfe5a

/// | CKB_RELATED_INFO_KEY | `CkbRelatedInfo.encode()` |

axon/core/api/README.md

Lines 1081 to 1087 in 835cb16

	#### Method `eth_getProof`
	##### Params
	* `DATA`, 20 Bytes - address of the account.
	* `ARRAY`, 32 Bytes - array of storage-keys which should be proofed and included. See eth_getStorageAt
	* `QUANTITY|TAG` - integer block number, or the string "latest" or "earliest", see the default block parameter

axon/core/api/README.md

Lines 1910 to 1917 in 835cb16

	#### Method `eth_getStorageAt`
	* `eth_getStorageAt(address,position,number)`
	* `address`: [`H160`](#type-H160)
	* `position`: [`U256`](#type-U256)
	* `number`: [`BlockId`](#type-BlockId)
	* result: [`Hex`](#type-Hex)
	Returns the value from a storage position at a given address.

In Further

If I'm incorrect, please point out.

I have only read some documents from the internet.

In my understand, the positions are defined as following:

contract Demo {
    uint     a = 1;
    uint128  b = 2;
    uint32   c = 3;

    /* ... omit ... */
}

storage(position = 0) is 0x0000000000000000000000000000000000000000000000000000000000000001
                                                                                          ^
storage(position = 1) is 0x0000000000000000000000000000000300000000000000000000000000000002
                                                          ^                               ^

Also, the position will be the key in the storage.

Since Axon system contracts use self-defined keys for all state variables, how could users to get those keys?

If one data has more than 256 bits, it will have more than 1 position.
If data type is array or map, it's more complex.
But each data for Axon system contracts has only one key, how to process these situations?

References

• May need another APIs to get the proofs of Axon's system contracts #1561
• Call the built-in Metadata contract causes an error. #1457

[yangby-cryptape]

Have been answered in #1561 (comment).

[KaoImin]

Duplicated with #1561