Merge pull request opentensor#955 from opentensor/feat/solidity-get-s…

…take

get stake interface in solidity

runtime/src/precompiles/solidity/staking.abi

@@ -18,28 +18,33 @@
         "type": "function"
     },
     {
-        inputs: [
-        {
-            internalType: "bytes32",
-            name: "hotkey",
-            type: "bytes32",
-        },
-        {
-            internalType: "bytes32",
-            name: "coldkey",
-            type: "bytes32",
-        },
+        "inputs": [
+            {
+                "internalType": "bytes32",
+                "name": "hotkey",
+                "type": "bytes32"
+            },
+            {
+                "internalType": "bytes32",
+                "name": "coldkey",
+                "type": "bytes32"
+            },
+            {
+                "internalType": "uint256",
+                "name": "netuid",
+                "type": "uint256"
+            }
         ],
-        name: "getStake",
-        outputs: [
-        {
-            internalType: "uint64",
-            name: "",
-            type: "uint64",
-        },
+        "name": "getStake",
+        "outputs": [
+            {
+                "internalType": "uint256",
+                "name": "",
+                "type": "uint256"
+            }
         ],
-        stateMutability: "view",
-        type: "function",
+        "stateMutability": "view",
+        "type": "function"
     },
     {
         "inputs": [
@@ -64,4 +69,4 @@
         "stateMutability": "nonpayable",
         "type": "function"
     }
-]
+]

runtime/src/precompiles/solidity/staking.sol

@@ -14,7 +14,7 @@ interface IStaking {
    * https://github.com/polkadot-evm/frontier/blob/2e219e17a526125da003e64ef22ec037917083fa/frame/evm/src/lib.rs#L739
    *
    * @param hotkey The hotkey public key (32 bytes).
-   * @param netuid The subnet to stake to (uint256). Currently a noop, functionality will be enabled with RAO.
+   * @param netuid The subnet to stake to (uint256).
    *
    * Requirements:
    * - `hotkey` must be a valid hotkey registered on the network, ensuring that the stake is
@@ -33,13 +33,25 @@ interface IStaking {
    *
    * @param hotkey The hotkey public key (32 bytes).
    * @param amount The amount to unstake in rao.
-   * @param netuid The subnet to stake to (uint256). Currently a noop, functionality will be enabled with RAO.
-
+   * @param netuid The subnet to stake to (uint256).
    *
    * Requirements:
    * - `hotkey` must be a valid hotkey registered on the network, ensuring that the stake is
    *   correctly attributed.
    * - The existing stake amount must be not lower than specified amount
    */
   function removeStake(bytes32 hotkey, uint256 amount, uint256 netuid) external;
+
+  /**
+  * @dev Returns the stake amount associated with the specified `hotkey` and `coldkey`.
+  *
+  * This function retrieves the current stake amount linked to a specific hotkey and coldkey pair.
+  * It is a view function, meaning it does not modify the state of the contract and is free to call.
+  *
+  * @param hotkey The hotkey public key (32 bytes).
+  * @param coldkey The coldkey public key (32 bytes).
+  * @param netuid The subnet the stake is on (uint256).
+  * @return The current stake amount in uint256 format.
+  */
+  function getStake(bytes32 hotkey, bytes32 coldkey, uint256 netuid) external view returns (uint256);
 }

runtime/src/precompiles/staking.rs

@@ -59,6 +59,9 @@ impl StakingPrecompile {
             id if id == get_method_id("removeStake(bytes32,uint256,uint256)") => {
                 Self::remove_stake(handle, &method_input)
             }
+            id if id == get_method_id("getStake(bytes32,bytes32,uint256)") => {
+                Self::get_stake(&method_input)
+            }
             _ => Err(PrecompileFailure::Error {
                 exit_status: ExitError::InvalidRange,
             }),
@@ -107,6 +110,45 @@ impl StakingPrecompile {
         Self::dispatch(handle, call)
     }
 
+    fn get_stake(data: &[u8]) -> PrecompileResult {
+        let (hotkey, coldkey) = Self::parse_hotkey_coldkey(data)?;
+        let netuid = Self::parse_netuid(data, 0x5E)?;
+
+        let stake = pallet_subtensor::Pallet::<Runtime>::get_stake_for_hotkey_and_coldkey_on_subnet(
+            &hotkey.into(),
+            &coldkey.into(),
+            netuid,
+        );
+
+        // Convert to EVM decimals
+        let stake_u256 = U256::from(stake);
+        let stake_eth =
+            <Runtime as pallet_evm::Config>::BalanceConverter::into_evm_balance(stake_u256)
+                .ok_or(ExitError::InvalidRange)?;
+
+        // Format output
+        let mut result = [0_u8; 32];
+        U256::to_big_endian(&stake_eth, &mut result);
+
+        Ok(PrecompileOutput {
+            exit_status: ExitSucceed::Returned,
+            output: result.into(),
+        })
+    }
+
+    fn parse_hotkey_coldkey(data: &[u8]) -> Result<([u8; 32], [u8; 32]), PrecompileFailure> {
+        if data.len() < 64 {
+            return Err(PrecompileFailure::Error {
+                exit_status: ExitError::InvalidRange,
+            });
+        }
+        let mut hotkey = [0u8; 32];
+        hotkey.copy_from_slice(get_slice(data, 0, 32)?);
+        let mut coldkey = [0u8; 32];
+        coldkey.copy_from_slice(get_slice(data, 32, 64)?);
+        Ok((hotkey, coldkey))
+    }
+
     fn parse_hotkey(data: &[u8]) -> Result<[u8; 32], PrecompileFailure> {
         if data.len() < 32 {
             return Err(PrecompileFailure::Error {