get stake interface in solidity

Author: open-junius

runtime/src/precompiles/solidity/staking.abi

@@ -17,6 +17,30 @@
         "stateMutability": "payable",
         "type": "function"
     },
+    {
+        "inputs": [
+            {
+                "internalType": "bytes32",
+                "name": "hotkey",
+                "type": "bytes32"
+            },
+            {
+                "internalType": "bytes32",
+                "name": "coldkey",
+                "type": "bytes32"
+            }
+        ],
+        "name": "getStake",
+        "outputs": [
+            {
+                "internalType": "uint64",
+                "name": "",
+                "type": "uint64"
+            }
+        ],
+        "stateMutability": "view",
+        "type": "function"
+    },
     {
         "inputs": [
             {
@@ -37,7 +61,7 @@
         ],
         "name": "removeStake",
         "outputs": [],
-        "stateMutability": "payable",
+        "stateMutability": "nonpayable",
         "type": "function"
     }
-]
+]

runtime/src/precompiles/solidity/staking.sol

@@ -42,4 +42,16 @@ interface IStaking {
    * - The existing stake amount must be not lower than specified amount
    */
   function removeStake(bytes32 hotkey, uint256 amount, uint16 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).
+   * @return The current stake amount in uint64 format.
+   */
+  function getStake(bytes32 hotkey, bytes32 coldkey) external view returns (uint64);
 }

runtime/src/precompiles/staking.rs

@@ -59,6 +59,9 @@ impl StakingPrecompile {
             id if id == get_method_id("removeStake(bytes32,uint256,uint16)") => {
                 Self::remove_stake(handle, &method_input)
             }
+            id if id == get_method_id("getStake(bytes32,bytes32)") => {
+                Self::get_stake(handle, &method_input)
+            }
             _ => Err(PrecompileFailure::Error {
                 exit_status: ExitError::InvalidRange,
             }),
@@ -101,6 +104,18 @@ impl StakingPrecompile {
         Self::dispatch(handle, call)
     }
 
+    fn get_stake(handle: &mut impl PrecompileHandle, data: &[u8]) -> PrecompileResult {
+        let hotkey: AccountId32 = Self::parse_hotkey(data)?.into();
+
+        let data =
+            pallet_subtensor::Pallet::<Runtime>::get_stake_for_coldkey_and_hotkey(&hotkey, &hotkey);
+
+        Ok(PrecompileOutput {
+            exit_status: ExitSucceed::Returned,
+            output: data.to_le_bytes().to_vec(),
+        })
+    }
+
     fn parse_hotkey(data: &[u8]) -> Result<[u8; 32], PrecompileFailure> {
         if data.len() < 32 {
             return Err(PrecompileFailure::Error {