Reimbursing for a callback in the Service Contract

keep-network · Jan 27, 2020 · 6c4848c · 6c4848c
1 parent 7790049
commit 6c4848c
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Showing 3 changed files with 47 additions and 26 deletions.
diff --git a/contracts/solidity/contracts/KeepRandomBeaconOperator.sol b/contracts/solidity/contracts/KeepRandomBeaconOperator.sol
@@ -502,6 +502,36 @@ contract KeepRandomBeaconOperator is ReentrancyGuard {
         currentEntryStartBlock = 0;
     }
 
+    /**
+     * @dev Reimbursment for calling customer specified callback for the relay entry request.
+     * @param callbackFunds Available funds for callback reimbursment.
+     * @param submitter Relay entry submitter address.
+     * @param surplusRecipient Surplus recipient address.
+     */
+    function reimburseCallback(uint256 callbackFunds, address payable submitter, address payable surplusRecipient)
+        public payable onlyServiceContract {
+
+        bool success; // Store status of external contract call.
+
+        // If we spent less on the callback than the customer transferred for the
+        // callback execution, we need to reimburse the difference.
+        if (msg.value < callbackFunds) {
+            uint256 callbackSurplus = callbackFunds.sub(msg.value);
+            // Reimburse submitter with his actual callback cost.
+            (success, ) = submitter.call.value(msg.value)("");
+            require(success, "Failed reimburse actual callback cost");
+
+            // Return callback surplus to the requestor.
+            (success, ) = surplusRecipient.call.value(callbackSurplus)("");
+            require(success, "Failed send callback surplus");
+
+        } else {
+            // Reimburse submitter with the callback payment sent by the requestor.
+            (success, ) = submitter.call.value(callbackFunds)("");
+            require(success, "Failed reimburse callback payment");
+        }
+    }
+
     /**
      * @dev Get rewards breakdown in wei for successful entry for the current signing request.
      */

diff --git a/contracts/solidity/contracts/KeepRandomBeaconServiceImplV1.sol b/contracts/solidity/contracts/KeepRandomBeaconServiceImplV1.sol
@@ -17,6 +17,11 @@ interface OperatorContract {
     ) external payable;
     function numberOfGroups() external view returns(uint256);
     function createGroup(uint256 newEntry, address payable submitter) external payable;
+    function reimburseCallback(
+        uint256 callbackFunds,
+        address payable submitter,
+        address payable surplusRecipient
+    ) external payable;
     function isGroupSelectionPossible() external view returns (bool);
 }
 
@@ -337,26 +342,12 @@ contract KeepRandomBeaconServiceImplV1 is DelayedWithdrawal, ReentrancyGuard {
         }
 
         // Obtain the actual callback gas expenditure and refund the surplus.
-        uint256 callbackSurplus = 0;
-        uint256 callbackFee = gasSpent.mul(gasPrice);
-
-        // If we spent less on the callback than the customer transferred for the
-        // callback execution, we need to reimburse the difference.
-        if (callbackFee < _callbacks[requestId].callbackFee) {
-            callbackSurplus = _callbacks[requestId].callbackFee.sub(callbackFee);
-            // Reimburse submitter with his actual callback cost.
-            (success, ) = submitter.call.value(callbackFee)("");
-            require(success, "Failed reimburse actual callback cost");
-
-            // Return callback surplus to the requestor.
-            (success, ) = _callbacks[requestId].surplusRecipient.call.value(callbackSurplus)("");
-            require(success, "Failed send callback surplus");
-
-        } else {
-            // Reimburse submitter with the callback payment sent by the requestor.
-            (success, ) = submitter.call.value(_callbacks[requestId].callbackFee)("");
-            require(success, "Failed reimburse callback payment");
-        }
+        // uint256 callbackFee = gasSpent.mul(gasPrice);
+
+        // revert("bbbb");
+        address latestOperatorContract = _operatorContracts[_operatorContracts.length.sub(1)];
+        OperatorContract(latestOperatorContract).reimburseCallback.value(gasSpent.mul(gasPrice))(
+            _callbacks[requestId].callbackFee, submitter, _callbacks[requestId].surplusRecipient);
     }
 
     /**

diff --git a/contracts/solidity/test/TestKeepRandomBeaconServicePricing.js b/contracts/solidity/test/TestKeepRandomBeaconServicePricing.js
@@ -108,11 +108,14 @@ contract('TestKeepRandomBeaconServicePricing', function(accounts) {
   });
 
   it("should send group reward to each operator.", async function() {
-    let entryFeeEstimate = await serviceContract.entryFeeEstimate(0)
+    let callbackGas = await callbackContract.callback.estimateGas(bls.groupSignature);
+    let excessCallbackGas = web3.utils.toBN(callbackGas).mul(web3.utils.toBN(2)); 
+    let entryFeeEstimate = await serviceContract.entryFeeEstimate(excessCallbackGas)
+
     let tx = await serviceContract.methods['requestRelayEntry(address,string,uint256)'](
       callbackContract.address,
       "callback(uint256)",
-      0,
+      excessCallbackGas,
       {value: entryFeeEstimate, from: requestor}
     );
 
@@ -161,10 +164,7 @@ contract('TestKeepRandomBeaconServicePricing', function(accounts) {
     // subsidy = 5250000000000000 - 207407407407407 * 5 - 210648148148148 = 4002314814814817 wei
 
     let entryFeeEstimate = await serviceContract.entryFeeEstimate(0)
-    let tx = await serviceContract.methods['requestRelayEntry(address,string,uint256)'](
-      callbackContract.address,
-      "callback(uint256)",
-      0,
+    let tx = await serviceContract.methods['requestRelayEntry()'](
       {value: entryFeeEstimate, from: requestor}
     );