feat: UsingWitnet._witnetBaseFeeOverheadPercentage()

contracts/apps/UsingWitnet.sol

@@ -12,21 +12,32 @@ abstract contract UsingWitnet
     is
         IWitnetRequestBoardEvents
 {
+    /// @dev Immutable reference to the Witnet Request Board contract.
     WitnetRequestBoard internal immutable __witnet;
+
+    /// @dev Default Security-Level Agreement parameters to be fulfilled by the Witnet blockchain
+    /// @dev when solving a data request.
     bytes32 private __witnetDefaultPackedSLA;
 
-    /// @dev Include an address to specify the WitnetRequestBoard entry point address.
-    /// @param _wrb The WitnetRequestBoard entry point address.
+    /// @dev Percentage over base fee to pay on every data request, 
+    /// @dev as to deal with volatility of evmGasPrice and evmWitPrice during the live time of 
+    /// @dev a data request (since being posted until a result gets reported back), at both the EVM and 
+    /// @dev the Witnet blockchain levels, respectivelly. 
+    uint16 private __witnetBaseFeeOverheadPercentage;
+
+    /// @param _wrb Address of the WitnetRequestBoard contract.
     constructor(WitnetRequestBoard _wrb) {
         require(
             _wrb.specs() == type(IWitnetRequestBoard).interfaceId,
             "UsingWitnet: uncompliant WitnetRequestBoard"
         );
         __witnet = _wrb;
         __witnetDefaultPackedSLA = WitnetV2.toBytes32(WitnetV2.RadonSLA({
-            witnessingCommitteeSize: 10,
-            witnessingWitTotalReward: 10 ** 9
+            witnessingCommitteeSize: 10, // up to 127
+            witnessingWitTotalReward: 10 ** 9 // 1.0 $WIT
         }));
+
+        __witnetBaseFeeOverheadPercentage = 10; // defaults to 10%
     }
 
     /// @dev Provides a convenient way for client contracts extending this to block the execution of the main logic of the
@@ -53,11 +64,14 @@ abstract contract UsingWitnet
     /// @notice Estimate the minimum reward required for posting a data request, using `tx.gasprice` as a reference.
     /// @dev Underestimates if the size of returned data is greater than `_resultMaxSize`. 
     /// @param _resultMaxSize Maximum expected size of returned data (in bytes).
-    function _witnetEstimateBaseFee(uint16 _resultMaxSize)
+    function _witnetEstimateEvmReward(uint16 _resultMaxSize)
         virtual internal view
         returns (uint256)
     {
-        return __witnet.estimateBaseFee(tx.gasprice, _resultMaxSize);
+        return (
+            (100 + _witnetBaseFeeOverheadPercentage())
+                * __witnet.estimateBaseFee(tx.gasprice, _resultMaxSize) 
+        ) / 100;
     }
 
     function _witnetCheckQueryResultAuditTrail(uint256 _witnetQueryId)
@@ -89,6 +103,10 @@ abstract contract UsingWitnet
         return WitnetV2.toRadonSLA(__witnetDefaultPackedSLA);
     }
 
+    function _witnetBaseFeeOverheadPercentage() virtual internal view returns (uint16) {
+        return __witnetBaseFeeOverheadPercentage;
+    }
+
     function __witnetRequestData(
             uint256 _witnetEvmReward, 
             WitnetV2.RadonSLA memory _witnetQuerySLA,
@@ -116,4 +134,8 @@ abstract contract UsingWitnet
     function __witnetSetDefaultSLA(WitnetV2.RadonSLA memory _defaultSLA) virtual internal {
         __witnetDefaultPackedSLA = WitnetV2.toBytes32(_defaultSLA);
     }
+
+    function __witnetSetBaseFeeOverheadPercentage(uint16 _baseFeeOverheadPercentage) virtual internal {
+        __witnetBaseFeeOverheadPercentage = _baseFeeOverheadPercentage;
+    }
 }

contracts/apps/UsingWitnetRandomness.sol

@@ -17,13 +17,18 @@ abstract contract UsingWitnetRandomness
 
     bytes32 internal immutable __witnetRandomnessRadHash;
 
+    /// @param _wrb Address of the WitnetRequestBoard contract.
+    /// @param _baseFeeOverheadPercentage Percentage over base fee to pay as on every data request.
+    /// @param _callbackGasLimit Maximum gas to be spent by the IWitnetConsumer's callback methods.
+    /// @param _defaultSLA Default Security-Level Agreement parameters to be fulfilled by the Witnet blockchain.
     constructor(
             WitnetRequestBoard _wrb, 
-            uint96 _randomizeCallbackGasLimit,
+            uint16 _baseFeeOverheadPercentage,
+            uint96 _callbackGasLimit,
             WitnetV2.RadonSLA memory _defaultSLA
         )
         UsingWitnet(_wrb)
-        WitnetConsumer(_randomizeCallbackGasLimit)
+        WitnetConsumer(_callbackGasLimit)
     {
         // On-chain building of the Witnet Randomness Request:
         {
@@ -59,10 +64,11 @@ abstract contract UsingWitnetRandomness
         }
         // Settle default randomize SLA:
         __witnetSetDefaultSLA(_defaultSLA);
+        __witnetSetBaseFeeOverheadPercentage(_baseFeeOverheadPercentage);
     }
 
-    function _witnetEstimateRandomizeBaseFee() internal view returns (uint256) {
-        return _witnetEstimateBaseFee(32);
+    function _witnetEstimateEvmReward() virtual override internal view returns (uint256) {
+        return _witnetEstimateEvmReward(32);
     }
 
     function _witnetRandomUniformUint32(uint32 _range, uint256 _nonce, bytes32 _seed) internal pure returns (uint32) {

contracts/apps/UsingWitnetRequest.sol

@@ -12,8 +12,12 @@ abstract contract UsingWitnetRequest
     bytes32 immutable internal __witnetRequestRadHash;
     uint16  immutable internal __witnetResultMaxSize;
 
+    /// @param _witnetRequest Address of the WitnetRequest contract containing the actual data request.
+    /// @param _baseFeeOverheadPercentage Percentage over base fee to pay as on every data request.
+    /// @param _defaultSLA Default Security-Level Agreement parameters to be fulfilled by the Witnet blockchain.
     constructor (
             WitnetRequest _witnetRequest,
+            uint16 _baseFeeOverheadPercentage,
             WitnetV2.RadonSLA memory _defaultSLA
         )
         UsingWitnet(_witnetRequest.witnet())
@@ -26,16 +30,14 @@ abstract contract UsingWitnetRequest
         __witnetResultMaxSize = _witnetRequest.resultDataMaxSize();
         __witnetRequestRadHash = _witnetRequest.radHash();
         __witnetSetDefaultSLA(_defaultSLA);
+        __witnetSetBaseFeeOverheadPercentage(_baseFeeOverheadPercentage);
     }
 
-    function _witnetEstimateBaseFee()
+    function _witnetEstimateEvmReward()
         virtual internal view
         returns (uint256)
     {
-        return __witnet.estimateBaseFee(
-            tx.gasprice,
-            __witnetResultMaxSize
-        );
+        return _witnetEstimateEvmReward(__witnetResultMaxSize);
     }
 
     function __witnetRequestData(

contracts/apps/UsingWitnetRequestTemplate.sol

@@ -11,19 +11,24 @@ abstract contract UsingWitnetRequestTemplate
 
     uint16 immutable internal __witnetResultMaxSize;
 
+    /// @param _witnetRequestTemplate Address of the WitnetRequestTemplate from which actual data requests will get built.
+    /// @param _baseFeeOverheadPercentage Percentage over base fee to pay as on every data request.
+    /// @param _defaultSLA Default Security-Level Agreement parameters to be fulfilled by the Witnet blockchain.
     constructor (
-            WitnetRequestTemplate _requestTemplate, 
+            WitnetRequestTemplate _witnetRequestTemplate, 
+            uint16 _baseFeeOverheadPercentage,
             WitnetV2.RadonSLA memory _defaultSLA
         )
-        UsingWitnet(_requestTemplate.witnet())
+        UsingWitnet(_witnetRequestTemplate.witnet())
     {
         require(
-            _requestTemplate.specs() == type(WitnetRequestTemplate).interfaceId,
+            _witnetRequestTemplate.specs() == type(WitnetRequestTemplate).interfaceId,
             "UsingWitnetRequestTemplate: uncompliant WitnetRequestTemplate"
         );
-        dataRequestTemplate = _requestTemplate;
-        __witnetResultMaxSize = _requestTemplate.resultDataMaxSize();
+        dataRequestTemplate = _witnetRequestTemplate;
+        __witnetResultMaxSize = _witnetRequestTemplate.resultDataMaxSize();
         __witnetSetDefaultSLA(_defaultSLA);
+        __witnetSetBaseFeeOverheadPercentage(_baseFeeOverheadPercentage);
     }
 
     function _witnetBuildRadHash(string[][] memory _witnetRequestArgs)
@@ -38,14 +43,11 @@ abstract contract UsingWitnetRequestTemplate
         return WitnetRequest(dataRequestTemplate.buildRequest(_witnetRequestArgs));
     }
 
-    function _witnetEstimateBaseFee()
+    function _witnetEstimateEvmReward()
         virtual internal view
         returns (uint256)
     {
-        return __witnet.estimateBaseFee(
-            tx.gasprice,
-            __witnetResultMaxSize
-        );
+        return _witnetEstimateEvmReward(__witnetResultMaxSize);
     }
 
     function __witnetRequestData(

contracts/apps/WitnetConsumer.sol

@@ -8,16 +8,18 @@ abstract contract WitnetConsumer
     is
         IWitnetConsumer,
         UsingWitnet
-{   
-    uint96 private immutable __witnetReportCallbackGasLimit;
+{ 
+    /// @dev Maximum gas to be spent by the IWitnetConsumer's callback methods.  
+    uint96 private immutable __witnetCallbackGasLimit;
 
     modifier onlyFromWitnet {
         require(msg.sender == address(__witnet), "WitnetConsumer: unauthorized");
         _;
     }
 
-    constructor (uint96 _maxCallbackGas) {
-        __witnetReportCallbackGasLimit = _maxCallbackGas;
+    /// @param _callbackGasLimit Maximum gas to be spent by the IWitnetConsumer's callback methods.
+    constructor (uint96 _callbackGasLimit) {
+        __witnetCallbackGasLimit = _callbackGasLimit;
     }
 
 
@@ -32,31 +34,41 @@ abstract contract WitnetConsumer
     /// ===============================================================================================================
     /// --- WitnetConsumer virtual methods ----------------------------------------------------------------------------
 
-    function _witnetEstimateBaseFee(uint16)
+    function _witnetCallbackGasLimit()
+        virtual internal view 
+        returns (uint96)
+    {
+        return __witnetCallbackGasLimit;
+    }
+
+    function _witnetEstimateEvmReward() virtual internal view returns (uint256) {
+        return (
+            (100 + _witnetBaseFeeOverheadPercentage())
+                * __witnet.estimateBaseFeeWithCallback(
+                    tx.gasprice,
+                    _witnetCallbackGasLimit()
+                )
+        ) / 100;
+    }
+
+    function _witnetEstimateEvmReward(uint16)
         virtual override internal view
         returns (uint256)
     {
-        return _witnetEstimateBaseFeeWithCallback(_witnetReportCallbackGasLimit());
+        return _witnetEstimateEvmReward();
     }
 
 
     /// @notice Estimate the minimum reward required for posting a data request, using `tx.gasprice` as a reference.
     /// @dev Underestimates if the size of returned data is greater than `_resultMaxSize`. 
     /// @param _callbackGasLimit Maximum gas to be spent when reporting the data request result.
-    function _witnetEstimateBaseFeeWithCallback(uint96 _callbackGasLimit)
+    function _witnetEstimateEvmRewardWithCallback(uint96 _callbackGasLimit)
         virtual internal view
         returns (uint256)
     {
         return __witnet.estimateBaseFeeWithCallback(tx.gasprice, _callbackGasLimit);
     }
 
-    function _witnetReportCallbackGasLimit()
-        virtual internal view 
-        returns (uint96)
-    {
-        return __witnetReportCallbackGasLimit;
-    }
-
     function __witnetRequestData(
             uint256 _witnetEvmReward, 
             WitnetV2.RadonSLA memory _witnetQuerySLA,
@@ -68,7 +80,7 @@ abstract contract WitnetConsumer
         return __witnet.postRequestWithCallback{value: _witnetEvmReward}(
             _witnetRadHash,
             _witnetQuerySLA,
-            __witnetReportCallbackGasLimit
+            __witnetCallbackGasLimit
         );
     }
 
@@ -82,7 +94,7 @@ abstract contract WitnetConsumer
         return __witnet.postRequestWithCallback{value: _witnetEvmReward}(
             _witnetRequestBytecode, 
             _witnetQuerySLA,
-            __witnetReportCallbackGasLimit
+            __witnetCallbackGasLimit
         );
     }
 

contracts/apps/WitnetRequestConsumer.sol

@@ -11,36 +11,35 @@ abstract contract WitnetRequestConsumer
 {
     using WitnetCBOR for WitnetCBOR.CBOR;
     using WitnetCBOR for WitnetCBOR.CBOR[];
-
+
+    /// @param _witnetRequest Address of the WitnetRequest contract containing the actual data request.
+    /// @param _baseFeeOverheadPercentage Percentage over base fee to pay as on every data request.
+    /// @param _callbackGasLimit Maximum gas to be spent by the IWitnetConsumer's callback methods.
+    /// @param _defaultSLA Default Security-Level Agreement parameters to be fulfilled by the Witnet blockchain.   
     constructor(
             WitnetRequest _witnetRequest, 
+            uint16 _baseFeeOverheadPercentage,
             uint96 _callbackGasLimit,
             WitnetV2.RadonSLA memory _defaultSLA
         )
-        UsingWitnetRequest(_witnetRequest, _defaultSLA)
+        UsingWitnetRequest(_witnetRequest, _baseFeeOverheadPercentage, _defaultSLA)
         WitnetConsumer(_callbackGasLimit)
-    {
-        require(
-            _witnetEstimateBaseFeeWithCallback(_callbackGasLimit)
-                > UsingWitnetRequest._witnetEstimateBaseFee(),
-            "WitnetRequestConsumer: insufficient callback gas limit"
-        );
-    }
+    {}
 
-    function _witnetEstimateBaseFee() 
-        virtual override
+    function _witnetEstimateEvmReward() 
+        virtual override(UsingWitnetRequest, WitnetConsumer)
         internal view
         returns (uint256)
     {
-        return WitnetConsumer._witnetEstimateBaseFee(__witnetResultMaxSize);
+        return WitnetConsumer._witnetEstimateEvmReward();
     } 
 
-    function _witnetEstimateBaseFee(uint16 _resultMaxSize)
+    function _witnetEstimateEvmReward(uint16)
         virtual override(UsingWitnet, WitnetConsumer)
         internal view
         returns (uint256)
     {
-        return WitnetConsumer._witnetEstimateBaseFee(_resultMaxSize);
+        return WitnetConsumer._witnetEstimateEvmReward();
     }
 
     function __witnetRequestData(

contracts/apps/WitnetRequestTemplateConsumer.sol

@@ -12,36 +12,34 @@ abstract contract WitnetRequestTemplateConsumer
     using WitnetCBOR for WitnetCBOR.CBOR;
     using WitnetCBOR for WitnetCBOR.CBOR[];
 
+    /// @param _witnetRequestTemplate Address of the WitnetRequestTemplate from which actual data requests will get built.
+    /// @param _baseFeeOverheadPercentage Percentage over base fee to pay as on every data request.
+    /// @param _callbackGasLimit Maximum gas to be spent by the IWitnetConsumer's callback methods.
+    /// @param _defaultSLA Default Security-Level Agreement parameters to be fulfilled by the Witnet blockchain.
     constructor(
-            WitnetRequestTemplate _requestTemplate, 
+            WitnetRequestTemplate _witnetRequestTemplate, 
+            uint16 _baseFeeOverheadPercentage,
             uint96 _callbackGasLimit,
             WitnetV2.RadonSLA memory _defaultSLA
         )
-        UsingWitnetRequestTemplate(_requestTemplate, _defaultSLA)
+        UsingWitnetRequestTemplate(_witnetRequestTemplate, _baseFeeOverheadPercentage, _defaultSLA)
         WitnetConsumer(_callbackGasLimit)
-    {
-        require(
-            _witnetEstimateBaseFeeWithCallback(_callbackGasLimit)
-                > UsingWitnetRequestTemplate._witnetEstimateBaseFee(),
-            "WitnetRequestTemplateConsumer: insufficient callback gas limit"
-        );
-
-    }
+    {}
 
-    function _witnetEstimateBaseFee()
-        virtual override
+    function _witnetEstimateEvmReward()
+        virtual override(UsingWitnetRequestTemplate, WitnetConsumer)
         internal view
         returns (uint256)
     {
-        return WitnetConsumer._witnetEstimateBaseFee(__witnetResultMaxSize);
+        return WitnetConsumer._witnetEstimateEvmReward(__witnetResultMaxSize);
     }
 
-    function _witnetEstimateBaseFee(uint16 _resultMaxSize) 
+    function _witnetEstimateEvmReward(uint16) 
         virtual override(UsingWitnet, WitnetConsumer) 
         internal view
         returns (uint256)
     {
-        return WitnetConsumer._witnetEstimateBaseFee(_resultMaxSize);
+        return WitnetConsumer._witnetEstimateEvmReward();
     } 
 
     function __witnetRequestData(

contracts/interfaces/V2/IWitnetConsumer.sol

@@ -27,7 +27,6 @@ interface IWitnetConsumer {
     /// @dev It should revert if called from any other address different to the WitnetRequestBoard being used
     /// @dev by the WitnetConsumer contract. 
     /// @param witnetQueryId The unique identifier of the Witnet query being reported.
-    /// @param witnetQueryId The unique identifier of the Witnet query being reported.
     /// @param witnetResultTallyHash Hash of the commit/reveal witnessing act that took place in the Witnet blockahin.
     /// @param witnetResultTimestamp Timestamp at which the reported value was captured by the Witnet blockchain. 
     /// @param witnetEvmFinalityBlock EVM block at which the provided data can be considered to be final.