Added freesGasTokensFromCollector.

To handle the case where GST2 is being traded and the balanceOf checks become confusing
0xProject · Mar 25, 2020 · a069919 · a069919
1 parent c9b9aab
commit a069919
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Showing 3 changed files with 34 additions and 6 deletions.
diff --git a/contracts/asset-proxy/contracts/src/bridges/CurveBridge.sol b/contracts/asset-proxy/contracts/src/bridges/CurveBridge.sol
@@ -62,7 +62,7 @@ contract CurveBridge is
         bytes calldata bridgeData
     )
         external
-        burnsGasTokens
+        freesGasTokensFromCollector
         returns (bytes4 success)
     {
         // Decode the bridge data to get the Curve metadata.

diff --git a/contracts/asset-proxy/contracts/src/bridges/MixinGasToken.sol b/contracts/asset-proxy/contracts/src/bridges/MixinGasToken.sol
@@ -24,18 +24,32 @@ import "../interfaces/IGasToken.sol";
 
 contract MixinGasToken is
     DeploymentConstants
- {
+{
 
-    /// @dev Burns gas tokens based on the amount of gas consumed in the function
-    modifier burnsGasTokens {
+    /// @dev Frees gas tokens based on the amount of gas consumed in the function
+    modifier freesGasTokens {
         uint256 gasBefore = gasleft();
         _;
         IGasToken gst = IGasToken(_getGstAddress());
-        if (address(gst) != address(0) && msg.sender == _getERC20BridgeProxyAddress()) {
+        if (address(gst) != address(0)) {
             // (gasUsed + FREE_BASE) / (2 * REIMBURSE - FREE_TOKEN)
-            //            14154             2400        6870
+            //            14154             24000        6870
             uint256 value = (gasBefore - gasleft() + 14154) / 41130;
             gst.freeUpTo(value);
         }
     }
+
+    /// @dev Frees gas tokens using the balance of `from`. Amount freed is based
+    ///     on the gas consumed in the function
+    modifier freesGasTokensFromCollector() {
+        uint256 gasBefore = gasleft();
+        _;
+        IGasToken gst = IGasToken(_getGstAddress());
+        if (address(gst) != address(0)) {
+            // (gasUsed + FREE_BASE) / (2 * REIMBURSE - FREE_TOKEN)
+            //            14154             24000        6870
+            uint256 value = (gasBefore - gasleft() + 14154) / 41130;
+            gst.freeFromUpTo(_getGstCollectorAddress(), value);
+        }
+    }
 }
diff --git a/contracts/utils/contracts/src/DeploymentConstants.sol b/contracts/utils/contracts/src/DeploymentConstants.sol
@@ -56,8 +56,12 @@ contract DeploymentConstants {
     address constant private DYDX_ADDRESS = 0x1E0447b19BB6EcFdAe1e4AE1694b0C3659614e4e;
     /// @dev Mainnet address of the GST2 contract
     address constant private GST_ADDRESS = 0x0000000000b3F879cb30FE243b4Dfee438691c04;
+    /// @dev Mainnet address of the GST Collector
+    address constant private GST_COLLECTOR_ADDRESS = address(0);
     // /// @dev Kovan address of the GST2 contract
     // address constant private GST_ADDRESS = address(0);
+    // /// @dev Kovan address of the GST Collector
+    // address constant private GST_COLLECTOR_ADDRESS = address(0);
 
     /// @dev Overridable way to get the `KyberNetworkProxy` address.
     /// @return kyberAddress The `IKyberNetworkProxy` address.
@@ -158,4 +162,14 @@ contract DeploymentConstants {
     {
         return GST_ADDRESS;
     }
+
+    /// @dev An overridable way to retrieve the GST Collector address.
+    /// @return collector The GST collector address.
+    function _getGstCollectorAddress()
+        internal
+        view
+        returns (address collector)
+    {
+        return GST_COLLECTOR_ADDRESS;
+    }
 }