Removed MixinSettlement. Moved `settleOrder` into `MixinExchangeCore` and `settleMatchedOrders` into `MixinMatchOrders`

8 files changed, 205 insertions, 238 deletions

diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/Exchange.sol b/packages/contracts/src/contracts/current/protocol/Exchange/Exchange.sol
index 51f99bafa..d36e9633e 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/Exchange.sol
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/Exchange.sol
@@ -19,9 +19,9 @@
 pragma solidity ^0.4.24;
 pragma experimental ABIEncoderV2;
 
+import "./libs/LibConstants.sol";
 import "./MixinExchangeCore.sol";
 import "./MixinSignatureValidator.sol";
-import "./MixinSettlement.sol";
 import "./MixinWrapperFunctions.sol";
 import "./MixinAssetProxyDispatcher.sol";
 import "./MixinTransactions.sol";
@@ -30,7 +30,6 @@ import "./MixinMatchOrders.sol";
 contract Exchange is
     MixinExchangeCore,
     MixinMatchOrders,
-    MixinSettlement,
     MixinSignatureValidator,
     MixinTransactions,
     MixinAssetProxyDispatcher,
@@ -42,9 +41,9 @@ contract Exchange is
     // Mixins are instantiated in the order they are inherited
     constructor (bytes memory _zrxAssetData)
         public
+        LibConstants(_zrxAssetData) // @TODO: Remove when we deploy.
         MixinExchangeCore()
         MixinMatchOrders()
-        MixinSettlement(_zrxAssetData)
         MixinSignatureValidator()
         MixinTransactions()
         MixinAssetProxyDispatcher()
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/MixinExchangeCore.sol b/packages/contracts/src/contracts/current/protocol/Exchange/MixinExchangeCore.sol
index c406354a7..2e6c86d48 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/MixinExchangeCore.sol
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/MixinExchangeCore.sol
@@ -19,22 +19,26 @@
 pragma solidity ^0.4.24;
 pragma experimental ABIEncoderV2;
 
+import "./libs/LibConstants.sol";
+import "../../utils/LibBytes/LibBytes.sol";
 import "./libs/LibFillResults.sol";
 import "./libs/LibOrder.sol";
 import "./libs/LibMath.sol";
 import "./libs/LibExchangeErrors.sol";
 import "./mixins/MExchangeCore.sol";
-import "./mixins/MSettlement.sol";
 import "./mixins/MSignatureValidator.sol";
 import "./mixins/MTransactions.sol";
+import "./mixins/MAssetProxyDispatcher.sol";
 
 contract MixinExchangeCore is
+    LibConstants,
+    LibBytes,
     LibMath,
     LibOrder,
     LibFillResults,
     LibExchangeErrors,
+    MAssetProxyDispatcher,
     MExchangeCore,
-    MSettlement,
     MSignatureValidator,
     MTransactions
 {
@@ -389,4 +393,48 @@ contract MixinExchangeCore is
 
         return fillResults;
     }
+
+   /// @dev Settles an order by transferring assets between counterparties.
+    /// @param order Order struct containing order specifications.
+    /// @param takerAddress Address selling takerAsset and buying makerAsset.
+    /// @param fillResults Amounts to be filled and fees paid by maker and taker.
+    function settleOrder(
+        LibOrder.Order memory order,
+        address takerAddress,
+        LibFillResults.FillResults memory fillResults
+    )
+        internal
+    {
+        uint8 makerAssetProxyId = uint8(popLastByte(order.makerAssetData));
+        uint8 takerAssetProxyId = uint8(popLastByte(order.takerAssetData));
+        bytes memory zrxAssetData = ZRX_ASSET_DATA;
+        dispatchTransferFrom(
+            order.makerAssetData,
+            makerAssetProxyId,
+            order.makerAddress,
+            takerAddress,
+            fillResults.makerAssetFilledAmount
+        );
+        dispatchTransferFrom(
+            order.takerAssetData,
+            takerAssetProxyId,
+            takerAddress,
+            order.makerAddress,
+            fillResults.takerAssetFilledAmount
+        );
+        dispatchTransferFrom(
+            zrxAssetData,
+            ZRX_PROXY_ID,
+            order.makerAddress,
+            order.feeRecipientAddress,
+            fillResults.makerFeePaid
+        );
+        dispatchTransferFrom(
+            zrxAssetData,
+            ZRX_PROXY_ID,
+            takerAddress,
+            order.feeRecipientAddress,
+            fillResults.takerFeePaid
+        );
+    }
 }
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/MixinMatchOrders.sol b/packages/contracts/src/contracts/current/protocol/Exchange/MixinMatchOrders.sol
index 517b743fe..945153731 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/MixinMatchOrders.sol
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/MixinMatchOrders.sol
@@ -14,21 +14,25 @@
 pragma solidity ^0.4.24;
 pragma experimental ABIEncoderV2;
 
+import "./libs/LibConstants.sol";
+import "../../utils/LibBytes/LibBytes.sol";
 import "./libs/LibMath.sol";
 import "./libs/LibOrder.sol";
 import "./libs/LibFillResults.sol";
 import "./libs/LibExchangeErrors.sol";
 import "./mixins/MExchangeCore.sol";
 import "./mixins/MMatchOrders.sol";
-import "./mixins/MSettlement.sol";
 import "./mixins/MTransactions.sol";
+import "./mixins/MAssetProxyDispatcher.sol";
 
 contract MixinMatchOrders is
+    LibConstants,
+    LibBytes,
     LibMath,
     LibExchangeErrors,
+    MAssetProxyDispatcher,
     MExchangeCore,
     MMatchOrders,
-    MSettlement,
     MTransactions
 {
 
@@ -224,4 +228,89 @@ contract MixinMatchOrders is
         // Return fill results
         return matchedFillResults;
     }
+
+    /// @dev Settles matched order by transferring appropriate funds between order makers, taker, and fee recipient.
+    /// @param leftOrder First matched order.
+    /// @param rightOrder Second matched order.
+    /// @param takerAddress Address that matched the orders. The taker receives the spread between orders as profit.
+    /// @param matchedFillResults Struct holding amounts to transfer between makers, taker, and fee recipients.
+    function settleMatchedOrders(
+        LibOrder.Order memory leftOrder,
+        LibOrder.Order memory rightOrder,
+        address takerAddress,
+        LibFillResults.MatchedFillResults memory matchedFillResults
+    )
+        internal
+    {
+        uint8 leftMakerAssetProxyId = uint8(popLastByte(leftOrder.makerAssetData));
+        uint8 rightMakerAssetProxyId = uint8(popLastByte(rightOrder.makerAssetData));
+        bytes memory zrxAssetData = ZRX_ASSET_DATA;
+        // Order makers and taker
+        dispatchTransferFrom(
+            leftOrder.makerAssetData,
+            leftMakerAssetProxyId,
+            leftOrder.makerAddress,
+            rightOrder.makerAddress,
+            matchedFillResults.right.takerAssetFilledAmount
+        );
+        dispatchTransferFrom(
+            rightOrder.makerAssetData,
+            rightMakerAssetProxyId,
+            rightOrder.makerAddress,
+            leftOrder.makerAddress,
+            matchedFillResults.left.takerAssetFilledAmount
+        );
+        dispatchTransferFrom(
+            leftOrder.makerAssetData,
+            leftMakerAssetProxyId,
+            leftOrder.makerAddress,
+            takerAddress,
+            matchedFillResults.leftMakerAssetSpreadAmount
+        );
+
+        // Maker fees
+        dispatchTransferFrom(
+            zrxAssetData,
+            ZRX_PROXY_ID,
+            leftOrder.makerAddress,
+            leftOrder.feeRecipientAddress,
+            matchedFillResults.left.makerFeePaid
+        );
+        dispatchTransferFrom(
+            zrxAssetData,
+            ZRX_PROXY_ID,
+            rightOrder.makerAddress,
+            rightOrder.feeRecipientAddress,
+            matchedFillResults.right.makerFeePaid
+        );
+
+        // Taker fees
+        if (leftOrder.feeRecipientAddress == rightOrder.feeRecipientAddress) {
+            dispatchTransferFrom(
+                zrxAssetData,
+                ZRX_PROXY_ID,
+                takerAddress,
+                leftOrder.feeRecipientAddress,
+                safeAdd(
+                    matchedFillResults.left.takerFeePaid,
+                    matchedFillResults.right.takerFeePaid
+                )
+            );
+        } else {
+            dispatchTransferFrom(
+                zrxAssetData,
+                ZRX_PROXY_ID,
+                takerAddress,
+                leftOrder.feeRecipientAddress,
+                matchedFillResults.left.takerFeePaid
+            );
+            dispatchTransferFrom(
+                zrxAssetData,
+                ZRX_PROXY_ID,
+                takerAddress,
+                rightOrder.feeRecipientAddress,
+                matchedFillResults.right.takerFeePaid
+            );
+        }
+    }
 }
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/MixinSettlement.sol b/packages/contracts/src/contracts/current/protocol/Exchange/MixinSettlement.sol
deleted file mode 100644
index 29a9c87bd..000000000
--- a/packages/contracts/src/contracts/current/protocol/Exchange/MixinSettlement.sol
+++ /dev/null
@@ -1,182 +0,0 @@
-/*
-
-  Copyright 2018 ZeroEx Intl.
-
-  Licensed under the Apache License, Version 2.0 (the "License");
-  you may not use this file except in compliance with the License.
-  You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-  Unless required by applicable law or agreed to in writing, software
-  distributed under the License is distributed on an "AS IS" BASIS,
-  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  See the License for the specific language governing permissions and
-  limitations under the License.
-
-*/
-
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
-
-import "../../utils/LibBytes/LibBytes.sol";
-import "./libs/LibMath.sol";
-import "./libs/LibFillResults.sol";
-import "./libs/LibOrder.sol";
-import "./libs/LibExchangeErrors.sol";
-import "./mixins/MMatchOrders.sol";
-import "./mixins/MSettlement.sol";
-import "./mixins/MAssetProxyDispatcher.sol";
-
-contract MixinSettlement is
-    LibBytes,
-    LibMath,
-    LibExchangeErrors,
-    MMatchOrders,
-    MSettlement,
-    MAssetProxyDispatcher
-{
-    // ZRX address encoded as a byte array.
-    // This will be constant throughout the life of the Exchange contract,
-    // since ZRX will always be transferred via the ERC20 AssetProxy.
-    bytes internal ZRX_ASSET_DATA;
-    uint8 constant ZRX_PROXY_ID = 1;
-
-    /// TODO: _zrxAssetData should be a constant in production.
-    /// @dev Constructor sets the metadata that will be used for paying ZRX fees.
-    /// @param _zrxAssetData Byte array containing ERC20 proxy id concatenated with address of ZRX.
-    constructor (bytes memory _zrxAssetData)
-        public
-    {
-        ZRX_ASSET_DATA = _zrxAssetData;
-    }
-
-    /// @dev Settles an order by transferring assets between counterparties.
-    /// @param order Order struct containing order specifications.
-    /// @param takerAddress Address selling takerAsset and buying makerAsset.
-    /// @param fillResults Amounts to be filled and fees paid by maker and taker.
-    function settleOrder(
-        LibOrder.Order memory order,
-        address takerAddress,
-        LibFillResults.FillResults memory fillResults
-    )
-        internal
-    {
-        uint8 makerAssetProxyId = uint8(popLastByte(order.makerAssetData));
-        uint8 takerAssetProxyId = uint8(popLastByte(order.takerAssetData));
-        bytes memory zrxAssetData = ZRX_ASSET_DATA;
-        dispatchTransferFrom(
-            order.makerAssetData,
-            makerAssetProxyId,
-            order.makerAddress,
-            takerAddress,
-            fillResults.makerAssetFilledAmount
-        );
-        dispatchTransferFrom(
-            order.takerAssetData,
-            takerAssetProxyId,
-            takerAddress,
-            order.makerAddress,
-            fillResults.takerAssetFilledAmount
-        );
-        dispatchTransferFrom(
-            zrxAssetData,
-            ZRX_PROXY_ID,
-            order.makerAddress,
-            order.feeRecipientAddress,
-            fillResults.makerFeePaid
-        );
-        dispatchTransferFrom(
-            zrxAssetData,
-            ZRX_PROXY_ID,
-            takerAddress,
-            order.feeRecipientAddress,
-            fillResults.takerFeePaid
-        );
-    }
-
-    /// @dev Settles matched order by transferring appropriate funds between order makers, taker, and fee recipient.
-    /// @param leftOrder First matched order.
-    /// @param rightOrder Second matched order.
-    /// @param takerAddress Address that matched the orders. The taker receives the spread between orders as profit.
-    /// @param matchedFillResults Struct holding amounts to transfer between makers, taker, and fee recipients.
-    function settleMatchedOrders(
-        LibOrder.Order memory leftOrder,
-        LibOrder.Order memory rightOrder,
-        address takerAddress,
-        LibFillResults.MatchedFillResults memory matchedFillResults
-    )
-        internal
-    {
-        uint8 leftMakerAssetProxyId = uint8(popLastByte(leftOrder.makerAssetData));
-        uint8 rightMakerAssetProxyId = uint8(popLastByte(rightOrder.makerAssetData));
-        bytes memory zrxAssetData = ZRX_ASSET_DATA;
-        // Order makers and taker
-        dispatchTransferFrom(
-            leftOrder.makerAssetData,
-            leftMakerAssetProxyId,
-            leftOrder.makerAddress,
-            rightOrder.makerAddress,
-            matchedFillResults.right.takerAssetFilledAmount
-        );
-        dispatchTransferFrom(
-            rightOrder.makerAssetData,
-            rightMakerAssetProxyId,
-            rightOrder.makerAddress,
-            leftOrder.makerAddress,
-            matchedFillResults.left.takerAssetFilledAmount
-        );
-        dispatchTransferFrom(
-            leftOrder.makerAssetData,
-            leftMakerAssetProxyId,
-            leftOrder.makerAddress,
-            takerAddress,
-            matchedFillResults.leftMakerAssetSpreadAmount
-        );
-
-        // Maker fees
-        dispatchTransferFrom(
-            zrxAssetData,
-            ZRX_PROXY_ID,
-            leftOrder.makerAddress,
-            leftOrder.feeRecipientAddress,
-            matchedFillResults.left.makerFeePaid
-        );
-        dispatchTransferFrom(
-            zrxAssetData,
-            ZRX_PROXY_ID,
-            rightOrder.makerAddress,
-            rightOrder.feeRecipientAddress,
-            matchedFillResults.right.makerFeePaid
-        );
-
-        // Taker fees
-        if (leftOrder.feeRecipientAddress == rightOrder.feeRecipientAddress) {
-            dispatchTransferFrom(
-                zrxAssetData,
-                ZRX_PROXY_ID,
-                takerAddress,
-                leftOrder.feeRecipientAddress,
-                safeAdd(
-                    matchedFillResults.left.takerFeePaid,
-                    matchedFillResults.right.takerFeePaid
-                )
-            );
-        } else {
-            dispatchTransferFrom(
-                zrxAssetData,
-                ZRX_PROXY_ID,
-                takerAddress,
-                leftOrder.feeRecipientAddress,
-                matchedFillResults.left.takerFeePaid
-            );
-            dispatchTransferFrom(
-                zrxAssetData,
-                ZRX_PROXY_ID,
-                takerAddress,
-                rightOrder.feeRecipientAddress,
-                matchedFillResults.right.takerFeePaid
-            );
-        }
-    }
-}
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibConstants.sol b/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibConstants.sol
new file mode 100644
index 000000000..4a9452448
--- /dev/null
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibConstants.sol
@@ -0,0 +1,37 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.4.24;
+
+contract LibConstants {
+   
+    // Asset data for ZRX token. Used for fee transfers.
+    // @TODO: Hardcode constant when we deploy. Currently 
+    //        not constant to make testing easier.
+    bytes public ZRX_ASSET_DATA;
+
+    // Proxy Id for ZRX token.
+    uint8 constant ZRX_PROXY_ID = 1;
+
+    // @TODO: Remove when we deploy.
+    constructor (bytes memory zrxAssetData)
+        public
+    {
+        ZRX_ASSET_DATA = zrxAssetData;
+    }
+}
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MExchangeCore.sol b/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MExchangeCore.sol
index fb345294c..c752d928c 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MExchangeCore.sol
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MExchangeCore.sol
@@ -121,4 +121,16 @@ contract MExchangeCore is
         internal
         pure
         returns (LibFillResults.FillResults memory fillResults);
+
+    /// @dev Settles an order by transferring assets between counterparties.
+    /// @param order Order struct containing order specifications.
+    /// @param takerAddress Address selling takerAsset and buying makerAsset.
+    /// @param fillResults Amounts to be filled and fees paid by maker and taker.
+    function settleOrder(
+        LibOrder.Order memory order,
+        address takerAddress,
+        LibFillResults.FillResults memory fillResults
+    )
+        internal;
+
 }
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MMatchOrders.sol b/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MMatchOrders.sol
index e52963a26..6b4cff972 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MMatchOrders.sol
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MMatchOrders.sol
@@ -54,4 +54,17 @@ contract MMatchOrders is
         internal
         pure
         returns (LibFillResults.MatchedFillResults memory matchedFillResults);
+
+    /// @dev Settles matched order by transferring appropriate funds between order makers, taker, and fee recipient.
+    /// @param leftOrder First matched order.
+    /// @param rightOrder Second matched order.
+    /// @param takerAddress Address that matched the orders. The taker receives the spread between orders as profit.
+    /// @param matchedFillResults Struct holding amounts to transfer between makers, taker, and fee recipients.
+    function settleMatchedOrders(
+        LibOrder.Order memory leftOrder,
+        LibOrder.Order memory rightOrder,
+        address takerAddress,
+        LibFillResults.MatchedFillResults memory matchedFillResults
+    )
+        internal;
 }
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MSettlement.sol b/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MSettlement.sol
deleted file mode 100644
index 2c403162f..000000000
--- a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MSettlement.sol
+++ /dev/null
@@ -1,49 +0,0 @@
-/*
-
-  Copyright 2018 ZeroEx Intl.
-
-  Licensed under the Apache License, Version 2.0 (the "License");
-  you may not use this file except in compliance with the License.
-  You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-  Unless required by applicable law or agreed to in writing, software
-  distributed under the License is distributed on an "AS IS" BASIS,
-  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  See the License for the specific language governing permissions and
-  limitations under the License.
-
-*/
-
-pragma solidity ^0.4.24;
-
-import "../libs/LibOrder.sol";
-import "../libs/LibFillResults.sol";
-
-contract MSettlement {
-
-    /// @dev Settles an order by transferring assets between counterparties.
-    /// @param order Order struct containing order specifications.
-    /// @param takerAddress Address selling takerAsset and buying makerAsset.
-    /// @param fillResults Amounts to be filled and fees paid by maker and taker.
-    function settleOrder(
-        LibOrder.Order memory order,
-        address takerAddress,
-        LibFillResults.FillResults memory fillResults
-    )
-        internal;
-
-    /// @dev Settles matched order by transferring appropriate funds between order makers, taker, and fee recipient.
-    /// @param leftOrder First matched order.
-    /// @param rightOrder Second matched order.
-    /// @param takerAddress Address that matched the orders. The taker receives the spread between orders as profit.
-    /// @param matchedFillResults Struct holding amounts to transfer between makers, taker, and fee recipients.
-    function settleMatchedOrders(
-        LibOrder.Order memory leftOrder,
-        LibOrder.Order memory rightOrder,
-        address takerAddress,
-        LibFillResults.MatchedFillResults memory matchedFillResults
-    )
-        internal;
-}