DPP factory and init

contracts/lib/FeeRateModel.sol

@@ -0,0 +1,44 @@
+/*
+
+    Copyright 2020 DODO ZOO.
+    SPDX-License-Identifier: Apache-2.0
+
+*/
+
+pragma solidity 0.6.9;
+pragma experimental ABIEncoderV2;
+
+import {InitializableOwnable} from "../lib/InitializableOwnable.sol";
+
+interface IFeeRateModel {
+    function getFeeRate(address trader) external view returns (uint256);
+    function init(address owner, uint256 feeRate) external;
+    function setFeeRate(uint256 newFeeRate) external;
+}
+
+contract FeeRateModel is InitializableOwnable {
+    //DEFAULT
+    uint256 public _FEE_RATE_;
+    mapping(address => uint256) feeMapping;
+
+    function init(address owner, uint256 feeRate) external {
+        initOwner(owner);
+        _FEE_RATE_ = feeRate;
+    }
+
+    function setSpecificFeeRate(address trader, uint256 feeRate) external onlyOwner {
+        require(trader != address(0), "INVALID ADDRESS!");
+        feeMapping[trader] = feeRate;
+    }
+
+    function setFeeRate(uint256 newFeeRate) external onlyOwner {
+        _FEE_RATE_ = newFeeRate;
+    }
+
+    function getFeeRate(address trader) external view returns (uint256) {
+        uint256 feeRate = feeMapping[trader];
+        if(feeRate == 0)
+            return _FEE_RATE_;
+        return feeRate;
+    }
+}