update DPPOracle

contracts/DODOPrivatePool/impl/DPPOracle/OracleAdapter.sol

@@ -0,0 +1,42 @@
+/*
+
+    Copyright 2021 DODO ZOO.
+    SPDX-License-Identifier: Apache-2.0
+
+*/
+
+pragma solidity 0.6.9;
+pragma experimental ABIEncoderV2;
+
+import {IOracle} from "../../intf/IOracle.sol";
+
+interface IWooracle {
+    function timestamp() external view returns (uint256);
+    function isFeasible(address base) external view returns (bool);
+    function getPrice(address base) external view returns (uint256);
+    function price(address base) external view returns (uint256 priceNow, bool feasible);
+}
+
+contract OracleAdapter is IOracle {
+    IWooracle oracle;
+
+    constructor(address oracleAddress) public {
+        oracle = IWooracle(oracleAddress);
+    }
+
+    function getPrice(address base) external override view returns (uint256 latestPrice,bool isValid,bool isStale,uint256 timestamp) {
+        latestPrice = oracle.getPrice(base);
+        isValid = oracle.isFeasible(base);
+        isStale = !isValid;
+        timestamp = oracle.timestamp();
+        return (latestPrice, isValid, isStale, timestamp);
+    }    
+
+    function prices(address base) external override view returns (uint256) {
+        return oracle.getPrice(base);
+    }
+    
+    function isFeasible(address base) external override view returns (bool) {
+        return oracle.isFeasible(base);
+    }
+}