CompositeSyncOracle

packages/foundry/contracts/oracles/composite/CompositeMultiOracle.sol

@@ -17,7 +17,7 @@ contract CompositeMultiOracle is IOracle, AccessControl {
     mapping(bytes6 => mapping(bytes6 => IOracle)) public sources;
     mapping(bytes6 => mapping(bytes6 => bytes6[])) public paths;
 
-    /// @notice Set or reset a Yearn Vault Token oracle source and its inverse
+    /// @notice Set or reset an oracle source and its inverse
     /// @param  baseId id used for underlying base token
     /// @param  quoteId id used for underlying quote token
     /// @param  source Oracle contract for source

packages/foundry/contracts/oracles/composite/CompositeSyncOracle.sol

@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: BUSL-1.1
+pragma solidity >=0.8.13;
+
+import { CompositeMultiOracle } from "./CompositeMultiOracle.sol";
+import { ICauldron } from "../../interfaces/ICauldron.sol";
+import "../../interfaces/DataTypes.sol";
+
+/**
+ * @dev A CompositeMultiOracle that can take sources from a Cauldron.
+ */
+contract CompositeSyncOracle is CompositeMultiOracle {
+
+    event MasterSet(ICauldron indexed master);
+
+    ICauldron public master;
+
+    /// @notice Set the master
+    /// @param master_ ICauldron contract used as master
+    function setMaster(
+        ICauldron master_
+    ) external auth {
+        master = master_;
+        emit MasterSet(master_);
+    }
+
+    /// @notice Copy an oracle source from the master. Only works if the source is not set yet.
+    /// @param baseId id used for underlying base token
+    /// @param quoteId id used for underlying quote token
+    function syncSource(
+        bytes6 baseId,
+        bytes6 quoteId
+    )
+        external
+        returns (IOracle source)
+    {
+        require(
+            sources[baseId][quoteId] == IOracle(address(0)) &&
+            sources[quoteId][baseId] == IOracle(address(0)),
+            "Only new sources"
+        );
+        require(master != ICauldron(address(0)), "Master not set");
+        DataTypes.SpotOracle memory spotOracle = master.spotOracles(baseId, quoteId);
+
+        source = spotOracle.oracle;
+        sources[baseId][quoteId] = source;
+        emit SourceSet(baseId, quoteId, source);
+
+        if (baseId != quoteId) {
+            sources[quoteId][baseId] = source;
+            emit SourceSet(quoteId, baseId, source);
+        }
+    }
+}