Merge pull request #14 from delta-mpc/zk

Zk

contracts/DataHub.sol

@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-3.0
+
+pragma solidity >=0.7.0 <0.9.0;
+
+contract DataHub {
+    address private owner;
+    event OwnerSet(address indexed oldOwner, address indexed newOwner);
+
+    struct DataRecord {
+        bytes32 commitment;
+        uint32 version;
+    }
+    mapping(address => mapping(string => DataRecord)) datahub;
+
+    event DataRegistered(
+        address indexed owner,
+        string name,
+        bytes32 commitment,
+        uint32 version
+    );
+
+    constructor() {
+        owner = msg.sender;
+        emit OwnerSet(address(0), owner);
+    }
+
+    function register(string calldata name, bytes32 commitment) public {
+        datahub[msg.sender][name].commitment = commitment;
+        datahub[msg.sender][name].version += 1;
+
+        emit DataRegistered(
+            msg.sender,
+            name,
+            commitment,
+            datahub[msg.sender][name].version
+        );
+    }
+
+    modifier dataExists(address addr, string calldata name) {
+        require(datahub[addr][name].version > 0);
+        _;
+    }
+
+    function getDataCommitment(address addr, string calldata name)
+        public
+        view
+        dataExists(addr, name)
+        returns (bytes32 commitment)
+    {
+        commitment = datahub[addr][name].commitment;
+    }
+
+    function getDataVersion(address addr, string calldata name)
+        public
+        view
+        dataExists(addr, name)
+        returns (uint32 version)
+    {
+        version = datahub[addr][name].version;
+    }
+}