Merge pull request #329 from 0xProject/feature/contracts/versioning

Implement stop-gap smart contract versioning

2 files changed, 105 insertions, 0 deletions

diff --git a/packages/contracts/src/current/utils/Ownable/Ownable.sol b/packages/contracts/src/current/utils/Ownable/Ownable.sol
new file mode 100644
index 000000000..9b3d6b9cf
--- /dev/null
+++ b/packages/contracts/src/current/utils/Ownable/Ownable.sol
@@ -0,0 +1,32 @@
+pragma solidity ^0.4.18;
+
+/*
+ * Ownable
+ *
+ * Base contract with an owner.
+ * Provides onlyOwner modifier, which prevents function from running if it is called by anyone other than the owner.
+ */
+
+contract Ownable {
+    address public owner;
+
+    function Ownable()
+        public
+    {
+        owner = msg.sender;
+    }
+
+    modifier onlyOwner() {
+        require(msg.sender == owner);
+        _;
+    }
+
+    function transferOwnership(address newOwner)
+        public
+        onlyOwner
+    {
+        if (newOwner != address(0)) {
+            owner = newOwner;
+        }
+    }
+}
diff --git a/packages/contracts/src/current/utils/SafeMath/SafeMath.sol b/packages/contracts/src/current/utils/SafeMath/SafeMath.sol
new file mode 100644
index 000000000..955a9e379
--- /dev/null
+++ b/packages/contracts/src/current/utils/SafeMath/SafeMath.sol
@@ -0,0 +1,73 @@
+pragma solidity ^0.4.18;
+
+contract SafeMath {
+    function safeMul(uint a, uint b)
+        internal
+        pure
+        returns (uint256)
+    {
+        uint c = a * b;
+        assert(a == 0 || c / a == b);
+        return c;
+    }
+
+    function safeDiv(uint a, uint b)
+        internal
+        pure
+        returns (uint256)
+    {
+        uint c = a / b;
+        return c;
+    }
+
+    function safeSub(uint a, uint b)
+        internal
+        pure
+        returns (uint256)
+    {
+        assert(b <= a);
+        return a - b;
+    }
+
+    function safeAdd(uint a, uint b)
+        internal
+        pure
+        returns (uint256)
+    {
+        uint c = a + b;
+        assert(c >= a);
+        return c;
+    }
+
+    function max64(uint64 a, uint64 b)
+        internal
+        pure
+        returns (uint256)
+    {
+        return a >= b ? a : b;
+    }
+
+    function min64(uint64 a, uint64 b)
+        internal
+        pure
+        returns (uint256)
+    {
+        return a < b ? a : b;
+    }
+
+    function max256(uint256 a, uint256 b)
+        internal
+        pure
+        returns (uint256)
+    {
+        return a >= b ? a : b;
+    }
+
+    function min256(uint256 a, uint256 b)
+        internal
+        pure
+        returns (uint256)
+    {
+        return a < b ? a : b;
+    }
+}