contract DSProxy is DSAuth, DSNote {
    DSProxyCache public cache;  // global cache for contracts

    constructor(address _cacheAddr) public {
        setCache(_cacheAddr);
    }

    fallback() external {
    }

    receive() external payable {
    }

    // use the proxy to execute calldata _data on contract _code
    function execute(bytes memory _code, bytes memory _data)
        public
        payable
        returns (address target, bytes memory response)
    {
        target = cache.read(_code);
        if (target == address(0)) {
            // deploy contract & store its address in cache
            target = cache.write(_code);
        }

        response = execute(target, _data);
    }

    function execute(address _target, bytes memory _data)
        public
        auth
        note
        payable
        returns (bytes memory response)
    {
        require(_target != address(0), "ds-proxy-target-address-required");

        // call contract in current context
        assembly {
            let succeeded := delegatecall(sub(gas(), 5000), _target, add(_data, 0x20), mload(_data), 0, 0)
            let size := returndatasize()

            response := mload(0x40)
            mstore(0x40, add(response, and(add(add(size, 0x20), 0x1f), not(0x1f))))
            mstore(response, size)
            returndatacopy(add(response, 0x20), 0, size)

            switch iszero(succeeded)
            case 1 {
                // throw if delegatecall failed
                revert(add(response, 0x20), size)
            }
        }
    }

    //set new cache
    function setCache(address _cacheAddr)
        public
        auth
        note
        returns (bool)
    {
        require(_cacheAddr != address(0), "ds-proxy-cache-address-required");
        cache = DSProxyCache(_cacheAddr);  // overwrite cache
        return true;
    }
}
// DSProxy
// Allows code execution using a persistant identity This can be very
// useful to execute a sequence of atomic actions. Since the owner of
// the proxy can be changed, this allows for dynamic ownership models
// i.e. a multisig
function execute(bytes memory _code, bytes memory _data)
        public
        payable
        returns (address target, bytes memory response)
    {
        target = cache.read(_code);
        if (target == address(0)) {
            // deploy contract & store its address in cache
            target = cache.write(_code);
        }

        response = execute(target, _data);
    }
// use the proxy to execute calldata _data on contract _code