noot

bool isUpgraded;
address newContract;
mapping (address => uint256) balances;

function setBalance(address _addr, uint256 _val) {
  if(isUpgraded){
      // function signature
      bytes4 sig = bytes4(keccak256("setBalance(address,uint256)")); //make sure the hash doesn't have spaces
      newContract.call(sig, _addr, _val); // call setBalance in new contract, passing in signature and parameters
  }

noot

contract OldContract {
    // _sig = bytes4(keccak256("callMe()"));
    function upgradeMe(bytes4 _sig) {
      newContract.call(_sig);
    }
}

contract NewContract {
    function callMe() {
      ...

noot

contract oldContract {
    bool isUpgraded;
    address newContract;
    mapping (address => uint256) balances;

    function setBalance(address _addr, uint256 _val) {
      if(isUpgraded){
          // function signature
          bytes4 sig = bytes4(keccak256("setBalance(address,uint256)")); //make sure the hash doesn't have spaces
          // delegate call will allow the called function to make changes on the values inside this contract

noot

pragma solidity ^0.4.19;

contract Transfers {
	mapping(address => uint) balance;

	function deposit() public payable {
		balance[msg.sender] += msg.value;
	}

	function withdraw(address _addr, uint _value) public {

noot

contract OldContract {
    // _sig = bytes4(keccak256("sum(uint,uint)"));
    
    function upgradeMe(bytes4 _sig, address _newContract, uint _a, uint _b) returns (uint ans) {
      assembly {
            // free memory pointer : 0x40
            
            let x := mload(0x40) // get empty storage location
            mstore ( x, sig ) // 4 bytes - place signature in empty storage
            mstore (add(x, 0x04), _a) // 32 bytes - place first argument next to 4-bit signature

noot

interface oldContract {
  function setBalance(address _addr, uint256 _val);
}

interface newContract {
  function setBalance(address _addr, uint256 _val);
}

contract oldContract {
  // same code as before

noot

contract Registry {
    address[] versions;
    uint currentVersion;
    mapping(address => bool) isUpdated;
    
    function addBalance(address _addr, uint256 _val) {
        bytes4 sig = bytes4(keccak256("addBalance(address,uint256)"));
        if(!isUpdated[_addr]) {
            bytes4 sigGet = bytes4(keccak256("getBalance(address)"));
            address prevVersion = versions[currVersion-1];

noot

pragma solidity ^0.4.0;
contract Asm {
    function bitwise(uint32 a, uint32 b) returns (bytes4) {
        assembly {
            let res := eq(a,b)
            mstore(0x0, res)
            return(0x0, 32)
        }    
    }
    

noot

var secrets = require("./secrets.json");
var HDWalletProvider = require("truffle-hdwallet-provider");
var Web3 = require('web3');
var web3 = new Web3(Web3.givenProvider || "ws://localhost:8545");

module.exports = {
  // See <http://truffleframework.com/docs/advanced/configuration>
  // to customize your Truffle configuration!
  networks: {
   development: {

noot

Keybase proof

I hereby claim:

• I am noot on github.
• I am leth (https://keybase.io/leth) on keybase.
• I have a public key whose fingerprint is 4301 553B 7AA4 7E3A 3841 1BE0 5C74 C182 02E3 3376

To claim this, I am signing this object: