pragma solidity ^0.4.23; import "../common/Controlled.sol"; contract Factory is Controlled { event NewKernel(address newKernel, bytes32 codeHash); struct Version { uint256 blockNumber; uint256 timestamp; address kernel; bytes32 codeHash; } mapping(bytes32 => uint256) hashToVersion; mapping(address => uint256) versionMap; Version[] versionLog; uint256 latestUpdate; address latestKernel; constructor(address _kernel) public { _setKernel(_kernel); } function setKernel(address _kernel) external onlyController { _setKernel(_kernel); } function getVersion(uint256 index) public view returns( uint256 blockNumber, uint256 timestamp, address kernel, bytes32 codeHash ) { return ( versionLog[index].blockNumber, versionLog[index].timestamp, versionLog[index].kernel, versionLog[index].codeHash ); } function isKernel(bytes32 _codeHash) public view returns (bool){ return hashToVersion[_codeHash] > 0; } function isKernel(address _addr) public view returns (bool){ return versionMap[_addr] > 0; } function getCodeHash(address _addr) public view returns (bytes32 codeHash) { bytes memory o_code; uint size; assembly { // retrieve the size of the code, this needs assembly size := extcodesize(_addr) } require (size > 0); assembly { // allocate output byte array - this could also be done without assembly // by using o_code = new bytes(size) o_code := mload(0x40) // new "memory end" including padding mstore(0x40, add(o_code, and(add(add(size, 0x20), 0x1f), not(0x1f)))) // store length in memory mstore(o_code, size) // actually retrieve the code, this needs assembly extcodecopy(_addr, add(o_code, 0x20), 0, size) } codeHash = keccak256(o_code); } function _setKernel(address _kernel) internal { require(_kernel != latestKernel); bytes32 _codeHash = getCodeHash(_kernel); versionMap[_kernel] = versionLog.length; hashToVersion[_codeHash] = versionLog.length; versionLog.push(Version({blockNumber: block.number, timestamp: block.timestamp, kernel: _kernel, codeHash: _codeHash})); latestUpdate = block.timestamp; latestKernel = _kernel; emit NewKernel(_kernel, _codeHash); } }