Contract Source Code:
File 1 of 1 : DSChief
// chief.sol - select an authority by consensus
// Copyright (C) 2017 DappHub, LLC
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity >=0.4.23;
contract DSMath {
function add(uint x, uint y) internal pure returns (uint z) {
require((z = x + y) >= x, "ds-math-add-overflow");
}
function sub(uint x, uint y) internal pure returns (uint z) {
require((z = x - y) <= x, "ds-math-sub-underflow");
}
function mul(uint x, uint y) internal pure returns (uint z) {
require(y == 0 || (z = x * y) / y == x, "ds-math-mul-overflow");
}
function min(uint x, uint y) internal pure returns (uint z) {
return x <= y ? x : y;
}
function max(uint x, uint y) internal pure returns (uint z) {
return x >= y ? x : y;
}
function imin(int x, int y) internal pure returns (int z) {
return x <= y ? x : y;
}
function imax(int x, int y) internal pure returns (int z) {
return x >= y ? x : y;
}
uint constant WAD = 10 ** 18;
uint constant RAY = 10 ** 27;
//rounds to zero if x*y < WAD / 2
function wmul(uint x, uint y) internal pure returns (uint z) {
z = add(mul(x, y), WAD / 2) / WAD;
}
//rounds to zero if x*y < WAD / 2
function rmul(uint x, uint y) internal pure returns (uint z) {
z = add(mul(x, y), RAY / 2) / RAY;
}
//rounds to zero if x*y < WAD / 2
function wdiv(uint x, uint y) internal pure returns (uint z) {
z = add(mul(x, WAD), y / 2) / y;
}
//rounds to zero if x*y < RAY / 2
function rdiv(uint x, uint y) internal pure returns (uint z) {
z = add(mul(x, RAY), y / 2) / y;
}
// This famous algorithm is called "exponentiation by squaring"
// and calculates x^n with x as fixed-point and n as regular unsigned.
//
// It's O(log n), instead of O(n) for naive repeated multiplication.
//
// These facts are why it works:
//
// If n is even, then x^n = (x^2)^(n/2).
// If n is odd, then x^n = x * x^(n-1),
// and applying the equation for even x gives
// x^n = x * (x^2)^((n-1) / 2).
//
// Also, EVM division is flooring and
// floor[(n-1) / 2] = floor[n / 2].
//
function rpow(uint x, uint n) internal pure returns (uint z) {
z = n % 2 != 0 ? x : RAY;
for (n /= 2; n != 0; n /= 2) {
x = rmul(x, x);
if (n % 2 != 0) {
z = rmul(z, x);
}
}
}
}
interface DSAuthority {
function canCall(
address src, address dst, bytes4 sig
) external view returns (bool);
}
contract DSAuthEvents {
event LogSetAuthority (address indexed authority);
event LogSetOwner (address indexed owner);
}
contract DSAuth is DSAuthEvents {
DSAuthority public authority;
address public owner;
constructor() public {
owner = msg.sender;
emit LogSetOwner(msg.sender);
}
function setOwner(address owner_)
public
auth
{
owner = owner_;
emit LogSetOwner(owner);
}
function setAuthority(DSAuthority authority_)
public
auth
{
authority = authority_;
emit LogSetAuthority(address(authority));
}
modifier auth {
require(isAuthorized(msg.sender, msg.sig), "ds-auth-unauthorized");
_;
}
function isAuthorized(address src, bytes4 sig) internal view returns (bool) {
if (src == address(this)) {
return true;
} else if (src == owner) {
return true;
} else if (authority == DSAuthority(0)) {
return false;
} else {
return authority.canCall(src, address(this), sig);
}
}
}
contract DSToken is DSMath, DSAuth {
bool public stopped;
uint256 public totalSupply;
mapping (address => uint256) public balanceOf;
mapping (address => mapping (address => uint256)) public allowance;
bytes32 public symbol;
uint256 public decimals = 18; // standard token precision. override to customize
bytes32 public name = ""; // Optional token name
constructor(bytes32 symbol_) public {
symbol = symbol_;
}
event Approval(address indexed src, address indexed guy, uint wad);
event Transfer(address indexed src, address indexed dst, uint wad);
event Mint(address indexed guy, uint wad);
event Burn(address indexed guy, uint wad);
event Stop();
event Start();
modifier stoppable {
require(!stopped, "ds-stop-is-stopped");
_;
}
function approve(address guy) external returns (bool) {
return approve(guy, uint(-1));
}
function approve(address guy, uint wad) public stoppable returns (bool) {
allowance[msg.sender][guy] = wad;
emit Approval(msg.sender, guy, wad);
return true;
}
function transfer(address dst, uint wad) external returns (bool) {
return transferFrom(msg.sender, dst, wad);
}
function transferFrom(address src, address dst, uint wad)
public
stoppable
returns (bool)
{
if (src != msg.sender && allowance[src][msg.sender] != uint(-1)) {
require(allowance[src][msg.sender] >= wad, "ds-token-insufficient-approval");
allowance[src][msg.sender] = sub(allowance[src][msg.sender], wad);
}
require(balanceOf[src] >= wad, "ds-token-insufficient-balance");
balanceOf[src] = sub(balanceOf[src], wad);
balanceOf[dst] = add(balanceOf[dst], wad);
emit Transfer(src, dst, wad);
return true;
}
function push(address dst, uint wad) external {
transferFrom(msg.sender, dst, wad);
}
function pull(address src, uint wad) external {
transferFrom(src, msg.sender, wad);
}
function move(address src, address dst, uint wad) external {
transferFrom(src, dst, wad);
}
function mint(uint wad) external {
mint(msg.sender, wad);
}
function burn(uint wad) external {
burn(msg.sender, wad);
}
function mint(address guy, uint wad) public auth stoppable {
balanceOf[guy] = add(balanceOf[guy], wad);
totalSupply = add(totalSupply, wad);
emit Mint(guy, wad);
}
function burn(address guy, uint wad) public auth stoppable {
if (guy != msg.sender && allowance[guy][msg.sender] != uint(-1)) {
require(allowance[guy][msg.sender] >= wad, "ds-token-insufficient-approval");
allowance[guy][msg.sender] = sub(allowance[guy][msg.sender], wad);
}
require(balanceOf[guy] >= wad, "ds-token-insufficient-balance");
balanceOf[guy] = sub(balanceOf[guy], wad);
totalSupply = sub(totalSupply, wad);
emit Burn(guy, wad);
}
function stop() public auth {
stopped = true;
emit Stop();
}
function start() public auth {
stopped = false;
emit Start();
}
function setName(bytes32 name_) external auth {
name = name_;
}
}
contract DSRoles is DSAuth, DSAuthority
{
mapping(address=>bool) _root_users;
mapping(address=>bytes32) _user_roles;
mapping(address=>mapping(bytes4=>bytes32)) _capability_roles;
mapping(address=>mapping(bytes4=>bool)) _public_capabilities;
function getUserRoles(address who)
public
view
returns (bytes32)
{
return _user_roles[who];
}
function getCapabilityRoles(address code, bytes4 sig)
public
view
returns (bytes32)
{
return _capability_roles[code][sig];
}
function isUserRoot(address who)
public
view
returns (bool)
{
return _root_users[who];
}
function isCapabilityPublic(address code, bytes4 sig)
public
view
returns (bool)
{
return _public_capabilities[code][sig];
}
function hasUserRole(address who, uint8 role)
public
view
returns (bool)
{
bytes32 roles = getUserRoles(who);
bytes32 shifted = bytes32(uint256(uint256(2) ** uint256(role)));
return bytes32(0) != roles & shifted;
}
function canCall(address caller, address code, bytes4 sig)
public
view
returns (bool)
{
if( isUserRoot(caller) || isCapabilityPublic(code, sig) ) {
return true;
} else {
bytes32 has_roles = getUserRoles(caller);
bytes32 needs_one_of = getCapabilityRoles(code, sig);
return bytes32(0) != has_roles & needs_one_of;
}
}
function BITNOT(bytes32 input) internal pure returns (bytes32 output) {
return (input ^ bytes32(uint(-1)));
}
function setRootUser(address who, bool enabled)
public
auth
{
_root_users[who] = enabled;
}
function setUserRole(address who, uint8 role, bool enabled)
public
auth
{
bytes32 last_roles = _user_roles[who];
bytes32 shifted = bytes32(uint256(uint256(2) ** uint256(role)));
if( enabled ) {
_user_roles[who] = last_roles | shifted;
} else {
_user_roles[who] = last_roles & BITNOT(shifted);
}
}
function setPublicCapability(address code, bytes4 sig, bool enabled)
public
auth
{
_public_capabilities[code][sig] = enabled;
}
function setRoleCapability(uint8 role, address code, bytes4 sig, bool enabled)
public
auth
{
bytes32 last_roles = _capability_roles[code][sig];
bytes32 shifted = bytes32(uint256(uint256(2) ** uint256(role)));
if( enabled ) {
_capability_roles[code][sig] = last_roles | shifted;
} else {
_capability_roles[code][sig] = last_roles & BITNOT(shifted);
}
}
}
contract DSNote {
event LogNote(
bytes4 indexed sig,
address indexed guy,
bytes32 indexed foo,
bytes32 indexed bar,
uint256 wad,
bytes fax
) anonymous;
modifier note {
bytes32 foo;
bytes32 bar;
uint256 wad;
assembly {
foo := calldataload(4)
bar := calldataload(36)
wad := callvalue()
}
_;
emit LogNote(msg.sig, msg.sender, foo, bar, wad, msg.data);
}
}
contract DSThing is DSAuth, DSNote, DSMath {
function S(string memory s) internal pure returns (bytes4) {
return bytes4(keccak256(abi.encodePacked(s)));
}
}
// The right way to use this contract is probably to mix it with some kind
// of `DSAuthority`, like with `ds-roles`.
// SEE DSChief
contract DSChiefApprovals is DSThing {
mapping(bytes32=>address[]) public slates;
mapping(address=>bytes32) public votes;
mapping(address=>uint256) public approvals;
mapping(address=>uint256) public deposits;
DSToken public GOV; // voting token that gets locked up
DSToken public IOU; // non-voting representation of a token, for e.g. secondary voting mechanisms
address public hat; // the chieftain's hat
uint256 public MAX_YAYS;
mapping(address=>uint256) public last;
bool public live;
uint256 constant LAUNCH_THRESHOLD = 80_000 * 10 ** 18; // 80K MKR launch threshold
event Etch(bytes32 indexed slate);
// IOU constructed outside this contract reduces deployment costs significantly
// lock/free/vote are quite sensitive to token invariants. Caution is advised.
constructor(DSToken GOV_, DSToken IOU_, uint MAX_YAYS_) public
{
GOV = GOV_;
IOU = IOU_;
MAX_YAYS = MAX_YAYS_;
}
function launch()
public
note
{
require(!live);
require(hat == address(0) && approvals[address(0)] >= LAUNCH_THRESHOLD);
live = true;
}
function lock(uint wad)
public
note
{
last[msg.sender] = block.number;
GOV.pull(msg.sender, wad);
IOU.mint(msg.sender, wad);
deposits[msg.sender] = add(deposits[msg.sender], wad);
addWeight(wad, votes[msg.sender]);
}
function free(uint wad)
public
note
{
require(block.number > last[msg.sender]);
deposits[msg.sender] = sub(deposits[msg.sender], wad);
subWeight(wad, votes[msg.sender]);
IOU.burn(msg.sender, wad);
GOV.push(msg.sender, wad);
}
function etch(address[] memory yays)
public
note
returns (bytes32 slate)
{
require( yays.length <= MAX_YAYS );
requireByteOrderedSet(yays);
bytes32 hash = keccak256(abi.encodePacked(yays));
slates[hash] = yays;
emit Etch(hash);
return hash;
}
function vote(address[] memory yays) public returns (bytes32)
// note both sub-calls note
{
bytes32 slate = etch(yays);
vote(slate);
return slate;
}
function vote(bytes32 slate)
public
note
{
require(slates[slate].length > 0 ||
slate == 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470, "ds-chief-invalid-slate");
uint weight = deposits[msg.sender];
subWeight(weight, votes[msg.sender]);
votes[msg.sender] = slate;
addWeight(weight, votes[msg.sender]);
}
// like `drop`/`swap` except simply "elect this address if it is higher than current hat"
function lift(address whom)
public
note
{
require(approvals[whom] > approvals[hat]);
hat = whom;
}
function addWeight(uint weight, bytes32 slate)
internal
{
address[] storage yays = slates[slate];
for( uint i = 0; i < yays.length; i++) {
approvals[yays[i]] = add(approvals[yays[i]], weight);
}
}
function subWeight(uint weight, bytes32 slate)
internal
{
address[] storage yays = slates[slate];
for( uint i = 0; i < yays.length; i++) {
approvals[yays[i]] = sub(approvals[yays[i]], weight);
}
}
// Throws unless the array of addresses is a ordered set.
function requireByteOrderedSet(address[] memory yays)
internal
pure
{
if( yays.length == 0 || yays.length == 1 ) {
return;
}
for( uint i = 0; i < yays.length - 1; i++ ) {
// strict inequality ensures both ordering and uniqueness
require(uint(yays[i]) < uint(yays[i+1]));
}
}
}
// `hat` address is unique root user (has every role) and the
// unique owner of role 0 (typically 'sys' or 'internal')
contract DSChief is DSRoles, DSChiefApprovals {
constructor(DSToken GOV, DSToken IOU, uint MAX_YAYS)
DSChiefApprovals (GOV, IOU, MAX_YAYS)
public
{
authority = this;
owner = address(0);
}
function setOwner(address owner_) public {
owner_;
revert();
}
function setAuthority(DSAuthority authority_) public {
authority_;
revert();
}
function isUserRoot(address who)
public view
returns (bool)
{
return (live && who == hat);
}
function setRootUser(address who, bool enabled) public {
who; enabled;
revert();
}
}