Combiner
The Combiner contracts are the most dynamic and heady of the fleet. Their job is to traverse responses (bytes32) from miners and come to a concurrence (bytes32). This agreed upon consensus is then used to reward() and punish() miners and is delivered to a developer’s final callback (address) contract.
Basic Combiner
The basic combiner waits until at least 1 (CCCE) is reserved behind a request and then it is open to responses. There is no limit to responses and a concurrence can be formed after a single result.
This combiner is for demonstration purposes only and shouldn’t be used in production because a single miner can create the concurrence.
pragma solidity ^0.4.11;
contract Combiner is Ownable, Addressed{
function Combiner(address _mainAddress) Addressed(_mainAddress) { }
event Debug( string debug );
event DebugGas( uint gas );
event DebugPointer( bytes32 _pointer );
enum Mode {
INIT,
COUNTING,
FEEDBACK,
CALLBACK,
DONE
}
// ------------------------ concurrence ---------------------------------- //
mapping (bytes32 => bytes32 ) public concurrence; //agreed upon consensus
mapping (bytes32 => uint256 ) public weight; //amount staked on concurrence
mapping (bytes32 => uint256 ) public timestamp; //amount staked on concurrence
// ------------------------ ----------- ---------------------------------- //
//req id //result //amount of token
mapping (bytes32 => mapping (bytes32 => uint256)) public staked;
mapping (bytes32 => mapping (bytes32 => uint32)) public miners;
//req id //current pointer
mapping ( bytes32 => bytes32 ) public current;
//req id //current mode
mapping (bytes32 => Mode ) public mode;
mapping (bytes32 => uint32 ) public correctMiners;
mapping (bytes32 => uint256 ) public reward;
//a combiner is "open" if it is open to new responses
function open(bytes32 _request) public constant returns (bool) {
if(mode[_request] != Mode.INIT) return false;
return isCombinerOpen(_request);
}
//a combiner is "ready" if it is ready to combine
function ready(bytes32 _request) public constant returns (bool) {
if(mode[_request] == Mode.DONE) return false;
if(mode[_request] != Mode.INIT) return true;
return isCombinerReady(_request);
}
//the main combine function finds a consensus, rewards miners, and delivers result
function combine(bytes32 _request) public returns (Mode) {
if(mode[_request] == Mode.INIT){
initializeHead(_request);
mode[_request] = Mode.COUNTING;
}
if(mode[_request] == Mode.COUNTING){
countResponses(_request);
if( current[_request]==0 ){
mode[_request] = Mode.FEEDBACK;
finalizeResponses(_request);
}
}
if(mode[_request] == Mode.FEEDBACK && msg.gas>90000){
feedbackLoop(_request);
if( current[_request]==0 ){
rewardCombinerMiner(_request);
// TODO TRIGGER THE CALLBACK HERE
// IT SHOULD SEND THE requestId, concurrence, weight, timestamp to the callback contract at function "concurrence"
mode[_request] = Mode.CALLBACK;
}
}
if(mode[_request] == Mode.CALLBACK && msg.gas>90000){
callback(_request);
mode[_request] = Mode.DONE;
}
if(mode[_request] == Mode.DONE){
// TODO RESET THE RESPONSES HERE TOO
// YOU NEED TO GO SET THE HEAD FOR THIS REQUEST ID TO 0x0
//correctMiners[_request] = 0;
//reward[_request] = 0;
//current[_request] = address(0);
//mode[_request] = Mode.INIT;
//instead let's just revert for now
//revert();
}
DebugPointer(current[_request]);
return mode[_request];
}
//------------Internal functions -------------------------
function isCombinerOpen(bytes32 _request) internal constant returns (bool) {
//make sure that the request exists and there are tokens reserved for it
Main mainContract = Main(mainAddress);
Token tokenContract = Token(mainContract.getContract('Token'));
Requests requestsContract = Requests(mainContract.getContract('Requests'));
address requestCombiner = requestsContract.getCombiner(_request);
if(requestCombiner==address(0)) return false;
if(requestCombiner!=address(this)) return false;
if(tokenContract.reserved(_request)<=0) return false;
return true;
}
function isCombinerReady(bytes32 _request) internal constant returns (bool) {
//make sure there is at least 1 token staked on at least 1 response to be ready to combine
Main mainContract = Main(mainAddress);
Token tokenContract = Token(mainContract.getContract('Token'));
Responses responsesContract = Responses(mainContract.getContract('Responses'));
bytes32 tmpCurrent = responsesContract.heads(_request);
if(tmpCurrent==0) return false;
uint256 tmpStaked = 0;
address miner;
bytes32 result;
bytes32 next;
while(tmpCurrent!=0) {
(miner,result,next) = responsesContract.getResponse(tmpCurrent);
tmpStaked += tokenContract.staked(miner,_request,tmpCurrent);
tmpCurrent = next;
}
return (tmpStaked>0);
}
function initializeHead(bytes32 _request) internal {
Debug("initializeHead");
DebugGas(msg.gas);
Main mainContract = Main(mainAddress);
Responses responsesContract = Responses(mainContract.getContract('Responses'));
current[_request] = responsesContract.heads(_request);
DebugPointer(current[_request]);
}
function countResponses(bytes32 _request) internal {
Debug("countResponses start");
DebugGas(msg.gas);
Main mainContract = Main(mainAddress);
Token tokenContract = Token(mainContract.getContract('Token'));
Responses responsesContract = Responses(mainContract.getContract('Responses'));
address miner;
bytes32 result;
bytes32 next;
//we want to drop out if gas is less than a safe amount to iterate again
while(current[_request]!=0 && msg.gas>80000){
Debug("countResponses iteration");
DebugGas(msg.gas);
(miner,result,next) = responsesContract.getResponse(current[_request]);
//keep track of total staked amounts for all the different results
staked[_request][result] += tokenContract.staked(miner,_request,current[_request]);
miners[_request][result]++;
//keep track of running best and how much is staked to it
// use >= here to make it 'first come first serve'
if(staked[_request][result] >= weight[_request]){
timestamp[_request] = block.timestamp;
weight[_request] = staked[_request][result];
concurrence[_request] = result;
correctMiners[_request] = miners[_request][result];
}
current[_request] = next;
}
DebugPointer(current[_request]);
}
function feedbackLoop(bytes32 _request) internal {
Debug("feedbackLoop start");
DebugGas(msg.gas);
Main mainContract = Main(mainAddress);
Token tokenContract = Token(mainContract.getContract('Token'));
Responses responsesContract = Responses(mainContract.getContract('Responses'));
address miner;
bytes32 result;
bytes32 next;
//we want to drop out if gas is less than a safe amount to iterate again
while(current[_request]!=0 && msg.gas>100000){
Debug("feedbackLoop iteration");
DebugGas(msg.gas);
(miner,result,next) = responsesContract.getResponse(current[_request]);
uint256 amountStaked;
if( concurrence[_request] == result ){
//they got it right
//return to them all of tokenContract.staked(miner,current[_request]);
amountStaked = tokenContract.staked(miner,_request,current[_request]);
if(amountStaked>0){
tokenContract.release(_request,current[_request],miner,amountStaked);
//reward with their split of the bounty
if( tokenContract.reserved(_request) >= reward[_request] ){
tokenContract.reward(_request,miner,reward[_request]);
}
}
}
else
{
//they got it wrong
//take a 10th of what they staked tokenContract.staked(miner,current[_request])
//I guess this can go back to the owner for now
//but eventually that should go somewhere better
amountStaked = tokenContract.staked(miner,_request,current[_request]);
uint256 punishment = amountStaked/10;
if(punishment<1) punishment=1;
amountStaked-=punishment;
tokenContract.punish(_request,current[_request],miner,punishment,owner);
tokenContract.release(_request,current[_request],miner,amountStaked);
//return the remaining amount of tokenContract.staked(miner,current[_request]); to them
}
current[_request] = next;
}
DebugPointer(current[_request]);
}
function finalizeResponses(bytes32 _request) internal {
Main mainContract = Main(mainAddress);
Token tokenContract = Token(mainContract.getContract('Token'));
Responses responsesContract = Responses(mainContract.getContract('Responses'));
//determine the reward split
uint32 rewardableMiners = correctMiners[_request];
//add a little on the top to incentivize miners to run the combine loop
//this causes a little to be left over and the last miner to run combine
// will be rewarded with the same bounty of the actual request/consensus
rewardableMiners++;
//set the reward by splitting up the reserved token by how many miners
//responded to the request... a little game theory will apply here,
//if a request is too heavily mined it's not worth much
reward[_request] = tokenContract.reserved(_request)/rewardableMiners;
if(reward[_request]<1) reward[_request]=1;
//reset the pointer back to the head so we can iterate through again
current[_request] = responsesContract.heads(_request);
}
function rewardCombinerMiner(bytes32 _request) internal {
Main mainContract = Main(mainAddress);
Token tokenContract = Token(mainContract.getContract('Token'));
uint256 amountLeft = tokenContract.reserved(_request);
if(amountLeft>0){
tokenContract.reward(_request,msg.sender,amountLeft);
}
}
function callback(bytes32 _request) internal {
Main mainContract = Main(mainAddress);
Token tokenContract = Token(mainContract.getContract('Token'));
Responses responsesContract = Responses(mainContract.getContract('Responses'));
//determine the reward split
uint32 rewardableMiners = correctMiners[_request];
//add a little on the top to incentivize miners to run the combine loop
//this causes a little to be left over and the last miner to run combine
// will be rewarded with the same bounty of the actual request/consensus
rewardableMiners++;
//set the reward by splitting up the reserved token by how many miners
//responded to the request... a little game theory will apply here,
//if a request is too heavily mined it's not worth much
reward[_request] = tokenContract.reserved(_request)/rewardableMiners;
if(reward[_request]<1) reward[_request]=1;
//reset the pointer back to the head so we can iterate through again if we have some later mode
//what will most likely happen is we move to the RESET mode and this is set back to address(0)
current[_request] = responsesContract.heads(_request);
}
}
contract Token {
mapping (bytes32 => uint256) public reserved;
mapping (address => mapping (bytes32 => mapping (bytes32 => uint256))) public staked;
function balanceOf(address _owner) public constant returns (uint256 balance) { }
function reward(bytes32 _request, address _miner, uint256 _value) public returns (bool) { }
function release(bytes32 _request, bytes32 _response, address _miner, uint256 _value) public returns (bool) { }
function punish(bytes32 _request, bytes32 _response, address _miner, uint256 _value, address _to) public returns (bool) { }
}
contract Responses{
mapping (bytes32 => bytes32) public heads;
function getResponse(bytes32 id) public constant returns (address,bytes32,bytes32) { }
}
contract Requests {
function getCombiner(bytes32 _id) public constant returns (address) { }
function getCallback(bytes32 _id) public constant returns (address) { }
}
import 'zeppelin-solidity/contracts/ownership/Ownable.sol';
import 'Addressed.sol';
Basic Current address ( http://relay.concurrence.io/combiner/address/basic ):
0x359A65F003eB7Ef07b52110Feaa84379131C38E3
Basic Current ABI ( http://relay.concurrence.io/combiner/abi/basic ):
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