The documentation for the Enigma Data Marketplace Smart Contract is available at https://enigmampc.github.io/marketplace/smart-contract.html.
The contract is made out of few smaller contracts. The api is split between 3 interfaces with full documentation:
- https://github.com/enigmampc/smart_contract_marketplace/blob/master/contracts/IBasicMarketplace.sol
- https://github.com/enigmampc/smart_contract_marketplace/blob/master/contracts/IMarketplace.sol
- https://github.com/enigmampc/smart_contract_marketplace/blob/master/contracts/IRecoverableMarketplace.sol
- Ganache test network (optional)
- Unix supporting OS.
- solc compiler
- nodeJS
- Truffle
NodeJS
sudo apt-get update && sudo apt-get -y upgrade
sudo apt-get -y install curl git vim build-essential
curl -sL https://deb.nodesource.com/setup_6.x | sudo -E bash -
sudo apt-get install -y nodejs
sudo npm install -g express
Truffle
sudo npm install -g truffle
The tests has to be deployed with an ERC20 Token, the original implementation is in /contracts/token. Due to that, the tokens are deployed as well in the migration file. There are 2 different tests:
-
Marketplace_Basic.js
-
Marketplace_System_Test.js
Each of the tests can be set to run with the Mock contract (i.e TestableMock.sol) or with the original.
To run Truffle tests
$ truffle develop
truffle(develop)> test
Migration is made with /migrations/3_deploy_conracts.js
There is an example of the ABI and deployment with pure Web3 that can be found in /scripts/deploy_contract.js
truffle compile
Use with --reset flag for restarting migrations.
truffle migrate
Web3 connection:
let EnigmaABI = require("../build/contracts/EnigmaToken.json");
let MarketPlaceABI = require ("../build/contracts/RecoverableMarketplace.json");
let contract = require('truffle-contract');
// contracts
let EnigmaContract = contract(EnigmaABI);
let MarketPlaceContract = contract(MarketPlaceABI);
// Web3
let Web3 = require('web3');
let provider = new Web3.providers.HttpProvider("http://localhost:8545"); //8545 // 9545
let web3 = new Web3(provider);
EnigmaContract.setProvider(provider);
MarketPlaceContract.setProvider(provider);
module.exports.web3= web3;
module.exports.EnigmaContract = EnigmaContract;
module.exports.MarketPlaceContract = MarketPlaceContract;Synchronous Example of Registration and then Subscription. The initial balance transfer is only for the test.
const utils = require("./utils");
const config = require("./config_web3");
const web3 = config.web3;
const EnigmaContract = config.EnigmaContract;
const MarketPlaceContract = config.MarketPlaceContract;
let gas = 740000; // some gas limit
let theOwner = web3.eth.accounts[0];
// provider
var _provider = {};
_provider.address = web3.eth.accounts[1];
_provider.dataName = "Data1";
_provider.price = 1500;
//subscriber
var _subscriber = {};
_subscriber.address = web3.eth.accounts[2];
async function transfer(from,to,amount){
let enigma = await EnigmaContract.deployed();
let tx = await enigma.transfer(to,amount,{from:from});
return tx;
}
async function register(provider){
let marketPlace = await MarketPlaceContract.deployed();
let enigma = await EnigmaContract.deployed();
let version = await marketPlace.MARKETPLACE_VERSION.call();
// register probider
let reg_tx = await marketPlace.register(provider.dataName,provider.price,provider.address,{from:provider.address,gas:gas});
// validate
let providerInfo = await marketPlace.getDataProviderInfo.call(provider.dataName);
return providerInfo;
}
async function subscribe(provider,subscriber){
let marketPlace = await MarketPlaceContract.deployed();
let enigma = await EnigmaContract.deployed();
// #1 approve the marketPlace as a spender in EnigmaToken
let tx_app = await enigma.approve(marketPlace.address,provider.price,{from:subscriber.address,gas:gas});
// validate allowed amount
let allowed = await enigma.allowance.call(subscriber.address,marketPlace.address);
console.log(allowed.toNumber());
// #2 subscribe to marketPlace
let tx_sub = await marketPlace.subscribe(provider.dataName,{from:subscriber.address,gas:gas});
//validate subscription // subscriber,dataSourceName,price,startTime,endTime,isUnExpired,isPaid,isPunishedProvider,isOrder
let subInfo = await marketPlace.checkAddressSubscription.call(subscriber.address,provider.dataName);
}
// registration + subscription
transfer(theOwner,_subscriber.address,_provider.price).then(tx=>{
register(_provider).then(info=>{
subscribe(_provider,_subscriber);
});
});In order to get all the providers list and their info one could use the following sample: (Note: the return param documentation can be found inside /IBasicMarketplace.sol or the documentation site mentioned above)
// get all providers + their info (provider[0] = 0x0 just an indicator)
async function getAllProviders(){
let providerInfo = [];
let marketPlace = await MarketPlaceContract.deployed();
let providers = await marketPlace.getAllProviders.call();
for(var i in providers){
let info = await marketPlace.getDataProviderInfo.call(web3.toAscii(providers[i]));
providerInfo.push({name: providers[i], info: info});
}
return providerInfo;
}
getAllProviders().then(providers=>{
// full list with details provider data.
});Asynchronous examples:
To register a data source.
var price = 100;
var owner = web3.eth.accounts[0];
var deployer = web3.eth.accounts[0];
var gasLimit = 999999; // some gas limit
marketPlace().then((instance)=>{
contract = instance;
return contract.register('data name',price,owner,{from:deployer,gas:gasLimit});
});Listen to Blockchain events:
marketPlace().then(instance=>{
eventRegistered = instance.Registered(); // => add filters Registered({from:, price:})
eventRegistered.watch((err,eventResult)=>{
// handle events...
// bytes to ascii
var name = web3.toAscii(eventResult.args.dataSourceName);
// stop watching for events.
eventRegistered.stopWatching();
});
});Approve the ERC20 token contract as a spender on behalf of X: Trigers Approval() event.
var allowance = 100;
var subscriber = web3.eth.accounts[0];
var gas = 99999;
marketPlace().
then(instance=>{mp = instance;return enigma();}).
then((instance)=>{ eng = instance; return eng.approve(mp.address,allowance,{from:subscriber,gas:gas})}).
then(txRecipt=>{ // tx recipt ...});allowance() and transferFrom() functions are encapsulated inside Marketplace, an internal safeTransfer() function
will run the payment process and trigger a SubscriptionPaid() event.
function safeToMarketPlaceTransfer(address _from, address _to, uint256 _amount)
internal
validPrice(_amount)
returns (bool){
require(_from != address(0) && _to == address(this));
require(mToken.allowance(_from,_to) >= _amount);
require(mToken.transferFrom(_from,_to,_amount));
SubscriptionDeposited(_from, _to, _amount);
return true;
}The following snippets are examples of how to work with loops outside the chain. The examples are implemented synchronously for readability purposes.
// get the providers number
async function getProvidersSize(){
let marketPlace = await marketPlace.deployed();
let providersNumber = await marketPlace.getProviderNamesSize.call();
return providersNumber.toNumber();
}// loop through all the providers name
async function getAllNames(providersSize){
var providersNames = [];
let marketPlace = await marketPlace.deployed();
for(var i=0; i<providersSize;i++){
let name = await marketPlace.getNameAt.call(i);
providersNames.push(name);
}
return providersNames;
}//loop through all the providers details
async function getAllProviders(providersNames){
var providersDetails = [];
let marketPlace = await marketPlace.deployed();
for(var i=0; i< providersNames.length;i++){
let provider = await marketPlace.getDataProviderInfo.call(providersNames[i]);
providersDetails.push({name:providersNames[i], info: provider});
}
}// withdraw funds
async function withdrawFunds(providerName, owner, gas){
let marketPlace = await marketPlace.deployed();
let subscriptionsNumber = await marketPlace.getSubscriptionsSize.call(providerName);
for(var i=0;i<subscriptionsNumber.toNumber();i++){
let withdraw = await marketPlace.getWithdrawAmountAt.call(providerName,i);
if(withdraw.toNumber() > 0){
let tx = await marketPlace.withrawProviderAt(providerName,i,{from:owner,gas:gas});
}
}
}// refund subscriber
async function refundSubscriber(providerName, subscriber, gas){
let marketPlace = await marketPlace.deployed();
let subscriptionsNumber = await marketPlace.getSubscriptionsSize.call(providerName);
for(var i = subscriptionsNumber.toNumber(); i>=0 ; i--){
let subscription = await marketPlace.checkSubscriptionAt.call(providerName,i);
if(subscription[0] == subscriber){ //0 is the index of the subscriber address
let refund = await marketPlace.getRefundAmountAt.call(providerName,i);
if(refund > 0){
let tx = await marketPlace.refundSubscriberAt(providerName,i,{from:subscriber,gas:gas});
}
}
}
}// is expired subscription
async function isSubscriptionExpired(prodiverName, index){
let marketPlace = await marketPlace.deployed();
let isExpired = await marketPlace.isExpiredSubscriptionAt.call(providerName,index);
return isExpired;
}// general function - traverse all orders and do something
async function forEachSubscription(providerName,callback){
let marketPlace = await marketPlace.deployed();
let subscriptionsNumber = await marketPlace.getSubscriptionsSize.call(providerName);
for(var i = subscriptionsNumber.toNumber(); i>=0 ; i--){
let subscription = await marketPlace.checkSubscriptionAt.call(providerName,i);
callback(subscription);
}
}// general function - traverse all providers and do something
async function forEachProvider(callback){
let marketPlace = await marketPlace.deployed();
let size = await marketPlace.getProviderNamesSize.call();
for(var i =0; i<size.toNumber();i++){
let name = await marketPlace.getNameAt.call(i);
let provider = await marketPlace.getDataProviderInfo.call(providersNames[i]);
callback({name:name, info:provider});
}
}Right after cloning the repository, you may encounter an error like the following when launching truffle:
$ truffle develop
Error: dlopen(smart_contract_marketplace/node_modules/scrypt/build/Release/scrypt.node, 1): no suitable image found. Did find:
smart_contract_marketplace/node_modules/scrypt/build/Release/scrypt.node: unknown file type, first eight bytes: 0x7F 0x45 0x4C 0x46 0x02 0x01 0x01 0x00
smart_contract_marketplace/node_modules/scrypt/build/Release/scrypt.node: unknown file type, first eight bytes: 0x7F 0x45 0x4C 0x46 0x02 0x01 0x01 0x00
at Object.Module._extensions..node (module.js:664:18)
at Module.load (module.js:554:32)
at tryModuleLoad (module.js:497:12)
at Function.Module._load (module.js:489:3)
at Module.require (module.js:579:17)
at require (internal/module.js:11:18)
at Object.<anonymous> (/Users/adityapalepu/Startups/enigma/smart_contract_marketplace/node_modules/scrypt/index.js:3:20)
at Module._compile (module.js:635:30)
at Object.Module._extensions..js (module.js:646:10)
at Module.load (module.js:554:32)
which can be fixed by removing and reinstalling the problematic node module:
$ rm -rf node_modules/scrypt
$ npm install
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