biot-core/aa_watcher.js

```sh $ npm install $ cd examples $ node balance.js ```

/*jslint node: true */
'use strict';
const walletGeneral = require('ocore/wallet_general.js');
const conf = require('ocore/conf.js');
const eventBus = require('ocore/event_bus.js');
const mutex = require('ocore/mutex.js');
const objectHash = require('ocore/object_hash.js');
const async = require('async');
const myWitnesses = require('ocore/my_witnesses.js');
const light = require('ocore/light.js');
const lightWallet = require('ocore/light_wallet.js');
const constants = require('ocore/constants.js');
const bcore = require('./core');

let db = require('ocore/db.js');
let tables = require('./sql/create_sqlite_tables.js');
const libToEs6 = require('./lib/toEs6');

let _db = {
	query: libToEs6.dbQuery,
	getIgnore: db.getIgnore,
	takeConnectionFromPool: db.takeConnectionFromPool,
	escape: db.escape
};



let my_address;
const assocJointsFromPeersCache = {};

eventBus.once('biot_ok', async () => {
	await tables.create();
	let wallets = await bcore.getWallets();
	my_address = (await bcore.getAddressesInWallet(wallets[0]))[0];
	console.error('====== my address: ', my_address);
	await _db.query("INSERT " + _db.getIgnore() + " INTO aa_channels_config (my_address) VALUES (?)", [my_address]);
	await treatUnitsFromAA(); // we look for units that weren't treated in case node was interrupted at bad time
	setInterval(lookForAndProcessTasks, 2000);
	eventBus.emit('aa_watcher_init');
});

if (conf.bLight) {
	eventBus.on('my_transactions_became_stable', function (arrUnits) {
		treatUnitsFromAA(arrUnits);
	});
} else {
	eventBus.on('new_aa_unit', async function (objUnit) {
		const channels = await _db.query("SELECT 1 FROM aa_channels WHERE aa_address=?", [objUnit.authors[0].address]);
		if (channels[0])
			treatUnitsFromAA([objUnit.unit]);
	});

	eventBus.on('my_transactions_became_stable', function (arrUnits) {
		updateLastMci(arrUnits); // once units from AA become stable, MCI is known and we can update last_updated_mci
	});
}

eventBus.on('new_my_transactions', function (arrUnits) {
	if (conf.bLight && !lightWallet.isFirstHistoryReceived()) // we ignore all new transactions that could come from a node resyncing from scratch - to do: find solution for full node
		return console.log("first history not processed");
	treatNewUnitsToAA(arrUnits);
});

eventBus.on('sequence_became_bad', function (arrUnits) {
	appDB.query("UPDATE aa_unconfirmed_units_from_peer SET is_bad_sequence=1 WHERE unit IN(?)", [arrUnits]);
});


function lookForAndProcessTasks() { // main loop for repetitive tasks
	if (conf.bLight && !lightWallet.isFirstHistoryReceived())
		return console.log("first history not processed");
	updateAddressesToWatch();
	confirmClosingIfTimeoutReached();
	deletePendingUnconfirmedUnits();
}

// some unconfirmed units may be left if unit from AA were disorderly received
async function deletePendingUnconfirmedUnits() {
	const unconfirmedUnitsRows = await _db.query("SELECT unit FROM aa_unconfirmed_units_from_peer");
	if (unconfirmedUnitsRows.length === 0)
		return;
	const mciAndUnitsRows = await _db.query("SELECT main_chain_index,unit FROM units WHERE unit IN ('" + unconfirmedUnitsRows.map(function (row) {
		return row.unit
	}).join("','") + "') AND is_stable=1");
	if (mciAndUnitsRows.length === 0)
		return;
	const sqlFilter = mciAndUnitsRows.map(function (row) {
		return "(unit='" + row.unit + "' AND last_updated_mci>=" + row.main_chain_index + ")";
	}).join(" OR ");
	_db.query("DELETE FROM aa_unconfirmed_units_from_peer WHERE unit IN (\n\
		SELECT unit FROM aa_unconfirmed_units_from_peer INNER JOIN aa_channels USING (aa_address) WHERE " + sqlFilter + ")");
}

async function updateAddressesToWatch() {
	let watched_addresses = (await _db.query("SELECT address FROM my_watched_addresses")).map(function (row) {
		return row.address
	}).join("','");
	let rows = await _db.query("SELECT aa_address FROM aa_channels WHERE aa_address NOT IN ('" + watched_addresses + "')");
	rows.forEach(function (row) {
		if (conf.bLight) {
			myWitnesses.readMyWitnesses(async function (witnesses) {
				const objRequest = {addresses: [row.aa_address], witnesses: witnesses};
				const network = require('ocore/network.js');
				network.requestFromLightVendor('light/get_history', objRequest, function (ws, request, response) {
					if (response.error || (!response.joints && !response.unstable_mc_joints))
						return walletGeneral.addWatchedAddress(row.aa_address, () => {
						});
					if (response.joints)
						response.joints.forEach(function (objUnit) {
							assocJointsFromPeersCache[objUnit.unit.unit] = objUnit.unit;
						})
					light.processHistory(response, objRequest.witnesses, {
						ifError: function (err) {
							console.log("error when processing history for " + row.aa_address + " " + err);
						},
						ifOk: function () {
							console.log("history processed for " + row.aa_address);
							treatUnitsAndAddWatchedAddress()
						}
					});
				});
			});
		} else {
			treatUnitsAndAddWatchedAddress()
		}

		async function treatUnitsAndAddWatchedAddress() {
			await treatUnitsFromAA(); // we treat units from AA first to get more recent confirmed states
			await treatNewUnitsToAA(null, row.aa_address);
			walletGeneral.addWatchedAddress(row.aa_address, () => {
			});
		}
	});
}


async function getSqlFilterForNewUnitsFromChannels() {
	return new Promise(async (resolve) => {
		const rows = await _db.query("SELECT last_updated_mci,aa_address FROM aa_channels");
		if (rows.length === 0)
			return resolve(" 0 ");
		let string = "(" + rows.map(function (row) {
			return " (author_address='" + row.aa_address + "' AND (main_chain_index>" + row.last_updated_mci + " OR main_chain_index IS NULL)) ";
		}).join(' OR ') + ")";
		resolve(string);
	});
}

async function getSqlFilterForNewUnitsFromPeers(aa_address) {
	return new Promise(async (resolve) => {
		const rows = await _db.query("SELECT last_updated_mci,peer_address,aa_address FROM aa_channels " + (aa_address ? " WHERE aa_address='" + aa_address + "'" : ""));
		if (rows.length === 0)
			return resolve(" 0 ");
		let string = "(" + rows.map(function (row) {
			return " (outputs.address='" + row.aa_address + "' AND author_address='" + row.peer_address + "' AND (main_chain_index>" + row.last_updated_mci + " OR main_chain_index IS NULL)) ";
		}).join(' OR ') + ")";
		resolve(string);
	});
}


function treatNewUnitsToAA(arrUnits, aa_address) {
	return new Promise(async (resolve) => {
		mutex.lock(['treatNewUnitsToAA'], async (unlock) => {
			const unitFilter = arrUnits ? " units.unit IN(" + arrUnits.map(_db.escape).join(',') + ") AND " : "";
			// we select units having output address and author matching known channels
			const new_units = await _db.query("SELECT DISTINCT timestamp,units.unit,main_chain_index,unit_authors.address AS author_address FROM units \n\
			CROSS JOIN unit_authors USING(unit)\n\
			CROSS JOIN outputs USING(unit)\n\
			WHERE " + unitFilter + await getSqlFilterForNewUnitsFromPeers(aa_address));
			if (new_units.length === 0) {
				unlock();
				console.log("nothing destinated to AA in these units");
				return resolve();
			}
			for (let i = 0; i < new_units.length; i++) {
				let new_unit = new_units[i];
				let channels = await _db.query("SELECT aa_address FROM aa_channels WHERE peer_address=?", [new_unit.author_address]);
				if (!channels[0])
					throw Error("channel not found");
				await treatNewOutputsToChannels(channels, new_unit);
			}
			unlock();
			resolve();
		});
	});
}

function treatNewOutputsToChannels(channels, new_unit) {
	return new Promise(async (resolve) => {
		async.eachSeries(channels, function (channel, eachCb) {
			mutex.lock([channel.aa_address], async function (unlock_aa) {
				let conn = await take_dbConnectionPromise();
				let connOr_db = conn;
				let lockedChannelRows = await connOr_db.nQuery("SELECT * FROM aa_channels WHERE aa_address=?", [channel.aa_address]);
				let lockedChannel = lockedChannelRows[0];
				let byteAmountRows = await connOr_db.nQuery("SELECT SUM(amount) AS amount FROM outputs WHERE unit=? AND address=? AND asset IS NULL", [new_unit.unit, channel.aa_address]);
				let byteAmount = byteAmountRows[0] ? byteAmountRows[0].amount : 0;
				if (byteAmount >= constants.MIN_BYTES_BOUNCE_FEE) { // check the minimum to not be bounced is reached
					let sqlAsset = lockedChannel.asset == 'base' ? "" : " AND asset=\"" + lockedChannel.asset + "\" ";
					let amountRows = await connOr_db.nQuery("SELECT SUM(amount) AS amount  FROM outputs WHERE unit=? AND address=?" + sqlAsset, [new_unit.unit, channel.aa_address]);
					let amount = amountRows[0].amount;

					let bHasDefinition = false;
					let bHasData = false;

					let joint = await getJointFromCacheStorageOrHub(connOr_db, new_unit.unit);
					if (joint) {
						joint.messages.forEach(function (message) {
							if (message.app == "definition" && message.payload.address == channel.aa_address) {
								bHasDefinition = true;
							}
							if (message.app == "data")
								bHasData = true;
						});
						// for this 3 statuses, we can take into account unconfirmed deposits since they shouldn't be refused by AA
						if (lockedChannel.status == "created" || lockedChannel.status == "closed" || lockedChannel.status == "open") {
							let unconfirmedUnitsRows = await conn.nQuery("SELECT close_channel,has_definition FROM aa_unconfirmed_units_from_peer WHERE aa_address=?", [channel.aa_address]);
							let bAlreadyBeenClosed = unconfirmedUnitsRows.some(function (row) {
								return row.close_channel
							});
							if (!bAlreadyBeenClosed && (lockedChannel.is_definition_confirmed === 1 || bHasDefinition)) { // we ignore unit if a closing request happened or no pending/confirmed definition is known
								let timestamp = Math.round(Date.now() / 1000);
								if (bHasData) // a deposit shouldn't have data, if it has data we consider it's a closing request and we flag it as so
									await conn.nQuery("INSERT  " + conn.getIgnore() + " INTO aa_unconfirmed_units_from_peer (aa_address,close_channel,unit,timestamp) VALUES (?,1,?,?)",
										[channel.aa_address, new_unit.unit, timestamp]);
								else if (lockedChannel.asset != 'base' || byteAmount > 10000) // deposit in bytes are possible only over 10000
									await conn.nQuery("INSERT  " + conn.getIgnore() + " INTO aa_unconfirmed_units_from_peer (aa_address,amount,unit,has_definition,timestamp) VALUES (?,?,?,?,?)",
										[channel.aa_address, amount, new_unit.unit, bHasDefinition ? 1 : 0, timestamp]);
							}
						}
					}
				}
				conn.release();
				unlock_aa();
				eachCb();
			});
		}, function () {
			resolve();
		});
	});
}

function getJointFromCacheStorageOrHub(conn, unit) {
	return new Promise(async (resolve) => {
		if (assocJointsFromPeersCache[unit])
			return resolve(assocJointsFromPeersCache[unit]);
		if (!conf.bLight) {
			return require('ocore/storage.js').readJoint(conn, unit, {
				ifFound: function (objJoint) {
					return resolve(objJoint.unit);
				},
				ifNotFound: function () {
					return resolve();
				}
			});
		}
		const network = require('ocore/network.js');
		network.requestFromLightVendor('get_joint', unit, function (ws, request, response) {
			if (response.joint) {
				resolve(response.joint.unit)
			} else {
				resolve();
			}
		});
		setTimeout(resolve, 1000);
	});
}

function take_dbConnectionPromise() {
	return new Promise( (resolve) => {
		db.takeConnectionFromPool(function (_conn) {
			_conn.nQuery = (query, params = []) => {
				return new Promise(resolve1 => {
					_conn.query(query, params, resolve1);
				})
			};
			resolve(_conn);
		});
	});
}

async function updateLastMci(arrUnits) {
	if (conf.bLight)
		throw Error("updateLastMci called by light node");
	if (arrUnits.length === 0)
		throw Error("arrUnits for updateLastMci cannot be empty");

	const stable_units = await dagDB.query("SELECT timestamp,units.unit,main_chain_index,unit_authors.address AS author_address FROM units \n\
	CROSS JOIN unit_authors USING(unit)\n\
	WHERE units.unit IN(" + arrUnits.map(dagDB.escape).join(',') + ") AND " + await getSqlFilterForNewUnitsFromChannels() + " GROUP BY units.unit ORDER BY main_chain_index,level ASC");

	for (var i = 0; i < stable_units.length; i++) {
		var stable_unit = stable_units[i];
		if (!stable_unit.main_chain_index)
			throw Error("No MCI for stable unit");
		var payloads = await dagDB.query("SELECT payload FROM messages WHERE unit=? AND app='data' ORDER BY message_index ASC LIMIT 1", [stable_unit.unit]);
		var payload = payloads[0] ? JSON.parse(payloads[0].payload) : {};
		if (payload.event_id)
			await appDB.query("UPDATE aa_channels SET last_updated_mci=? WHERE last_event_id>=? AND aa_address=?",
				[stable_unit.main_chain_index, payload.event_id, stable_unit.author_address])
	}
}


function treatUnitsFromAA(arrUnits) {
	return new Promise(async (resolve_1) => {
		mutex.lock(['treatUnitsFromAA'], async (unlock) => {
			const unitFilter = arrUnits ? " units.unit IN(" + arrUnits.map(_db.escape).join(',') + ") AND " : "";
			const isStableFilter = conf.bLight ? " AND is_stable=1 AND sequence='good' " : ""; // unit from AA from can always be considered as stable on full node
			const new_units = await _db.query("SELECT timestamp,units.unit,main_chain_index,unit_authors.address AS author_address FROM units \n\
			CROSS JOIN unit_authors USING(unit)\n\
			WHERE " + unitFilter + await getSqlFilterForNewUnitsFromChannels() + isStableFilter + " GROUP BY units.unit ORDER BY main_chain_index,level ASC");

			if (new_units.length === 0) {
				unlock();
				console.log("nothing concerns payment channel in these units");
				return resolve_1();
			}

			for (let i = 0; i < new_units.length; i++) {
				let new_unit = new_units[i];
				await treatUnitFromAA(new_unit);
			}
			unlock();
			return resolve_1();
		});
	});
}


function treatUnitFromAA(new_unit) {
	return new Promise(async (resolve) => {
		mutex.lock([new_unit.author_address], async function (unlock_aa) {
			let connOr_db = await take_dbConnectionPromise();
			let channels = await connOr_db.nQuery("SELECT * FROM aa_channels WHERE aa_address=?", [new_unit.author_address]);
			if (!channels[0])
				throw Error("channel not found");
			let channel = channels[0];

			let payloads = await connOr_db.nQuery("SELECT payload FROM messages WHERE unit=? AND app='data' ORDER BY message_index ASC LIMIT 1", [new_unit.unit]);
			let payload = payloads[0] ? JSON.parse(payloads[0].payload) : [];
			function setLastUpdatedMciAndEventIdAndOtherFields(fields) {
				return new Promise(async (resolve_2) => {
					let strSetFields = "";
					if (fields)
						for (let key in fields) {
							strSetFields += "," + key + "='" + fields[key] + "'";
						}
					await connOr_db.nQuery("UPDATE aa_channels SET last_updated_mci=?,last_event_id=?,is_definition_confirmed=1" + strSetFields + "\n\
					WHERE aa_address=? AND last_event_id<?", [new_unit.main_chain_index ? new_unit.main_chain_index : channel.last_updated_mci, payload.event_id, new_unit.author_address, payload.event_id]);
					return resolve_2();
				});
			}

			//once AA state is updated by an unit, we delete the corresponding unit from unconfirmed units table
			if (payload && payload.trigger_unit) {
				await connOr_db.nQuery("DELETE FROM aa_unconfirmed_units_from_peer WHERE unit=?", [payload.trigger_unit]);
				delete assocJointsFromPeersCache[payload.trigger_unit];
			}
			//channel is open and received funding
			if (payload && payload.open) {
				await connOr_db.nQuery("UPDATE aa_my_deposits SET is_confirmed_by_aa=1 WHERE unit=?", [payload.trigger_unit]);
				await setLastUpdatedMciAndEventIdAndOtherFields({
					status: "open",
					period: payload.period,
					amount_deposited_by_peer: payload[channel.peer_address],
					amount_deposited_by_me: payload[my_address]
				})
				if (payload[my_address] > 0)
					eventBus.emit("my_deposit_became_stable", payload[my_address], payload.trigger_unit);
				else
					eventBus.emit("peer_deposit_became_stable", payload[channel.peer_address], payload.trigger_unit);
			}

			//closing requested by one party
			if (payload && payload.closing) {
				let status;
				if (payload.initiated_by === my_address)
					status = "closing_initiated_by_me_acknowledged";
				else {
					status = "closing_initiated_by_peer";
					if (payload[channel.peer_address] >= channel.amount_spent_by_peer) {
						confirmClosing(new_unit.author_address, payload.period, channel.overpayment_from_peer); //peer is honest, we send confirmation for closing
					} else {
						confirmClosing(new_unit.author_address, payload.period, channel.overpayment_from_peer, channel.last_message_from_peer); //peer isn't honest, we confirm closing with a fraud proof
					}
				}
				await setLastUpdatedMciAndEventIdAndOtherFields({
					status: status,
					period: payload.period,
					close_timestamp: new_unit.timestamp
				});
			}
			//AA confirms that channel is closed
			if (payload && payload.closed) {
				await setLastUpdatedMciAndEventIdAndOtherFields(
					{
						status: "closed",
						is_peer_ready: 0,
						period: payload.period,
						amount_spent_by_peer: 0,
						amount_spent_by_me: 0,
						amount_deposited_by_peer: 0,
						amount_deposited_by_me: 0,
						overpayment_from_peer: 0,
						amount_possibly_lost_by_me: 0,
						last_message_from_peer: ''
					});
				const rows = await connOr_db.nQuery("SELECT SUM(amount) AS amount FROM outputs WHERE unit=? AND address=?", [new_unit.unit, my_address]);
				if (payload.fraud_proof)
					eventBus.emit("channel_closed_with_fraud_proof", new_unit.author_address, rows[0] ? rows[0].amount : 0);
				else
					eventBus.emit("channel_closed", new_unit.author_address, rows[0] ? rows[0].amount : 0);
			}
			//AA refused a deposit, we still have to update flag in my_deposits table so it's not considered as pending anymore
			if (payload && payload.refused) {
				const result = await connOr_db.nQuery("UPDATE aa_my_deposits SET is_confirmed_by_aa=1 WHERE unit=?", [payload.trigger_unit]);
				if (result.affectedRows !== 0)
					eventBus.emit("refused_deposit", payload.trigger_unit);
				await setLastUpdatedMciAndEventIdAndOtherFields({});
			}
			connOr_db.release();
			unlock_aa();
			resolve();
		});
	});
}

// check if frontend authored a closing request, used only in high availability mode
function treatClosingRequests() {
	mutex.lock(['treatClosingRequests'], async function (unlock) {
		const rows = await _db.query("SELECT aa_address,amount_spent_by_peer,amount_spent_by_me,last_message_from_peer, period FROM aa_channels WHERE closing_authored=1");
		if (rows.length === 0)
			return unlock();

		async.eachSeries(rows, async (row, cb) => {

				const payload = {close: 1, period: row.period};
				if (row.amount_spent_by_me > 0)
					payload.transferredFromMe = row.amount_spent_by_me;
				if (row.amount_spent_by_peer > 0)
					payload.sentByPeer = JSON.parse(row.last_message_from_peer);

				const options = {
					messages: [{
						app: 'data',
						payload_location: "inline",
						payload_hash: objectHash.getBase64Hash(payload),
						payload: payload
					}],
					change_address: my_address,
					base_outputs: [{address: row.aa_address, amount: 10000}],
					spend_unconfirmed: 'all'
				}
				options.wallet = (await bcore.getWallets())[0];
				let [error, unit] = await bcore.sendMultiPayment(options);
				if (error)
					console.error("error when closing channel " + error);
				else {
					await _db.query("UPDATE aa_channels SET closing_authored=0 WHERE aa_address=?", [row.aa_address]);
					await _db.query("UPDATE aa_channels SET status='closing_initiated_by_me' WHERE aa_address=? AND (status='open' OR status='created')", [row.aa_address]);
				}
				cb();
			},
			function () {
				unlock();
			});

	});
}


function confirmClosing(aa_address, period, overpayment_from_peer, fraud_proof) {
	return new Promise((resolve) => {
		mutex.lock(['confirm_' + aa_address], async (unlock) => {
			let payload;
			if (fraud_proof) {
				payload = {fraud_proof: 1, period: period, sentByPeer: JSON.parse(fraud_proof)};
			} else {
				payload = {confirm: 1, period: period};
			}
			if (overpayment_from_peer > 0)
				payload.additionnalTransferredFromMe = overpayment_from_peer;

			const options = {
				messages: [{
					app: 'data',
					payload_location: "inline",
					payload_hash: objectHash.getBase64Hash(payload),
					payload: payload
				}],
				change_address: my_address,
				base_outputs: [{address: aa_address, amount: 10000}],
				spend_unconfirmed: 'all'
			}
			options.wallet = (await bcore.getWallets())[0];

			let [error, unit] = await bcore.sendMultiPayment(options);
			if (error)
				console.log("error when closing channel " + error);
			else
				await _db.query("UPDATE aa_channels SET status='confirmed_by_me' WHERE aa_address=?", [aa_address]);
			unlock();
			resolve();
		});
	});
}

async function confirmClosingIfTimeoutReached() {
	const current_ts = Math.round(Date.now() / 1000);
	const rows = await _db.query("SELECT aa_address,period FROM aa_channels WHERE status='closing_initiated_by_me_acknowledged' AND close_timestamp < (? - timeout)", [current_ts]);
	rows.forEach(function (row) {
		confirmClosing(row.aa_address, row.period);
	});
}