exchangemarket/src/backup/slave.js
2023-03-11 23:23:17 +05:30

436 lines
17 KiB
JavaScript

'use strict';
const keys = require("../keys");
const DB = require("../database");
const {
BACKUP_INTERVAL,
BACKUP_SYNC_TIMEOUT,
CHECKSUM_INTERVAL,
HASH_N_ROW
} = require("../_constants")["backup"];
var masterWS = null; //Container for Master websocket connection
var intervalID = null;
function startSlaveProcess(ws, init) {
if (!ws) throw Error("Master WS connection required");
//stop existing process
stopSlaveProcess();
//set masterWS
ws.on('message', processDataFromMaster);
masterWS = ws;
let sinks_stored = {};
Promise.all([keys.getStoredList(), keys.getDiscardedList()]).then(result => {
let stored_list = result[0],
discarded_list = result[1];
for (let group in stored_list) {
sinks_stored[group] = [];
for (let id of stored_list[group])
if (!(id in discarded_list))
sinks_stored[group].push(id);
}
}).catch(error => console.error(error)).finally(_ => {
//inform master
let message = {
floID: keys.node_id,
pubKey: keys.node_pub,
sinks: sinks_stored,
req_time: Date.now(),
type: "SLAVE_CONNECT"
}
message.sign = floCrypto.signData(message.type + "|" + message.req_time, keys.node_priv);
ws.send(JSON.stringify(message));
//start sync
if (init)
requestInstance.open();
intervalID = setInterval(() => requestInstance.open(), BACKUP_INTERVAL);
})
}
function stopSlaveProcess() {
if (masterWS !== null) {
masterWS.onclose = () => null;
masterWS.close();
requestInstance.close();
masterWS = null;
}
if (intervalID !== null) {
clearInterval(intervalID);
intervalID = null;
}
}
function requestBackupSync(checksum_trigger, ws) {
return new Promise((resolve, reject) => {
DB.query('SELECT MAX(u_time) as last_time FROM _backup').then(result => {
let request = {
floID: keys.node_id,
pubKey: keys.node_pub,
type: "BACKUP_SYNC",
last_time: result[0].last_time,
checksum: checksum_trigger,
req_time: Date.now()
};
request.sign = floCrypto.signData(request.type + "|" + request.req_time, keys.node_priv);
ws.send(JSON.stringify(request));
resolve(request);
}).catch(error => reject(error))
})
}
const requestInstance = {
ws: null,
cache: null,
checksum: null,
delete_data: null,
add_data: null,
request: null,
onetime: null,
last_response_time: null,
checksum_count_down: 0
};
requestInstance.open = function (ws = null) {
const self = this;
//Check if there is an active request
if (self.request) {
console.log("A request is already active");
if (self.last_response_time < Date.now() - BACKUP_SYNC_TIMEOUT)
self.close();
else
return;
}
//Use websocket connection if passed, else use masterWS if available
if (ws) {
ws.on('message', processDataFromMaster);
self.onetime = true;
} else if (masterWS)
ws = masterWS;
else return console.warn("Not connected to master");
requestBackupSync(!self.checksum_count_down || self.onetime, ws).then(request => {
self.request = request;
self.cache = [];
self.last_response_time = Date.now();
self.ws = ws;
}).catch(error => console.error(error))
}
requestInstance.close = function () {
const self = this;
if (self.onetime)
self.ws.close();
else
self.checksum_count_down = self.checksum_count_down ? self.checksum_count_down - 1 : CHECKSUM_INTERVAL;
self.onetime = null;
self.ws = null;
self.cache = null;
self.checksum = null;
self.delete_data = null;
self.add_data = null;
self.request = null;
self.last_response_time = null;
}
function processDataFromMaster(message) {
try {
message = JSON.parse(message);
//console.debug("Master:", message);
if (message.command.startsWith("SYNC"))
processBackupData(message);
else switch (message.command) {
case "SINK_SHARE":
storeSinkShare(message.group, message.sinkID, message.share, message.ref);
break;
case "SEND_SHARE":
sendSinkShare(message.group, message.sinkID, message.pubKey);
break;
case "REQUEST_ERROR":
console.log(message.error);
if (message.type === "BACKUP_SYNC")
requestInstance.close();
break;
}
} catch (error) {
console.error(error);
}
}
function storeSinkShare(group, sinkID, share, ref) {
share = floCrypto.decryptData(share, keys.node_priv);
keys.addShare(group, sinkID, ref, share)
.then(_ => null).catch(error => console.error(error));
}
function sendSinkShare(group, sinkID, pubKey) {
keys.getShares(group, sinkID).then(({ ref, shares }) => {
shares.forEach(s => {
let response = {
type: "SINK_SHARE",
sinkID, ref,
share: floCrypto.encryptData(s, pubKey),
floID: keys.node_id,
pubKey: keys.node_pub,
req_time: Date.now()
}
response.sign = floCrypto.signData(response.type + "|" + response.req_time, keys.node_priv); //TODO: strengthen signature
masterWS.send(JSON.stringify(response));
})
}).catch(error => console.error(error));
}
function processBackupData(response) {
//TODO: Sync improvements needed. (2 types)
//1. Either sync has to be completed or rollback all
//2. Each table/data should be treated as independent chunks
const self = requestInstance;
self.last_response_time = Date.now();
switch (response.command) {
case "SYNC_END":
if (response.status) {
storeBackupData(self.cache, self.checksum).then(result => {
updateBackupTable(self.add_data, self.delete_data);
if (result) {
console.log("Backup Sync completed successfully");
self.close();
} else
console.log("Waiting for re-sync data");
}).catch(_ => {
console.warn("Backup Sync was not successful");
self.close();
});
} else {
console.info("Backup Sync was not successful! Failed info: ", response.info);
self.close();
}
break;
case "SYNC_DELETE":
self.delete_data = response.delete_data;
self.cache.push(cacheBackupData(null, response.delete_data));
break;
case "SYNC_HEADER":
self.add_data = response.add_data;
break;
case "SYNC_UPDATE":
self.cache.push(cacheBackupData(response.table, response.data));
break;
case "SYNC_CHECKSUM":
self.checksum = response.checksum;
break;
case "SYNC_HASH":
verifyHash(response.hashes)
.then(mismatch => requestTableChunks(mismatch, self.ws))
.catch(error => {
console.error(error);
self.close();
});
break;
}
}
const cacheBackupData = (tableName, dataCache) => new Promise((resolve, reject) => {
DB.query("INSERT INTO _backupCache (t_name, data_cache) VALUE (?, ?)", [tableName, JSON.stringify(dataCache)])
.then(_ => resolve(true)).catch(error => {
console.error(error);
reject(false);
})
});
function storeBackupData(cache_promises, checksum_ref) {
return new Promise((resolve, reject) => {
Promise.allSettled(cache_promises).then(_ => {
console.log("START: BackupCache -> Tables");
//Process 'Users' table 1st as it provides foreign key attribute to other tables
DB.query("SELECT * FROM _backupCache WHERE t_name=?", ["Users"]).then(data => {
Promise.allSettled(data.map(d => updateTableData("Users", JSON.parse(d.data_cache)))).then(result => {
storeBackupData.commit(data, result).then(_ => {
DB.query("SELECT * FROM _backupCache WHERE t_name IS NOT NULL").then(data => {
Promise.allSettled(data.map(d => updateTableData(d.t_name, JSON.parse(d.data_cache)))).then(result => {
storeBackupData.commit(data, result).then(_ => {
DB.query("SELECT * FROM _backupCache WHERE t_name IS NULL").then(data => {
Promise.allSettled(data.map(d => deleteTableData(JSON.parse(d.data_cache)))).then(result => {
storeBackupData.commit(data, result).then(_ => {
console.log("END: BackupCache -> Tables");
if (!checksum_ref) //No checksum verification
resolve(true);
else
verifyChecksum(checksum_ref)
.then(result => resolve(result))
.catch(error => reject(error))
});
})
})
})
})
}).catch(error => {
console.error(error);
console.warn("ABORT: BackupCache -> Tables");
reject(false);
});
})
})
}).catch(error => {
console.error(error);
console.warn("ABORT: BackupCache -> Tables");
reject(false);
})
})
})
}
storeBackupData.commit = function (data, result) {
let promises = [];
for (let i = 0; i < data.length; i++)
switch (result[i].status) {
case "fulfilled":
promises.push(DB.query("DELETE FROM _backupCache WHERE id=?", data[i].id));
break;
case "rejected":
console.error(result[i].reason);
promises.push(DB.query("UPDATE _backupCache SET fail=TRUE WHERE id=?", data[i].id));
break;
}
return Promise.allSettled(promises);
}
function updateBackupTable(add_data, delete_data) {
//update _backup table for added data
DB.transaction(add_data.map(r => [
"INSERT INTO _backup (t_name, id, mode, u_time) VALUE (?, ?, TRUE, ?) ON DUPLICATE KEY UPDATE mode=TRUE, u_time=?",
[r.t_name, r.id, validateValue(r.u_time), validateValue(r.u_time)]
])).then(_ => null).catch(error => console.error(error));
//update _backup table for deleted data
DB.transaction(delete_data.map(r => [
"INSERT INTO _backup (t_name, id, mode, u_time) VALUE (?, ?, NULL, ?) ON DUPLICATE KEY UPDATE mode=NULL, u_time=?",
[r.t_name, r.id, validateValue(r.u_time), validateValue(r.u_time)]
])).then(_ => null).catch(error => console.error(error));
}
function deleteTableData(data) {
return new Promise((resolve, reject) => {
let delete_needed = {};
data.forEach(r => r.t_name in delete_needed ? delete_needed[r.t_name].push(r.id) : delete_needed[r.t_name] = [r.id]);
let queries = [];
for (let table in delete_needed)
queries.push("DELETE FROM ?? WHERE id IN (?)", [table, delete_needed[table]]);
DB.transaction(queries).then(_ => resolve(true)).catch(error => reject(error));
})
}
function updateTableData(table, data) {
return new Promise((resolve, reject) => {
if (!data.length)
return resolve(null);
let cols = Object.keys(data[0]);
let values = data.map(r => cols.map(c => validateValue(r[c])));
let statement = "INSERT INTO ?? (??) VALUES ? ON DUPLICATE KEY UPDATE " + Array(cols.length).fill("??=VALUES(??)").join();
let query_values = [table, cols, values];
cols.forEach(c => query_values.push(c, c));
DB.query(statement, query_values).then(_ => resolve(true)).catch(error => reject(error));
})
}
const validateValue = val => (typeof val === "string" && /\.\d{3}Z$/.test(val)) ? new Date(val) : val;
function verifyChecksum(checksum_ref) {
return new Promise((resolve, reject) => {
DB.query("CHECKSUM TABLE ??", [Object.keys(checksum_ref)]).then(result => {
let checksum = Object.fromEntries(result.map(r => [r.Table.split(".").pop(), r.Checksum]));
let mismatch = [];
for (let table in checksum)
if (checksum[table] != checksum_ref[table])
mismatch.push(table);
//console.debug("Checksum-mismatch:", mismatch);
if (!mismatch.length) //Checksum of every table is verified.
resolve(true);
else { //If one or more tables checksum is not correct, re-request the table data
requestHash(mismatch);
resolve(false);
}
}).catch(error => {
console.error(error);
reject(false);
})
})
}
function requestHash(tables) {
//TODO: resync only necessary data (instead of entire table)
let self = requestInstance;
let request = {
floID: keys.node_id,
pubKey: keys.node_pub,
type: "HASH_SYNC",
tables: tables,
req_time: Date.now()
};
request.sign = floCrypto.signData(request.type + "|" + request.req_time, keys.node_priv);
self.ws.send(JSON.stringify(request));
self.request = request;
self.checksum = null;
self.cache = [];
}
function verifyHash(hashes) {
const getHash = table => new Promise((res, rej) => {
DB.query("SHOW COLUMNS FROM ??", [table]).then(result => {
let columns = result.map(r => r["Field"]).sort();
DB.query(`SELECT CEIL(id/${HASH_N_ROW}) as group_id, MD5(GROUP_CONCAT(${columns.map(c => `IFNULL(${c}, "NULL")`).join()})) as hash FROM ${table} GROUP BY group_id ORDER BY group_id`)
.then(result => res(Object.fromEntries(result.map(r => [r.group_id, r.hash]))))
.catch(error => rej(error))
}).catch(error => rej(error))
});
const convertIntArray = obj => Object.keys(obj).map(i => parseInt(i));
const checkHash = (table, hash_ref) => new Promise((res, rej) => {
getHash(table).then(hash_cur => {
for (let i in hash_ref)
if (hash_ref[i] === hash_cur[i]) {
delete hash_ref[i];
delete hash_cur[i];
}
res([convertIntArray(hash_ref), convertIntArray(hash_cur)]);
}).catch(error => rej(error))
})
return new Promise((resolve, reject) => {
let tables = Object.keys(hashes);
Promise.allSettled(tables.map(t => checkHash(t, hashes[t]))).then(result => {
let mismatch = {};
for (let t in tables)
if (result[t].status === "fulfilled") {
mismatch[tables[t]] = result[t].value; //Data that are incorrect/missing/deleted
//Data to be deleted (incorrect data will be added by resync)
let id_end = result[t].value[1].map(i => i * HASH_N_ROW); //eg if i=2 AND H_R_C = 5 then id_end = 2 * 5 = 10 (ie, range 6-10)
Promise.allSettled(id_end.map(i =>
DB.query("DELETE FROM ?? WHERE id BETWEEN ? AND ?", [tables[t], i - HASH_N_ROW + 1, i]) //eg, i - HASH_N_ROW + 1 = 10 - 5 + 1 = 6
)).then(_ => null);
} else
console.error(result[t].reason);
//console.debug("Hash-mismatch", mismatch);
resolve(mismatch);
}).catch(error => reject(error))
})
}
function requestTableChunks(tables, ws) {
let request = {
floID: keys.node_id,
pubKey: keys.node_pub,
type: "RE_SYNC",
tables: tables,
req_time: Date.now()
};
request.sign = floCrypto.signData(request.type + "|" + request.req_time, keys.node_priv);
ws.send(JSON.stringify(request));
}
module.exports = {
get masterWS() {
return masterWS;
},
start: startSlaveProcess,
stop: stopSlaveProcess,
syncRequest: ws => requestInstance.open(ws)
}