lix-website/themes/lix/assets/bootstrap/node_modules/log4js/lib/clustering.js

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2024-04-27 03:39:10 +00:00
const debug = require('debug')('log4js:clustering');
const LoggingEvent = require('./LoggingEvent');
const configuration = require('./configuration');
let disabled = false;
let cluster = null;
try {
// eslint-disable-next-line global-require
cluster = require('cluster');
} catch (e) {
debug('cluster module not present');
disabled = true;
}
const listeners = [];
let pm2 = false;
let pm2InstanceVar = 'NODE_APP_INSTANCE';
const isPM2Master = () => pm2 && process.env[pm2InstanceVar] === '0';
const isMaster = () =>
disabled || (cluster && cluster.isMaster) || isPM2Master();
const sendToListeners = (logEvent) => {
listeners.forEach((l) => l(logEvent));
};
// in a multi-process node environment, worker loggers will use
// process.send
const receiver = (worker, message) => {
// prior to node v6, the worker parameter was not passed (args were message, handle)
debug('cluster message received from worker ', worker, ': ', message);
if (worker.topic && worker.data) {
message = worker;
worker = undefined;
}
if (message && message.topic && message.topic === 'log4js:message') {
debug('received message: ', message.data);
const logEvent = LoggingEvent.deserialise(message.data);
sendToListeners(logEvent);
}
};
if (!disabled) {
configuration.addListener((config) => {
// clear out the listeners, because configure has been called.
listeners.length = 0;
({
pm2,
disableClustering: disabled,
pm2InstanceVar = 'NODE_APP_INSTANCE',
} = config);
debug(`clustering disabled ? ${disabled}`);
debug(`cluster.isMaster ? ${cluster && cluster.isMaster}`);
debug(`pm2 enabled ? ${pm2}`);
debug(`pm2InstanceVar = ${pm2InstanceVar}`);
debug(`process.env[${pm2InstanceVar}] = ${process.env[pm2InstanceVar]}`);
// just in case configure is called after shutdown
if (pm2) {
process.removeListener('message', receiver);
}
if (cluster && cluster.removeListener) {
cluster.removeListener('message', receiver);
}
if (disabled || config.disableClustering) {
debug('Not listening for cluster messages, because clustering disabled.');
} else if (isPM2Master()) {
// PM2 cluster support
// PM2 runs everything as workers - install pm2-intercom for this to work.
// we only want one of the app instances to write logs
debug('listening for PM2 broadcast messages');
process.on('message', receiver);
} else if (cluster && cluster.isMaster) {
debug('listening for cluster messages');
cluster.on('message', receiver);
} else {
debug('not listening for messages, because we are not a master process');
}
});
}
module.exports = {
onlyOnMaster: (fn, notMaster) => (isMaster() ? fn() : notMaster),
isMaster,
send: (msg) => {
if (isMaster()) {
sendToListeners(msg);
} else {
if (!pm2) {
msg.cluster = {
workerId: cluster.worker.id,
worker: process.pid,
};
}
process.send({ topic: 'log4js:message', data: msg.serialise() });
}
},
onMessage: (listener) => {
listeners.push(listener);
},
};