enigma-bbs/core/config_cache.js

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/* jslint node: true */
'use strict';
// deps
const paths = require('path');
const fs = require('graceful-fs');
const hjson = require('hjson');
const sane = require('sane');
const _ = require('lodash');
module.exports = new (class ConfigCache {
constructor() {
this.cache = new Map(); // path->parsed config
}
getConfigWithOptions(options, cb) {
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options.hotReload = _.get(options, 'hotReload', true);
const cached = this.cache.has(options.filePath);
if (options.forceReCache || !cached) {
this.recacheConfigFromFile(options.filePath, (err, config) => {
if (!err && !cached) {
if (options.hotReload) {
const watcher = sane(paths.dirname(options.filePath), {
glob: `**/${paths.basename(options.filePath)}`,
});
watcher.on('change', (fileName, fileRoot) => {
require('./logger.js').log.info(
{ fileName, fileRoot },
'Configuration file changed; re-caching'
);
this.recacheConfigFromFile(
paths.join(fileRoot, fileName),
err => {
if (!err) {
if (options.callback) {
options.callback({
fileName,
fileRoot,
configCache: this,
});
}
}
}
);
});
}
}
return cb(err, config, true);
});
} else {
return cb(null, this.cache.get(options.filePath), false);
}
}
getConfig(filePath, cb) {
return this.getConfigWithOptions({ filePath }, cb);
}
recacheConfigFromFile(path, cb) {
fs.readFile(path, { encoding: 'utf-8' }, (err, data) => {
if (err) {
return cb(err);
}
let parsed;
try {
parsed = hjson.parse(data);
this.cache.set(path, parsed);
} catch (e) {
try {
require('./logger.js').log.error(
{ filePath: path, error: e.message },
'Failed to re-cache'
);
} catch (ignored) {
// nothing - we may be failing to parse the config in which we can't log here!
}
return cb(e);
}
return cb(null, parsed);
});
}
})();