ramirez/src/jsonDb.js

69 lines
1.4 KiB
JavaScript

const fs = require('fs');
const path = require('path');
const config = require('../config');
const dbDir = config.dbDir || `${__dirname}/../db`;
const databases = {};
class JSONDB {
constructor(path, def = {}, useCloneByDefault = false) {
this.path = path;
this.useCloneByDefault = useCloneByDefault;
this.load = new Promise(resolve => {
fs.readFile(path, {encoding: 'utf8'}, (err, data) => {
if (err) return resolve(def);
let unserialized;
try { unserialized = JSON.parse(data); }
catch (e) { unserialized = def; }
resolve(unserialized);
});
});
}
get(clone) {
if (clone == null) clone = this.useCloneByDefault;
return this.load.then(data => {
if (clone) return JSON.parse(JSON.stringify(data));
else return data;
});
}
save(newData) {
const serialized = JSON.stringify(newData);
this.load = new Promise((resolve, reject) => {
fs.writeFile(this.path, serialized, {encoding: 'utf8'}, () => {
resolve(newData);
});
});
return this.get();
}
}
function getDb(dbName, def) {
if (! databases[dbName]) {
const dbPath = path.resolve(dbDir, `${dbName}.json`);
databases[dbName] = new JSONDB(dbPath, def);
}
return databases[dbName];
}
function get(dbName, def) {
return getDb(dbName, def).get();
}
function save(dbName, data) {
return getDb(dbName, data).save(data);
}
module.exports = {
get,
save,
};