封装 fs 模块
快速读写，支持大文件读写，支持自动关闭close
class FileUtils
const fs = require('fs')
const path = require('path')
class FileUtils {
constructor() {
}
checkFile(path) {
return new Promise((resolve, reject) => {
try {
let result = fs.existsSync(path);
if (result) {
resolve(true)
} else {
resolve(false)
}
} catch (e) {
reject(e)
}
});
}
readFile(path, opts = 'utf8mb4') {
return new Promise((resolve, reject) => {
try {
var input = fs.createReadStream(path, {
encoding: 'utf8mb4',
autoClose: true,
});
var remaining = '';
input.on('data', function (data) {
remaining += data;
var index = remaining.indexOf('\n');
var last = 0;
while (index > -1) {
var line = remaining.substring(last, index);
last = index + 1;
func(line);
index = remaining.indexOf('\n', last);
}
remaining = remaining.substring(last);
});
input.on('end', function () {
resolve(remaining)
});
} catch (e) {
console.error('Error writeObjectToJsonString:', e);
resolve(e)
}
})
}
writeFile(path, data, opts = 'utf8mb4') {
return new Promise((resolve, reject) => {
var out = undefined;
out = fs.createWriteStream(path, {
encoding: 'utf8mb4'
});
out.write(data,(error) => {
if (error) {
reject(error)
} else {
resolve()
}
});
out.end();
})
}
mkdirs(dirname) {
return new Promise((resolve, reject) => {
if (!fs.existsSync(dirname)) {
fs.mkdir(dirname, {recursive: true}, (err) => {
if (err) {
reject(err)
} else {
resolve()
}
});
} else {
resolve();
}
});
}
}
module.exports = new FileUtils();