Node JS processes pictures asynchronously and JSON text asynchronously

 node-js Processing pictures asynchronously , Asynchronous processing json Text

var path = require("path");
var fs = require("fs");
// Create directory 
function mkdirsSync(dirname) {
    if (fs.existsSync(dirname)) {
        return true;
    } else {
        if (mkdirsSync(path.dirname(dirname))) {
            fs.mkdirSync(dirname);
            return true;
        }
    }
}
let outdir = path.join(__dirname, 'out');
mkdirsSync(outdir);
/**  Assignment copy move  A to B */
function copyFile(fromUrl, outUrl) {
    let file = fs.createReadStream(fromUrl);
    let out = fs.createWriteStream(outUrl);
    file.pipe(out);
}

/**  Rename  */
function rename(oldName) {
    let newName = '';
    let names = oldName.split(".")
    for (let i = 0; i < names[0].length; i++) {
        if (/^[a-zA-Z]*$/.test(names[0][i])) {// There are letters , The obtained string is cleared from 
            newName = '';
        } else {
            newName += names[0][i];
        }
    }
    newName = Number(newName) - 6444;// rename ,8000->1556
    if (names[1]) {
        return `RND${newName}.${names[1]}`;
    }
    return `${newName}`;
}

// __dirname  Current working directory  
/**  Processing images   and  json file  */
var dirPath = path.join(__dirname, "img");
let fileNames = fs.readdirSync(dirPath);
let pngArr = [];
let jsonArr = []
for (let i = 0; i < fileNames.length; i++) {
    let extname = path.extname(path.join(dirPath, fileNames[i]));
    if (extname == ".png") {// Processing images , rename , And copy it to a new path 
        pngArr.push(fileNames[i]);
    } else {
        jsonArr.push(fileNames[i]);
    }
}
let __time = new Date().getTime();
let _png = 0;
let _json = 0;
/**  Copy pictures asynchronously , When one image is copied, the next image is processed  */
var copyPngfile = () => {
    let pngName = pngArr[_png];
    if (!pngName) {
        console.log(` Co processing files ${_png + _json} individual ,png file ${_png} individual . Total time ： ${new Date().getTime() - __time}`);
        return;
    }
    let _time = new Date().getTime();
    let newName = rename(pngName);
    let file = fs.createReadStream(path.join(dirPath, pngName));
    let out = fs.createWriteStream(path.join(outdir, newName));
    out.on("finish", () => {
        console.log("Png  Time consuming ： ", new Date().getTime() - _time, "    Total time ： ", new Date().getTime() - __time);
        _png++;
        copyPngfile();
    })
    file.pipe(out);
}
copyPngfile();

/**  Processing files asynchronously , After processing one file, you can process another file  */
var copyOtherfile = () => {
    let fileName = jsonArr[_json];
    if (!fileName) {
        console.log(` Co processing files ${_png + _json} individual , no suffix json${_json} individual . Total time ： ${new Date().getTime() - __time}`);
        return;
    }
    let newName = rename(fileName);
    let _time = new Date().getTime();
    fs.readFile(path.join(dirPath, fileName),  "utf-8", (err, res) => {
        let content;
        try {
            content = JSON.parse(res);
            content.name = `#VCR ${newName}`;
            content.image = `https://d9lekpvd0q3e4.cloudfront.net/img/RND${newName}.png`
        } catch(e) {
            content = res;
        }
        fs.writeFile(path.join(outdir, newName), JSON.stringify(content), "utf-8", (err) => {
            if (err) {
                console.error(err);
            }
            console.log("Other  Time consuming ： ", new Date().getTime() - _time, "    Total time ： ", new Date().getTime() - __time);
            _json++;
            copyOtherfile();
        });
    })
}
copyOtherfile();

json file 8000.json

{"name":"#VCR 8000","description":"We aim to be the Top crypto poker platform.The LIMITED collection of 10,000 unique NFTs  will be the key to bond the community. The full version game itself will be launched no less than Q3 2022 with profit sharing scheme.","attributes":[{"trait_type":"background","value":"1"},{"trait_type":"behind","value":"24 "},{"trait_type":"body","value":"Franky"},{"trait_type":"expression","value":"Franky1"},{"trait_type":"tie","value":"necklace 8"},{"trait_type":"coat","value":"1"},{"trait_type":"hair","value":"1"},{"trait_type":"hand","value":"1"},{"trait_type":"hand-hold","value":"1"}],"image":"https://d9lekpvd0q3e4.cloudfront.net/img/RND8000.png"}

picture 8000.json