Compressing File Uploaded From Multer using Nodejs Zlib - node.js

Question

I am trying to compress an uploaded file using nodejs zlib.The compression works but trying to uncompress it throws an error.I created a compress route which is a post request to upload the file to be compressed:
app.post('/compress', upload.single('file'), (req, res) => {
try {
var streamInstance = new stream.Readable();
const destination = createWriteStream(`compressed/${req.file.originalname}.gz`);
const source = streamInstance.push(Buffer.from(JSON.stringify(req.file)))
res.json(source)
streamInstance.push(null);
pipeline(source, gzip, destination, (err, file) => {
if (err) {
console.log(err)
return res.json('An error occurred:', err);
} else {
console.log({
file: file
})
return res.json(file)
}
})
} catch (err) {
console.log(err)
res.json(err)
}
})
This add the compressed file in the compressed directory but trying to uncompress it throws an error.
Is there another method i could use in compressing this file using zlib?

Answer 1

Multer gives the ability to use the memoryStorage method.So you can get the actual buffer of that file.With that you can use this:
var storage = multer.memoryStorage()
var upload = multer({
storage: storage
})
app.post('/compress', upload.single('file'), async (req, res) => {
try {
const destination = `compressed/${req.file.originalname}.gz`;
await zlib.gzip(req.file.buffer, async (err, response) => {
if (err) {
return res.status(500).json({error:err})
} else {
await fs.appendFile(path.join(__dirname,destination), response, (err, data) => {
if (err) {
return res.status(500).json({error:err})
} else {
res.download(path.join(__dirname,destination),`${req.file.originalname}.gz`);
}
})
}
})
} catch (err) {
console.log(err)
res.json(err)
}
})