Uncompress gzipped http request body to json in Node.js - node.js

Question

I have a windows 8 application connecting to a web service written in Node.js. On the windows 8 side I compressed my request body to gzip. But on the Node.js side I found that my req.body type was Object.
I cannot use zlib to uncomporess the body since it's not a stream.
I can use zlib to uncomporess the req, but I don't know how to retrieve the req.body content from the unzipped stream and parse the body in JSON format.
BTW, I reviewed my request through Fiddler and it told me the request body was gzipped, and I can see my raw body through Fiddler after unzipped so the request should be correct.
Updated
Below is my Node.js app
(function () {
var express = require("express");
var zlib = require("zlib");
var app = express();
var port = 12345;
app.configure(function () {
app.use(express.compress());
app.use(express.bodyParser());
});
app.post("/test", function (req, res) {
var request = req.body;
req.pipe(zlib.createGunzip());
var response = {
status: 0,
value: "OK"
};
res.send(200, response);
});
console.log("started at port %d", port);
app.listen(port);
})();
And below is my windows store app code (partial)
private async void button1_Click_1(object sender, RoutedEventArgs e)
{
var message = new
{
Name = "Shaun",
Value = "12345678901234567890123456789012345678901234567890"
};
var json = await JsonConvert.SerializeObjectAsync(message, Formatting.Indented);
var bytes = Encoding.UTF8.GetBytes(json);
var client = new HttpClient();
client.BaseAddress = new Uri("http://192.168.56.1:12345/");
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
client.DefaultRequestHeaders.ExpectContinue = false;
var jsonContent = new JsonContent(message);
var gzipContent = new GZipContent3(jsonContent);
var res = await client.PostAsync("test", gzipContent);
var dialog = new Windows.UI.Popups.MessageDialog(":)", "完成");
await dialog.ShowAsync();
}
internal class GZipContent3 : ByteArrayContent
{
public GZipContent3(HttpContent content)
: base(LoadGZipBytes(content))
{
//base.Headers.ContentType = content.Headers.ContentType;
base.Headers.ContentType = new MediaTypeHeaderValue("x-application/x-gzip");
base.Headers.ContentEncoding.Add("gzip");
}
private static byte[] LoadGZipBytes(HttpContent content)
{
var source = content.ReadAsByteArrayAsync().Result;
byte[] buffer;
using (var outStream = new MemoryStream())
{
using (var gzip = new GZipStream(outStream, CompressionMode.Compress, true))
{
gzip.Write(source, 0, source.Length);
}
buffer = outStream.ToArray();
}
return buffer;
}
}
internal class JsonContent : StringContent
{
private const string defaultMediaType = "application/json";
public JsonContent(string json)
: base(json)
{
var mediaTypeHeaderValue = new MediaTypeHeaderValue(defaultMediaType);
mediaTypeHeaderValue.CharSet = Encoding.UTF8.WebName;
base.Headers.ContentType = mediaTypeHeaderValue;
}
public JsonContent(object content)
: this(GetJson(content))
{
}
private static string GetJson(object content)
{
if (content == null)
{
throw new ArgumentNullException("content");
}
var json = JsonConvert.SerializeObject(content, Formatting.Indented);
return json;
}
}

Answer 1

http://www.senchalabs.org/connect/json.html. Basically you need to write your own middleware based on connect.json() that pipes through an uncompression stream like connect.compress() but the opposite direction: http://www.senchalabs.org/connect/compress.html
Also, make sure you're sending the correct Content-Encoding header in your request.
If you show me what you have so far I can help you further.

Answer 2

I was working on similar thing and finally landed on
function getGZipped(req, callback) {
var gunzip = zlib.createGunzip();
req.pipe(gunzip);
var buffer = [];
gunzip.on('data', function (data) {
// decompression chunk ready, add it to the buffer
buffer.push(data);
}).on('end', function () {
//response and decompression complete, join the buffer and return
callback(null, JSON.parse(buffer));
}).on('error', function (e) {
callback(e);
});
}