Examples: send data as form

examples/browser.html

@@ -43,7 +43,14 @@ var resultAsUint8Array = pako.deflate(data);
 var resultAsBinString  = pako.deflate(data, { to: 'string' });
 
 
-// Send data to server /////////////////////////////////////////////////////////
+// Send data to server
+//
+// Use multipart/form-data:
+//
+// - small overhead
+// - well known format, easy to process anywhere
+//
+/////////////////////////////////////////////////////////
 
 function sendModern() {
   var xhr = new XMLHttpRequest;
@@ -52,11 +59,13 @@ function sendModern() {
 
   xhr.open('POST', 'http://localhost:8000/', true);
 
-  // We could make this work everywhere, if send data as base64 string.
+  var formData = new FormData(document.forms.person);
-  // But that will add 25% of size.
+  var blob     = new Blob([ resultAsUint8Array ], { type: 'application/octet-stream'});
-  xhr.send(resultAsUint8Array);
 
-  setTimeout(sendModern, 2000);
+  formData.append('binson', blob);
+  xhr.send(formData);
+
+  setTimeout(sendModern, 5000);
 }
 
 function sendAncient() {
@@ -64,10 +73,26 @@ function sendAncient() {
 
   console.log('Sending data in ancient browsers...');
 
-  xhr.open('POST', 'http://localhost:8000/', true);
+  // Emulate form body. But since we can send intact only 7-bit
-  xhr.send(resultAsBinString);
+  // characters, wrap binary data to base64. That will add 30% of size.
+  var boundary = '----' + String(Math.random()).slice(2);
 
-  setTimeout(sendAncient, 2000);
+  var data = '';
+
+  data += '--' + boundary + '\r\n';
+  data += 'Content-Disposition: form-data; name="binson"; filename="blob"\r\n';
+  data += 'Content-Type: application/octet-stream\r\n';
+  data += 'Content-Transfer-Encoding: base64\r\n'
+  data += '\r\n';
+  data += btoa(resultAsBinString) + '\r\n';
+  data += '--' + boundary + '--\r\n';
+
+
+  xhr.open('POST', 'http://localhost:8000/');
+  xhr.setRequestHeader('Content-Type', 'multipart/form-data; boundary=' + boundary);
+  xhr.send(data);
+
+  setTimeout(sendAncient, 5000);
 }
 
 sendModern();

examples/server.js

@@ -2,39 +2,76 @@
 
 /*eslint-disable no-console*/
 
-const http = require('http');
+const http       = require('http');
-const pako = require('../');
+const pako       = require('../');
+const multiparty = require('multiparty');
+const Promise    = require('bluebird');
+const fs         = require('fs');
+
+
+const MULTIPART_RE    = /^multipart\/form-data(?:;|$)/i;
+const MAX_FIELDS_SIZE = 100 * 1024;       // 100kb
+const MAX_FILES_SIZE  = 10 * 1024 * 1024; // 10mb
+
+
+function error(msg) {
+  let e = new Error(msg);
+  e.statusCode = 400;
+  return e;
+}
+
 
 
 const server = http.createServer((req, res) => {
-  var buf = [];
 
-  req.on('data', data => buf.push(data));
+  console.log('--- received request');
 
-  req.on('end', () => {
+  // Quick hack to bypass security restrictions when demo html is opened from
-    console.log('--- received request');
+  // file system. Don't do such things on production.
+  res.setHeader('Access-Control-Allow-Origin', '*');
+
+  Promise.coroutine(function* () {
+    //
+    // Check request size early by header and terminate immediately for big data
+    //
+    let length = parseInt((req.headers['content-length'] || '0'), 10);
+
+    if (!length || isNaN(length)) throw error('Length required');
+
+    if (!MULTIPART_RE.test(req.headers['content-type'])) {
+      throw error('Expect form data');
+    }
+
+    let err = null;
+
+    let form = new multiparty.Form({
+      maxFieldsSize: MAX_FIELDS_SIZE,
+      maxFilesSize: MAX_FILES_SIZE
+    });
+
+    let files = yield new Promise(resolve => {
+      form.parse(req, function (e, fields, files) {
+        if (e) err = e;
+        resolve(files);
+      });
+    });
+
+    if (err) {
+      err.statusCode = err.statusCode || 400;
+      throw err;
+    }
 
     // In ideal world, we should process data as stream to minimize memory use
     // on big data (and use node's `zlib` inflate).
     //
     // But that's just a quick sample to explain data reencoding steps from
     // browser to server. Feel free to improve.
+    let bin = yield Promise.fromCallback(cb => {
+      fs.readFile(files.binson[0].path, cb);
+    });
 
-    // Join all pending chunks.
+    // Kludge - here we should cleanup all files
-    let bin = Buffer.concat(buf);
+    fs.unlinkSync(files.binson[0].path);
-
-    // Test header to understand if data was sent as raw binary (modern browser)
-    // or string (utf8) format. If utf8 - reencode to binary.
-    //
-    // We could also use base64 encoding for strings on client side, but that
-    // needs more libraries for old browsers (for unsupported `window.btoa()`).
-    //
-    // If you don't need IE8/9 support - just drop this part.
-    if (/UTF-8/i.test(String(req.headers['content-type']))) {
-      console.log('--- data has utf-8 encoding');
-
-      bin = Buffer.from(bin.toString(), 'binary');
-    }
 
     // Decompress binary content
     // Note! Can throw error on bad data
@@ -48,17 +85,14 @@ const server = http.createServer((req, res) => {
     let obj = JSON.parse(decoded);
 
     console.log('--- received object is: ', obj);
-
-    // Quick hack to bypass security restrictions when demo html is opened from
-    // file system. Don't do such things on production.
-    res.setHeader('Access-Control-Allow-Origin', '*');
     res.end('ok');
+  })()
+  .catch(err => {
+    console.log(err);
+    res.statusCode = err.statusCode || 400;
+    res.end(err.message);
   });
 
-  req.on('error', () => {
-    res.setHeader('Access-Control-Allow-Origin', '*');
-    res.end('error');
-  });
 });
 
 server.listen(8000);

package.json

@@ -21,20 +21,22 @@
   "license": "MIT",
   "repository": "nodeca/pako",
   "devDependencies": {
-    "mocha": "^3.2.0",
-    "benchmark": "*",
     "ansi": "*",
+    "async": "*",
+    "benchmark": "*",
+    "bluebird": "^3.5.0",
     "browserify": "*",
     "eslint": "^3.12.2",
     "eslint-plugin-nodeca": "~1.0.3",
-    "uglify-js": "*",
-    "istanbul": "*",
-    "ndoc": "*",
-    "lodash": "*",
-    "async": "*",
     "grunt": "^1.0.1",
     "grunt-cli": "^1.2.0",
+    "grunt-contrib-connect": "^1.0.2",
     "grunt-saucelabs": "^9.0.0",
-    "grunt-contrib-connect": "^1.0.2"
+    "istanbul": "*",
+    "lodash": "*",
+    "mocha": "^3.2.0",
+    "multiparty": "^4.1.3",
+    "ndoc": "*",
+    "uglify-js": "*"
   }
 }