From 52360efd207bec90b10256071eb3ffb72028715c Mon Sep 17 00:00:00 2001
From: Alexandre Felipe <o.alexandre.felipe@gmail.com>
Date: Fri, 2 Dec 2022 16:17:50 +0000
Subject: [PATCH] Informatino about library download size

---
 scripts/wasm_transport_info.js | 153 +++++++++++++++++++++++++++++++++
 1 file changed, 153 insertions(+)
 create mode 100644 scripts/wasm_transport_info.js

diff --git a/scripts/wasm_transport_info.js b/scripts/wasm_transport_info.js
new file mode 100644
index 000000000..61e8e47df
--- /dev/null
+++ b/scripts/wasm_transport_info.js
@@ -0,0 +1,153 @@
+// server example
+// https://nodejs.org/api/zlib.html#compressing-http-requests-and-responses
+// Running a gzip operation on every request is quite expensive.
+// It would be much more efficient to cache the compressed buffer.
+const zlib = require('node:zlib');
+const http = require('node:http');
+const fs = require('node:fs');
+const { pipeline, Duplex, Writable, Transform } = require('node:stream');
+
+class ByteCounter extends Transform {
+  constructor(options){
+    super(options)
+    this.byteLength = 0
+  }
+  _transform(chunk, encoding, callback){
+    this.byteLength += chunk.byteLength;
+    this.push(chunk, encoding);
+    callback(null)
+  }
+}
+
+class NullSinc extends Writable {
+  _write(chunk, encoding, callback){
+    callback(null)
+  }
+}
+
+
+
+function retrieveFile(path, acceptEncoding){
+  const raw = fs.createReadStream(__dirname + '/../lib/build/wasm' + path);
+  const onError = (err) => {
+    if (err) {
+      // If an error occurs, there's not much we can do because
+      // the server has already sent the 200 response code and
+      // some amount of data has already been sent to the client.
+      // The best we can do is terminate the response immediately
+      // and log the error.
+      content.end();
+      console.error('An error occurred:', err);
+    }
+  };
+  
+  const uncompressed = new ByteCounter()
+  const content = new ByteCounter()
+  let encoding;
+  // Note: This is not a conformant accept-encoding parser.
+  // See https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.3
+  if (/\bbr\b/.test(acceptEncoding)) {
+    encoding = 'br'
+    pipeline(raw, uncompressed, zlib.createBrotliCompress(),  content, onError);
+  } else if (/\bdeflate\b/.test(acceptEncoding)) {
+    encoding = 'deflate'
+    pipeline(raw, uncompressed, zlib.createDeflate(), content, onError);
+  } else if (/\bgzip\b/.test(acceptEncoding)) {
+    encoding = 'gzip'
+    pipeline(raw, uncompressed, zlib.createGzip(), content, onError);
+  } else {
+    encoding = 'identity'
+    pipeline(raw, uncompressed, content, onError);
+  }
+  content.once('end', () => {
+    console.log(`${path}, ${encoding}, size: ${content.byteLength}`)
+  })
+  return {content, encoding}
+}
+function getTime(){
+  const [sec, nsec] = process.hrtime()
+  return sec + 1e-9*nsec
+}
+async function compare() {
+  const sizeTable = {}
+  const timeTable = {}
+  for(const mode of ['relperf', 'relsize', 'dev']){
+    for(const feature of ['coi', 'eh', 'mvp']){
+      const key = `${mode}-${feature}`;
+      sizeTable[key] = {}
+      timeTable[key] = {}
+      for(const encoding of ['br', 'gzip', 'deflate', 'identity']){
+        console.time(key + ' ' + encoding)
+        try{
+          const nl = new NullSinc()
+          const t0 = getTime()
+          const {content} = retrieveFile(`/${key}/duckdb_wasm.wasm`, encoding)
+          content.pipe(nl);
+          await new Promise(resolve => content.once('end', resolve))
+          timeTable[key][encoding] = getTime() - t0;
+          sizeTable[key][encoding] = content.byteLength;  
+        }catch(e) {
+          console.log(e)
+          console.log(`${key} ${encoding} failed`)
+        }
+        console.timeEnd(key + ' ' + encoding)
+      }
+    }
+  }
+  console.log('Writing results to to misc/compression.json')
+  fs.writeFileSync(__dirname + '/../misc/compression.json', 
+    JSON.stringify({size: sizeTable, time: timeTable}, null, 2))
+}
+
+if(process.argv.includes('--compare')){
+  compare()
+}
+
+// If you want to check it externally
+
+let port = +process.env['PORT'] || 1337
+if(process.argv.includes('--port')){
+  port = process.argv[process.argv.indexOf('--port')]
+}
+
+if(process.argv.includes('--serve')){
+  http.createServer((request, response) => {
+    // Store both a compressed and an uncompressed version of the resource.
+    let acceptEncoding = request.headers['accept-encoding'];
+    if (!acceptEncoding) {
+      acceptEncoding = '';
+    }
+    const [path, queryEncoding] = request.url.split('?')
+    console.log(request.url, acceptEncoding)
+    const {content, encoding} = retrieveFile(path, queryEncoding || acceptEncoding)
+    response.writeHead(200, {
+      'Content-Encoding': encoding, 
+      'Access-Control-Allow-Origin': "*",
+      'Vary': "Accept-Encoding"
+    })
+    content.pipe(response);
+  
+  }).listen(port);
+
+  // To test the serve you could do something like
+  // curl -H --compressed 'Accept-Encoding: gzip' 127.0.0.1:1337/relperf-coi/duckdb_wasm.wasm | wc -c
+  // curl -H 'Accept-Encoding: gzip' 127.0.0.1:1337/relperf-coi/duckdb_wasm.wasm | wc -c
+  // curl -H 'Accept-Encoding: br' 127.0.0.1:1337/relperf-coi/duckdb_wasm.wasm | wc -c
+  // 
+  // You could also test it from a browser
+  async function _checkIntegrity(){
+    const ref = await (await fetch('http://127.0.0.1:1337/relperf-coi/duckdb_wasm.wasm?identity')).text()
+    
+    if(ref !== await (await fetch('http://127.0.0.1:1337/relperf-coi/duckdb_wasm.wasm?br')).text()){
+      console.log('Brotli encoding failed')
+    }
+  
+    if(ref !== await (await fetch('http://127.0.0.1:1337/relperf-coi/duckdb_wasm.wasm?deflate')).text()){
+      console.log('Deflate failed')
+    }
+  
+    if(ref !== await (await fetch('http://127.0.0.1:1337/relperf-coi/duckdb_wasm.wasm?gzip')).text()){
+      console.log('gzip failed')
+    }
+  }
+}