Code files

Chapter09/async-opt/calculate-average.js

@@ -0,0 +1,23 @@
+'use strict'
+
+const MongoClient = require('mongodb').MongoClient
+const url = 'mongodb://localhost:27017/test';
+var count = 0
+var max = 1000
+
+MongoClient.connect(url, function(err, db) {
+  if (err) { throw err }
+  const collection = db.collection('data')
+  const average = db.collection('averages')
+
+  collection.find({}).toArray(function (err, data) {
+    if (err) { throw err }
+    average.insert({
+      value: data.reduce((acc, v) => acc + v, 0) / data.length
+    }, function (err) {
+      if (err) { throw err }
+      db.close()
+    })
+  })
+})
+

Chapter09/async-opt/load.js

@@ -0,0 +1,26 @@
+'use strict'
+
+const MongoClient = require('mongodb').MongoClient
+const url = 'mongodb://localhost:27017/test';
+var count = 0
+var max = 1000
+
+MongoClient.connect(url, function(err, db) {
+  if (err) { throw err }
+  const collection = db.collection('data')
+
+  function insert (err) {
+    if (err) throw err
+
+    if (count++ === max) {
+      return db.close()
+    }
+
+    collection.insert({
+      value: Math.random() * 1000000
+    }, insert)
+  }
+
+  insert()
+})
+

Chapter09/async-opt/package.json

@@ -0,0 +1,17 @@
+{
+  "name": "async-opt",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "express": "^4.14.0",
+    "fastq": "^1.4.1",
+    "lru-cache": "^4.0.1",
+    "mongodb": "^2.1.18"
+  }
+}

Chapter09/async-opt/server-average.js

@@ -0,0 +1,19 @@
+'use strict'
+
+const MongoClient = require('mongodb').MongoClient
+const express = require('express')
+const app = express()
+
+var url = 'mongodb://localhost:27017/test';
+
+MongoClient.connect(url, function(err, db) {
+  if (err) { throw err }
+  const collection = db.collection('data')
+  app.get('/hello', (req, res) => {
+    collection.findOne({}, function sum (err, data) {
+      res.send('' + data.value)
+    })
+  })
+
+  app.listen(3000)
+})

Chapter09/async-opt/server-cache.js

@@ -0,0 +1,56 @@
+'use strict'
+
+const MongoClient = require('mongodb').MongoClient
+const express = require('express')
+const LRU = require('lru-cache')
+const fastq = require('fastq')
+const app = express()
+
+var url = 'mongodb://localhost:27017/test';
+
+function sum (data) {
+  var sum = 0
+  const l = data.length
+  for (var i = 0; i < l; i++) {
+    sum += data[i].value
+  }
+  return sum
+}
+
+MongoClient.connect(url, function(err, db) {
+  if (err) { throw err }
+  const collection = db.collection('data')
+  const queue = fastq(work)
+  const cache = LRU({
+    maxAge: 1000 * 5 // 5 seconds
+  })
+
+  function work (req, done) {
+    const elem = cache.get('average')
+    if (elem) {
+      done(null, elem)
+      return
+    }
+    collection.find({}).toArray(function (err, data) {
+      if (err) {
+        done(err)
+        return
+      }
+      const result = sum(data) / data.length
+      cache.set('average', result)
+      done(null, result)
+    })
+  }
+
+  app.get('/hello', (req, res) => {
+    queue.push(req, function (err, result) {
+      if (err) {
+        res.send(err.message)
+        return
+      }
+      res.send('' + result)
+    })
+  })
+
+  app.listen(3000)
+})

Chapter09/async-opt/server-no-reduce.js

@@ -0,0 +1,29 @@
+'use strict'
+
+const MongoClient = require('mongodb').MongoClient
+const express = require('express')
+const app = express()
+
+var url = 'mongodb://localhost:27017/test'
+
+MongoClient.connect(url, function(err, db) {
+  if (err) { throw err }
+  const collection = db.collection('data')
+  app.get('/hello', (req, res) => {
+    collection.find({}).toArray(function sum (err, data) {
+      if (err) {
+        res.send(err)
+        return
+      }
+      var sum = 0
+      const l = data.length
+      for (var i = 0; i < l; i++) {
+        sum += data[i].value
+      }
+      const result = sum / data.length
+      res.send('' + result)
+    })
+  })
+
+  app.listen(3000)
+})

Chapter09/async-opt/server-one-sum-fn.js

@@ -0,0 +1,33 @@
+'use strict'
+
+const MongoClient = require('mongodb').MongoClient
+const express = require('express')
+const app = express()
+
+var url = 'mongodb://localhost:27017/test';
+
+function sum (data) {
+  var sum = 0
+  const l = data.length
+  for (var i = 0; i < l; i++) {
+    sum += data[i].value
+  }
+  return sum
+}
+
+MongoClient.connect(url, function(err, db) {
+  if (err) { throw err }
+  const collection = db.collection('data')
+  app.get('/hello', (req, res) => {
+    collection.find({}).toArray(function (err, data) {
+      if (err) {
+        res.send(err)
+        return
+      }
+      const result = sum(data) / data.length
+      res.send('' + result)
+    })
+  })
+
+  app.listen(3000)
+})

Chapter09/async-opt/server.js

@@ -0,0 +1,26 @@
+'use strict'
+
+const MongoClient = require('mongodb').MongoClient
+const express = require('express')
+const app = express()
+
+var url = 'mongodb://localhost:27017/test';
+
+
+MongoClient.connect(url, function(err, db) {
+  if (err) { throw err }
+  const collection = db.collection('data')
+  app.get('/hello', (req, res) => {
+    collection.find({}).toArray(function sum (err, data) {
+      if (err) {
+        res.send(err)
+        return
+      }
+      const total = data.reduce((acc, d) => acc + d.value, 0)
+      const result = total / data.length
+      res.send('' + result)
+    })
+  })
+
+  app.listen(3000)
+})

Chapter09/async-opt/server2.js

@@ -0,0 +1,27 @@
+'use strict'
+
+const MongoClient = require('mongodb').MongoClient
+const express = require('express')
+const app = express()
+
+var url = 'mongodb://localhost:27017/test';
+
+
+MongoClient.connect(url, function(err, db) {
+  if (err) { throw err }
+  const collection = db.collection('data')
+  app.get('/hello', (req, res) => {
+    var count = 0
+    var result = 0
+    collection.find({})
+      .on('data', function (chunk) {
+        count++
+        result += chunk.value
+      })
+      .on('end', function () {
+        res.send('' + (result / count))
+      })
+  })
+
+  app.listen(3000)
+})

Chapter09/bench-http/measuring-post-performance/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "bench-http",
+  "version": "0.0.1",
+  "description": "",
+  "main": "server.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "",
+  "license": "UNLICENSED",
+  "dependencies": {
+    "body-parser": "^1.15.2",
+    "express": "^4.13.4"
+  }
+}

Chapter09/bench-http/measuring-post-performance/server.js

@@ -0,0 +1,14 @@
+'use strict'
+
+const express = require('express')
+const bodyParser = require('body-parser')
+const app = express()
+
+app.use(bodyParser.json())
+app.use(bodyParser.urlencoded({extended: false}))
+
+app.post('/echo', (req, res) => {
+  res.send(req.body)
+})
+
+app.listen(3000)

Chapter09/bench-http/package.json

@@ -0,0 +1,14 @@
+{
+  "name": "bench-http",
+  "version": "0.0.1",
+  "description": "",
+  "main": "server.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "",
+  "license": "UNLICENSED",
+  "dependencies": {
+    "express": "^4.13.4"
+  }
+}

Chapter09/bench-http/profiling-for-production/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "bench-http",
+  "version": "0.0.1",
+  "description": "",
+  "main": "server.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "",
+  "license": "UNLICENSED",
+  "dependencies": {
+    "express": "^4.13.4",
+    "jade": "^1.11.0"
+  }
+}

Chapter09/bench-http/profiling-for-production/server.js

@@ -0,0 +1,14 @@
+'use strict'
+
+const express = require('express')
+const path = require('path')
+const app = express()
+
+app.set('views', path.join(__dirname, 'views'));
+app.set('view engine', 'jade');
+
+app.get('/hello', (req, res) => {
+  res.render('hello', { title: 'Express' });
+})
+
+app.listen(3000)

Chapter09/bench-http/profiling-for-production/views/hello.jade

@@ -0,0 +1,7 @@
+doctype html
+html
+  head
+    title= title
+    link(rel='stylesheet', href='/stylesheets/style.css')
+  body
+    h1= title

Chapter09/bench-http/server.js

@@ -0,0 +1,10 @@
+'use strict'
+
+const express = require('express')
+const app = express()
+
+app.get('/hello', (req, res) => {
+  res.send('hello world')
+})
+
+app.listen(3000)

Chapter09/hello-server/package.json

@@ -0,0 +1,16 @@
+{
+  "name": "hello-server",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "David Mark Clements",
+  "license": "MIT",
+  "dependencies": {
+    "express": "^4.14.0",
+    "jade": "^1.11.0"
+  }
+}

Chapter09/hello-server/server.js

@@ -0,0 +1,12 @@
+const express = require('express')
+const path = require('path')
+const app = express()
+
+app.set('views', path.join(__dirname, 'views'));
+app.set('view engine', 'jade');
+
+app.get('/hello', (req, res) => {
+  res.render('hello', { title: 'Express' });
+})
+
+app.listen(3000)

Chapter09/hello-server/views/hello.jade

@@ -0,0 +1,7 @@
+doctype html
+html
+  head
+    title= title
+    link(rel='stylesheet', href='/stylesheets/style.css')
+  body
+    h1= title

Chapter09/name-server/climem-enabled/index.js

@@ -0,0 +1,16 @@
+const http = require('http')
+const starwarsName = require('starwars-names').random
+const names = {}
+
+http.createServer((req, res) => {
+  res.end(`Your unique name is:  ${createName(req)} \n`)
+}).listen(8080)
+
+function createName () {
+  var result = starwarsName()
+  if (names[result]) {
+    result += names[result]++
+  }
+  names[result] = 1
+  return result
+}

Chapter09/name-server/climem-enabled/package.json

@@ -0,0 +1,18 @@
+{
+  "name": "name-server",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "David Mark Clements",
+  "license": "MIT",
+  "dependencies": {
+    "starwars-names": "^1.6.0"
+  },
+  "devDependencies": {
+    "climem": "^1.0.2"
+  }
+}

Chapter09/name-server/index.js

@@ -0,0 +1,16 @@
+const http = require('http')
+const starwarsName = require('starwars-names').random
+const names = {}
+
+http.createServer((req, res) => {
+  res.end(`Your unique name is:  ${createName(req)} \n`)
+}).listen(8080)
+
+function createName () {
+  var result = starwarsName()
+  if (names[result]) {
+    result += names[result]++
+  }
+  names[result] = 1
+  return result
+}

Chapter09/name-server/non-leaky/index.js

@@ -0,0 +1,15 @@
+const http = require('http')
+const starwarsName = require('starwars-names').random
+const names = {}
+
+http.createServer((req, res) => {
+  res.end(`Your unique name is:  ${createName(req)} \n`)
+}).listen(8080)
+
+function createName () {
+  var result = starwarsName()
+  names[result] = names[result] ? 
+    names[result] + 1 :
+    1
+  return result + names[result]
+}

Chapter09/name-server/non-leaky/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "name-server",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "David Mark Clements",
+  "license": "MIT",
+  "dependencies": {
+    "sillyname": "^0.1.0"
+  }
+}

Chapter09/name-server/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "name-server",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "David Mark Clements",
+  "license": "MIT",
+  "dependencies": {
+    "starwars-names": "^1.6.0"
+  }
+}

Chapter09/sync-opt/bench.js

@@ -0,0 +1,33 @@
+'use strict'
+
+const benchmark = require('benchmark')
+const slow = require('./slow')
+const noCollection = require('./no-collections')
+
+const suite = new benchmark.Suite()
+
+const numbers = []
+
+for (let i = 0; i < 1000; i++) {
+  numbers.push(Math.random() * i)
+}
+
+suite.add('slow', function () {
+  slow(12, numbers)
+})
+
+suite.add('no-collections', function () {
+  noCollection(12, numbers)
+})
+
+suite.on('complete', print)
+
+suite.run()
+
+function print () {
+  for (var i = 0; i < this.length; i++) {
+    console.log(this[i].toString())
+  }
+
+  console.log('Fastest is', this.filter('fastest').map('name')[0])
+}

Chapter09/sync-opt/checking-optimization-status/bench.js

@@ -0,0 +1,42 @@
+'use strict'
+
+const benchmark = require('benchmark')
+const slow = require('./slow')
+const noCollection = require('./no-collections')
+const noTryCatch = require('./no-try-catch')
+const funcStatus = require('./func-status')
+
+const suite = new benchmark.Suite()
+
+const numbers = []
+
+for (let i = 0; i < 1000; i++) {
+  numbers.push(Math.random() * i)
+}
+
+suite.add('slow', function () {
+  slow(12, numbers)
+})
+
+suite.add('no-collections', function () {
+  noCollection(12, numbers)
+})
+
+suite.add('no-try-catch', function () {
+  noTryCatch(12, numbers)
+})
+
+suite.on('complete', print)
+
+suite.run()
+
+function print () {
+  for (var i = 0; i < this.length; i++) {
+    console.log(this[i].toString())
+  }
+  funcStatus('slow', slow)
+  funcStatus('noCollection', noCollection)
+  funcStatus('noTryCatch', noTryCatch)
+
+  console.log('Fastest is', this.filter('fastest').map('name')[0])
+}

Chapter09/sync-opt/checking-optimization-status/func-status.js

@@ -0,0 +1,15 @@
+'use strict'
+
+function printStatus (name, fn) {
+  switch(%GetOptimizationStatus(fn)) {
+    case 1: console.log(`${name} function is optimized`); break;
+    case 2: console.log(`${name} function is not optimized`); break;
+    case 3: console.log(`${name} function is always optimized`); break;
+    case 4: console.log(`${name} function is never optimized`); break;
+    case 6: console.log(`${name} function is maybe deoptimized`); break;
+    case 7: console.log(`${name} function is optimized by TurboFan`); break;
+    default: console.log(`${name} function optimization status unknown`); break;
+  }
+}
+
+module.exports = printStatus

Chapter09/sync-opt/checking-optimization-status/no-collections-vs-no-try-catch.js

@@ -0,0 +1,28 @@
+'use strict'
+
+const benchmark = require('benchmark')
+const noCollection = require('./no-collections')
+
+const suite = new benchmark.Suite()
+
+const numbers = []
+
+for (let i = 0; i < 1000; i++) {
+  numbers.push(Math.random() * i)
+}
+
+suite.add('no-collections', function () {
+  noCollection(12, numbers)
+})
+
+suite.on('complete', print)
+
+suite.run()
+
+function print () {
+  for (var i = 0; i < this.length; i++) {
+    console.log(this[i].toString())
+  }
+
+  console.log('Fastest is', this.filter('fastest').map('name')[0])
+}

Chapter09/sync-opt/checking-optimization-status/no-collections.js

@@ -0,0 +1,15 @@
+'use strict'
+
+function divideByAndSum (num, array) {
+  var result = 0
+  try {
+    for (var i = 0; i < array.length; i++) {
+      result += array[i] / num
+    }
+  } catch (err) {
+    // to guard for division by zero
+    return 0
+  }
+}
+
+module.exports = divideByAndSum

Chapter09/sync-opt/checking-optimization-status/no-try-catch-bench.js

@@ -0,0 +1,28 @@
+'use strict'
+
+const benchmark = require('benchmark')
+const noTryCatch = require('./no-try-catch')
+
+const suite = new benchmark.Suite()
+
+const numbers = []
+
+for (let i = 0; i < 1000; i++) {
+  numbers.push(Math.random() * i)
+}
+
+suite.add('no-try-catch', function () {
+  noTryCatch(12, numbers)
+})
+
+suite.on('complete', print)
+
+suite.run()
+
+function print () {
+  for (var i = 0; i < this.length; i++) {
+    console.log(this[i].toString())
+  }
+
+  console.log('Fastest is', this.filter('fastest').map('name')[0])
+}

Chapter09/sync-opt/checking-optimization-status/no-try-catch.js

@@ -0,0 +1,17 @@
+'use strict'
+
+function divideByAndSum (num, array) {
+  var result = 0
+
+  if (num === 0) {
+    return 0
+  }
+
+  for (var i = 0; i < array.length; i++) {
+    result += array[i] / num
+  }
+
+  return result
+}
+
+module.exports = divideByAndSum

Chapter09/sync-opt/checking-optimization-status/slow.js

@@ -0,0 +1,16 @@
+'use strict'
+
+function divideByAndSum (num, array) {
+  try {
+    array.map(function (item) {
+      return item / num
+    }).reduce(function (acc, item) {
+      return acc + item
+    }, 0)
+  } catch (err) {
+    // to guard for division by zero
+    return 0
+  }
+}
+
+module.exports = divideByAndSum

Chapter09/sync-opt/function-inlining/bench.js

@@ -0,0 +1,38 @@
+'use strict'
+
+const benchmark = require('benchmark')
+const slow = require('./slow')
+const noCollection = require('./no-collections')
+const noTryCatch = require('./no-try-catch')
+
+const suite = new benchmark.Suite()
+
+const numbers = []
+
+for (let i = 0; i < 1000; i++) {
+  numbers.push(Math.random() * i)
+}
+
+suite.add('slow', function () {
+  slow(12, numbers)
+})
+
+suite.add('no-collections', function () {
+  noCollection(12, numbers)
+})
+
+suite.add('no-try-catch', function () {
+  noTryCatch(12, numbers)
+})
+
+suite.on('complete', print)
+
+suite.run()
+
+function print () {
+  for (var i = 0; i < this.length; i++) {
+    console.log(this[i].toString())
+  }
+
+  console.log('Fastest is', this.filter('fastest').map('name')[0])
+}

Chapter09/sync-opt/function-inlining/initial-bench.js

@@ -0,0 +1,29 @@
+'use strict'
+
+const benchmark = require('benchmark')
+const noCollection = require('./no-collections')
+const noTryCatch = require('./no-try-catch')
+
+const suite = new benchmark.Suite()
+
+const numbers = []
+
+for (let i = 0; i < 1000; i++) {
+  numbers.push(Math.random() * i)
+}
+
+suite.add('no-collections', function () {
+  noCollection(12, numbers)
+})
+
+suite.on('complete', print)
+
+suite.run()
+
+function print () {
+  for (var i = 0; i < this.length; i++) {
+    console.log(this[i].toString())
+  }
+
+  console.log('Fastest is', this.filter('fastest').map('name')[0])
+}

Chapter09/sync-opt/function-inlining/no-collections-vs-no-try-catch.js

@@ -0,0 +1,28 @@
+'use strict'
+
+const benchmark = require('benchmark')
+const noCollection = require('./no-collections')
+
+const suite = new benchmark.Suite()
+
+const numbers = []
+
+for (let i = 0; i < 1000; i++) {
+  numbers.push(Math.random() * i)
+}
+
+suite.add('no-collections', function () {
+  noCollection(12, numbers)
+})
+
+suite.on('complete', print)
+
+suite.run()
+
+function print () {
+  for (var i = 0; i < this.length; i++) {
+    console.log(this[i].toString())
+  }
+
+  console.log('Fastest is', this.filter('fastest').map('name')[0])
+}

Chapter09/sync-opt/function-inlining/no-collections.js

@@ -0,0 +1,15 @@
+'use strict'
+
+function divideByAndSum (num, array) {
+  var result = 0
+  try {
+    for (var i = 0; i < array.length; i++) {
+      result += array[i] / num
+    }
+  } catch (err) {
+    // to guard for division by zero
+    return 0
+  }
+}
+
+module.exports = divideByAndSum

Chapter09/sync-opt/function-inlining/no-try-catch-bench.js

@@ -0,0 +1,28 @@
+'use strict'
+
+const benchmark = require('benchmark')
+const noTryCatch = require('./no-try-catch')
+
+const suite = new benchmark.Suite()
+
+const numbers = []
+
+for (let i = 0; i < 1000; i++) {
+  numbers.push(Math.random() * i)
+}
+
+suite.add('no-try-catch', function () {
+  noTryCatch(12, numbers)
+})
+
+suite.on('complete', print)
+
+suite.run()
+
+function print () {
+  for (var i = 0; i < this.length; i++) {
+    console.log(this[i].toString())
+  }
+
+  console.log('Fastest is', this.filter('fastest').map('name')[0])
+}

Chapter09/sync-opt/function-inlining/no-try-catch.js

@@ -0,0 +1,17 @@
+'use strict'
+
+function divideByAndSum (num, array) {
+  var result = 0
+
+  if (num === 0) {
+    return 0
+  }
+
+  for (var i = 0; i < array.length; i++) {
+    result += array[i] / num
+  }
+
+  return result
+}
+
+module.exports = divideByAndSum

Chapter09/sync-opt/function-inlining/slow.js

@@ -0,0 +1,16 @@
+'use strict'
+
+function divideByAndSum (num, array) {
+  try {
+    array.map(function (item) {
+      return item / num
+    }).reduce(function (acc, item) {
+      return acc + item
+    }, 0)
+  } catch (err) {
+    // to guard for division by zero
+    return 0
+  }
+}
+
+module.exports = divideByAndSum

Chapter09/sync-opt/initial-bench.js

@@ -0,0 +1,28 @@
+'use strict'
+
+const benchmark = require('benchmark')
+const slow = require('./slow')
+
+const suite = new benchmark.Suite()
+
+const numbers = []
+
+for (let i = 0; i < 1000; i++) {
+  numbers.push(Math.random() * i)
+}
+
+suite.add('slow', function () {
+  slow(12, numbers)
+})
+
+suite.on('complete', print)
+
+suite.run()
+
+function print () {
+  for (var i = 0; i < this.length; i++) {
+    console.log(this[i].toString())
+  }
+
+  console.log('Fastest is', this.filter('fastest').map('name')[0])
+}

Chapter09/sync-opt/no-collections.js

@@ -0,0 +1,15 @@
+'use strict'
+
+function divideByAndSum (num, array) {
+  var result = 0
+  try {
+    for (var i = 0; i < array.length; i++) {
+      result += array[i] / num
+    }
+  } catch (err) {
+    // to guard for division by zero
+    return 0
+  }
+}
+
+module.exports = divideByAndSum

Chapter09/sync-opt/package.json

@@ -0,0 +1,14 @@
+{
+  "name": "sync-opt",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "benchmark": "^2.1.0"
+  }
+}

Chapter09/sync-opt/slow.js

@@ -0,0 +1,16 @@
+'use strict'
+
+function divideByAndSum (num, array) {
+  try {
+    array.map(function (item) {
+      return item / num
+    }).reduce(function (acc, item) {
+      return acc + item
+    }, 0)
+  } catch (err) {
+    // to guard for division by zero
+    return 0
+  }
+}
+
+module.exports = divideByAndSum