perf(encoder): add worker pool

package-lock.json

@@ -3898,6 +3898,11 @@
         "loader-utils": "^0.2.16"
       }
     },
+    "generic-pool": {
+      "version": "3.6.1",
+      "resolved": "https://registry.npmjs.org/generic-pool/-/generic-pool-3.6.1.tgz",
+      "integrity": "sha512-iMmD/pY4q0+V+f8o4twE9JPeqfNuX+gJAaIPB3B0W1lFkBOtTxBo6B0HxHPgGhzQA8jego7EWopcYq/UDJO2KA=="
+    },
     "get-port": {
       "version": "3.2.0",
       "resolved": "https://registry.npmjs.org/get-port/-/get-port-3.2.0.tgz",
@@ -5444,14 +5449,19 @@
         "os-tmpdir": "^1.0.0"
       }
     },
-    "p-limit": {
-      "version": "2.2.0",
-      "resolved": "https://registry.npmjs.org/p-limit/-/p-limit-2.2.0.tgz",
-      "integrity": "sha512-pZbTJpoUsCzV48Mc9Nh51VbwO0X9cuPFE8gYwx9BTCt9SF8/b7Zljd2fVgOxhIF/HDTKgpVzs+GPhyKfjLLFRQ==",
+    "p-event": {
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/p-event/-/p-event-4.0.0.tgz",
+      "integrity": "sha512-5VKoUdeAfIlAXmASmre9vGlKjnwGwbr5Zwd3GZU2KmkaRgxEOeUUS5Oyh0qYMx8Y+0VTvvNjNIlqIvMpI/DKSw==",
       "requires": {
-        "p-try": "^2.0.0"
+        "p-timeout": "^2.0.1"
       }
     },
+    "p-finally": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/p-finally/-/p-finally-1.0.0.tgz",
+      "integrity": "sha1-P7z7FbiZpEEjs0ttzBi3JDNqLK4="
+    },
     "p-locate": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/p-locate/-/p-locate-2.0.0.tgz",
@@ -5478,10 +5488,13 @@
         }
       }
     },
-    "p-try": {
-      "version": "2.0.0",
-      "resolved": "https://registry.npmjs.org/p-try/-/p-try-2.0.0.tgz",
-      "integrity": "sha512-hMp0onDKIajHfIkdRk3P4CdCmErkYAxxDtP3Wx/4nZ3aGlau2VKh3mZpcuFkH27WQkL/3WBCPOktzA9ZOAnMQQ=="
+    "p-timeout": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/p-timeout/-/p-timeout-2.0.1.tgz",
+      "integrity": "sha512-88em58dDVB/KzPEx1X0N3LwFfYZPyDc4B6eF38M1rk9VTZMbxXXgjugz8mmwpS9Ox4BDZ+t6t3QP5+/gazweIA==",
+      "requires": {
+        "p-finally": "^1.0.0"
+      }
     },
     "pako": {
       "version": "1.0.10",
@@ -6406,11 +6419,6 @@
       "integrity": "sha512-7PiHtLll5LdnKIMw100I+8xJXR5gW2QwWYkT6iJva0bXitZKa/XMrSbdmg3r2Xnaidz9Qumd0VPaMrZlF9V9sA==",
       "dev": true
     },
-    "promises-progress": {
-      "version": "1.0.3",
-      "resolved": "https://registry.npmjs.org/promises-progress/-/promises-progress-1.0.3.tgz",
-      "integrity": "sha512-qeVptRZbEqo/JhWVmaAGIG14QnAXXyLj7EI+HKhduqKCl3mMVslMeqxC3tPyxy3N7ffqwbe56vrxqweyKHe1Yg=="
-    },
     "proto-list": {
       "version": "1.2.4",
       "resolved": "https://registry.npmjs.org/proto-list/-/proto-list-1.2.4.tgz",

package.json

@@ -11,11 +11,11 @@
   "dependencies": {
     "@babel/runtime": "^7.3.4",
     "eventemitter3": "^3.1.0",
+    "generic-pool": "^3.6.1",
     "gif-writer": "^0.9.3",
     "objectFitPolyfill": "^2.1.1",
-    "p-limit": "^2.2.0",
+    "p-event": "^4.0.0",
     "postcss-modules": "^1.4.1",
-    "promises-progress": "^1.0.3",
     "vue": "^2.6.6",
     "vuex": "^3.0.1"
   },

src/services/encode-core.js

@@ -0,0 +1,79 @@
+import EventEmitter from 'eventemitter3'
+
+import {
+  GifWriter,
+  MedianCutColorReducer,
+  IndexedColorImage
+} from 'gif-writer'
+
+import { calcProgress } from '/services/util.js'
+
+class OutputStream {
+  constructor () {
+    this.buffer = []
+  }
+
+  writeByte (b) {
+    this.buffer.push(b)
+  }
+
+  writeBytes (bb) {
+    Array.prototype.push.apply(this.buffer, bb)
+  }
+}
+
+export function write (indexedColorImages, imageWidth, imageHeight, delay) {
+  const emitter = new EventEmitter()
+
+  // yup, this is the browser nextTick implementation we are waiting for :facepalm:
+  Promise.resolve().then(() => {
+    emitter.emit('progress', 0)
+
+    const outputStream = new OutputStream()
+    const writer = new GifWriter(outputStream)
+
+    writer.writeHeader()
+
+    writer.writeLogicalScreenInfo({
+      width: imageWidth,
+      height: imageHeight
+    })
+
+    writer.writeLoopControlInfo(0)
+
+    indexedColorImages.forEach((indexedColorImage, index, { length }) => {
+      writer.writeTableBasedImageWithGraphicControl(indexedColorImage, { delayTimeInMS: delay })
+      emitter.emit('progress', calcProgress(0, 0.99, (index + 1) / length))
+    })
+
+    writer.writeTrailer()
+    emitter.emit('progress', 1)
+
+    emitter.emit('done', outputStream.buffer)
+  })
+
+  return emitter
+}
+
+export function convertImageDataToIndexedColorImage (imageData, paletteSize) {
+  const reducer = new MedianCutColorReducer(imageData, paletteSize)
+
+  const paletteData = reducer.process()
+
+  const data = Array.from(imageData.data)
+  const indexedColorImageData = []
+
+  for (let index = 0, length = data.length; index < length; index += 4) {
+    const [r, g, b] = data.slice(index, index + 4) // r,g,b,a
+    indexedColorImageData.push(reducer.map(r, g, b))
+  }
+
+  return new IndexedColorImage(
+    {
+      width: imageData.width,
+      height: imageData.height
+    },
+    indexedColorImageData,
+    paletteData
+  )
+}

src/services/encode.worker.js

@@ -1,31 +1,49 @@
-import { GifWriter } from 'gif-writer'
-import pLimit from 'p-limit'
+import genericPool from 'generic-pool'
+import pEvent from 'p-event'
+import { write } from '/services/encode-core.js'
+import { promisesProgress, calcProgress } from '/services/util.js'
 
 onmessage = handleMessage
 
+const workerPool = genericPool.createPool({
+  create () {
+    return new Worker('/services/quantize-color.worker.js')
+  },
+  destroy (worker) {
+    worker.terminate()
+  }
+}, {
+  min: 0,
+  max: 4
+})
+
 async function handleMessage (event) {
   const { imageDataList, imageWidth, imageHeight, paletteSize, delayTime } = event.data
 
-  const outputStream = new OutputStream()
-  const writer = new GifWriter(outputStream)
-
   postProgressMessage(0)
 
-  writer.writeHeader()
-
-  writer.writeLogicalScreenInfo({
-    width: imageWidth,
-    height: imageHeight
-  })
-
-  writer.writeLoopControlInfo(0)
-
   console.time('quantization')
 
-  const limit = pLimit(8)
-
   const promises = imageDataList
-    .map(imageData => limit(() => convertImageDataToIndexedColorImage(imageData, paletteSize)))
+    .map(async imageData => {
+      const worker = await workerPool.acquire()
+
+      const indexedColorImage = await new Promise((resolve, reject) => {
+        worker.onerror = reject
+        worker.onmessageerror = reject
+        worker.onmessage = event => {
+          resolve(event.data)
+        }
+
+        worker.postMessage({
+          imageData,
+          paletteSize
+        })
+      })
+
+      await workerPool.release(worker)
+      return indexedColorImage
+    })
 
   const progressPromises = promisesProgress(promises, function (value) {
     postProgressMessage(calcProgress(0, 0.9, value))
@@ -35,65 +53,17 @@ async function handleMessage (event) {
 
   console.timeEnd('quantization')
 
-  indexedColorImages.forEach((indexedColorImage, index, { length }) => {
-    writer.writeTableBasedImageWithGraphicControl(indexedColorImage, { delayTimeInMS: delayTime })
-    postProgressMessage(calcProgress(0.9, 1, (index + 1) / length))
-  })
+  console.time('write')
 
-  writer.writeTrailer()
+  const writing = write(indexedColorImages, imageWidth, imageHeight, delayTime)
 
-  postDoneMessage(outputStream.buffer)
-}
+  writing.on('progress', value => postProgressMessage(calcProgress(0.9, 1, value)))
 
-class OutputStream {
-  constructor () {
-    this.buffer = []
-  }
+  const buffer = await pEvent(writing, 'done')
 
-  writeByte (b) {
-    this.buffer.push(b)
-  }
+  console.timeEnd('write')
 
-  writeBytes (bb) {
-    Array.prototype.push.apply(this.buffer, bb)
-  }
-}
-
-function promisesProgress (promises, progress) {
-  let complete = 0
-
-  return promises.map(p => {
-    return p.then(x => {
-      progress(++complete / promises.length)
-      return p
-    })
-  })
-}
-
-function convertImageDataToIndexedColorImage (imageData, paletteSize) {
-  return new Promise((resolve, reject) => {
-    const worker = new Worker('/services/quantize-color.worker.js')
-
-    worker.onerror = reject
-    worker.onmessageerror = reject
-    worker.onmessage = event => {
-      resolve(event.data)
-    }
-
-    worker.postMessage({
-      imageData,
-      paletteSize
-    })
-  })
-}
-
-function calcProgress (from, to, value) {
-  return from + ((to - from) * value)
-}
-
-
-function calcProgress2 (from, to, steps, current) {
-  return from + ((to - from) / steps * current)
+  postDoneMessage(buffer)
 }
 
 function postProgressMessage (value) {

src/services/quantize-color.worker.js

@@ -1,4 +1,4 @@
-import { MedianCutColorReducer, IndexedColorImage } from 'gif-writer'
+import { convertImageDataToIndexedColorImage } from '/services/encode-core.js'
 
 onmessage = handleMessage
 
@@ -9,26 +9,3 @@ function handleMessage (event) {
 
   postMessage(indexedColorImage)
 }
-
-function convertImageDataToIndexedColorImage (imageData, paletteSize) {
-  const reducer = new MedianCutColorReducer(imageData, paletteSize)
-
-  const paletteData = reducer.process()
-
-  const data = Array.from(imageData.data)
-  const indexedColorImageData = []
-
-  for (let index = 0, length = data.length; index < length; index += 4) {
-    const [r, g, b, a] = data.slice(index, index + 4) // r,g,b,a
-    indexedColorImageData.push(reducer.map(r, g, b))
-  }
-
-  return new IndexedColorImage(
-    {
-      width: imageData.width,
-      height: imageData.height
-    },
-    indexedColorImageData,
-    paletteData
-  )
-}

src/services/util.js

@@ -0,0 +1,14 @@
+export function calcProgress (from, to, value) {
+  return from + ((to - from) * value)
+}
+
+export function promisesProgress (promises, progress) {
+  let complete = 0
+
+  return promises.map(p => {
+    return p.then(x => {
+      progress(++complete / promises.length)
+      return p
+    })
+  })
+}

src/store.js

@@ -31,7 +31,7 @@ export default new Vuex.Store({
   },
   mutations: {
     updateWelcomed (state, welcome) {
-      state.welcomed = welcome;
+      state.welcomed = welcome
     },
     startCamera (state, mediaStream) {
       state.mediaStream = mediaStream