perf: make the most of streamed rendering

README.md

@@ -2,7 +2,7 @@
 [![npm version](https://img.shields.io/npm/v/liquidjs.svg?logo=npm&style=flat-square)](https://www.npmjs.org/package/liquidjs)
 [![npm downloads](https://img.shields.io/npm/dm/liquidjs.svg?style=flat-square)](https://www.npmjs.org/package/liquidjs)
 [![Coverage](https://img.shields.io/coveralls/harttle/liquidjs.svg?style=flat-square)](https://coveralls.io/github/harttle/liquidjs?branch=master)
-[![Build Status](https://img.shields.io/github/checks-status/harttle/liquidjs/master?style=flat-square)](https://travis-ci.org/harttle/liquidjs)
+[![Build Status](https://img.shields.io/github/workflow/status/harttle/liquidjs/Check/master.svg?style=flat-square)](https://github.com/harttle/liquidjs/actions/workflows/check.yml?query=branch%3Amaster)
 [![David dependencies](https://img.shields.io/david/harttle/liquidjs.svg?style=flat-square)](https://david-dm.org/harttle/liquidjs)
 [![DUB license](https://img.shields.io/dub/l/vibe-d.svg?style=flat-square)](https://github.com/harttle/liquidjs/blob/master/LICENSE)
 [![semantic-release](https://img.shields.io/badge/%20%20%F0%9F%93%A6%F0%9F%9A%80-semantic--release-e10079.svg?style=flat-square)](https://github.com/harttle/liquidjs)

demo/nodejs/index.js

@@ -3,7 +3,7 @@ const { Liquid } = require('liquidjs')
 const engine = new Liquid({
   root: __dirname,
   extname: '.liquid',
-  globals: {title: 'LiquidJS Demo'}
+  globals: { title: 'LiquidJS Demo' }
 })
 
 engine.registerTag('header', {
@@ -21,6 +21,16 @@ const ctx = {
   todos: ['fork and clone', 'make it better', 'make a pull request']
 }
 
-engine.renderFile('todolist', ctx)
-  .then(console.log)
-  .catch(err => console.error(err.stack))
+async function main () {
+  console.log('==========renderFile===========')
+  const html = await engine.renderFile('todolist', ctx)
+  console.log(html)
+
+  console.log('===========Streamed===========')
+  const tpls = await engine.parseFile('todolist')
+  engine.renderToNodeStream(tpls, ctx)
+    .on('data', data => process.stdout.write(data))
+    .on('end', () => console.log(''))
+}
+
+main()

demo/nodejs/package.json

@@ -7,6 +7,6 @@
     "start": "node index.js"
   },
   "dependencies": {
-    "liquidjs": "*"
+    "liquidjs": "latest"
   }
 }

src/builtin/tags/block.ts

@@ -1,45 +1,39 @@
 import BlockMode from '../../context/block-mode'
 import { BlockDrop } from '../../drop/block-drop'
-import { ParseStream, TagToken, TopLevelToken, Template, Context, TagImpl, Emitter } from '../../types'
+import { TagToken, TopLevelToken, Template, Context, TagImpl, Emitter } from '../../types'
 
 export default {
   parse (this: TagImpl, token: TagToken, remainTokens: TopLevelToken[]) {
     const match = /\w+/.exec(token.args)
     this.block = match ? match[0] : ''
     this.tpls = [] as Template[]
-    const stream: ParseStream = this.liquid.parser.parseStream(remainTokens)
-      .on('tag:endblock', () => stream.stop())
+    this.liquid.parser.parseStream(remainTokens)
+      .on('tag:endblock', function () { this.stop() })
       .on('template', (tpl: Template) => this.tpls.push(tpl))
-      .on('end', () => {
-        throw new Error(`tag ${token.getText()} not closed`)
-      })
-    stream.start()
+      .on('end', () => { throw new Error(`tag ${token.getText()} not closed`) })
+      .start()
   },
 
   * render (this: TagImpl, ctx: Context, emitter: Emitter) {
     const blockRender = this.getBlockRender(ctx)
-    yield this.emitHTML(ctx, emitter, blockRender)
+    if (ctx.getRegister('blockMode') === BlockMode.STORE) {
+      ctx.getRegister('blocks')[this.block] = blockRender
+    } else {
+      yield blockRender(new BlockDrop(), emitter)
+    }
   },
 
   getBlockRender (this: TagImpl, ctx: Context) {
     const { liquid, tpls } = this
-    const extendedBlockRender = ctx.getRegister('blocks')[this.block]
-    const defaultBlockRender = function * (superBlock: BlockDrop) {
+    const renderChild = ctx.getRegister('blocks')[this.block]
+    const renderCurrent = function * (superBlock: BlockDrop, emitter: Emitter) {
+      // add {{ block.super }} support when rendering
       ctx.push({ block: superBlock })
-      const result = yield liquid.renderer.renderTemplates(tpls, ctx)
+      yield liquid.renderer.renderTemplates(tpls, ctx, emitter)
       ctx.pop()
-      return result
-    }
-    return extendedBlockRender
-      ? (superBlock: BlockDrop) => extendedBlockRender(new BlockDrop(() => defaultBlockRender(superBlock)))
-      : defaultBlockRender
-  },
-
-  * emitHTML (this: TagImpl, ctx: Context, emitter: Emitter, blockRender: (block: BlockDrop) => string) {
-    if (ctx.getRegister('blockMode', BlockMode.OUTPUT) === BlockMode.STORE) {
-      ctx.getRegister('blocks')[this.block] = blockRender
-    } else {
-      emitter.write(yield blockRender(new BlockDrop()))
     }
+    return renderChild
+      ? (superBlock: BlockDrop, emitter: Emitter) => renderChild(new BlockDrop(() => renderCurrent(superBlock, emitter)), emitter)
+      : renderCurrent
   }
 }

src/builtin/tags/layout.ts

@@ -1,6 +1,7 @@
 import { assert, Tokenizer, Emitter, Hash, TagToken, TopLevelToken, Context, TagImplOptions } from '../../types'
 import BlockMode from '../../context/block-mode'
 import { parseFilePath, renderFilePath } from './render'
+import { BlankDrop } from '../../drop/blank-drop'
 
 export default {
   parseFilePath,
@@ -16,8 +17,7 @@ export default {
     const { renderer } = liquid
     if (file === null) {
       ctx.setRegister('blockMode', BlockMode.OUTPUT)
-      const html = yield renderer.renderTemplates(this.tpls, ctx)
-      emitter.write(html)
+      yield renderer.renderTemplates(this.tpls, ctx, emitter)
       return
     }
     const filepath = yield this.renderFilePath(this['file'], ctx, liquid)
@@ -28,13 +28,14 @@ export default {
     ctx.setRegister('blockMode', BlockMode.STORE)
     const html = yield renderer.renderTemplates(this.tpls, ctx)
     const blocks = ctx.getRegister('blocks')
-    if (blocks[''] === undefined) blocks[''] = () => html
+
+    // set whole content to anonymous block if anonymous doesn't specified
+    if (blocks[''] === undefined) blocks[''] = (parent: BlankDrop, emitter: Emitter) => emitter.write(html)
     ctx.setRegister('blockMode', BlockMode.OUTPUT)
 
     // render the layout file use stored blocks
     ctx.push(yield hash.render(ctx))
-    const partial = yield renderer.renderTemplates(templates, ctx)
+    yield renderer.renderTemplates(templates, ctx, emitter)
     ctx.pop()
-    emitter.write(partial)
   }
 } as TagImplOptions

src/context/context.ts

@@ -18,8 +18,8 @@ export class Context {
     this.globals = opts.globals
     this.environments = env
   }
-  public getRegister (key: string, defaultValue = {}) {
-    return (this.registers[key] = this.registers[key] || defaultValue)
+  public getRegister (key: string) {
+    return (this.registers[key] = this.registers[key] || {})
   }
   public setRegister (key: string, value: any) {
     return (this.registers[key] = value)

src/drop/block-drop.ts

@@ -3,10 +3,14 @@ import { Drop } from './drop'
 export class BlockDrop extends Drop {
   constructor (
     // the block render from layout template
-    private superBlockRender: () => Iterable<string> = () => ''
+    private superBlockRender: () => Iterable<any> = () => ''
   ) {
     super()
   }
+  /**
+   * Provide parent access in child block by
+   * {{ block.super }}
+   */
   public super () {
     return this.superBlockRender()
   }

src/emitters/emitter.ts

@@ -1,4 +1,11 @@
 export interface Emitter {
+  /**
+   * Write a html value into emitter
+   * @param html string, Drop or other primitive value
+   */
   write (html: any): void;
-  end (): void;
+  /**
+   * Buffered string
+   */
+  buffer: string;
 }

src/emitters/keeping-type-emitter.ts

@@ -1,7 +1,8 @@
 import { stringify, toValue } from '../util/underscore'
+import { Emitter } from '../types'
 
-export class KeepingTypeEmitter {
-  public html: any = '';
+export class KeepingTypeEmitter implements Emitter {
+  public buffer: any = '';
 
   public write (html: any) {
     html = toValue(html)
@@ -9,14 +10,10 @@ export class KeepingTypeEmitter {
     // I.E:
     // {{ my-port }} -> 42
     // {{ my-host }}:{{ my-port }} -> 'host:42'
-    if (typeof html !== 'string' && this.html === '') {
-      this.html = html
+    if (typeof html !== 'string' && this.buffer === '') {
+      this.buffer = html
     } else {
-      this.html = stringify(this.html) + stringify(html)
+      this.buffer = stringify(this.buffer) + stringify(html)
     }
   }
-
-  public end () {
-    return this.html
-  }
 }

src/emitters/simple-emitter.ts

@@ -2,13 +2,9 @@ import { stringify } from '../util/underscore'
 import { Emitter } from './emitter'
 
 export class SimpleEmitter implements Emitter {
-  public html: any = '';
+  public buffer = '';
 
   public write (html: any) {
-    this.html += stringify(html)
-  }
-
-  public end () {
-    return this.html
+    this.buffer += stringify(html)
   }
 }

src/emitters/streamed-emitter.ts

@@ -1,7 +1,7 @@
 import { stringify } from '../util/underscore'
 
 export class StreamedEmitter {
-  public html: any = '';
+  public buffer = '';
   public stream = new (require('stream').PassThrough)()
   public write (html: any) {
     this.stream.write(stringify(html))

src/render/emitter.ts

@@ -1,15 +0,0 @@
-export interface Emitter {
-  /**
-   * Write a html value into emitter
-   * @param html string, Drop or other primitive value
-   */
-  write (html: any): void;
-  /**
-   * Notify the emitter render has ended
-   */
-  end (): void;
-  /**
-   * Collect rendered string value immediately
-   */
-  collect (): string;
-}

src/render/render.ts

@@ -10,7 +10,7 @@ import { KeepingTypeEmitter } from '../emitters/keeping-type-emitter'
 export class Render {
   public renderTemplatesToNodeStream (templates: Template[], ctx: Context): NodeJS.ReadableStream {
     const emitter = new StreamedEmitter()
-    toThenable(this.renderTemplates(templates, ctx, emitter))
+    toThenable(this.renderTemplates(templates, ctx, emitter)).then(() => emitter.end())
     return emitter.stream
   }
   public * renderTemplates (templates: Template[], ctx: Context, emitter?: Emitter): IterableIterator<any> {
@@ -29,6 +29,6 @@ export class Render {
         throw err
       }
     }
-    return emitter.end()
+    return emitter.buffer
   }
 }