Fix memory leak (#591)

index.d.ts

@@ -345,16 +345,17 @@ declare module '@react-pdf/renderer' {
     const pdf: (
       document: React.ReactElement<DocumentProps>,
     ) => {
+      container: any;
       isDirty: () => boolean;
       updateContainer: (document: React.ReactElement<any>) => void;
-      toBuffer: () => NodeJS.ReadableStream;
+      toBuffer: () => Promise<NodeJS.ReadableStream>;
       toBlob: () => Promise<Blob>;
       toString: () => string;
     };
 
     const renderToStream: (
       document: React.ReactElement<DocumentProps>,
-    ) => NodeJS.ReadableStream;
+    ) => Promise<NodeJS.ReadableStream>;
 
     const renderToFile: (
       document: React.ReactElement<DocumentProps>,

src/elements/Document.js

@@ -31,6 +31,7 @@ class Document {
   removeChild(child) {
     const i = this.children.indexOf(child);
     child.parent = null;
+    child.cleanup();
     this.children.slice(i, 1);
   }
 
@@ -122,6 +123,14 @@ class Document {
     this.props = newProps;
   }
 
+  cleanup() {
+    this.subpages.forEach(p => p.cleanup());
+  }
+
+  finish() {
+    this.children.forEach(c => c.cleanup());
+  }
+
   getLayoutData() {
     return {
       type: this.name,

src/elements/Node.js

@@ -37,6 +37,8 @@ class Node {
       this.children.splice(index, 1);
       this.layout.removeChild(child.layout);
     }
+
+    child.cleanup();
   }
 
   removeAllChilds() {
@@ -133,6 +135,12 @@ class Node {
 
   onAppendDynamically() {}
 
+  cleanup() {
+    this.children.forEach(c => c.cleanup());
+    this.layout.unsetMeasureFunc();
+    Yoga.Node.destroy(this.layout);
+  }
+
   get position() {
     return this.layout.getPositionType() === Yoga.POSITION_TYPE_ABSOLUTE
       ? 'absolute'

src/elements/Note.js

@@ -25,6 +25,8 @@ class Note extends Base {
       child.parent = null;
       this.children.splice(index, 1);
     }
+
+    child.cleanup();
   }
 
   applyProps() {

src/elements/Root.js

@@ -16,16 +16,26 @@ class Root {
   }
 
   removeChild() {
+    this.document.cleanup();
     this.document = null;
   }
 
   markDirty() {
     this.isDirty = true;
   }
 
+  cleanup() {
+    this.document.cleanup();
+  }
+
+  finish() {
+    this.document.finish();
+  }
+
   async render() {
     this.instance = new PDFDocument({ autoFirstPage: false });
     await this.document.render();
+    this.cleanup();
     this.isDirty = false;
   }
 }

src/elements/Text.js

@@ -80,6 +80,8 @@ class Text extends Base {
       this.computed = false;
       this.attributedString = null;
       this.markDirty();
+
+      child.cleanup();
     }
   }
 

src/elements/TextInstance.js

@@ -22,6 +22,8 @@ class TextInstance {
     return new this.constructor(this.root, this.value);
   }
 
+  cleanup() {}
+
   update(value) {
     this.value = value;
     this.parent.computed = false;

src/index.js

@@ -57,10 +57,10 @@ const pdf = input => {
     });
   }
 
-  function toBuffer() {
-    callOnRender();
+  async function toBuffer() {
+    await container.render();
 
-    container.render();
+    callOnRender();
 
     return container.instance;
   }
@@ -87,6 +87,7 @@ const pdf = input => {
 
   return {
     isDirty,
+    container,
     updateContainer,
     toBuffer,
     toBlob,

src/node.js

@@ -15,12 +15,15 @@ import {
   createInstance,
 } from './index';
 
-export const renderToStream = function(element) {
-  return pdf(element).toBuffer();
+export const renderToStream = async function(element) {
+  const instance = pdf(element);
+  const buffer = await instance.toBuffer();
+  instance.container.finish();
+  return buffer;
 };
 
-export const renderToFile = function(element, filePath, callback) {
-  const output = renderToStream(element);
+export const renderToFile = async function(element, filePath, callback) {
+  const output = await renderToStream(element);
   const stream = fs.createWriteStream(filePath);
 
   output.pipe(stream);