From bbbd0d52e9944b1832c19c4c88cf86b81672fd49 Mon Sep 17 00:00:00 2001
From: Sergii Stotskyi <sergiy.stotskiy@gmail.com>
Date: Wed, 7 Sep 2016 04:53:42 +0300
Subject: [PATCH] feat(file): adds chunked blob writing (#529)

This prevents devices crashing when user picks a big file to write
---
 src/plugins/file.ts | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/src/plugins/file.ts b/src/plugins/file.ts
index 7c2fd28a63..2ad7defa20 100644
--- a/src/plugins/file.ts
+++ b/src/plugins/file.ts
@@ -1119,6 +1119,10 @@ export class File {
    * @private
    */
   private static write(writer: FileWriter, gu: string | Blob): Promise<void> {
+    if (gu instanceof Blob) {
+      return this.writeFileInChunks(writer, gu);
+    }
+
     return new Promise<void>((resolve, reject) => {
       writer.onwriteend = (evt) => {
         if (writer.error) {
@@ -1130,4 +1134,32 @@ export class File {
       writer.write(gu);
     });
   }
+
+  /**
+   * @private
+   */
+  private static writeFileInChunks(writer: FileWriter, file: Blob) {
+    const BLOCK_SIZE = 1024 * 1024;
+    let writtenSize = 0;
+
+    function writeNextChunk() {
+      const size = Math.min(BLOCK_SIZE, file.size - writtenSize);
+      const chunk = file.slice(writtenSize, writtenSize + size);
+
+      writtenSize += size;
+      writer.write(chunk);
+    }
+
+    return new Promise((resolve, reject) => {
+      writer.onerror = reject;
+      writer.onwrite = () => {
+        if (writtenSize < file.size) {
+          writeNextChunk();
+        } else {
+          resolve();
+        }
+      };
+      writeNextChunk();
+    });
+  }
 }