Make sure buffer is a DataView

Author: davidbrochart

jupyterlab_widgets/src/manager.ts

@@ -133,14 +133,7 @@ export abstract class LabWidgetManager extends ManagerBase
             ) {
               const data = msg.content.data as any;
               const buffer_paths = data.buffer_paths || [];
-              // Make sure the buffers are DataViews
-              const buffers = (msg.buffers || []).map(b => {
-                if (b instanceof DataView) {
-                  return b;
-                } else {
-                  return new DataView(b instanceof ArrayBuffer ? b : b.buffer);
-                }
-              });
+              const buffers = msg.buffers || [];
               put_buffers(data.state, buffer_paths, buffers);
               info.resolve({ comm, msg });
             }

packages/base/src/utils.ts

@@ -100,18 +100,25 @@ export function reject(message: string, log: boolean) {
 export function put_buffers(
   state: Dict<BufferJSON>,
   buffer_paths: (string | number)[][],
-  buffers: DataView[]
+  buffers: any[]
 ): void {
   for (let i = 0; i < buffer_paths.length; i++) {
     const buffer_path = buffer_paths[i];
-    // say we want to set state[x][y][z] = buffers[i]
+    // make sure the buffers are DataViews
+    let buffer = buffers[i];
+    if (!(buffer instanceof DataView)) {
+      buffer = new DataView(
+        buffer instanceof ArrayBuffer ? buffer : buffer.buffer
+      );
+    }
+    // say we want to set state[x][y][z] = buffer
     let obj = state as any;
     // we first get obj = state[x][y]
     for (let j = 0; j < buffer_path.length - 1; j++) {
       obj = obj[buffer_path[j]];
     }
-    // and then set: obj[z] = buffers[i]
-    obj[buffer_path[buffer_path.length - 1]] = buffers[i];
+    // and then set: obj[z] = buffer
+    obj[buffer_path[buffer_path.length - 1]] = buffer;
   }
 }