Merge pull request #8120 from jasongrout/arraybuffers

Make it possible for msg.buffers in javascript to be either ArrayBuffers or views

IPython/html/static/services/kernels/serialize.js

@@ -1,123 +1,126 b''
 // Copyright (c) IPython Development Team.
 // Distributed under the terms of the Modified BSD License.
 
 define([
     'underscore',
     ], function (_) {
     "use strict";
     
     var _deserialize_array_buffer = function (buf) {
         var data = new DataView(buf);
         // read the header: 1 + nbufs 32b integers
         var nbufs = data.getUint32(0);
         var offsets = [];
         var i;
         for (i = 1; i <= nbufs; i++) {
             offsets.push(data.getUint32(i * 4));
         }
         var json_bytes = new Uint8Array(buf.slice(offsets[0], offsets[1]));
         var msg = JSON.parse(
             (new TextDecoder('utf8')).decode(json_bytes)
         );
         // the remaining chunks are stored as DataViews in msg.buffers
         msg.buffers = [];
         var start, stop;
         for (i = 1; i < nbufs; i++) {
             start = offsets[i];
             stop = offsets[i+1] || buf.byteLength;
             msg.buffers.push(new DataView(buf.slice(start, stop)));
         }
         return msg;
     };
     
     var _deserialize_binary = function(data) {
         /**
          * deserialize the binary message format
          * callback will be called with a message whose buffers attribute
          * will be an array of DataViews.
          */
         if (data instanceof Blob) {
             // data is Blob, have to deserialize from ArrayBuffer in reader callback
             var reader = new FileReader();
             var promise = new Promise(function(resolve, reject) {
                 reader.onload = function () {
                     var msg = _deserialize_array_buffer(this.result);
                     resolve(msg);
                 };
             });
             reader.readAsArrayBuffer(data);
             return promise;
         } else {
             // data is ArrayBuffer, can deserialize directly
             var msg = _deserialize_array_buffer(data);
             return msg;
         }
     };
 
     var deserialize = function (data) {
         /**
          * deserialize a message and return a promise for the unpacked message
          */
         if (typeof data === "string") {
             // text JSON message
             return Promise.resolve(JSON.parse(data));
         } else {
             // binary message
             return Promise.resolve(_deserialize_binary(data));
         }
     };
     
     var _serialize_binary = function (msg) {
         /**
          * implement the binary serialization protocol
          * serializes JSON message to ArrayBuffer
          */
         msg = _.clone(msg);
         var offsets = [];
         var buffers = [];
-        msg.buffers.map(function (buf) {
-            buffers.push(buf);
-        });
+        var i;
+        for (i = 0; i < msg.buffers.length; i++) {
+            // msg.buffers elements could be either views or ArrayBuffers
+            // buffers elements are ArrayBuffers
+            var b = msg.buffers[i];
+            buffers.push(b.buffer instanceof ArrayBuffer ? b.buffer : b);
+        }
         delete msg.buffers;
         var json_utf8 = (new TextEncoder('utf8')).encode(JSON.stringify(msg));
         buffers.unshift(json_utf8);
         var nbufs = buffers.length;
         offsets.push(4 * (nbufs + 1));
-        var i;
         for (i = 0; i + 1 < buffers.length; i++) {
             offsets.push(offsets[offsets.length-1] + buffers[i].byteLength);
         }
         var msg_buf = new Uint8Array(
             offsets[offsets.length-1] + buffers[buffers.length-1].byteLength
         );
         // use DataView.setUint32 for network byte-order
         var view = new DataView(msg_buf.buffer);
         // write nbufs to first 4 bytes
         view.setUint32(0, nbufs);
         // write offsets to next 4 * nbufs bytes
         for (i = 0; i < offsets.length; i++) {
             view.setUint32(4 * (i+1), offsets[i]);
         }
         // write all the buffers at their respective offsets
         for (i = 0; i < buffers.length; i++) {
-            msg_buf.set(new Uint8Array(buffers[i].buffer), offsets[i]);
+            msg_buf.set(new Uint8Array(buffers[i]), offsets[i]);
         }
         
         // return raw ArrayBuffer
         return msg_buf.buffer;
     };
     
     var serialize = function (msg) {
         if (msg.buffers && msg.buffers.length) {
             return _serialize_binary(msg);
         } else {
             return JSON.stringify(msg);
         }
     };
     
     var exports = {
         deserialize : deserialize,
         serialize: serialize
     };
     return exports;
 });