xref: /aosp_15_r20/external/perfetto/ui/src/engine/index.ts (revision 6dbdd20afdafa5e3ca9b8809fa73465d530080dc)
1// Copyright (C) 2018 The Android Open Source Project
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//      http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15import {WasmBridge} from './wasm_bridge';
16
17const selfWorker = self as {} as Worker;
18const wasmBridge = new WasmBridge();
19
20// There are two message handlers here:
21// 1. The Worker (self.onmessage) handler.
22// 2. The MessagePort handler.
23// The sequence of actions is the following:
24// 1. The frontend does one postMessage({port: MessagePort}) on the Worker
25//    scope. This message transfers the MessagePort.
26//    This is the only postMessage we'll ever receive here.
27// 2. All the other messages (i.e. the TraceProcessor RPC binary pipe) will be
28//    received on the MessagePort.
29
30// Receives the boostrap message from the frontend with the MessagePort.
31selfWorker.onmessage = (msg: MessageEvent) => {
32  const port = msg.data as MessagePort;
33  wasmBridge.initialize(port);
34};
35