1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
|
// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
/// <reference path="../../core/internal.d.ts" />
"use strict";
((window) => {
const core = window.Deno.core;
const webidl = window.__bootstrap.webidl;
const { setTarget } = window.__bootstrap.event;
const { DOMException } = window.__bootstrap.domException;
const {
ArrayPrototypeIndexOf,
ArrayPrototypeSplice,
ArrayPrototypePush,
Symbol,
Uint8Array,
ObjectDefineProperty,
Map,
MapPrototypeSet,
MapPrototypeGet,
FunctionPrototypeCall,
} = window.__bootstrap.primordials;
const handlerSymbol = Symbol("eventHandlers");
function makeWrappedHandler(handler) {
function wrappedHandler(...args) {
if (typeof wrappedHandler.handler !== "function") {
return;
}
return FunctionPrototypeCall(wrappedHandler.handler, this, ...args);
}
wrappedHandler.handler = handler;
return wrappedHandler;
}
// TODO(lucacasonato) reuse when we can reuse code between web crates
function defineEventHandler(emitter, name) {
// HTML specification section 8.1.5.1
ObjectDefineProperty(emitter, `on${name}`, {
get() {
// TODO(bnoordhuis) The "BroadcastChannel should have an onmessage
// event" WPT test expects that .onmessage !== undefined. Returning
// null makes it pass but is perhaps not exactly in the spirit.
if (!this[handlerSymbol]) {
return null;
}
return MapPrototypeGet(this[handlerSymbol], name)?.handler ?? null;
},
set(value) {
if (!this[handlerSymbol]) {
this[handlerSymbol] = new Map();
}
let handlerWrapper = MapPrototypeGet(this[handlerSymbol], name);
if (handlerWrapper) {
handlerWrapper.handler = value;
} else {
handlerWrapper = makeWrappedHandler(value);
this.addEventListener(name, handlerWrapper);
}
MapPrototypeSet(this[handlerSymbol], name, handlerWrapper);
},
configurable: true,
enumerable: true,
});
}
const _name = Symbol("[[name]]");
const _closed = Symbol("[[closed]]");
const channels = [];
let rid = null;
async function recv() {
while (channels.length > 0) {
const message = await core.opAsync("op_broadcast_recv", rid);
if (message === null) {
break;
}
const [name, data] = message;
dispatch(null, name, new Uint8Array(data));
}
core.close(rid);
rid = null;
}
function dispatch(source, name, data) {
for (const channel of channels) {
if (channel === source) continue; // Don't self-send.
if (channel[_name] !== name) continue;
if (channel[_closed]) continue;
const go = () => {
if (channel[_closed]) return;
const event = new MessageEvent("message", {
data: core.deserialize(data), // TODO(bnoordhuis) Cache immutables.
origin: "http://127.0.0.1",
});
setTarget(event, channel);
channel.dispatchEvent(event);
};
defer(go);
}
}
// Defer to avoid starving the event loop. Not using queueMicrotask()
// for that reason: it lets promises make forward progress but can
// still starve other parts of the event loop.
function defer(go) {
setTimeout(go, 1);
}
class BroadcastChannel extends EventTarget {
[_name];
[_closed] = false;
get name() {
return this[_name];
}
constructor(name) {
super();
const prefix = "Failed to construct 'BroadcastChannel'";
webidl.requiredArguments(arguments.length, 1, { prefix });
this[_name] = webidl.converters["DOMString"](name, {
prefix,
context: "Argument 1",
});
this[webidl.brand] = webidl.brand;
ArrayPrototypePush(channels, this);
if (rid === null) {
// Create the rid immediately, otherwise there is a time window (and a
// race condition) where messages can get lost, because recv() is async.
rid = core.opSync("op_broadcast_subscribe");
recv();
}
}
postMessage(message) {
webidl.assertBranded(this, BroadcastChannel);
const prefix = "Failed to execute 'postMessage' on 'BroadcastChannel'";
webidl.requiredArguments(arguments.length, 1, { prefix });
if (this[_closed]) {
throw new DOMException("Already closed", "InvalidStateError");
}
if (typeof message === "function" || typeof message === "symbol") {
throw new DOMException("Uncloneable value", "DataCloneError");
}
const data = core.serialize(message);
// Send to other listeners in this VM.
dispatch(this, this[_name], new Uint8Array(data));
// Send to listeners in other VMs.
defer(() => core.opAsync("op_broadcast_send", [rid, this[_name]], data));
}
close() {
webidl.assertBranded(this, BroadcastChannel);
this[_closed] = true;
const index = ArrayPrototypeIndexOf(channels, this);
if (index === -1) return;
ArrayPrototypeSplice(channels, index, 1);
if (channels.length === 0) core.opSync("op_broadcast_unsubscribe", rid);
}
}
defineEventHandler(BroadcastChannel.prototype, "message");
defineEventHandler(BroadcastChannel.prototype, "messageerror");
window.__bootstrap.broadcastChannel = { BroadcastChannel };
})(this);
|
