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
// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.

mod in_memory_broadcast_channel;

pub use in_memory_broadcast_channel::InMemoryBroadcastChannel;
pub use in_memory_broadcast_channel::InMemoryBroadcastChannelResource;

use async_trait::async_trait;
use deno_core::error::AnyError;
use deno_core::include_js_files;
use deno_core::op;
use deno_core::Extension;
use deno_core::OpState;
use deno_core::Resource;
use deno_core::ResourceId;
use deno_core::ZeroCopyBuf;
use std::cell::RefCell;
use std::path::PathBuf;
use std::rc::Rc;

#[async_trait]
pub trait BroadcastChannel: Clone {
  type Resource: Resource;

  fn subscribe(&self) -> Result<Self::Resource, AnyError>;

  fn unsubscribe(&self, resource: &Self::Resource) -> Result<(), AnyError>;

  async fn send(
    &self,
    resource: &Self::Resource,
    name: String,
    data: Vec<u8>,
  ) -> Result<(), AnyError>;

  async fn recv(
    &self,
    resource: &Self::Resource,
  ) -> Result<Option<Message>, AnyError>;
}

pub type Message = (String, Vec<u8>);

struct Unstable(bool); // --unstable

#[op]
pub fn op_broadcast_subscribe<BC>(
  state: &mut OpState,
) -> Result<ResourceId, AnyError>
where
  BC: BroadcastChannel + 'static,
{
  let unstable = state.borrow::<Unstable>().0;

  if !unstable {
    eprintln!(
      "Unstable API 'BroadcastChannel'. The --unstable flag must be provided.",
    );
    std::process::exit(70);
  }

  let bc = state.borrow::<BC>();
  let resource = bc.subscribe()?;
  Ok(state.resource_table.add(resource))
}

#[op]
pub fn op_broadcast_unsubscribe<BC>(
  state: &mut OpState,
  rid: ResourceId,
) -> Result<(), AnyError>
where
  BC: BroadcastChannel + 'static,
{
  let resource = state.resource_table.get::<BC::Resource>(rid)?;
  let bc = state.borrow::<BC>();
  bc.unsubscribe(&resource)
}

#[op]
pub async fn op_broadcast_send<BC>(
  state: Rc<RefCell<OpState>>,
  rid: ResourceId,
  name: String,
  buf: ZeroCopyBuf,
) -> Result<(), AnyError>
where
  BC: BroadcastChannel + 'static,
{
  let resource = state.borrow().resource_table.get::<BC::Resource>(rid)?;
  let bc = state.borrow().borrow::<BC>().clone();
  bc.send(&resource, name, buf.to_vec()).await
}

#[op]
pub async fn op_broadcast_recv<BC>(
  state: Rc<RefCell<OpState>>,
  rid: ResourceId,
) -> Result<Option<Message>, AnyError>
where
  BC: BroadcastChannel + 'static,
{
  let resource = state.borrow().resource_table.get::<BC::Resource>(rid)?;
  let bc = state.borrow().borrow::<BC>().clone();
  bc.recv(&resource).await
}

pub fn init<BC: BroadcastChannel + 'static>(
  bc: BC,
  unstable: bool,
) -> Extension {
  Extension::builder()
    .js(include_js_files!(
      prefix "deno:ext/broadcast_channel",
      "01_broadcast_channel.js",
    ))
    .ops(vec![
      op_broadcast_subscribe::decl::<BC>(),
      op_broadcast_unsubscribe::decl::<BC>(),
      op_broadcast_send::decl::<BC>(),
      op_broadcast_recv::decl::<BC>(),
    ])
    .state(move |state| {
      state.put(bc.clone());
      state.put(Unstable(unstable));
      Ok(())
    })
    .build()
}

pub fn get_declaration() -> PathBuf {
  PathBuf::from(env!("CARGO_MANIFEST_DIR"))
    .join("lib.deno_broadcast_channel.d.ts")
}