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
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
use std::cell::RefCell;
use std::io::{Read, Write};
use cast::cast_channel;
use errors::Error;
use utils;
#[derive(Debug, Clone)]
pub enum CastMessagePayload {
String(String),
Binary(Vec<u8>),
}
#[derive(Debug, Clone)]
pub struct CastMessage {
pub namespace: String,
pub source: String,
pub destination: String,
pub payload: CastMessagePayload,
}
pub struct MessageManager<S>
where
S: Write + Read,
{
message_buffer: RefCell<Vec<CastMessage>>,
stream: RefCell<S>,
request_counter: RefCell<i32>,
}
impl<S> MessageManager<S>
where
S: Write + Read,
{
pub fn new(stream: S) -> Self {
MessageManager {
stream: RefCell::new(stream),
message_buffer: RefCell::new(vec![]),
request_counter: RefCell::new(1),
}
}
pub fn send(&self, message: CastMessage) -> Result<(), Error> {
let mut raw_message = cast_channel::CastMessage::new();
raw_message.set_protocol_version(cast_channel::CastMessage_ProtocolVersion::CASTV2_1_0);
raw_message.set_namespace(message.namespace);
raw_message.set_source_id(message.source);
raw_message.set_destination_id(message.destination);
match message.payload {
CastMessagePayload::String(payload) => {
raw_message.set_payload_type(cast_channel::CastMessage_PayloadType::STRING);
raw_message.set_payload_utf8(payload);
}
CastMessagePayload::Binary(payload) => {
raw_message.set_payload_type(cast_channel::CastMessage_PayloadType::BINARY);
raw_message.set_payload_binary(payload);
}
};
let message_content_buffer = utils::to_vec(&raw_message)?;
let message_length_buffer =
utils::write_u32_to_buffer(message_content_buffer.len() as u32)?;
let writer = &mut *self.stream.borrow_mut();
writer.write_all(&message_length_buffer)?;
writer.write_all(&message_content_buffer)?;
debug!("Message sent: {:?}", raw_message);
Ok(())
}
pub fn receive(&self) -> Result<CastMessage, Error> {
let mut message_buffer = self.message_buffer.borrow_mut();
if message_buffer.is_empty() {
self.read()
} else {
Ok(message_buffer.remove(0))
}
}
pub fn receive_find_map<F, B>(&self, f: F) -> Result<B, Error>
where
F: Fn(&CastMessage) -> Result<Option<B>, Error>,
{
loop {
let message = self.read()?;
match f(&message)? {
Some(r) => return Ok(r),
None => self.message_buffer.borrow_mut().push(message),
}
}
}
pub fn generate_request_id(&self) -> i32 {
let request_id = *self.request_counter.borrow() + 1;
*self.request_counter.borrow_mut() = request_id;
request_id
}
fn read(&self) -> Result<CastMessage, Error> {
let mut buffer: [u8; 4] = [0; 4];
let reader = &mut *self.stream.borrow_mut();
reader.read_exact(&mut buffer)?;
let length = utils::read_u32_from_buffer(&buffer)?;
let mut buffer: Vec<u8> = Vec::with_capacity(length as usize);
let mut limited_reader = reader.take(u64::from(length));
limited_reader.read_to_end(&mut buffer)?;
let raw_message = utils::from_vec::<cast_channel::CastMessage>(buffer.to_vec())?;
debug!("Message received: {:?}", raw_message);
Ok(CastMessage {
namespace: raw_message.get_namespace().to_string(),
source: raw_message.get_source_id().to_string(),
destination: raw_message.get_destination_id().to_string(),
payload: match raw_message.get_payload_type() {
cast_channel::CastMessage_PayloadType::STRING => {
CastMessagePayload::String(raw_message.get_payload_utf8().to_string())
}
cast_channel::CastMessage_PayloadType::BINARY => {
CastMessagePayload::Binary(raw_message.get_payload_binary().to_owned())
}
},
})
}
}