因为protobuf的序列化效率和大小都非常好,所以它在网络通信上面应用越来越多;而webosocket也随着web3.0应用越来越广泛,而将这两个结合在一起的也会慢慢形成一种趋势;本人是为了测试自已写的一个c# websocket,所以在web上面结合pb也写了一个js实例:
1.首先下载protobuf.js
2.引入protobuf相关js文件
<script src="/js/protobuf.js?1.1.11"></script>
3.创建proto文件
1 package wenlipackage;2 syntax = proto3;3 4 message wsmessage {
5 required string id = 1;6 required string content = 2;7 required string sender = 3;8 required string time = 4;9 }
js的protobuf格式类型有
field typeexpected js type (create, encode)conversion (fromobject)
s-/u-/int32
s-/fixed32 number (32 bit integer) value | 0 if signed
value >>> 0 if unsigned
s-/u-/int64
s-/fixed64 long-like (optimal)
number (53 bit integer) long.fromvalue(value) with long.js
parseint(value, 10) otherwise
float
double number number(value)
bool boolean boolean(value)
string string string(value)
bytes uint8array (optimal)
buffer (optimal under node)
array.<number> (8 bit integers) base64.decode(value) if a string
object with non-zero .length is assumed to be buffer-like
enum number (32 bit integer) looks up the numeric id if a string
message valid message message.fromobject(value)
4.初始化protobuf,对相关数据进行序列化和反序列化
1 <script type="text/javascript">
2 var wsmessage;
3 var wsmessage;
4 var buffer;
5 protobuf.load(/proto/message.proto, function (err, root) {
6 if (err) throw err;
7 wsmessage = root.lookup(wenlipackage.wsmessage);
8 wsmessage = wsmessage.create({ id: 1, content: hello, sender: web, time: new date().gettime() });
9 buffer = wsmessage.encode(wsmessage).finish();
10 });
11 </script>
wsmessage是一个解码编码器
wsmessage是具体的某个定义的proto实例
是一个8位无符号的字节数组
5.连接到websocket并发送序列化的消息和接收反序列化的消息
1 <script type="text/javascript"> 2 var wsuri = ws://127.0.0.1:8082/; 3 var output; 4 function init() { 5 output = document.getelementbyid(output); 6
testwebsocket(); 7 } 8 function testwebsocket() { 9 websocket = new websocket(wsuri);10 websocket.onopen = function (evt) {11 onopen(evt)12 };
websocket.onclose = function (evt) {14 onclose(evt)15 };16 websocket.onmessage = function (evt) {17 onmessage(evt)18 };19
websocket.onerror = function (evt) {20 onerror(evt)21 };22 }23 function onopen(evt) {24 writetoscreen(connected);25 dosend(buffer);
}27 function onclose(evt) {28 writetoscreen(disconnected);29 }30 function onmessage(evt) {31 var reader = new filereader();32 reader.readasarraybuffer(evt.data);
reader.onload = function (e) {34 var buf = new uint8array(reader.result);35 writetoscreen('<span style="color: blue;">response: ' + wsmessage.decode(buf).content + '</span>');36 }37 }38
function onerror(evt) {39 writetoscreen('<span style="color: red;">error:</span> ' + evt.data);40 }41 function dosend(message) {42 writetoscreen(sent: + wsmessage.content);43
websocket.send(buffer);44 }45 function writetoscreen(message) {46 var pre = document.createelement(p);47 pre.style.wordwrap = break-word;48
pre.innerhtml = message;49
output.appendchild(pre);50 }51 window.addeventlistener(load, init, false);52 </script>
上面因为我的websocket server 返回一是二进制,所以浏览器接收到的是一个blob,这里注意对blob的处理
6.互通测试
以上就是protobuf.js的下载与使用详解的详细内容。