4.3 Lib v0.3 组件图

由上图可以看出，Lib 主要由 protobuf 定义(packet.proto) 和 commons 通用组件组成。客户端与服务器通信采用二进制协议，并采用 protobuf 序列化/反序列化协议。

通信协议

+--------+----------------------+
| length |     packet data      |
+--------+----------------------+

Protobuf 定义

syntax = "proto3";

package lib;

option go_package = "github.com/huoyijie/GoChat/lib";

enum PackKind {
  // Server
  PONG    =  0;
  ERR     =  1;
  RES     =  2;
  PUSH    =  3;
  // All
  MSG     =  4;
  // Client
  PING    =  5;
  SIGNUP  =  6;
  SIGNIN  =  7;
  TOKEN   =  8;
  SIGNOUT =  9;
  USERS   = 10;
}

message Packet {
  PackKind kind = 1;
  uint64   id   = 2;
  bytes    data = 3;
}

message Ping{
  bytes payload = 1;
}

message Pong{
  bytes payload = 1;
}

message Auth {
  string username = 1;
  bytes  passhash = 2;
}

message Signup {
  Auth auth = 1;
}

message Signin {
  Auth auth = 1;
}

message Token {
  bytes token = 1;
}

message TokenRes {
  int32  code     = 1;
  uint64 id       = 2;
  string username = 3;
  bytes  token    = 4;
}

message Signout {}

message SignoutRes {
  int32 code  = 1;
}

message User {
  string username = 1;
  bool   online   = 2;
}

message Users {}

message UsersRes {
  int32         code  = 1;
  repeated User users = 2;
}

enum MsgKind {
  TEXT = 0;
}

message Msg {
  int64   id   = 1;
  MsgKind kind = 2;
  string  from = 3;
  string  to   = 4;
  bytes   data = 5;
}

message ErrRes {
  int32 code  = 1;
}

enum PushKind {
  ONLINE  = 0;
}

message Push {
  PushKind kind = 1;
  bytes    data = 2;
}

enum OnlineKind {
  ON  = 0;
  OFF = 1;
}

message Online {
  OnlineKind kind     = 1;
  string     username = 2;
}

Commons

主要是封装一些工具方法和错误码定义，如编解码、加解密等。