egg_im/docs/流程图/消息单发.puml

@startuml
participant c1.d1
participant c1.d2
participant c2.d3
participant c2.d4
participant connect
participant logic

c1.d1 -> logic: c1给c2用户发送消息
logic --> c1.d1 : 返回消息发送成功

logic -> logic: 获取c1用户下一个消息序列号
logic -> logic: 将消息持久化到c1用户的消息列表
logic -> logic: 查询c1用户其他在线设备
logic --> connect: 给设备d2发送消息
connect --> c1.d2: 给设备d2发送消息
c1.d2 ->connect : 消息ack
connect -> logic: 消息ack

logic -> logic: 获取c2用户下一个消息序列号
logic -> logic: 将消息持久化到c2用户的消息列表
logic -> logic: 查询c2用户所有在线设备
logic -> connect: 给设备d3发送消息
connect -> c2.d3: 给设备d3发送消息
c2.d3 ->connect : 消息ack
connect -> logic: 消息ack
logic -> connect: 给设备d4发送消息
connect -> c2.d4: 给设备d4发送消息
c2.d4 ->connect : 消息ack
connect -> logic: 消息ack
@enduml