关于dubbo:聊聊dubbogo的DubboProtocol

序

本文次要钻研一下dubbo-go的DubboProtocol

DubboProtocol

dubbo-go-v1.4.2/protocol/dubbo/dubbo_protocol.go

// dubbo protocol constantconst (    // DUBBO ...    DUBBO = "dubbo")func init() {    extension.SetProtocol(DUBBO, GetProtocol)}var (    dubboProtocol *DubboProtocol)// DubboProtocol ...type DubboProtocol struct {    protocol.BaseProtocol    serverMap  map[string]*Server    serverLock sync.Mutex}

DubboProtocol嵌套了protocol.BaseProtocol，定义了serverMap、serverLock属性

GetProtocol

dubbo-go-v1.4.2/protocol/dubbo/dubbo_protocol.go

// GetProtocol ...func GetProtocol() protocol.Protocol {    if dubboProtocol == nil {        dubboProtocol = NewDubboProtocol()    }    return dubboProtocol}

GetProtocol办法通过NewDubboProtocol创立dubboProtocol

NewDubboProtocol

dubbo-go-v1.4.2/protocol/dubbo/dubbo_protocol.go

// NewDubboProtocol ...func NewDubboProtocol() *DubboProtocol {    return &DubboProtocol{        BaseProtocol: protocol.NewBaseProtocol(),        serverMap:    make(map[string]*Server),    }}

NewDubboProtocol办法实例化了DubboProtocol

Export

dubbo-go-v1.4.2/protocol/dubbo/dubbo_protocol.go

// Export ...func (dp *DubboProtocol) Export(invoker protocol.Invoker) protocol.Exporter {    url := invoker.GetUrl()    serviceKey := url.ServiceKey()    exporter := NewDubboExporter(serviceKey, invoker, dp.ExporterMap())    dp.SetExporterMap(serviceKey, exporter)    logger.Infof("Export service: %s", url.String())    // start server    dp.openServer(url)    return exporter}

Export办法通过NewDubboExporter创立exporter，而后更新到DubboProtocol的exporterMap中，之后执行DubboProtocol的openServer

openServer

dubbo-go-v1.4.2/protocol/dubbo/dubbo_protocol.go

func (dp *DubboProtocol) openServer(url common.URL) {    _, ok := dp.serverMap[url.Location]    if !ok {        _, ok := dp.ExporterMap().Load(url.ServiceKey())        if !ok {            panic("[DubboProtocol]" + url.Key() + "is not existing")        }        dp.serverLock.Lock()        _, ok = dp.serverMap[url.Location]        if !ok {            srv := NewServer()            dp.serverMap[url.Location] = srv            srv.Start(url)        }        dp.serverLock.Unlock()    }}

openServer办法先依据url.Location从serverMap获取Server，获取不到则执行dp.ExporterMap().Load(url.ServiceKey())，之后再次应用dp.serverMap[url.Location]获取，获取不到则执行NewServer，放到dp.serverMap中，而后执行srv.Start(url)

Refer

dubbo-go-v1.4.2/protocol/dubbo/dubbo_protocol.go

// Refer ...func (dp *DubboProtocol) Refer(url common.URL) protocol.Invoker {    //default requestTimeout    var requestTimeout = config.GetConsumerConfig().RequestTimeout    requestTimeoutStr := url.GetParam(constant.TIMEOUT_KEY, config.GetConsumerConfig().Request_Timeout)    if t, err := time.ParseDuration(requestTimeoutStr); err == nil {        requestTimeout = t    }    invoker := NewDubboInvoker(url, NewClient(Options{        ConnectTimeout: config.GetConsumerConfig().ConnectTimeout,        RequestTimeout: requestTimeout,    }))    dp.SetInvokers(invoker)    logger.Infof("Refer service: %s", url.String())    return invoker}

Refer办法先获取requestTimeout，之后通过NewDubboInvoker创立invoker，而后执行dp.SetInvokers(invoker)

Destroy

dubbo-go-v1.4.2/protocol/dubbo/dubbo_protocol.go

// Destroy ...func (dp *DubboProtocol) Destroy() {    logger.Infof("DubboProtocol destroy.")    dp.BaseProtocol.Destroy()    // stop server    for key, server := range dp.serverMap {        delete(dp.serverMap, key)        server.Stop()    }}

Destroy办法先执行dp.BaseProtocol.Destroy()，之后遍历dp.serverMap，执行delete(dp.serverMap, key)及server.Stop()

小结

DubboProtocol嵌套了protocol.BaseProtocol，定义了serverMap、serverLock属性；Export办法通过NewDubboExporter创立exporter，而后更新到DubboProtocol的exporterMap中，之后执行DubboProtocol的openServer；Refer办法先获取requestTimeout，之后通过NewDubboInvoker创立invoker，而后执行dp.SetInvokers(invoker)；Destroy办法先执行dp.BaseProtocol.Destroy()，之后遍历dp.serverMap，执行delete(dp.serverMap, key)及server.Stop()

doc

dubbo_protocol