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本文次要钻研一下dubbo-go的apolloConfiguration

apolloConfiguration

dubbo-go-v1.4.2/config_center/apollo/impl.go

const (    apolloProtocolPrefix = "http://"    apolloConfigFormat   = "%s.%s")type apolloConfiguration struct {    url *common.URL    listeners sync.Map    appConf   *agollo.AppConfig    parser    parser.ConfigurationParser}
  • apolloConfiguration定义了url、listeners、appConf、parser属性

newApolloConfiguration

dubbo-go-v1.4.2/config_center/apollo/impl.go

func newApolloConfiguration(url *common.URL) (*apolloConfiguration, error) {    c := &apolloConfiguration{        url: url,    }    configAddr := c.getAddressWithProtocolPrefix(url)    configCluster := url.GetParam(constant.CONFIG_CLUSTER_KEY, "")    appId := url.GetParam(constant.CONFIG_APP_ID_KEY, "")    namespaces := getProperties(url.GetParam(constant.CONFIG_NAMESPACE_KEY, cc.DEFAULT_GROUP))    c.appConf = &agollo.AppConfig{        AppId:         appId,        Cluster:       configCluster,        NamespaceName: namespaces,        Ip:            configAddr,    }    agollo.InitCustomConfig(func() (*agollo.AppConfig, error) {        return c.appConf, nil    })    return c, agollo.Start()}
  • newApolloConfiguration办法创立AppConfig，而后执行agollo.InitCustomConfig，最初执行agollo.Start()

GetProperties

dubbo-go-v1.4.2/config_center/apollo/impl.go

func (c *apolloConfiguration) GetProperties(key string, opts ...cc.Option) (string, error) {    /**     * when group is not null, we are getting startup configs(config file) from Config Center, for example:     * key=dubbo.propertie     */    config := agollo.GetConfig(key)    if config == nil {        return "", errors.New(fmt.Sprintf("nothing in namespace:%s ", key))    }    return config.GetContent(agollo.Properties), nil}
  • GetProperties办法先执行agollo.GetConfig(key)获取Config，之后通过config.GetContent(agollo.Properties)获取属性

AddListener

dubbo-go-v1.4.2/config_center/apollo/impl.go

func (c *apolloConfiguration) AddListener(key string, listener cc.ConfigurationListener, opts ...cc.Option) {    k := &cc.Options{}    for _, opt := range opts {        opt(k)    }    key = k.Group + key    l, _ := c.listeners.LoadOrStore(key, NewApolloListener())    l.(*apolloListener).AddListener(listener)}
  • AddListener办法执行c.listeners.LoadOrStore(key, NewApolloListener())及l.(*apolloListener).AddListener(listener)

RemoveListener

dubbo-go-v1.4.2/config_center/apollo/impl.go

func (c *apolloConfiguration) RemoveListener(key string, listener cc.ConfigurationListener, opts ...cc.Option) {    k := &cc.Options{}    for _, opt := range opts {        opt(k)    }    key = k.Group + key    l, ok := c.listeners.Load(key)    if ok {        l.(*apolloListener).RemoveListener(listener)    }}
  • RemoveListener办法执行l.(*apolloListener).RemoveListener(listener)

NewApolloListener

dubbo-go-v1.4.2/config_center/apollo/listener.go

type apolloListener struct {    listeners map[config_center.ConfigurationListener]struct{}}// NewApolloListener ...func NewApolloListener() *apolloListener {    return &apolloListener{        listeners: make(map[config_center.ConfigurationListener]struct{}, 0),    }}
  • NewApolloListener创立apolloListener

OnChange

dubbo-go-v1.4.2/config_center/apollo/listener.go

// OnChange ...func (a *apolloListener) OnChange(changeEvent *agollo.ChangeEvent) {    for key, change := range changeEvent.Changes {        for listener := range a.listeners {            listener.Process(&config_center.ConfigChangeEvent{                ConfigType: getChangeType(change.ChangeType),                Key:        key,                Value:      change.NewValue,            })        }    }}
  • OnChange办法接管ChangeEvent，之后遍历listeners，执行listener.Process回调

小结

apolloConfiguration定义了url、listeners、appConf、parser属性；newApolloConfiguration办法创立AppConfig，而后执行agollo.InitCustomConfig，最初执行agollo.Start()

doc

  • apollo/impl.go