mirror of https://github.com/chrislusf/seaweedfs
63 lines
1.7 KiB
Go
63 lines
1.7 KiB
Go
package pb
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import (
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"github.com/seaweedfs/seaweedfs/weed/glog"
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"reflect"
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)
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// ServerDiscovery encodes a way to find at least 1 instance of a service,
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// and provides utility functions to refresh the instance list
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type ServerDiscovery struct {
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list []ServerAddress
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srvRecord *ServerSrvAddress
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}
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func NewServiceDiscoveryFromMap(m map[string]ServerAddress) (sd *ServerDiscovery) {
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sd = &ServerDiscovery{}
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for _, s := range m {
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sd.list = append(sd.list, s)
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}
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return sd
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}
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// RefreshBySrvIfAvailable performs a DNS SRV lookup and updates list with the results
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// of the lookup
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func (sd *ServerDiscovery) RefreshBySrvIfAvailable() {
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if sd.srvRecord == nil {
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return
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}
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newList, err := sd.srvRecord.LookUp()
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if err != nil {
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glog.V(0).Infof("failed to lookup SRV for %s: %v", *sd.srvRecord, err)
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}
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if newList == nil || len(newList) == 0 {
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glog.V(0).Infof("looked up SRV for %s, but found no well-formed names", *sd.srvRecord)
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return
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}
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if !reflect.DeepEqual(sd.list, newList) {
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sd.list = newList
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}
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}
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// GetInstances returns a copy of the latest known list of addresses
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// call RefreshBySrvIfAvailable prior to this in order to get a more up-to-date view
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func (sd *ServerDiscovery) GetInstances() (addresses []ServerAddress) {
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for _, a := range sd.list {
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addresses = append(addresses, a)
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}
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return addresses
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}
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func (sd *ServerDiscovery) GetInstancesAsStrings() (addresses []string) {
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for _, i := range sd.list {
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addresses = append(addresses, string(i))
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}
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return addresses
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}
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func (sd *ServerDiscovery) GetInstancesAsMap() (addresses map[string]ServerAddress) {
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addresses = make(map[string]ServerAddress)
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for _, i := range sd.list {
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addresses[string(i)] = i
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}
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return addresses
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}
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