sugardb/internal/memberlist/event_delegate.go

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// Copyright 2024 Kelvin Clement Mwinuka
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package memberlist
import (
"encoding/json"
"github.com/hashicorp/memberlist"
"log"
)
type EventDelegate struct {
options EventDelegateOpts
}
type EventDelegateOpts struct {
incrementNodes func()
decrementNodes func()
removeRaftServer func(meta NodeMeta) error
}
func NewEventDelegate(opts EventDelegateOpts) *EventDelegate {
return &EventDelegate{
options: opts,
}
}
// NotifyJoin implements EventDelegate interface
func (eventDelegate *EventDelegate) NotifyJoin(node *memberlist.Node) {
eventDelegate.options.incrementNodes()
}
// NotifyLeave implements EventDelegate interface
func (eventDelegate *EventDelegate) NotifyLeave(node *memberlist.Node) {
eventDelegate.options.decrementNodes()
var meta NodeMeta
err := json.Unmarshal(node.Meta, &meta)
if err != nil {
log.Println("Could not get leaving node's metadata.")
return
}
err = eventDelegate.options.removeRaftServer(meta)
if err != nil {
log.Println(err)
}
}
// NotifyUpdate implements EventDelegate interface
func (eventDelegate *EventDelegate) NotifyUpdate(node *memberlist.Node) {
// No-Op
}