drone/app/store/cache/evictor.go

80 lines
1.8 KiB
Go

// Copyright 2023 Harness, Inc.
//
// 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 cache
import (
"bytes"
"context"
"encoding/gob"
"github.com/harness/gitness/pubsub"
"github.com/rs/zerolog/log"
)
type Evictor[T any] struct {
nameSpace string
topicName string
bus pubsub.PubSub
}
func NewEvictor[T any](
nameSpace string,
topicName string,
bus pubsub.PubSub,
) Evictor[T] {
return Evictor[T]{
nameSpace: nameSpace,
topicName: topicName,
bus: bus,
}
}
func (e Evictor[T]) Subscribe(ctx context.Context, fn func(key T) error) {
if e.bus == nil {
return
}
_ = e.bus.Subscribe(ctx, e.topicName, func(payload []byte) error {
var key T
err := gob.NewDecoder(bytes.NewReader(payload)).Decode(&key)
if err != nil {
log.Ctx(ctx).Warn().Err(err).Msgf("failed to process update event from type: %T", key)
return err
}
return fn(key)
}, pubsub.WithChannelNamespace(e.nameSpace))
}
func (e Evictor[T]) Evict(ctx context.Context, key T) {
if e.bus == nil {
return
}
buf := bytes.NewBuffer(nil)
_ = gob.NewEncoder(buf).Encode(key)
err := e.bus.Publish(
ctx,
e.topicName,
buf.Bytes(),
pubsub.WithPublishNamespace(e.nameSpace),
)
if err != nil {
log.Ctx(ctx).Warn().Err(err).Msgf("failed to publish update event for type %T", key)
}
}