polardbxoperator/pkg/util/config/driver.go

117 lines
2.2 KiB
Go

/*
Copyright 2021 Alibaba Group Holding Limited.
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 config
import (
"context"
"sync"
"time"
"github.com/go-logr/logr"
"github.com/alibaba/polardbx-operator/pkg/util/config/bundle"
"github.com/alibaba/polardbx-operator/pkg/util/config/loader"
)
type ParseFunc func(bundle bundle.Bundle) (interface{}, error)
type Watcher func(interface{})
type WatchDriver interface {
Start(ctx context.Context) error
}
type watchDriver struct {
once sync.Once
logger logr.Logger
loader loader.Loader
parser ParseFunc
watchers []Watcher
interval time.Duration
}
func (w *watchDriver) drive(ctx context.Context) error {
b, err := w.loader.Load(ctx)
if err != nil {
return err
}
c, err := w.parser(b)
if err != nil {
return err
}
for _, watcher := range w.watchers {
watcher(c)
}
return nil
}
func (w *watchDriver) start(ctx context.Context) {
select {
case <-ctx.Done():
return
default:
}
for {
err := w.drive(ctx)
if err != nil {
w.logger.Error(err, "Watch failed.")
}
select {
case <-ctx.Done():
return
case <-time.After(w.interval):
}
}
}
func (w *watchDriver) Start(ctx context.Context) error {
var err error
w.once.Do(func() {
err = w.drive(ctx)
if err != nil {
return
}
go w.start(ctx)
})
return err
}
type WatchDriverOptions struct {
Logger logr.Logger
Interval time.Duration
Watchers []Watcher
}
func NewConfigWatchDriver(loader loader.Loader, parser ParseFunc, opts WatchDriverOptions) WatchDriver {
if opts.Logger == nil {
opts.Logger = logr.DiscardLogger{}
}
return &watchDriver{
logger: opts.Logger,
loader: loader,
parser: parser,
watchers: opts.Watchers,
interval: opts.Interval,
}
}