parallel.go

/*
 * Copyright 2023 RisingWave Labs
 *
 * 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 ctrlkit

import (
	"context"
	"fmt"

	ctrl "sigs.k8s.io/controller-runtime"

	"github.com/risingwavelabs/ctrlkit/internal"
)

var _ internal.Decorator = &parallelAction{}

type parallelAction struct {
	inner Action
}

// Inner implements the Decorator.
func (act *parallelAction) Inner() Action {
	return act.inner
}

// SetInner implements the Decorator.
func (act *parallelAction) SetInner(inner Action) {
	act.inner = inner
}

// Name implements the Decorator.
func (act *parallelAction) Name() string {
	return "Parallel"
}

// Description implements the Action.
func (act *parallelAction) Description() string {
	return fmt.Sprintf("Parallel(%s)", act.inner.Description())
}

// Run implements the Action.
func (act *parallelAction) Run(ctx context.Context) (result ctrl.Result, err error) {
	done := make(chan bool)
	panicChan := make(chan any)

	go func() {
		defer func() {
			if r := recover(); r != nil {
				panicChan <- r
			}
		}()
		result, err = act.inner.Run(ctx)
		close(done)
	}()

	select {
	case r := <-panicChan:
		panic(r)
	case <-done:
		return
	}
}

// Parallel wraps the action and runs it in parallel.
func Parallel(act Action) Action {
	switch act := act.(type) {
	case *parallelAction:
		return act
	default:
		return &parallelAction{inner: act}
	}
}