// Licensed to Elasticsearch B.V. under one or more contributor
// license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright
// ownership. Elasticsearch B.V. licenses this file to you 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 op

import "sync"

type Canceler struct {
	lock   sync.RWMutex
	done   chan struct{}
	active bool
}

func NewCanceler() *Canceler {
	return &Canceler{
		done:   make(chan struct{}),
		active: true,
	}
}

func (c *Canceler) Cancel() {
	c.lock.Lock()
	c.active = false
	c.lock.Unlock()

	close(c.done)
}

func (c *Canceler) Done() <-chan struct{} {
	return c.done
}