/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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 engine

import (
	"context"
)

type Entry struct {
	Key   string `json:"key"`
	Value []byte `json:"value"`
}

type Engine interface {
	ID() string
	Leader() string
	LeaderChange() <-chan bool
	IsReady(ctx context.Context) bool

	Get(ctx context.Context, key string) ([]byte, error)
	Exists(ctx context.Context, key string) (bool, error)
	Set(ctx context.Context, key string, value []byte) error
	Delete(ctx context.Context, key string) error
	List(ctx context.Context, prefix string) ([]Entry, error)

	Close() error
}
