// 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 cache

import "errors"

var ErrNoSuchKey = errors.New("there's no such key existing in cache")

type Cache interface {
	// Set puts key and value into cache.
	// First parameter for extra should be time.Time object denoting expected survival time.
	// If survival time equals 0 or less, the key will always be survival.
	Set(key string, value bool, extra ...interface{}) error

	// Get returns result for key,
	// If there's no such key existing in cache,
	// ErrNoSuchKey will be returned.
	Get(key string) (bool, error)

	// Delete will remove the specific key in cache.
	// If there's no such key existing in cache,
	// ErrNoSuchKey will be returned.
	Delete(key string) error

	// Clear deletes all the items stored in cache.
	Clear() error
}