/*
 * 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 kvstore

// Cacher manages cache of some data source, e.g. etcd, kubernetes.
// An user can do nothing but read the managed cache.
type Cacher interface {
	// Cache gets the cache that Cacher manages.
	Cache() CacheReader
}

// Cache stores k-v data.
type Cache interface {
	CacheReader
	// Put puts a k-v
	Put(k string, v *KeyValue)
	// Remove removes a k-v data
	Remove(k string)
	// MarkDirty mark k-v data dirty
	MarkDirty()
	// Dirty k-v data is dirty or not
	Dirty() bool
	// Clear clear all k-v data
	Clear()
}

// CacheReader reads k-v data.
type CacheReader interface {
	Name() string // The name of implementation
	Size() int    // the bytes size of the cache
	// Get gets a value by input key
	Get(k string) *KeyValue
	// GetAll gets all the data stored in Cache
	GetAll(arr *[]*KeyValue) int
	// GetPrefix gets values by the key prefix
	GetPrefix(prefix string, arr *[]*KeyValue) int
	// ForEach executes the given function for each of the k-v
	ForEach(iter func(k string, v *KeyValue) (next bool))
}