rclone/vendor/go.opencensus.io/trace/lrumap.go
2019-11-14 21:51:34 +00:00

62 lines
1.5 KiB
Go

// Copyright 2019, OpenCensus Authors
//
// 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 trace
import (
"github.com/golang/groupcache/lru"
)
// A simple lru.Cache wrapper that tracks the keys of the current contents and
// the cumulative number of evicted items.
type lruMap struct {
cacheKeys map[lru.Key]bool
cache *lru.Cache
droppedCount int
}
func newLruMap(size int) *lruMap {
lm := &lruMap{
cacheKeys: make(map[lru.Key]bool),
cache: lru.New(size),
droppedCount: 0,
}
lm.cache.OnEvicted = func(key lru.Key, value interface{}) {
delete(lm.cacheKeys, key)
lm.droppedCount++
}
return lm
}
func (lm lruMap) len() int {
return lm.cache.Len()
}
func (lm lruMap) keys() []interface{} {
keys := []interface{}{}
for k := range lm.cacheKeys {
keys = append(keys, k)
}
return keys
}
func (lm *lruMap) add(key, value interface{}) {
lm.cacheKeys[lru.Key(key)] = true
lm.cache.Add(lru.Key(key), value)
}
func (lm *lruMap) get(key interface{}) (interface{}, bool) {
return lm.cache.Get(key)
}