forked from scionproto/scion
/
memrevcache.go
83 lines (73 loc) · 2.05 KB
/
memrevcache.go
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// Copyright 2018 ETH Zurich, Anapaya Systems
//
// 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 memrevcache
import (
"sync"
"time"
cache "github.com/patrickmn/go-cache"
"github.com/scionproto/scion/go/lib/ctrl/path_mgmt"
"github.com/scionproto/scion/go/lib/revcache"
)
var _ revcache.RevCache = (*memRevCache)(nil)
type memRevCache struct {
// Do not embed or use type directly to reduce the cache's API surface
c *cache.Cache
lock sync.RWMutex
}
// New creates a new RevCache, backed by an in memory cache.
func New(defaultExpiration, cleanupInterval time.Duration) revcache.RevCache {
return &memRevCache{
c: cache.New(defaultExpiration, cleanupInterval),
}
}
func (c *memRevCache) Get(k *revcache.Key) (*path_mgmt.SignedRevInfo, bool) {
c.lock.RLock()
defer c.lock.RUnlock()
return c.get(k.String())
}
func (c *memRevCache) get(key string) (*path_mgmt.SignedRevInfo, bool) {
obj, ok := c.c.Get(key)
if !ok {
return nil, false
}
return obj.(*path_mgmt.SignedRevInfo), true
}
func (c *memRevCache) Insert(rev *path_mgmt.SignedRevInfo) bool {
c.lock.Lock()
defer c.lock.Unlock()
newInfo, err := rev.RevInfo()
if err != nil {
panic(err)
}
ttl := newInfo.Expiration().Sub(time.Now())
if ttl <= 0 {
return false
}
k := revcache.NewKey(newInfo.IA(), newInfo.IfID)
key := k.String()
val, ok := c.get(key)
if !ok {
c.c.Set(key, rev, ttl)
return true
}
existingInfo, err := val.RevInfo()
if err != nil {
panic(err)
}
if newInfo.Timestamp().After(existingInfo.Timestamp()) {
c.c.Set(key, rev, ttl)
return true
}
return false
}