istio.io/istio@v0.0.0-20240520182934-d79c90f27776/pkg/ledger/trie_cache.go (about)

     1  // Copyright 2019 Istio Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package ledger
    16  
    17  import (
    18  	"sync"
    19  	"time"
    20  
    21  	"istio.io/istio/pkg/cache"
    22  )
    23  
    24  type cacheDB struct {
    25  	// updatedNodes that have will be flushed to disk
    26  	updatedNodes byteCache
    27  	// updatedMux is a lock for updatedNodes
    28  	updatedMux sync.RWMutex
    29  }
    30  
    31  // byteCache implements a modified ExpiringCache interface, returning byte arrays
    32  // for ease of integration with smt calls.
    33  type byteCache struct {
    34  	cache cache.ExpiringCache
    35  }
    36  
    37  // Set inserts an entry in the cache. This will replace any entry with
    38  // the same key that is already in the cache. The entry may be automatically
    39  // expunged from the cache at some point, depending on the eviction policies
    40  // of the cache and the options specified when the cache was created.
    41  func (b *byteCache) Set(key hash, value [][]byte) {
    42  	b.cache.Set(key, value)
    43  }
    44  
    45  // Get retrieves the value associated with the supplied key if the key
    46  // is present in the cache.
    47  func (b *byteCache) Get(key hash) (value [][]byte, ok bool) {
    48  	ivalue, ok := b.cache.Get(key)
    49  	if ok {
    50  		value, _ = ivalue.([][]byte)
    51  	}
    52  	return
    53  }
    54  
    55  // SetWithExpiration inserts an entry in the cache with a requested expiration time.
    56  // This will replace any entry with the same key that is already in the cache.
    57  // The entry will be automatically expunged from the cache at or slightly after the
    58  // requested expiration time.
    59  func (b *byteCache) SetWithExpiration(key hash, value [][]byte, expiration time.Duration) {
    60  	b.cache.SetWithExpiration(key, value, expiration)
    61  }