package cache import ( "fmt" "strings" "time" "github.com/bluele/gcache" cid "github.com/nspcc-dev/neofs-sdk-go/container/id" oid "github.com/nspcc-dev/neofs-sdk-go/object/id" ) /* This is an implementation of cache which keeps unsorted lists of objects' IDs (all versions) for a specified bucket and a prefix. The cache contains gcache whose entries have a key: ObjectsListKey struct and a value: list of ids. After putting a record, it lives for a while (default value is 60 seconds). When we receive a request from a user, we try to find the suitable and non-expired cache entry, go through the list and get ObjectInfos from common object cache or with a request to NeoFS. When we put an object into a container, we invalidate entries with prefixes that are prefixes of the object's name. */ type ( // ObjectsListCache contains cache for ListObjects and ListObjectVersions. ObjectsListCache struct { cache gcache.Cache } // ObjectsListKey is a key to find a ObjectsListCache's entry. ObjectsListKey struct { cid string prefix string } ) const ( // DefaultObjectsListCacheLifetime is a default lifetime of entries in cache of ListObjects. DefaultObjectsListCacheLifetime = time.Second * 60 // DefaultObjectsListCacheSize is a default size of cache of ListObjects. DefaultObjectsListCacheSize = 1e5 ) // DefaultObjectsListConfig returns new default cache expiration values. func DefaultObjectsListConfig() *Config { return &Config{Size: DefaultObjectsListCacheSize, Lifetime: DefaultObjectsListCacheLifetime} } // NewObjectsListCache is a constructor which creates an object of ListObjectsCache with the given lifetime of entries. func NewObjectsListCache(config *Config) *ObjectsListCache { gc := gcache.New(config.Size).LRU().Expiration(config.Lifetime).Build() return &ObjectsListCache{cache: gc} } // Get returns a list of ObjectInfo. func (l *ObjectsListCache) Get(key ObjectsListKey) []oid.ID { entry, err := l.cache.Get(key) if err != nil { return nil } result, ok := entry.([]oid.ID) if !ok { return nil } return result } // Put puts a list of objects to cache. func (l *ObjectsListCache) Put(key ObjectsListKey, oids []oid.ID) error { if len(oids) == 0 { return fmt.Errorf("list is empty, cid: %s, prefix: %s", key.cid, key.prefix) } return l.cache.Set(key, oids) } // CleanCacheEntriesContainingObject deletes entries containing specified object. func (l *ObjectsListCache) CleanCacheEntriesContainingObject(objectName string, cid *cid.ID) { cidStr := cid.String() keys := l.cache.Keys(true) for _, key := range keys { k, ok := key.(ObjectsListKey) if !ok { continue } if cidStr == k.cid && strings.HasPrefix(objectName, k.prefix) { l.cache.Remove(k) } } } // CreateObjectsListCacheKey returns ObjectsListKey with the given CID and prefix. func CreateObjectsListCacheKey(cid *cid.ID, prefix string) ObjectsListKey { p := ObjectsListKey{ cid: cid.String(), prefix: prefix, } return p }