package blobovniczatree import ( "errors" "fmt" "path/filepath" "strconv" "sync" "github.com/hashicorp/golang-lru/simplelru" "github.com/nspcc-dev/hrw" "github.com/nspcc-dev/neofs-node/pkg/local_object_storage/blobovnicza" "github.com/nspcc-dev/neofs-node/pkg/local_object_storage/blobstor/common" "github.com/nspcc-dev/neofs-node/pkg/local_object_storage/blobstor/compression" oid "github.com/nspcc-dev/neofs-sdk-go/object/id" "go.uber.org/zap" ) // Blobovniczas represents the storage of the "small" objects. // // Each object is stored in Blobovnicza's (B-s). // B-s are structured in a multilevel directory hierarchy // with fixed depth and width (configured by BlobStor). // // Example (width = 4, depth = 3): // // x===============================x // |[0] [1] [2] [3]| // | \ / | // | \ / | // | \ / | // | \ / | // |[0] [1] [2] [3]| // | | / | // | | / | // | | / | // | | / | // |[0](F) [1](A) [X] [X]| // x===============================x // // Elements of the deepest level are B-s. // B-s are allocated dynamically. At each moment of the time there is // an active B (ex. A), set of already filled B-s (ex. F) and // a list of not yet initialized B-s (ex. X). After filling the active B // it becomes full, and next B becomes initialized and active. // // Active B and some of the full B-s are cached (LRU). All cached // B-s are intitialized and opened. // // Object is saved as follows: // 1. at each level, according to HRW, the next one is selected and // dives into it until we reach the deepest; // 2. at the B-s level object is saved to the active B. If active B // is full, next B is opened, initialized and cached. If there // is no more X candidates, goto 1 and process next level. // // After the object is saved in B, path concatenation is returned // in system path format as B identifier (ex. "0/1/1" or "3/2/1"). type Blobovniczas struct { cfg // cache of opened filled Blobovniczas opened *simplelru.LRU // lruMtx protects opened cache. // It isn't RWMutex because `Get` calls must // lock this mutex on write, as LRU info is updated. // It must be taken after activeMtx in case when eviction is possible // i.e. `Add`, `Purge` and `Remove` calls. lruMtx sync.Mutex // mutex to exclude parallel bbolt.Open() calls // bbolt.Open() deadlocks if it tries to open already opened file openMtx sync.Mutex // list of active (opened, non-filled) Blobovniczas activeMtx sync.RWMutex active map[string]blobovniczaWithIndex } type blobovniczaWithIndex struct { ind uint64 blz *blobovnicza.Blobovnicza } var _ common.Storage = (*Blobovniczas)(nil) var errPutFailed = errors.New("could not save the object in any blobovnicza") // NewBlobovniczaTree returns new instance of blobovnizas tree. func NewBlobovniczaTree(opts ...Option) (blz *Blobovniczas) { blz = new(Blobovniczas) initConfig(&blz.cfg) for i := range opts { opts[i](&blz.cfg) } cache, err := simplelru.NewLRU(blz.openedCacheSize, func(key interface{}, value interface{}) { if _, ok := blz.active[filepath.Dir(key.(string))]; ok { return } else if err := value.(*blobovnicza.Blobovnicza).Close(); err != nil { blz.log.Error("could not close Blobovnicza", zap.String("id", key.(string)), zap.String("error", err.Error()), ) } else { blz.log.Debug("blobovnicza successfully closed on evict", zap.String("id", key.(string)), ) } }) if err != nil { // occurs only if the size is not positive panic(fmt.Errorf("could not create LRU cache of size %d: %w", blz.openedCacheSize, err)) } cp := uint64(1) for i := uint64(0); i < blz.blzShallowDepth; i++ { cp *= blz.blzShallowWidth } blz.opened = cache blz.active = make(map[string]blobovniczaWithIndex, cp) return blz } // activates and returns activated blobovnicza of p-level (dir). // // returns error if blobvnicza could not be activated. func (b *Blobovniczas) getActivated(p string) (blobovniczaWithIndex, error) { return b.updateAndGet(p, nil) } // updates active blobovnicza of p-level (dir). // // if current active blobovnicza's index is not old, it remains unchanged. func (b *Blobovniczas) updateActive(p string, old *uint64) error { b.log.Debug("updating active blobovnicza...", zap.String("path", p)) _, err := b.updateAndGet(p, old) b.log.Debug("active blobovnicza successfully updated", zap.String("path", p)) return err } // updates and returns active blobovnicza of p-level (dir). // // if current active blobovnicza's index is not old, it is returned unchanged. func (b *Blobovniczas) updateAndGet(p string, old *uint64) (blobovniczaWithIndex, error) { b.activeMtx.RLock() active, ok := b.active[p] b.activeMtx.RUnlock() if ok { if old != nil { if active.ind == b.blzShallowWidth-1 { return active, errors.New("no more Blobovniczas") } else if active.ind != *old { // sort of CAS in order to control concurrent // updateActive calls return active, nil } } else { return active, nil } active.ind++ } var err error if active.blz, err = b.openBlobovnicza(filepath.Join(p, u64ToHexString(active.ind))); err != nil { return active, err } b.activeMtx.Lock() defer b.activeMtx.Unlock() // check 2nd time to find out if it blobovnicza was activated while thread was locked tryActive, ok := b.active[p] if ok && tryActive.blz == active.blz { return tryActive, nil } // Remove from opened cache (active blobovnicza should always be opened). // Because `onEvict` callback is called in `Remove`, we need to update // active map beforehand. b.active[p] = active activePath := filepath.Join(p, u64ToHexString(active.ind)) b.lruMtx.Lock() b.opened.Remove(activePath) if ok { b.opened.Add(filepath.Join(p, u64ToHexString(tryActive.ind)), tryActive.blz) } b.lruMtx.Unlock() b.log.Debug("blobovnicza successfully activated", zap.String("path", activePath)) return active, nil } // returns hash of the object address. func addressHash(addr *oid.Address, path string) uint64 { var a string if addr != nil { a = addr.EncodeToString() } return hrw.Hash([]byte(a + path)) } // converts uint64 to hex string. func u64ToHexString(ind uint64) string { return strconv.FormatUint(ind, 16) } // converts uint64 hex string to uint64. func u64FromHexString(str string) uint64 { v, err := strconv.ParseUint(str, 16, 64) if err != nil { panic(fmt.Sprintf("blobovnicza name is not an index %s", str)) } return v } // Type implements common.Storage. func (b *Blobovniczas) Type() string { return "blobovniczas" } // SetCompressor implements common.Storage. func (b *Blobovniczas) SetCompressor(cc *compression.Config) { b.compression = cc }