package placement import ( "sync" "github.com/nspcc-dev/neofs-api-go/pkg/container" "github.com/nspcc-dev/neofs-api-go/pkg/netmap" "github.com/nspcc-dev/neofs-api-go/pkg/object" "github.com/nspcc-dev/neofs-node/pkg/network" "github.com/pkg/errors" ) // Builder is an interface of the // object placement vector builder. type Builder interface { // BuildPlacement returns the list of placement vectors // for object according to the placement policy. // // Must return all container nodes if object identifier // is nil. BuildPlacement(*object.Address, *netmap.PlacementPolicy) ([]netmap.Nodes, error) } // Option represents placement traverser option. type Option func(*cfg) // Traverser represents utility for controlling // traversal of object placement vectors. type Traverser struct { mtx *sync.RWMutex vectors []netmap.Nodes rem []int } type cfg struct { rem int addr *object.Address policy *netmap.PlacementPolicy builder Builder } const invalidOptsMsg = "invalid traverser options" var errNilBuilder = errors.New("placement builder is nil") var errNilPolicy = errors.New("placement policy is nil") func defaultCfg() *cfg { return &cfg{ addr: object.NewAddress(), } } // NewTraverser creates, initializes with options and returns Traverser instance. func NewTraverser(opts ...Option) (*Traverser, error) { cfg := defaultCfg() for i := range opts { if opts[i] != nil { opts[i](cfg) } } if cfg.builder == nil { return nil, errors.Wrap(errNilBuilder, invalidOptsMsg) } else if cfg.policy == nil { return nil, errors.Wrap(errNilPolicy, invalidOptsMsg) } ns, err := cfg.builder.BuildPlacement(cfg.addr, cfg.policy) if err != nil { return nil, errors.Wrap(err, "could not build placement") } rs := cfg.policy.Replicas() rem := make([]int, 0, len(rs)) for i := range rs { cnt := cfg.rem if cnt == 0 { cnt = int(rs[i].Count()) } rem = append(rem, cnt) } return &Traverser{ mtx: new(sync.RWMutex), rem: rem, vectors: ns, }, nil } // Next returns next unprocessed address of the object placement. // // Returns nil if no nodes left or traversal operation succeeded. func (t *Traverser) Next() []*network.Address { t.mtx.Lock() defer t.mtx.Unlock() t.skipEmptyVectors() if len(t.vectors) == 0 { return nil } else if len(t.vectors[0]) < t.rem[0] { return nil } count := t.rem[0] if count < 0 { count = len(t.vectors[0]) } addrs := make([]*network.Address, 0, count) for i := 0; i < count; i++ { addr, err := network.AddressFromString(t.vectors[0][i].Address()) if err != nil { // TODO: log error return nil } addrs = append(addrs, addr) } t.vectors[0] = t.vectors[0][count:] return addrs } func (t *Traverser) skipEmptyVectors() { for i := 0; i < len(t.vectors); i++ { // don't use range, slice changes in body if len(t.vectors[i]) == 0 && t.rem[i] <= 0 || t.rem[0] == 0 { t.vectors = append(t.vectors[:i], t.vectors[i+1:]...) t.rem = append(t.rem[:i], t.rem[i+1:]...) i-- } else { break } } } // SubmitSuccess writes single succeeded node operation. func (t *Traverser) SubmitSuccess() { t.mtx.Lock() if len(t.rem) > 0 { t.rem[0]-- } t.mtx.Unlock() } // Success returns true if traversal operation succeeded. func (t *Traverser) Success() bool { t.mtx.RLock() defer t.mtx.RUnlock() for i := range t.rem { if t.rem[i] > 0 { return false } } return true } // UseBuilder is a placement builder setting option. // // Overlaps UseNetworkMap option. func UseBuilder(b Builder) Option { return func(c *cfg) { c.builder = b } } // ForContainer is a traversal container setting option. func ForContainer(cnr *container.Container) Option { return func(c *cfg) { c.policy = cnr.PlacementPolicy() c.addr.SetContainerID(container.CalculateID(cnr)) } } // ForObject is a processing object setting option. func ForObject(id *object.ID) Option { return func(c *cfg) { c.addr.SetObjectID(id) } } // SuccessAfter is a success number setting option. // // Option has no effect if the number is not positive. func SuccessAfter(v int) Option { return func(c *cfg) { if v > 0 { c.rem = v } } } // WithoutSuccessTracking disables success tracking in traversal. func WithoutSuccessTracking() Option { return func(c *cfg) { c.rem = -1 } }