package libnetwork import ( "encoding/json" "fmt" "sync" "github.com/docker/libnetwork/datastore" ) type endpointCnt struct { n *network Count uint64 dbIndex uint64 dbExists bool sync.Mutex } const epCntKeyPrefix = "endpoint_count" func (ec *endpointCnt) Key() []string { ec.Lock() defer ec.Unlock() return []string{epCntKeyPrefix, ec.n.id} } func (ec *endpointCnt) KeyPrefix() []string { ec.Lock() defer ec.Unlock() return []string{epCntKeyPrefix, ec.n.id} } func (ec *endpointCnt) Value() []byte { ec.Lock() defer ec.Unlock() b, err := json.Marshal(ec) if err != nil { return nil } return b } func (ec *endpointCnt) SetValue(value []byte) error { ec.Lock() defer ec.Unlock() return json.Unmarshal(value, &ec) } func (ec *endpointCnt) Index() uint64 { ec.Lock() defer ec.Unlock() return ec.dbIndex } func (ec *endpointCnt) SetIndex(index uint64) { ec.Lock() ec.dbIndex = index ec.dbExists = true ec.Unlock() } func (ec *endpointCnt) Exists() bool { ec.Lock() defer ec.Unlock() return ec.dbExists } func (ec *endpointCnt) Skip() bool { ec.Lock() defer ec.Unlock() return !ec.n.persist } func (ec *endpointCnt) New() datastore.KVObject { ec.Lock() defer ec.Unlock() return &endpointCnt{ n: ec.n, } } func (ec *endpointCnt) CopyTo(o datastore.KVObject) error { ec.Lock() defer ec.Unlock() dstEc := o.(*endpointCnt) dstEc.n = ec.n dstEc.Count = ec.Count dstEc.dbExists = ec.dbExists dstEc.dbIndex = ec.dbIndex return nil } func (ec *endpointCnt) DataScope() string { return ec.n.DataScope() } func (ec *endpointCnt) EndpointCnt() uint64 { ec.Lock() defer ec.Unlock() return ec.Count } func (ec *endpointCnt) updateStore() error { store := ec.n.getController().getStore(ec.DataScope()) if store == nil { return fmt.Errorf("store not found for scope %s on endpoint count update", ec.DataScope()) } // make a copy of count and n to avoid being overwritten by store.GetObject count := ec.EndpointCnt() n := ec.n for { if err := ec.n.getController().updateToStore(ec); err == nil || err != datastore.ErrKeyModified { return err } if err := store.GetObject(datastore.Key(ec.Key()...), ec); err != nil { return fmt.Errorf("could not update the kvobject to latest on endpoint count update: %v", err) } ec.Lock() ec.Count = count ec.n = n ec.Unlock() } } func (ec *endpointCnt) setCnt(cnt uint64) error { ec.Lock() ec.Count = cnt ec.Unlock() return ec.updateStore() } func (ec *endpointCnt) atomicIncDecEpCnt(inc bool) error { retry: ec.Lock() if inc { ec.Count++ } else { if ec.Count > 0 { ec.Count-- } } ec.Unlock() store := ec.n.getController().getStore(ec.DataScope()) if store == nil { return fmt.Errorf("store not found for scope %s", ec.DataScope()) } if err := ec.n.getController().updateToStore(ec); err != nil { if err == datastore.ErrKeyModified { if err := store.GetObject(datastore.Key(ec.Key()...), ec); err != nil { return fmt.Errorf("could not update the kvobject to latest when trying to atomic add endpoint count: %v", err) } goto retry } return err } return nil } func (ec *endpointCnt) IncEndpointCnt() error { return ec.atomicIncDecEpCnt(true) } func (ec *endpointCnt) DecEndpointCnt() error { return ec.atomicIncDecEpCnt(false) }