package cache import ( "fmt" "sync" "github.com/nspcc-dev/neofs-api-go/pkg/client" "github.com/nspcc-dev/neofs-node/pkg/network" ) type ( // ClientCache is a structure around neofs-api-go/pkg/client to reuse // already created clients. ClientCache struct { mu *sync.RWMutex clients map[string]client.Client opts []client.Option } ) // NewSDKClientCache creates instance of client cache. // `opts` are used for new client creation. func NewSDKClientCache(opts ...client.Option) *ClientCache { return &ClientCache{ mu: new(sync.RWMutex), clients: make(map[string]client.Client), opts: opts, } } // Get function returns existing client or creates a new one. func (c *ClientCache) Get(netAddr *network.Address) (client.Client, error) { hostAddr, err := netAddr.HostAddrString() if err != nil { return nil, fmt.Errorf("could not parse address as a string: %w", err) } c.mu.RLock() if cli, ok := c.clients[hostAddr]; ok { // todo: check underlying connection neofs-api-go#196 c.mu.RUnlock() return cli, nil } c.mu.RUnlock() // if client is not found in cache, then create a new one c.mu.Lock() defer c.mu.Unlock() // check once again if client is missing in cache, concurrent routine could // create client while this routine was locked on `c.mu.Lock()`. if cli, ok := c.clients[hostAddr]; ok { return cli, nil } opts := append(c.opts, client.WithAddress(hostAddr)) cli, err := client.New(opts...) if err != nil { return nil, err } c.clients[hostAddr] = cli return cli, nil }