package server import ( "github.com/gorilla/websocket" "github.com/nspcc-dev/neo-go/pkg/core/block" "github.com/nspcc-dev/neo-go/pkg/core/state" "github.com/nspcc-dev/neo-go/pkg/core/transaction" "github.com/nspcc-dev/neo-go/pkg/rpc/request" "github.com/nspcc-dev/neo-go/pkg/rpc/response" "go.uber.org/atomic" ) type ( // subscriber is an event subscriber. subscriber struct { writer chan<- *websocket.PreparedMessage ws *websocket.Conn overflown atomic.Bool // These work like slots as there is not a lot of them (it's // cheaper doing it this way rather than creating a map), // pointing to EventID is an obvious overkill at the moment, but // that's not for long. feeds [maxFeeds]feed } feed struct { event response.EventID filter interface{} } ) const ( // Maximum number of subscriptions per one client. maxFeeds = 16 // This sets notification messages buffer depth, it may seem to be quite // big, but there is a big gap in speed between internal event processing // and networking communication that is combined with spiky nature of our // event generation process, which leads to lots of events generated in // short time and they will put some pressure to this buffer (consider // ~500 invocation txs in one block with some notifications). At the same // time this channel is about sending pointers, so it's doesn't cost // a lot in terms of memory used. notificationBufSize = 1024 ) func (f *feed) Matches(r *response.Notification) bool { if r.Event != f.event { return false } if f.filter == nil { return true } switch f.event { case response.BlockEventID: filt := f.filter.(request.BlockFilter) b := r.Payload[0].(*block.Block) return int(b.PrimaryIndex) == filt.Primary case response.TransactionEventID: filt := f.filter.(request.TxFilter) tx := r.Payload[0].(*transaction.Transaction) senderOK := filt.Sender == nil || tx.Sender().Equals(*filt.Sender) signerOK := true if filt.Signer != nil { signerOK = false for i := range tx.Signers { if tx.Signers[i].Account.Equals(*filt.Signer) { signerOK = true break } } } return senderOK && signerOK case response.NotificationEventID: filt := f.filter.(request.NotificationFilter) notification := r.Payload[0].(*state.NotificationEvent) hashOk := filt.Contract == nil || notification.ScriptHash.Equals(*filt.Contract) nameOk := filt.Name == nil || notification.Name == *filt.Name return hashOk && nameOk case response.ExecutionEventID: filt := f.filter.(request.ExecutionFilter) applog := r.Payload[0].(*state.AppExecResult) return applog.VMState.String() == filt.State } return false }