package oracle import ( "errors" "net/http" "net/url" "time" "github.com/nspcc-dev/neo-go/pkg/core/state" "github.com/nspcc-dev/neo-go/pkg/core/storage" "github.com/nspcc-dev/neo-go/pkg/core/transaction" "github.com/nspcc-dev/neo-go/pkg/crypto/keys" "go.uber.org/zap" ) const defaultMaxConcurrentRequests = 10 type request struct { ID uint64 Req *state.OracleRequest } func (o *Oracle) runRequestWorker() { for { select { case <-o.close: return case req := <-o.requestCh: acc := o.getAccount() if acc == nil { continue } err := o.processRequest(acc.PrivateKey(), req) if err != nil { o.Log.Debug("can't process request", zap.Uint64("id", req.ID), zap.Error(err)) } } } } // RemoveRequests removes all data associated with requests // which have been processed by oracle contract. func (o *Oracle) RemoveRequests(ids []uint64) { o.respMtx.Lock() defer o.respMtx.Unlock() for _, id := range ids { delete(o.responses, id) } } // AddRequests saves all requests in-fly for further processing. func (o *Oracle) AddRequests(reqs map[uint64]*state.OracleRequest) { if len(reqs) == 0 { return } select { case o.requestMap <- reqs: default: select { case old := <-o.requestMap: for id, r := range old { reqs[id] = r } default: } o.requestMap <- reqs } } // ProcessRequestsInternal processes provided requests synchronously. func (o *Oracle) ProcessRequestsInternal(reqs map[uint64]*state.OracleRequest) { acc := o.getAccount() if acc == nil { return } // Process actual requests. for id, req := range reqs { if err := o.processRequest(acc.PrivateKey(), request{ID: id, Req: req}); err != nil { o.Log.Debug("can't process request", zap.Error(err)) } } } func (o *Oracle) processRequest(priv *keys.PrivateKey, req request) error { if req.Req == nil { o.processFailedRequest(priv, req) return nil } incTx := o.getResponse(req.ID, true) if incTx == nil { return nil } resp := &transaction.OracleResponse{ID: req.ID} u, err := url.ParseRequestURI(req.Req.URL) if err == nil && !o.MainCfg.AllowPrivateHost { err = o.URIValidator(u) } if err != nil { resp.Code = transaction.Forbidden } else if u.Scheme == "http" { r, err := o.Client.Get(req.Req.URL) switch { case err != nil: resp.Code = transaction.Error case r.StatusCode == http.StatusOK: result, err := readResponse(r.Body, transaction.MaxOracleResultSize) if err != nil { if errors.Is(err, ErrResponseTooLarge) { resp.Code = transaction.ResponseTooLarge } else { resp.Code = transaction.Error } break } if req.Req.Filter != nil { res, err := filter(result, *req.Req.Filter) if err != nil { resp.Code = transaction.Error break } result = res } resp.Code = transaction.Success resp.Result = result case r.StatusCode == http.StatusForbidden: resp.Code = transaction.Forbidden case r.StatusCode == http.StatusNotFound: resp.Code = transaction.NotFound case r.StatusCode == http.StatusRequestTimeout: resp.Code = transaction.Timeout default: resp.Code = transaction.Error } } currentHeight := o.Chain.BlockHeight() _, h, err := o.Chain.GetTransaction(req.Req.OriginalTxID) if err != nil { if !errors.Is(err, storage.ErrKeyNotFound) { return err } // The only reason tx can be not found is if it wasn't yet persisted from DAO. h = currentHeight } tx, err := o.CreateResponseTx(int64(req.Req.GasForResponse), h, resp) if err != nil { return err } backupTx, err := o.CreateResponseTx(int64(req.Req.GasForResponse), h, &transaction.OracleResponse{ ID: req.ID, Code: transaction.ConsensusUnreachable, }) if err != nil { return err } incTx.Lock() incTx.request = req.Req incTx.tx = tx incTx.backupTx = backupTx incTx.reverifyTx() txSig := priv.Sign(tx.GetSignedPart()) incTx.addResponse(priv.PublicKey(), txSig, false) backupSig := priv.Sign(backupTx.GetSignedPart()) incTx.addResponse(priv.PublicKey(), backupSig, true) readyTx, ready := incTx.finalize(o.getOracleNodes(), false) if ready { ready = !incTx.isSent incTx.isSent = true } incTx.time = time.Now() incTx.attempts++ incTx.Unlock() o.getBroadcaster().SendResponse(priv, resp, txSig) if ready { o.getOnTransaction()(readyTx) } return nil } func (o *Oracle) processFailedRequest(priv *keys.PrivateKey, req request) { // Request is being processed again. incTx := o.getResponse(req.ID, false) if incTx == nil { // Request was processed by other oracle nodes. return } else if incTx.isSent { // Tx was sent but not yet persisted. Try to pool it again. o.getOnTransaction()(incTx.tx) return } // Don't process request again, fallback to backup tx. incTx.Lock() readyTx, ready := incTx.finalize(o.getOracleNodes(), true) if ready { ready = !incTx.isSent incTx.isSent = true } incTx.time = time.Now() incTx.attempts++ txSig := incTx.backupSigs[string(priv.PublicKey().Bytes())].sig incTx.Unlock() o.getBroadcaster().SendResponse(priv, getFailedResponse(req.ID), txSig) if ready { o.getOnTransaction()(readyTx) } }