// Copyright 2021-2023 EMQ Technologies Co., Ltd. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. package memory import ( "fmt" "regexp" "strings" "github.com/lf-edge/ekuiper/internal/io/memory/pubsub" "github.com/lf-edge/ekuiper/pkg/api" "github.com/lf-edge/ekuiper/pkg/cast" ) type source struct { topic string topicRegex *regexp.Regexp bufferLength int } func (s *source) Open(ctx api.StreamContext, consumer chan<- api.SourceTuple, _ chan<- error) { ch := pubsub.CreateSub(s.topic, s.topicRegex, fmt.Sprintf("%s_%s_%d", ctx.GetRuleId(), ctx.GetOpId(), ctx.GetInstanceId()), s.bufferLength) for { select { case v, opened := <-ch: if !opened { return } consumer <- v case <-ctx.Done(): return } } } func (s *source) Configure(datasource string, props map[string]interface{}) error { s.topic = datasource s.bufferLength = 1024 if c, ok := props["bufferLength"]; ok { if bl, err := cast.ToInt(c, cast.STRICT); err != nil || bl > 0 { s.bufferLength = bl } } if strings.ContainsAny(datasource, "+#") { r, err := getRegexp(datasource) if err != nil { return err } s.topicRegex = r } return nil } func getRegexp(topic string) (*regexp.Regexp, error) { if len(topic) == 0 { return nil, fmt.Errorf("invalid empty topic") } levels := strings.Split(topic, "/") for i, level := range levels { if level == "#" && i != len(levels)-1 { return nil, fmt.Errorf("invalid topic %s: # must at the last level", topic) } } regstr := strings.Replace(strings.ReplaceAll(topic, "+", "([^/]+)"), "#", ".", 1) return regexp.Compile(regstr) } func (s *source) Close(ctx api.StreamContext) error { ctx.GetLogger().Debugf("closing memory source") pubsub.CloseSourceConsumerChannel(s.topic, fmt.Sprintf("%s_%s_%d", ctx.GetRuleId(), ctx.GetOpId(), ctx.GetInstanceId())) return nil }