// Copyright (C) 2019-2020 Zilliz. All rights reserved. // // 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 flowgraph import ( "context" "fmt" "log" "sync" "time" ) type Node interface { Name() string MaxQueueLength() int32 MaxParallelism() int32 Operate(in []Msg) []Msg IsInputNode() bool Close() } type BaseNode struct { maxQueueLength int32 maxParallelism int32 } type nodeCtx struct { node Node inputChannels []chan Msg inputMessages []Msg downstream []*nodeCtx downstreamInputChanIdx map[string]int NumActiveTasks int64 NumCompletedTasks int64 } func (nodeCtx *nodeCtx) Start(ctx context.Context, wg *sync.WaitGroup) { if nodeCtx.node.IsInputNode() { // fmt.Println("start InputNode.inStream") inStream, ok := nodeCtx.node.(*InputNode) if !ok { log.Fatal("Invalid inputNode") } (*inStream.inStream).Start() } for { select { case <-ctx.Done(): wg.Done() //fmt.Println(nodeCtx.node.Name(), "closed") return default: // inputs from inputsMessages for Operate inputs := make([]Msg, 0) var res []Msg if !nodeCtx.node.IsInputNode() { nodeCtx.collectInputMessages(ctx) inputs = nodeCtx.inputMessages } n := nodeCtx.node res = n.Operate(inputs) downstreamLength := len(nodeCtx.downstreamInputChanIdx) if len(nodeCtx.downstream) < downstreamLength { log.Println("nodeCtx.downstream length = ", len(nodeCtx.downstream)) } if len(res) < downstreamLength { // log.Println("node result length = ", len(res)) break } w := sync.WaitGroup{} for i := 0; i < downstreamLength; i++ { w.Add(1) go nodeCtx.downstream[i].ReceiveMsg(&w, res[i], nodeCtx.downstreamInputChanIdx[nodeCtx.downstream[i].node.Name()]) } w.Wait() } } } func (nodeCtx *nodeCtx) Close() { for _, channel := range nodeCtx.inputChannels { close(channel) fmt.Println("close inputChannel") } nodeCtx.node.Close() } func (nodeCtx *nodeCtx) ReceiveMsg(wg *sync.WaitGroup, msg Msg, inputChanIdx int) { defer wg.Done() defer func() { err := recover() if err != nil { log.Println(err) } }() nodeCtx.inputChannels[inputChanIdx] <- msg //fmt.Println((*nodeCtx.node).Name(), "receive to input channel ", inputChanIdx) } func (nodeCtx *nodeCtx) collectInputMessages(exitCtx context.Context) { inputsNum := len(nodeCtx.inputChannels) nodeCtx.inputMessages = make([]Msg, inputsNum) // init inputMessages, // receive messages from inputChannels, // and move them to inputMessages. for i := 0; i < inputsNum; i++ { channel := nodeCtx.inputChannels[i] select { case <-exitCtx.Done(): return case msg, ok := <-channel: if !ok { // TODO: add status log.Println("input channel closed") return } nodeCtx.inputMessages[i] = msg } } // timeTick alignment check if len(nodeCtx.inputMessages) > 1 { t := nodeCtx.inputMessages[0].TimeTick() latestTime := t for i := 1; i < len(nodeCtx.inputMessages); i++ { if t < nodeCtx.inputMessages[i].TimeTick() { latestTime = nodeCtx.inputMessages[i].TimeTick() } } // wait for time tick sign := make(chan struct{}) go func() { for i := 0; i < len(nodeCtx.inputMessages); i++ { for nodeCtx.inputMessages[i].TimeTick() != latestTime { fmt.Println("try to align timestamp, t1 =", latestTime, ", t2 =", nodeCtx.inputMessages[i].TimeTick()) channel := nodeCtx.inputChannels[i] select { case <-exitCtx.Done(): return case msg, ok := <-channel: if !ok { log.Println("input channel closed") return } nodeCtx.inputMessages[i] = msg } } } sign <- struct{}{} }() select { case <-time.After(10 * time.Second): panic("Fatal, misaligned time tick, please restart pulsar") case <-sign: } } } func (node *BaseNode) MaxQueueLength() int32 { return node.maxQueueLength } func (node *BaseNode) MaxParallelism() int32 { return node.maxParallelism } func (node *BaseNode) SetMaxQueueLength(n int32) { node.maxQueueLength = n } func (node *BaseNode) SetMaxParallelism(n int32) { node.maxParallelism = n } func (node *BaseNode) IsInputNode() bool { return false } func (node *BaseNode) Close() { //TODO }