lostluck commented on a change in pull request #15409: URL: https://github.com/apache/beam/pull/15409#discussion_r705803299
########## File path: sdks/go/examples/snippets/09triggers.go ########## @@ -0,0 +1,88 @@ +// Licensed to the Apache Software Foundation (ASF) under one or more +// contributor license agreements. See the NOTICE file distributed with +// this work for additional information regarding copyright ownership. +// The ASF licenses this file to You 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 snippets contains code used in the Beam Programming Guide +// as examples for the Apache Beam Go SDK. These snippets are compiled +// and their tests run to ensure correctness. However, due to their +// piecemeal pedagogical use, they may not be the best example of +// production code. +// +// The Beam Programming Guide can be found at https://beam.apache.org/documentation/programming-guide/. +package snippets + +import ( + "time" + + "github.com/apache/beam/sdks/v2/go/pkg/beam" + "github.com/apache/beam/sdks/v2/go/pkg/beam/core/graph/window" + "github.com/apache/beam/sdks/v2/go/pkg/beam/testing/teststream" + "github.com/apache/beam/sdks/v2/go/pkg/beam/transforms/stats" +) + +// TriggerElementCount tests the ElementCount Trigger, it waits for atleast N elements to be ready +// to fire an output pane +func TriggerElementCount(s beam.Scope) beam.PCollection { + con := teststream.NewConfig() + con.AddElements(1000, 1.0, 2.0, 3.0) + con.AdvanceWatermark(2000) + con.AddElements(6000, 4.0, 5.0) + con.AdvanceWatermark(10000) + con.AddElements(52000, 10.0) + con.AdvanceWatermark(53000) + + col := teststream.Create(s, con) + + // waits only for two elements to arrive and fires output after that and never fires that. + // For the trigger to fire every 2 elements, combine it with Repeat Trigger + tr := window.Trigger{Kind: window.ElementCountTrigger, ElementCount: 2} + windowed := beam.WindowInto(s, window.NewGlobalWindows(), col, beam.WindowTrigger{Name: tr}, beam.AccumulationMode{Mode: window.Discarding}) + sums := stats.Sum(s, windowed) + return sums +} + +// TriggerAfterProcessingTime tests the AfterProcessingTime Trigger, it fires output panes once 't' processing time has passed +// Not yet supported by the flink runner: +// java.lang.UnsupportedOperationException: Advancing Processing time is not supported by the Flink Runner. +func TriggerAfterProcessingTime(s beam.Scope) beam.PCollection { + con := teststream.NewConfig() + con.AdvanceProcessingTime(100) + con.AddElements(1000, 1.0, 2.0, 3.0) + con.AdvanceProcessingTime(2000) + con.AddElements(22000, 4.0) + + col := teststream.Create(s, con) Review comment: Note: unless you'reusing these with the [START foo] [END foo] comments, there's no reason to duplicate all this code to this file. It's not even necessary to have a proper test stream input or a fully executable test pipeline. Either use the code for snippets or delete it. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
