damccorm commented on code in PR #17574: URL: https://github.com/apache/beam/pull/17574#discussion_r868242085
########## sdks/go/pkg/beam/registration/iter.go: ########## @@ -0,0 +1,129 @@ +// 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 registration + +import ( + "fmt" + "io" + "reflect" + + "github.com/apache/beam/sdks/v2/go/pkg/beam/core/runtime/exec" +) + +type iter1[T any] struct { + s exec.ReStream + + // cur is the "current" stream, if any. + cur exec.Stream +} + +func (v *iter1[T]) Init() error { + cur, err := v.s.Open() + if err != nil { + return err + } + v.cur = cur + return nil +} + +func (v *iter1[T]) Value() interface{} { + return v.invoke +} + +func (v *iter1[T]) Reset() error { + if err := v.cur.Close(); err != nil { + return err + } + v.cur = nil + return nil +} + +func (v *iter1[T]) invoke(value *T) bool { + elm, err := v.cur.Read() + if err != nil { + if err == io.EOF { + return false + } + panic(fmt.Sprintf("broken stream: %v", err)) + } + *value = elm.Elm.(T) + return true +} + +type iter2[T1, T2 any] struct { + s exec.ReStream + + // cur is the "current" stream, if any. + cur exec.Stream +} + +func (v *iter2[T1, T2]) Init() error { + cur, err := v.s.Open() + if err != nil { + return err + } + v.cur = cur + return nil +} + +func (v *iter2[T1, T2]) Value() interface{} { + return v.invoke +} + +func (v *iter2[T1, T2]) Reset() error { + if err := v.cur.Close(); err != nil { + return err + } + v.cur = nil + return nil +} + +func (v *iter2[T1, T2]) invoke(key *T1, value *T2) bool { + elm, err := v.cur.Read() + if err != nil { + if err == io.EOF { + return false + } + panic(fmt.Sprintf("broken stream: %v", err)) + } + *key = elm.Elm.(T1) + *value = elm.Elm2.(T2) + return true +} + +// Iter1 registers parameters from your DoFn with a +// signature func(*T) bool and optimizes their execution. +// This must be done by passing in type parameters of all inputs as constraints, +// aka: registration.Iter1[T]() Review Comment: Ah, got it - I added an example (and as a bonus added an emitter example with timestamps) -- 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]
