lostluck commented on code in PR #29900: URL: https://github.com/apache/beam/pull/29900#discussion_r1446720005
########## sdks/go/pkg/beam/runners/prism/internal/engine/timers.go: ########## @@ -0,0 +1,174 @@ +// 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 engine + +import ( + "bytes" + "encoding/binary" + "fmt" + "io" + "math" + + "github.com/apache/beam/sdks/v2/go/pkg/beam/core/graph/coder" + "github.com/apache/beam/sdks/v2/go/pkg/beam/core/graph/mtime" + "github.com/apache/beam/sdks/v2/go/pkg/beam/core/graph/window" + "github.com/apache/beam/sdks/v2/go/pkg/beam/core/typex" + "google.golang.org/protobuf/encoding/protowire" +) + +// DecodeTimer extracts timers to elements for insertion into their keyed queues. +// Returns the key bytes, tag, window exploded elements, and the hold timestamp. +// If the timer has been cleared, no elements will be returned. Any existing timers +// for the tag *must* be cleared from the pending queue. +func decodeTimer(keyDec func(io.Reader) []byte, globalWindow bool, raw []byte) ([]byte, string, []element) { Review Comment: 1. We do. It's tested as part of the pipelines that execute. I refer you to the test coverage. https://app.codecov.io/gh/apache/beam/pull/29900/blob/sdks/go/pkg/beam/runners/prism/internal/engine/timers.go#L36 This decoder/encoder approach also avoids unnecessary layers of error handling vs what was designed in the Go SDK. Further, believe me. If the decoder function didn't work, the pipelines won't execute successfully. How I know that is left as an exercise. 2. This is too big a question for this comment. The short answer is:, we didn't need anything more than a func, the language has first class functions, and there was no need to hide that it's a function. Interfaces add additional indirection (and yes, possibly documentation), but also require additional implementation indirection. If we did interfaces, we end up with code like the following to wrap everything: https://github.com/apache/beam/blob/master/sdks/go/pkg/beam/core/runtime/exec/coder.go#L40 This has less value than you would think. 3. Yes we can. 4. In the function `decodeTimer` we need the `raw []byte` of the timer we are decoding. Within the function `decodeTimer` it's wasteful to repeat `timer` everywhere. We're already within a `timer` specific context. So what would one gain for the only input parameter where bytes would come in to be decoded, to call it `rawTimer`? -- 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]
