johannaojeling commented on code in PR #25809: URL: https://github.com/apache/beam/pull/25809#discussion_r1147858543
########## sdks/go/pkg/beam/io/fileio/match.go: ########## @@ -0,0 +1,181 @@ +// 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 fileio provides transforms for matching and reading files. +package fileio + +import ( + "context" + "fmt" + "strings" + + "github.com/apache/beam/sdks/v2/go/pkg/beam" + "github.com/apache/beam/sdks/v2/go/pkg/beam/io/filesystem" + "github.com/apache/beam/sdks/v2/go/pkg/beam/register" +) + +func init() { + register.DoFn3x1[context.Context, string, func(FileMetadata), error](&matchFn{}) + register.Emitter1[FileMetadata]() +} + +// emptyTreatment controls how empty matches of a pattern are treated. +type emptyTreatment int + +const ( + // emptyAllow allows empty matches. + emptyAllow emptyTreatment = iota + // emptyDisallow disallows empty matches. + emptyDisallow + // emptyAllowIfWildcard allows empty matches if the pattern contains a wildcard. + emptyAllowIfWildcard +) + +type matchOption struct { + EmptyTreatment emptyTreatment +} + +// MatchOptionFn is a function that can be passed to MatchFiles or MatchAll to configure options for +// matching files. +type MatchOptionFn func(*matchOption) + +// MatchEmptyAllow specifies that empty matches are allowed. +func MatchEmptyAllow() MatchOptionFn { + return func(o *matchOption) { + o.EmptyTreatment = emptyAllow + } +} + +// MatchEmptyDisallow specifies that empty matches are not allowed. +func MatchEmptyDisallow() MatchOptionFn { + return func(o *matchOption) { + o.EmptyTreatment = emptyDisallow + } +} + +// MatchFiles finds all files matching the glob pattern and returns a PCollection<FileMetadata> of +// the matching files. MatchFiles accepts a variadic number of MatchOptionFn that can be used to +// configure the treatment of empty matches. By default, empty matches are allowed if the pattern +// contains a wildcard. +func MatchFiles(s beam.Scope, glob string, opts ...MatchOptionFn) beam.PCollection { + s = s.Scope("fileio.MatchFiles") + + filesystem.ValidateScheme(glob) + return MatchAll(s, beam.Create(s, glob), opts...) +} + +// MatchAll finds all files matching the glob patterns given by the incoming PCollection<string> and +// returns a PCollection<FileMetadata> of the matching files. MatchAll accepts a variadic number of +// MatchOptionFn that can be used to configure the treatment of empty matches. By default, empty +// matches are allowed if the pattern contains a wildcard. +func MatchAll(s beam.Scope, col beam.PCollection, opts ...MatchOptionFn) beam.PCollection { + s = s.Scope("fileio.MatchAll") + + option := &matchOption{ + EmptyTreatment: emptyAllowIfWildcard, Review Comment: I haven't provided any option functions for setting what is already the default value, i.e. there is no `MatchEmptyAllowIfWildcard()`, because it doesn't make much sense? Unless it should be included for clarity/documentation purposes? -- 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]
