gotosocial/vendor/github.com/go-openapi/runtime/csv.go
tobi fd8a724e77
[chore] Bump go swagger (#2871)
* bump go swagger version

* bump swagger version
2024-04-26 11:31:10 +02:00

350 lines
8.7 KiB
Go

// Copyright 2015 go-swagger maintainers
//
// 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 runtime
import (
"bytes"
"context"
"encoding"
"encoding/csv"
"errors"
"fmt"
"io"
"reflect"
"golang.org/x/sync/errgroup"
)
// CSVConsumer creates a new CSV consumer.
//
// The consumer consumes CSV records from a provided reader into the data passed by reference.
//
// CSVOpts options may be specified to alter the default CSV behavior on the reader and the writer side (e.g. separator, skip header, ...).
// The defaults are those of the standard library's csv.Reader and csv.Writer.
//
// Supported output underlying types and interfaces, prioritized in this order:
// - *csv.Writer
// - CSVWriter (writer options are ignored)
// - io.Writer (as raw bytes)
// - io.ReaderFrom (as raw bytes)
// - encoding.BinaryUnmarshaler (as raw bytes)
// - *[][]string (as a collection of records)
// - *[]byte (as raw bytes)
// - *string (a raw bytes)
//
// The consumer prioritizes situations where buffering the input is not required.
func CSVConsumer(opts ...CSVOpt) Consumer {
o := csvOptsWithDefaults(opts)
return ConsumerFunc(func(reader io.Reader, data interface{}) error {
if reader == nil {
return errors.New("CSVConsumer requires a reader")
}
if data == nil {
return errors.New("nil destination for CSVConsumer")
}
csvReader := csv.NewReader(reader)
o.applyToReader(csvReader)
closer := defaultCloser
if o.closeStream {
if cl, isReaderCloser := reader.(io.Closer); isReaderCloser {
closer = cl.Close
}
}
defer func() {
_ = closer()
}()
switch destination := data.(type) {
case *csv.Writer:
csvWriter := destination
o.applyToWriter(csvWriter)
return pipeCSV(csvWriter, csvReader, o)
case CSVWriter:
csvWriter := destination
// no writer options available
return pipeCSV(csvWriter, csvReader, o)
case io.Writer:
csvWriter := csv.NewWriter(destination)
o.applyToWriter(csvWriter)
return pipeCSV(csvWriter, csvReader, o)
case io.ReaderFrom:
var buf bytes.Buffer
csvWriter := csv.NewWriter(&buf)
o.applyToWriter(csvWriter)
if err := bufferedCSV(csvWriter, csvReader, o); err != nil {
return err
}
_, err := destination.ReadFrom(&buf)
return err
case encoding.BinaryUnmarshaler:
var buf bytes.Buffer
csvWriter := csv.NewWriter(&buf)
o.applyToWriter(csvWriter)
if err := bufferedCSV(csvWriter, csvReader, o); err != nil {
return err
}
return destination.UnmarshalBinary(buf.Bytes())
default:
// support *[][]string, *[]byte, *string
if ptr := reflect.TypeOf(data); ptr.Kind() != reflect.Ptr {
return errors.New("destination must be a pointer")
}
v := reflect.Indirect(reflect.ValueOf(data))
t := v.Type()
switch {
case t.Kind() == reflect.Slice && t.Elem().Kind() == reflect.Slice && t.Elem().Elem().Kind() == reflect.String:
csvWriter := &csvRecordsWriter{}
// writer options are ignored
if err := pipeCSV(csvWriter, csvReader, o); err != nil {
return err
}
v.Grow(len(csvWriter.records))
v.SetCap(len(csvWriter.records)) // in case Grow was unnessary, trim down the capacity
v.SetLen(len(csvWriter.records))
reflect.Copy(v, reflect.ValueOf(csvWriter.records))
return nil
case t.Kind() == reflect.Slice && t.Elem().Kind() == reflect.Uint8:
var buf bytes.Buffer
csvWriter := csv.NewWriter(&buf)
o.applyToWriter(csvWriter)
if err := bufferedCSV(csvWriter, csvReader, o); err != nil {
return err
}
v.SetBytes(buf.Bytes())
return nil
case t.Kind() == reflect.String:
var buf bytes.Buffer
csvWriter := csv.NewWriter(&buf)
o.applyToWriter(csvWriter)
if err := bufferedCSV(csvWriter, csvReader, o); err != nil {
return err
}
v.SetString(buf.String())
return nil
default:
return fmt.Errorf("%v (%T) is not supported by the CSVConsumer, %s",
data, data, "can be resolved by supporting CSVWriter/Writer/BinaryUnmarshaler interface",
)
}
}
})
}
// CSVProducer creates a new CSV producer.
//
// The producer takes input data then writes as CSV to an output writer (essentially as a pipe).
//
// Supported input underlying types and interfaces, prioritized in this order:
// - *csv.Reader
// - CSVReader (reader options are ignored)
// - io.Reader
// - io.WriterTo
// - encoding.BinaryMarshaler
// - [][]string
// - []byte
// - string
//
// The producer prioritizes situations where buffering the input is not required.
func CSVProducer(opts ...CSVOpt) Producer {
o := csvOptsWithDefaults(opts)
return ProducerFunc(func(writer io.Writer, data interface{}) error {
if writer == nil {
return errors.New("CSVProducer requires a writer")
}
if data == nil {
return errors.New("nil data for CSVProducer")
}
csvWriter := csv.NewWriter(writer)
o.applyToWriter(csvWriter)
closer := defaultCloser
if o.closeStream {
if cl, isWriterCloser := writer.(io.Closer); isWriterCloser {
closer = cl.Close
}
}
defer func() {
_ = closer()
}()
if rc, isDataCloser := data.(io.ReadCloser); isDataCloser {
defer rc.Close()
}
switch origin := data.(type) {
case *csv.Reader:
csvReader := origin
o.applyToReader(csvReader)
return pipeCSV(csvWriter, csvReader, o)
case CSVReader:
csvReader := origin
// no reader options available
return pipeCSV(csvWriter, csvReader, o)
case io.Reader:
csvReader := csv.NewReader(origin)
o.applyToReader(csvReader)
return pipeCSV(csvWriter, csvReader, o)
case io.WriterTo:
// async piping of the writes performed by WriteTo
r, w := io.Pipe()
csvReader := csv.NewReader(r)
o.applyToReader(csvReader)
pipe, _ := errgroup.WithContext(context.Background())
pipe.Go(func() error {
_, err := origin.WriteTo(w)
_ = w.Close()
return err
})
pipe.Go(func() error {
defer func() {
_ = r.Close()
}()
return pipeCSV(csvWriter, csvReader, o)
})
return pipe.Wait()
case encoding.BinaryMarshaler:
buf, err := origin.MarshalBinary()
if err != nil {
return err
}
rdr := bytes.NewBuffer(buf)
csvReader := csv.NewReader(rdr)
return bufferedCSV(csvWriter, csvReader, o)
default:
// support [][]string, []byte, string (or pointers to those)
v := reflect.Indirect(reflect.ValueOf(data))
t := v.Type()
switch {
case t.Kind() == reflect.Slice && t.Elem().Kind() == reflect.Slice && t.Elem().Elem().Kind() == reflect.String:
csvReader := &csvRecordsWriter{
records: make([][]string, v.Len()),
}
reflect.Copy(reflect.ValueOf(csvReader.records), v)
return pipeCSV(csvWriter, csvReader, o)
case t.Kind() == reflect.Slice && t.Elem().Kind() == reflect.Uint8:
buf := bytes.NewBuffer(v.Bytes())
csvReader := csv.NewReader(buf)
o.applyToReader(csvReader)
return bufferedCSV(csvWriter, csvReader, o)
case t.Kind() == reflect.String:
buf := bytes.NewBufferString(v.String())
csvReader := csv.NewReader(buf)
o.applyToReader(csvReader)
return bufferedCSV(csvWriter, csvReader, o)
default:
return fmt.Errorf("%v (%T) is not supported by the CSVProducer, %s",
data, data, "can be resolved by supporting CSVReader/Reader/BinaryMarshaler interface",
)
}
}
})
}
// pipeCSV copies CSV records from a CSV reader to a CSV writer
func pipeCSV(csvWriter CSVWriter, csvReader CSVReader, opts csvOpts) error {
for ; opts.skippedLines > 0; opts.skippedLines-- {
_, err := csvReader.Read()
if err != nil {
if errors.Is(err, io.EOF) {
return nil
}
return err
}
}
for {
record, err := csvReader.Read()
if err != nil {
if errors.Is(err, io.EOF) {
break
}
return err
}
if err := csvWriter.Write(record); err != nil {
return err
}
}
csvWriter.Flush()
return csvWriter.Error()
}
// bufferedCSV copies CSV records from a CSV reader to a CSV writer,
// by first reading all records then writing them at once.
func bufferedCSV(csvWriter *csv.Writer, csvReader *csv.Reader, opts csvOpts) error {
for ; opts.skippedLines > 0; opts.skippedLines-- {
_, err := csvReader.Read()
if err != nil {
if errors.Is(err, io.EOF) {
return nil
}
return err
}
}
records, err := csvReader.ReadAll()
if err != nil {
return err
}
return csvWriter.WriteAll(records)
}