mirror of
https://github.com/superseriousbusiness/gotosocial.git
synced 2024-11-05 00:39:59 +00:00
351 lines
8.7 KiB
Go
351 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)
|
|
}
|