110 lines
2.8 KiB
Go
110 lines
2.8 KiB
Go
// Copyright 2021 The Gitea Authors. All rights reserved.
|
|
// Use of this source code is governed by a MIT-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package csv
|
|
|
|
import (
|
|
"bytes"
|
|
"encoding/csv"
|
|
stdcsv "encoding/csv"
|
|
"errors"
|
|
"io"
|
|
"regexp"
|
|
"strings"
|
|
|
|
"code.gitea.io/gitea/modules/translation"
|
|
"code.gitea.io/gitea/modules/util"
|
|
)
|
|
|
|
var quoteRegexp = regexp.MustCompile(`["'][\s\S]+?["']`)
|
|
|
|
// CreateReader creates a csv.Reader with the given delimiter.
|
|
func CreateReader(input io.Reader, delimiter rune) *stdcsv.Reader {
|
|
rd := stdcsv.NewReader(input)
|
|
rd.Comma = delimiter
|
|
rd.TrimLeadingSpace = true
|
|
return rd
|
|
}
|
|
|
|
// CreateReaderAndGuessDelimiter tries to guess the field delimiter from the content and creates a csv.Reader.
|
|
func CreateReaderAndGuessDelimiter(rd io.Reader) (*stdcsv.Reader, error) {
|
|
var data = make([]byte, 1e4)
|
|
size, err := util.ReadAtMost(rd, data)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
delimiter := guessDelimiter(data[:size])
|
|
|
|
var newInput io.Reader
|
|
if size < 1e4 {
|
|
newInput = bytes.NewReader(data[:size])
|
|
} else {
|
|
newInput = io.MultiReader(bytes.NewReader(data), rd)
|
|
}
|
|
|
|
return CreateReader(newInput, delimiter), nil
|
|
}
|
|
|
|
// guessDelimiter scores the input CSV data against delimiters, and returns the best match.
|
|
// Reads at most 10k bytes & 10 lines.
|
|
func guessDelimiter(data []byte) rune {
|
|
maxLines := 10
|
|
maxBytes := util.Min(len(data), 1e4)
|
|
text := string(data[:maxBytes])
|
|
text = quoteRegexp.ReplaceAllLiteralString(text, "")
|
|
lines := strings.SplitN(text, "\n", maxLines+1)
|
|
lines = lines[:util.Min(maxLines, len(lines))]
|
|
|
|
delimiters := []rune{',', ';', '\t', '|', '@'}
|
|
bestDelim := delimiters[0]
|
|
bestScore := 0.0
|
|
for _, delim := range delimiters {
|
|
score := scoreDelimiter(lines, delim)
|
|
if score > bestScore {
|
|
bestScore = score
|
|
bestDelim = delim
|
|
}
|
|
}
|
|
|
|
return bestDelim
|
|
}
|
|
|
|
// scoreDelimiter uses a count & regularity metric to evaluate a delimiter against lines of CSV.
|
|
func scoreDelimiter(lines []string, delim rune) float64 {
|
|
countTotal := 0
|
|
countLineMax := 0
|
|
linesNotEqual := 0
|
|
|
|
for _, line := range lines {
|
|
if len(line) == 0 {
|
|
continue
|
|
}
|
|
|
|
countLine := strings.Count(line, string(delim))
|
|
countTotal += countLine
|
|
if countLine != countLineMax {
|
|
if countLineMax != 0 {
|
|
linesNotEqual++
|
|
}
|
|
countLineMax = util.Max(countLine, countLineMax)
|
|
}
|
|
}
|
|
|
|
return float64(countTotal) * (1 - float64(linesNotEqual)/float64(len(lines)))
|
|
}
|
|
|
|
// FormatError converts csv errors into readable messages.
|
|
func FormatError(err error, locale translation.Locale) (string, error) {
|
|
var perr *csv.ParseError
|
|
if errors.As(err, &perr) {
|
|
if perr.Err == csv.ErrFieldCount {
|
|
return locale.Tr("repo.error.csv.invalid_field_count", perr.Line), nil
|
|
}
|
|
return locale.Tr("repo.error.csv.unexpected", perr.Line, perr.Column), nil
|
|
}
|
|
|
|
return "", err
|
|
}
|