debian-mirror-gitlab/workhorse/internal/utils/svg/svg.go
2021-02-22 17:27:13 +05:30

42 lines
1 KiB
Go

// Copyright (c) 2016 Tomas Aparicio. All rights reserved.
//
// Use of this source code is governed by a MIT License
// license that can be found in the LICENSE file or at
// https://github.com/h2non/go-is-svg/blob/master/LICENSE.
package svg
import (
"regexp"
"unicode/utf8"
)
var (
htmlCommentRegex = regexp.MustCompile(`(?i)<!--([\s\S]*?)-->`)
svgRegex = regexp.MustCompile(`(?i)^\s*(?:<\?xml[^>]*>\s*)?(?:<!doctype svg[^>]*>\s*)?<svg[^>]*>`)
)
// isBinary checks if the given buffer is a binary file.
func isBinary(buf []byte) bool {
if len(buf) < 24 {
return false
}
for i := 0; i < 24; i++ {
charCode, _ := utf8.DecodeRuneInString(string(buf[i]))
if charCode == 65533 || charCode <= 8 {
return true
}
}
return false
}
// Is returns true if the given buffer is a valid SVG image.
func Is(buf []byte) bool {
return !isBinary(buf) && svgRegex.Match(htmlCommentRegex.ReplaceAll(buf, []byte{}))
}
// IsSVG returns true if the given buffer is a valid SVG image.
// Alias to: Is()
func IsSVG(buf []byte) bool {
return Is(buf)
}