grafana/pkg/util/svg.go
2023-12-06 14:00:53 -08:00

57 lines
1.8 KiB
Go

// The MIT License
//
//Copyright (c) 2016 Tomas Aparicio
//
//Permission is hereby granted, free of charge, to any person
//obtaining a copy of this software and associated documentation
//files (the "Software"), to deal in the Software without
//restriction, including without limitation the rights to use,
//copy, modify, merge, publish, distribute, sublicense, and/or sell
//copies of the Software, and to permit persons to whom the
//Software is furnished to do so, subject to the following
//conditions:
//
//The above copyright notice and this permission notice shall be
//included in all copies or substantial portions of the Software.
//
//THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
//EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
//OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
//NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
//HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
//WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
//FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
//OTHER DEALINGS IN THE SOFTWARE.
package util
import (
"regexp"
"unicode/utf8"
)
var (
// nolint:gosimple
htmlCommentRegex = regexp.MustCompile("(?i)<!--([\\s\\S]*?)-->")
svgRegex = regexp.MustCompile(`(?i)^\s*(?:<\?xml[^>]*>\s*)?(?:<!doctype svg[^>]*>\s*)?<svg[^>]*>[^*]*<\/svg>\s*$`)
)
// 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 IsSVG(buf []byte) bool {
return !isBinary(buf) && svgRegex.Match(htmlCommentRegex.ReplaceAll(buf, []byte{}))
}