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forgejo/modules/mahonia/translate.go

51 lines
922 B
Go

package mahonia
import "unicode/utf8"
// Translate enables a Decoder to implement go-charset's Translator interface.
func (d Decoder) Translate(data []byte, eof bool) (n int, cdata []byte, err error) {
cdata = make([]byte, len(data)+1)
destPos := 0
for n < len(data) {
rune, size, status := d(data[n:])
switch status {
case STATE_ONLY:
n += size
continue
case NO_ROOM:
if !eof {
return n, cdata[:destPos], nil
}
rune = 0xfffd
n = len(data)
default:
n += size
}
if rune < 128 {
if destPos >= len(cdata) {
cdata = doubleLength(cdata)
}
cdata[destPos] = byte(rune)
destPos++
} else {
if destPos+utf8.RuneLen(rune) > len(cdata) {
cdata = doubleLength(cdata)
}
destPos += utf8.EncodeRune(cdata[destPos:], rune)
}
}
return n, cdata[:destPos], nil
}
func doubleLength(b []byte) []byte {
b2 := make([]byte, 2*len(b))
copy(b2, b)
return b2
}