gitea/modules/charset/escape_stream.go

288 lines
7.3 KiB
Go

// Copyright 2022 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package charset
import (
"fmt"
"regexp"
"strings"
"unicode"
"unicode/utf8"
"code.gitea.io/gitea/modules/translation"
"golang.org/x/net/html"
)
// VScode defaultWordRegexp
var defaultWordRegexp = regexp.MustCompile(`(-?\d*\.\d\w*)|([^\` + "`" + `\~\!\@\#\$\%\^\&\*\(\)\-\=\+\[\{\]\}\\\|\;\:\'\"\,\.\<\>\/\?\s\x00-\x1f]+)`)
func NewEscapeStreamer(locale translation.Locale, next HTMLStreamer, allowed ...rune) HTMLStreamer {
allowedM := make(map[rune]bool, len(allowed))
for _, v := range allowed {
allowedM[v] = true
}
return &escapeStreamer{
escaped: &EscapeStatus{},
PassthroughHTMLStreamer: *NewPassthroughStreamer(next),
locale: locale,
ambiguousTables: AmbiguousTablesForLocale(locale),
allowed: allowedM,
}
}
type escapeStreamer struct {
PassthroughHTMLStreamer
escaped *EscapeStatus
locale translation.Locale
ambiguousTables []*AmbiguousTable
allowed map[rune]bool
}
func (e *escapeStreamer) EscapeStatus() *EscapeStatus {
return e.escaped
}
// Text tells the next streamer there is a text
func (e *escapeStreamer) Text(data string) error {
sb := &strings.Builder{}
pos, until, next := 0, 0, 0
if len(data) > len(UTF8BOM) && data[:len(UTF8BOM)] == string(UTF8BOM) {
_, _ = sb.WriteString(data[:len(UTF8BOM)])
pos = len(UTF8BOM)
}
dataBytes := []byte(data)
for pos < len(data) {
nextIdxs := defaultWordRegexp.FindStringIndex(data[pos:])
if nextIdxs == nil {
until = len(data)
next = until
} else {
until, next = nextIdxs[0]+pos, nextIdxs[1]+pos
}
// from pos until until we know that the runes are not \r\t\n or even ' '
runes := make([]rune, 0, next-until)
positions := make([]int, 0, next-until+1)
for pos < until {
r, sz := utf8.DecodeRune(dataBytes[pos:])
positions = positions[:0]
positions = append(positions, pos, pos+sz)
types, confusables, _ := e.runeTypes(r)
if err := e.handleRunes(dataBytes, []rune{r}, positions, types, confusables, sb); err != nil {
return err
}
pos += sz
}
for i := pos; i < next; {
r, sz := utf8.DecodeRune(dataBytes[i:])
runes = append(runes, r)
positions = append(positions, i)
i += sz
}
positions = append(positions, next)
types, confusables, runeCounts := e.runeTypes(runes...)
if runeCounts.needsEscape() {
if err := e.handleRunes(dataBytes, runes, positions, types, confusables, sb); err != nil {
return err
}
} else {
_, _ = sb.Write(dataBytes[pos:next])
}
pos = next
}
if sb.Len() > 0 {
if err := e.PassthroughHTMLStreamer.Text(sb.String()); err != nil {
return err
}
}
return nil
}
func (e *escapeStreamer) handleRunes(data []byte, runes []rune, positions []int, types []runeType, confusables []rune, sb *strings.Builder) error {
for i, r := range runes {
switch types[i] {
case brokenRuneType:
if sb.Len() > 0 {
if err := e.PassthroughHTMLStreamer.Text(sb.String()); err != nil {
return err
}
sb.Reset()
}
end := positions[i+1]
start := positions[i]
if err := e.brokenRune(data[start:end]); err != nil {
return err
}
case ambiguousRuneType:
if sb.Len() > 0 {
if err := e.PassthroughHTMLStreamer.Text(sb.String()); err != nil {
return err
}
sb.Reset()
}
if err := e.ambiguousRune(r, confusables[0]); err != nil {
return err
}
confusables = confusables[1:]
case invisibleRuneType:
if sb.Len() > 0 {
if err := e.PassthroughHTMLStreamer.Text(sb.String()); err != nil {
return err
}
sb.Reset()
}
if err := e.invisibleRune(r); err != nil {
return err
}
default:
_, _ = sb.WriteRune(r)
}
}
return nil
}
func (e *escapeStreamer) brokenRune(bs []byte) error {
e.escaped.Escaped = true
e.escaped.HasBadRunes = true
if err := e.PassthroughHTMLStreamer.StartTag("span", html.Attribute{
Key: "class",
Val: "broken-code-point",
}); err != nil {
return err
}
if err := e.PassthroughHTMLStreamer.Text(fmt.Sprintf("<%X>", bs)); err != nil {
return err
}
return e.PassthroughHTMLStreamer.EndTag("span")
}
func (e *escapeStreamer) ambiguousRune(r, c rune) error {
e.escaped.Escaped = true
e.escaped.HasAmbiguous = true
if err := e.PassthroughHTMLStreamer.StartTag("span", html.Attribute{
Key: "class",
Val: "ambiguous-code-point",
}, html.Attribute{
Key: "data-tooltip-content",
Val: e.locale.Tr("repo.ambiguous_character", r, c),
}); err != nil {
return err
}
if err := e.PassthroughHTMLStreamer.StartTag("span", html.Attribute{
Key: "class",
Val: "char",
}); err != nil {
return err
}
if err := e.PassthroughHTMLStreamer.Text(string(r)); err != nil {
return err
}
if err := e.PassthroughHTMLStreamer.EndTag("span"); err != nil {
return err
}
return e.PassthroughHTMLStreamer.EndTag("span")
}
func (e *escapeStreamer) invisibleRune(r rune) error {
e.escaped.Escaped = true
e.escaped.HasInvisible = true
if err := e.PassthroughHTMLStreamer.StartTag("span", html.Attribute{
Key: "class",
Val: "escaped-code-point",
}, html.Attribute{
Key: "data-escaped",
Val: fmt.Sprintf("[U+%04X]", r),
}); err != nil {
return err
}
if err := e.PassthroughHTMLStreamer.StartTag("span", html.Attribute{
Key: "class",
Val: "char",
}); err != nil {
return err
}
if err := e.PassthroughHTMLStreamer.Text(string(r)); err != nil {
return err
}
if err := e.PassthroughHTMLStreamer.EndTag("span"); err != nil {
return err
}
return e.PassthroughHTMLStreamer.EndTag("span")
}
type runeCountType struct {
numBasicRunes int
numNonConfusingNonBasicRunes int
numAmbiguousRunes int
numInvisibleRunes int
numBrokenRunes int
}
func (counts runeCountType) needsEscape() bool {
if counts.numBrokenRunes > 0 {
return true
}
if counts.numBasicRunes == 0 &&
counts.numNonConfusingNonBasicRunes > 0 {
return false
}
return counts.numAmbiguousRunes > 0 || counts.numInvisibleRunes > 0
}
type runeType int
const (
basicASCIIRuneType runeType = iota // <- This is technically deadcode but its self-documenting so it should stay
brokenRuneType
nonBasicASCIIRuneType
ambiguousRuneType
invisibleRuneType
)
func (e *escapeStreamer) runeTypes(runes ...rune) (types []runeType, confusables []rune, runeCounts runeCountType) {
types = make([]runeType, len(runes))
for i, r := range runes {
var confusable rune
switch {
case r == utf8.RuneError:
types[i] = brokenRuneType
runeCounts.numBrokenRunes++
case r == ' ' || r == '\t' || r == '\n':
runeCounts.numBasicRunes++
case e.allowed[r]:
if r > 0x7e || r < 0x20 {
types[i] = nonBasicASCIIRuneType
runeCounts.numNonConfusingNonBasicRunes++
} else {
runeCounts.numBasicRunes++
}
case unicode.Is(InvisibleRanges, r):
types[i] = invisibleRuneType
runeCounts.numInvisibleRunes++
case unicode.IsControl(r):
types[i] = invisibleRuneType
runeCounts.numInvisibleRunes++
case isAmbiguous(r, &confusable, e.ambiguousTables...):
confusables = append(confusables, confusable)
types[i] = ambiguousRuneType
runeCounts.numAmbiguousRunes++
case r > 0x7e || r < 0x20:
types[i] = nonBasicASCIIRuneType
runeCounts.numNonConfusingNonBasicRunes++
default:
runeCounts.numBasicRunes++
}
}
return types, confusables, runeCounts
}