package json import ( "io" "github.com/xtls/xray-core/v1/common/buf" ) // State is the internal state of parser. type State byte const ( StateContent State = iota StateEscape StateDoubleQuote StateDoubleQuoteEscape StateSingleQuote StateSingleQuoteEscape StateComment StateSlash StateMultilineComment StateMultilineCommentStar ) // Reader is a reader for filtering comments. // It supports Java style single and multi line comment syntax, and Python style single line comment syntax. type Reader struct { io.Reader state State br *buf.BufferedReader } // Read implements io.Reader.Read(). Buffer must be at least 3 bytes. func (v *Reader) Read(b []byte) (int, error) { if v.br == nil { v.br = &buf.BufferedReader{Reader: buf.NewReader(v.Reader)} } p := b[:0] for len(p) < len(b)-2 { x, err := v.br.ReadByte() if err != nil { if len(p) == 0 { return 0, err } return len(p), nil } switch v.state { case StateContent: switch x { case '"': v.state = StateDoubleQuote p = append(p, x) case '\'': v.state = StateSingleQuote p = append(p, x) case '\\': v.state = StateEscape case '#': v.state = StateComment case '/': v.state = StateSlash default: p = append(p, x) } case StateEscape: p = append(p, '\\', x) v.state = StateContent case StateDoubleQuote: switch x { case '"': v.state = StateContent p = append(p, x) case '\\': v.state = StateDoubleQuoteEscape default: p = append(p, x) } case StateDoubleQuoteEscape: p = append(p, '\\', x) v.state = StateDoubleQuote case StateSingleQuote: switch x { case '\'': v.state = StateContent p = append(p, x) case '\\': v.state = StateSingleQuoteEscape default: p = append(p, x) } case StateSingleQuoteEscape: p = append(p, '\\', x) v.state = StateSingleQuote case StateComment: if x == '\n' { v.state = StateContent p = append(p, '\n') } case StateSlash: switch x { case '/': v.state = StateComment case '*': v.state = StateMultilineComment default: p = append(p, '/', x) } case StateMultilineComment: switch x { case '*': v.state = StateMultilineCommentStar case '\n': p = append(p, '\n') } case StateMultilineCommentStar: switch x { case '/': v.state = StateContent case '*': // Stay case '\n': p = append(p, '\n') default: v.state = StateMultilineComment } default: panic("Unknown state.") } } return len(p), nil }