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author | Sebastian P <5564491+s3lph@users.noreply.github.com> | 2020-10-01 22:50:56 +0200 |
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committer | GitHub <noreply@github.com> | 2020-10-01 22:50:56 +0200 |
commit | 214a6a13861b9fd495797386f36507373728e577 (patch) | |
tree | a2eb9541924b432ecf7a0807f42281296fa144a4 /vendor/github.com/vincent-petithory/dataurl/lex.go | |
parent | e7781dc79c0c556f60eb64a93a95a5da494dcf2d (diff) | |
download | matterbridge-msglm-214a6a13861b9fd495797386f36507373728e577.tar.gz matterbridge-msglm-214a6a13861b9fd495797386f36507373728e577.tar.bz2 matterbridge-msglm-214a6a13861b9fd495797386f36507373728e577.zip |
Add Mumble support (#1245)
Diffstat (limited to 'vendor/github.com/vincent-petithory/dataurl/lex.go')
-rw-r--r-- | vendor/github.com/vincent-petithory/dataurl/lex.go | 521 |
1 files changed, 521 insertions, 0 deletions
diff --git a/vendor/github.com/vincent-petithory/dataurl/lex.go b/vendor/github.com/vincent-petithory/dataurl/lex.go new file mode 100644 index 00000000..1a8717f5 --- /dev/null +++ b/vendor/github.com/vincent-petithory/dataurl/lex.go @@ -0,0 +1,521 @@ +package dataurl + +import ( + "fmt" + "strings" + "unicode" + "unicode/utf8" +) + +type item struct { + t itemType + val string +} + +func (i item) String() string { + switch i.t { + case itemEOF: + return "EOF" + case itemError: + return i.val + } + if len(i.val) > 10 { + return fmt.Sprintf("%.10q...", i.val) + } + return fmt.Sprintf("%q", i.val) +} + +type itemType int + +const ( + itemError itemType = iota + itemEOF + + itemDataPrefix + + itemMediaType + itemMediaSep + itemMediaSubType + itemParamSemicolon + itemParamAttr + itemParamEqual + itemLeftStringQuote + itemRightStringQuote + itemParamVal + + itemBase64Enc + + itemDataComma + itemData +) + +const eof rune = -1 + +func isTokenRune(r rune) bool { + return r <= unicode.MaxASCII && + !unicode.IsControl(r) && + !unicode.IsSpace(r) && + !isTSpecialRune(r) +} + +func isTSpecialRune(r rune) bool { + return r == '(' || + r == ')' || + r == '<' || + r == '>' || + r == '@' || + r == ',' || + r == ';' || + r == ':' || + r == '\\' || + r == '"' || + r == '/' || + r == '[' || + r == ']' || + r == '?' || + r == '=' +} + +// See http://tools.ietf.org/html/rfc2045 +// This doesn't include extension-token case +// as it's handled separatly +func isDiscreteType(s string) bool { + if strings.HasPrefix(s, "text") || + strings.HasPrefix(s, "image") || + strings.HasPrefix(s, "audio") || + strings.HasPrefix(s, "video") || + strings.HasPrefix(s, "application") { + return true + } + return false +} + +// See http://tools.ietf.org/html/rfc2045 +// This doesn't include extension-token case +// as it's handled separatly +func isCompositeType(s string) bool { + if strings.HasPrefix(s, "message") || + strings.HasPrefix(s, "multipart") { + return true + } + return false +} + +func isURLCharRune(r rune) bool { + // We're a bit permissive here, + // by not including '%' in delims + // This is okay, since url unescaping will validate + // that later in the parser. + return r <= unicode.MaxASCII && + !(r >= 0x00 && r <= 0x1F) && r != 0x7F && /* control */ + // delims + r != ' ' && + r != '<' && + r != '>' && + r != '#' && + r != '"' && + // unwise + r != '{' && + r != '}' && + r != '|' && + r != '\\' && + r != '^' && + r != '[' && + r != ']' && + r != '`' +} + +func isBase64Rune(r rune) bool { + return (r >= 'a' && r <= 'z') || + (r >= 'A' && r <= 'Z') || + (r >= '0' && r <= '9') || + r == '+' || + r == '/' || + r == '=' || + r == '\n' +} + +type stateFn func(*lexer) stateFn + +// lexer lexes the data URL scheme input string. +// The implementation is from the text/template/parser package. +type lexer struct { + input string + start int + pos int + width int + seenBase64Item bool + items chan item +} + +func (l *lexer) run() { + for state := lexBeforeDataPrefix; state != nil; { + state = state(l) + } + close(l.items) +} + +func (l *lexer) emit(t itemType) { + l.items <- item{t, l.input[l.start:l.pos]} + l.start = l.pos +} + +func (l *lexer) next() (r rune) { + if l.pos >= len(l.input) { + l.width = 0 + return eof + } + r, l.width = utf8.DecodeRuneInString(l.input[l.pos:]) + l.pos += l.width + return r +} + +func (l *lexer) backup() { + l.pos -= l.width +} + +func (l *lexer) ignore() { + l.start = l.pos +} + +func (l *lexer) errorf(format string, args ...interface{}) stateFn { + l.items <- item{itemError, fmt.Sprintf(format, args...)} + return nil +} + +func lex(input string) *lexer { + l := &lexer{ + input: input, + items: make(chan item), + } + go l.run() // Concurrently run state machine. + return l +} + +const ( + dataPrefix = "data:" + mediaSep = '/' + paramSemicolon = ';' + paramEqual = '=' + dataComma = ',' +) + +// start lexing by detecting data prefix +func lexBeforeDataPrefix(l *lexer) stateFn { + if strings.HasPrefix(l.input[l.pos:], dataPrefix) { + return lexDataPrefix + } + return l.errorf("missing data prefix") +} + +// lex data prefix +func lexDataPrefix(l *lexer) stateFn { + l.pos += len(dataPrefix) + l.emit(itemDataPrefix) + return lexAfterDataPrefix +} + +// lex what's after data prefix. +// it can be the media type/subtype separator, +// the base64 encoding, or the comma preceding the data +func lexAfterDataPrefix(l *lexer) stateFn { + switch r := l.next(); { + case r == paramSemicolon: + l.backup() + return lexParamSemicolon + case r == dataComma: + l.backup() + return lexDataComma + case r == eof: + return l.errorf("missing comma before data") + case r == 'x' || r == 'X': + if l.next() == '-' { + return lexXTokenMediaType + } + return lexInDiscreteMediaType + case isTokenRune(r): + return lexInDiscreteMediaType + default: + return l.errorf("invalid character after data prefix") + } +} + +func lexXTokenMediaType(l *lexer) stateFn { + for { + switch r := l.next(); { + case r == mediaSep: + l.backup() + return lexMediaType + case r == eof: + return l.errorf("missing media type slash") + case isTokenRune(r): + default: + return l.errorf("invalid character for media type") + } + } +} + +func lexInDiscreteMediaType(l *lexer) stateFn { + for { + switch r := l.next(); { + case r == mediaSep: + l.backup() + // check it's valid discrete type + if !isDiscreteType(l.input[l.start:l.pos]) && + !isCompositeType(l.input[l.start:l.pos]) { + return l.errorf("invalid media type") + } + return lexMediaType + case r == eof: + return l.errorf("missing media type slash") + case isTokenRune(r): + default: + return l.errorf("invalid character for media type") + } + } +} + +func lexMediaType(l *lexer) stateFn { + if l.pos > l.start { + l.emit(itemMediaType) + } + return lexMediaSep +} + +func lexMediaSep(l *lexer) stateFn { + l.next() + l.emit(itemMediaSep) + return lexAfterMediaSep +} + +func lexAfterMediaSep(l *lexer) stateFn { + for { + switch r := l.next(); { + case r == paramSemicolon || r == dataComma: + l.backup() + return lexMediaSubType + case r == eof: + return l.errorf("incomplete media type") + case isTokenRune(r): + default: + return l.errorf("invalid character for media subtype") + } + } +} + +func lexMediaSubType(l *lexer) stateFn { + if l.pos > l.start { + l.emit(itemMediaSubType) + } + return lexAfterMediaSubType +} + +func lexAfterMediaSubType(l *lexer) stateFn { + switch r := l.next(); { + case r == paramSemicolon: + l.backup() + return lexParamSemicolon + case r == dataComma: + l.backup() + return lexDataComma + case r == eof: + return l.errorf("missing comma before data") + default: + return l.errorf("expected semicolon or comma") + } +} + +func lexParamSemicolon(l *lexer) stateFn { + l.next() + l.emit(itemParamSemicolon) + return lexAfterParamSemicolon +} + +func lexAfterParamSemicolon(l *lexer) stateFn { + switch r := l.next(); { + case r == eof: + return l.errorf("unterminated parameter sequence") + case r == paramEqual || r == dataComma: + return l.errorf("unterminated parameter sequence") + case isTokenRune(r): + l.backup() + return lexInParamAttr + default: + return l.errorf("invalid character for parameter attribute") + } +} + +func lexBase64Enc(l *lexer) stateFn { + if l.pos > l.start { + if v := l.input[l.start:l.pos]; v != "base64" { + return l.errorf("expected base64, got %s", v) + } + l.seenBase64Item = true + l.emit(itemBase64Enc) + } + return lexDataComma +} + +func lexInParamAttr(l *lexer) stateFn { + for { + switch r := l.next(); { + case r == paramEqual: + l.backup() + return lexParamAttr + case r == dataComma: + l.backup() + return lexBase64Enc + case r == eof: + return l.errorf("unterminated parameter sequence") + case isTokenRune(r): + default: + return l.errorf("invalid character for parameter attribute") + } + } +} + +func lexParamAttr(l *lexer) stateFn { + if l.pos > l.start { + l.emit(itemParamAttr) + } + return lexParamEqual +} + +func lexParamEqual(l *lexer) stateFn { + l.next() + l.emit(itemParamEqual) + return lexAfterParamEqual +} + +func lexAfterParamEqual(l *lexer) stateFn { + switch r := l.next(); { + case r == '"': + l.emit(itemLeftStringQuote) + return lexInQuotedStringParamVal + case r == eof: + return l.errorf("missing comma before data") + case isTokenRune(r): + return lexInParamVal + default: + return l.errorf("invalid character for parameter value") + } +} + +func lexInQuotedStringParamVal(l *lexer) stateFn { + for { + switch r := l.next(); { + case r == eof: + return l.errorf("unclosed quoted string") + case r == '\\': + return lexEscapedChar + case r == '"': + l.backup() + return lexQuotedStringParamVal + case r <= unicode.MaxASCII: + default: + return l.errorf("invalid character for parameter value") + } + } +} + +func lexEscapedChar(l *lexer) stateFn { + switch r := l.next(); { + case r <= unicode.MaxASCII: + return lexInQuotedStringParamVal + case r == eof: + return l.errorf("unexpected eof") + default: + return l.errorf("invalid escaped character") + } +} + +func lexInParamVal(l *lexer) stateFn { + for { + switch r := l.next(); { + case r == paramSemicolon || r == dataComma: + l.backup() + return lexParamVal + case r == eof: + return l.errorf("missing comma before data") + case isTokenRune(r): + default: + return l.errorf("invalid character for parameter value") + } + } +} + +func lexQuotedStringParamVal(l *lexer) stateFn { + if l.pos > l.start { + l.emit(itemParamVal) + } + l.next() + l.emit(itemRightStringQuote) + return lexAfterParamVal +} + +func lexParamVal(l *lexer) stateFn { + if l.pos > l.start { + l.emit(itemParamVal) + } + return lexAfterParamVal +} + +func lexAfterParamVal(l *lexer) stateFn { + switch r := l.next(); { + case r == paramSemicolon: + l.backup() + return lexParamSemicolon + case r == dataComma: + l.backup() + return lexDataComma + case r == eof: + return l.errorf("missing comma before data") + default: + return l.errorf("expected semicolon or comma") + } +} + +func lexDataComma(l *lexer) stateFn { + l.next() + l.emit(itemDataComma) + if l.seenBase64Item { + return lexBase64Data + } + return lexData +} + +func lexData(l *lexer) stateFn { +Loop: + for { + switch r := l.next(); { + case r == eof: + break Loop + case isURLCharRune(r): + default: + return l.errorf("invalid data character") + } + } + if l.pos > l.start { + l.emit(itemData) + } + l.emit(itemEOF) + return nil +} + +func lexBase64Data(l *lexer) stateFn { +Loop: + for { + switch r := l.next(); { + case r == eof: + break Loop + case isBase64Rune(r): + default: + return l.errorf("invalid data character") + } + } + if l.pos > l.start { + l.emit(itemData) + } + l.emit(itemEOF) + return nil +} |