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authorSebastian P <5564491+s3lph@users.noreply.github.com>2020-10-01 22:50:56 +0200
committerGitHub <noreply@github.com>2020-10-01 22:50:56 +0200
commit214a6a13861b9fd495797386f36507373728e577 (patch)
treea2eb9541924b432ecf7a0807f42281296fa144a4 /vendor/github.com/vincent-petithory/dataurl/lex.go
parente7781dc79c0c556f60eb64a93a95a5da494dcf2d (diff)
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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.go521
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
+}