diff options
Diffstat (limited to 'vendor/github.com/tdewolff/parse/common.go')
| -rw-r--r-- | vendor/github.com/tdewolff/parse/common.go | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/vendor/github.com/tdewolff/parse/common.go b/vendor/github.com/tdewolff/parse/common.go new file mode 100644 index 0000000..3b7158e --- /dev/null +++ b/vendor/github.com/tdewolff/parse/common.go @@ -0,0 +1,231 @@ +// Package parse contains a collection of parsers for various formats in its subpackages. +package parse // import "github.com/tdewolff/parse" + +import ( + "bytes" + "encoding/base64" + "errors" + "net/url" +) + +// ErrBadDataURI is returned by DataURI when the byte slice does not start with 'data:' or is too short. +var ErrBadDataURI = errors.New("not a data URI") + +// Number returns the number of bytes that parse as a number of the regex format (+|-)?([0-9]+(\.[0-9]+)?|\.[0-9]+)((e|E)(+|-)?[0-9]+)?. +func Number(b []byte) int { + if len(b) == 0 { + return 0 + } + i := 0 + if b[i] == '+' || b[i] == '-' { + i++ + if i >= len(b) { + return 0 + } + } + firstDigit := (b[i] >= '0' && b[i] <= '9') + if firstDigit { + i++ + for i < len(b) && b[i] >= '0' && b[i] <= '9' { + i++ + } + } + if i < len(b) && b[i] == '.' { + i++ + if i < len(b) && b[i] >= '0' && b[i] <= '9' { + i++ + for i < len(b) && b[i] >= '0' && b[i] <= '9' { + i++ + } + } else if firstDigit { + // . could belong to the next token + i-- + return i + } else { + return 0 + } + } else if !firstDigit { + return 0 + } + iOld := i + if i < len(b) && (b[i] == 'e' || b[i] == 'E') { + i++ + if i < len(b) && (b[i] == '+' || b[i] == '-') { + i++ + } + if i >= len(b) || b[i] < '0' || b[i] > '9' { + // e could belong to next token + return iOld + } + for i < len(b) && b[i] >= '0' && b[i] <= '9' { + i++ + } + } + return i +} + +// Dimension parses a byte-slice and returns the length of the number and its unit. +func Dimension(b []byte) (int, int) { + num := Number(b) + if num == 0 || num == len(b) { + return num, 0 + } else if b[num] == '%' { + return num, 1 + } else if b[num] >= 'a' && b[num] <= 'z' || b[num] >= 'A' && b[num] <= 'Z' { + i := num + 1 + for i < len(b) && (b[i] >= 'a' && b[i] <= 'z' || b[i] >= 'A' && b[i] <= 'Z') { + i++ + } + return num, i - num + } + return num, 0 +} + +// Mediatype parses a given mediatype and splits the mimetype from the parameters. +// It works similar to mime.ParseMediaType but is faster. +func Mediatype(b []byte) ([]byte, map[string]string) { + i := 0 + for i < len(b) && b[i] == ' ' { + i++ + } + b = b[i:] + n := len(b) + mimetype := b + var params map[string]string + for i := 3; i < n; i++ { // mimetype is at least three characters long + if b[i] == ';' || b[i] == ' ' { + mimetype = b[:i] + if b[i] == ' ' { + i++ + for i < n && b[i] == ' ' { + i++ + } + if i < n && b[i] != ';' { + break + } + } + params = map[string]string{} + s := string(b) + PARAM: + i++ + for i < n && s[i] == ' ' { + i++ + } + start := i + for i < n && s[i] != '=' && s[i] != ';' && s[i] != ' ' { + i++ + } + key := s[start:i] + for i < n && s[i] == ' ' { + i++ + } + if i < n && s[i] == '=' { + i++ + for i < n && s[i] == ' ' { + i++ + } + start = i + for i < n && s[i] != ';' && s[i] != ' ' { + i++ + } + } else { + start = i + } + params[key] = s[start:i] + for i < n && s[i] == ' ' { + i++ + } + if i < n && s[i] == ';' { + goto PARAM + } + break + } + } + return mimetype, params +} + +// DataURI parses the given data URI and returns the mediatype, data and ok. +func DataURI(dataURI []byte) ([]byte, []byte, error) { + if len(dataURI) > 5 && bytes.Equal(dataURI[:5], []byte("data:")) { + dataURI = dataURI[5:] + inBase64 := false + var mediatype []byte + i := 0 + for j := 0; j < len(dataURI); j++ { + c := dataURI[j] + if c == '=' || c == ';' || c == ',' { + if c != '=' && bytes.Equal(TrimWhitespace(dataURI[i:j]), []byte("base64")) { + if len(mediatype) > 0 { + mediatype = mediatype[:len(mediatype)-1] + } + inBase64 = true + i = j + } else if c != ',' { + mediatype = append(append(mediatype, TrimWhitespace(dataURI[i:j])...), c) + i = j + 1 + } else { + mediatype = append(mediatype, TrimWhitespace(dataURI[i:j])...) + } + if c == ',' { + if len(mediatype) == 0 || mediatype[0] == ';' { + mediatype = []byte("text/plain") + } + data := dataURI[j+1:] + if inBase64 { + decoded := make([]byte, base64.StdEncoding.DecodedLen(len(data))) + n, err := base64.StdEncoding.Decode(decoded, data) + if err != nil { + return nil, nil, err + } + data = decoded[:n] + } else if unescaped, err := url.QueryUnescape(string(data)); err == nil { + data = []byte(unescaped) + } + return mediatype, data, nil + } + } + } + } + return nil, nil, ErrBadDataURI +} + +// QuoteEntity parses the given byte slice and returns the quote that got matched (' or ") and its entity length. +func QuoteEntity(b []byte) (quote byte, n int) { + if len(b) < 5 || b[0] != '&' { + return 0, 0 + } + if b[1] == '#' { + if b[2] == 'x' { + i := 3 + for i < len(b) && b[i] == '0' { + i++ + } + if i+2 < len(b) && b[i] == '2' && b[i+2] == ';' { + if b[i+1] == '2' { + return '"', i + 3 // " + } else if b[i+1] == '7' { + return '\'', i + 3 // ' + } + } + } else { + i := 2 + for i < len(b) && b[i] == '0' { + i++ + } + if i+2 < len(b) && b[i] == '3' && b[i+2] == ';' { + if b[i+1] == '4' { + return '"', i + 3 // " + } else if b[i+1] == '9' { + return '\'', i + 3 // ' + } + } + } + } else if len(b) >= 6 && b[5] == ';' { + if EqualFold(b[1:5], []byte{'q', 'u', 'o', 't'}) { + return '"', 6 // " + } else if EqualFold(b[1:5], []byte{'a', 'p', 'o', 's'}) { + return '\'', 6 // ' + } + } + return 0, 0 +} |