// Minify minifies SVG data, it reads from r and writes to w.
func Minify(m minify.Minifier, _ string, w io.Writer, r io.Reader) error {
var tag svg.Hash
attrMinifyBuffer := buffer.NewWriter(make([]byte, 0, 64))
attrByteBuffer := make([]byte, 0, 64)
l := xml.NewLexer(r)
tb := xml.NewTokenBuffer(l)
for {
t := *tb.Shift()
if t.TokenType == xml.CDATAToken {
var useCDATA bool
if t.Data, useCDATA = xml.EscapeCDATAVal(&attrByteBuffer, t.Data); !useCDATA {
t.TokenType = xml.TextToken
}
}
SWITCH:
switch t.TokenType {
case xml.ErrorToken:
if l.Err() == io.EOF {
return nil
}
return l.Err()
case xml.TextToken:
t.Data = parse.ReplaceMultiple(parse.Trim(t.Data, parse.IsWhitespace), parse.IsWhitespace, ' ')
if tag == svg.Style && len(t.Data) > 0 {
if err := m.Minify("text/css", w, buffer.NewReader(t.Data)); err != nil {
if err == minify.ErrNotExist { // no minifier, write the original
if _, err := w.Write(t.Data); err != nil {
return err
}
} else {
return err
}
}
} else if _, err := w.Write(t.Data); err != nil {
return err
}
case xml.CDATAToken:
if _, err := w.Write(cdataStartBytes); err != nil {
return err
}
t.Data = parse.ReplaceMultiple(parse.Trim(t.Data, parse.IsWhitespace), parse.IsWhitespace, ' ')
if tag == svg.Style && len(t.Data) > 0 {
if err := m.Minify("text/css", w, buffer.NewReader(t.Data)); err != nil {
if err == minify.ErrNotExist { // no minifier, write the original
if _, err := w.Write(t.Data); err != nil {
return err
}
} else {
return err
}
}
} else if _, err := w.Write(t.Data); err != nil {
return err
}
if _, err := w.Write(cdataEndBytes); err != nil {
return err
}
case xml.StartTagPIToken:
for {
if t := *tb.Shift(); t.TokenType == xml.StartTagClosePIToken || t.TokenType == xml.ErrorToken {
break
}
}
case xml.StartTagToken:
tag = svg.ToHash(t.Data)
if containerTagMap[tag] { // skip empty containers
i := 0
for {
next := tb.Peek(i)
i++
if next.TokenType == xml.EndTagToken && svg.ToHash(next.Data) == tag || next.TokenType == xml.StartTagCloseVoidToken || next.TokenType == xml.ErrorToken {
for j := 0; j < i; j++ {
tb.Shift()
}
break SWITCH
} else if next.TokenType != xml.AttributeToken && next.TokenType != xml.StartTagCloseToken {
break
}
}
} else if tag == svg.Metadata {
for {
if t := *tb.Shift(); t.TokenType == xml.EndTagToken && svg.ToHash(t.Data) == tag || t.TokenType == xml.StartTagCloseVoidToken || t.TokenType == xml.ErrorToken {
break
}
}
break
} else if tag == svg.Line || tag == svg.Rect {
// TODO: shape2path also for polygon and polyline
// x1, y1, x2, y2 float64 := 0, 0, 0, 0
// valid := true
// i := 0
// for {
// next := tb.Peek(i)
// i++
// if next.TokenType != xml.AttributeToken {
// break
// }
// v *int
// attr := svg.ToHash(next.Data)
// if tag == svg.Line {
// if attr == svg.X1 {
// v = &x1
// } else if attr == svg.Y1 {
// v = &y1
// } else if attr == svg.X2 {
// v = &x2
// } else if attr == svg.Y2 {
// v = &Y2
// } else {
// continue
// }
// } else if attr == svg.X { // rect
// v = &x1
// } else if attr == svg.Y {
// v = &y1
// } else if attr == svg.Width {
// v = &x2
// } else if attr == svg.Height {
// v = &Y2
// } else if attr == svg.Rx || attr == svg.Ry {
// valid = false
// break
// } else {
// continue
// }
// }
// if valid {
// t.Data = pathBytes
// }
}
if _, err := w.Write(ltBytes); err != nil {
return err
}
if _, err := w.Write(t.Data); err != nil {
return err
}
case xml.AttributeToken:
if len(t.AttrVal) < 2 {
continue
}
attr := svg.ToHash(t.Data)
val := parse.ReplaceMultiple(parse.Trim(t.AttrVal[1:len(t.AttrVal)-1], parse.IsWhitespace), parse.IsWhitespace, ' ')
if tag == svg.Svg && attr == svg.Version {
continue
}
if _, err := w.Write(spaceBytes); err != nil {
return err
}
if _, err := w.Write(t.Data); err != nil {
return err
}
if _, err := w.Write(isBytes); err != nil {
return err
}
if attr == svg.Style {
attrMinifyBuffer.Reset()
if m.Minify("text/css;inline=1", attrMinifyBuffer, buffer.NewReader(val)) == nil {
val = attrMinifyBuffer.Bytes()
}
} else if attr == svg.D {
val = shortenPathData(val)
} else if attr == svg.ViewBox {
j := 0
newVal := val[:0]
for i := 0; i < 4; i++ {
if i != 0 {
if j >= len(val) || val[j] != ' ' && val[j] != ',' {
newVal = append(newVal, val[j:]...)
break
}
newVal = append(newVal, ' ')
j++
}
if dim, n := shortenDimension(val[j:]); n > 0 {
newVal = append(newVal, dim...)
j += n
} else {
newVal = append(newVal, val[j:]...)
break
}
}
val = newVal
} else if colorAttrMap[attr] && len(val) > 0 {
parse.ToLower(val)
if val[0] == '#' {
if name, ok := minifyCSS.ShortenColorHex[string(val)]; ok {
val = name
} else if len(val) == 7 && val[1] == val[2] && val[3] == val[4] && val[5] == val[6] {
val[2] = val[3]
val[3] = val[5]
val = val[:4]
}
} else if hex, ok := minifyCSS.ShortenColorName[css.ToHash(val)]; ok {
val = hex
} else if len(val) > 5 && parse.Equal(val[:4], []byte("rgb(")) && val[len(val)-1] == ')' {
// TODO: handle rgb(x, y, z) and hsl(x, y, z)
}
} else if dim, n := shortenDimension(val); n == len(val) {
val = dim
}
// prefer single or double quotes depending on what occurs more often in value
val = xml.EscapeAttrVal(&attrByteBuffer, val)
if _, err := w.Write(val); err != nil {
return err
}
case xml.StartTagCloseToken:
next := tb.Peek(0)
skipExtra := false
if next.TokenType == xml.TextToken && parse.IsAllWhitespace(next.Data) {
next = tb.Peek(1)
skipExtra = true
}
if next.TokenType == xml.EndTagToken {
// collapse empty tags to single void tag
tb.Shift()
if skipExtra {
tb.Shift()
}
if _, err := w.Write(voidBytes); err != nil {
return err
}
} else {
if _, err := w.Write(gtBytes); err != nil {
return err
}
}
case xml.StartTagCloseVoidToken:
if _, err := w.Write(voidBytes); err != nil {
return err
}
case xml.EndTagToken:
if _, err := w.Write(endBytes); err != nil {
return err
}
if _, err := w.Write(t.Data); err != nil {
return err
}
if _, err := w.Write(gtBytes); err != nil {
return err
}
}
}
}
// Minify minifies HTML data, it reads from r and writes to w.
func Minify(m minify.Minifier, _ string, w io.Writer, r io.Reader) error {
var rawTag html.Hash
var rawTagMediatype []byte
omitSpace := true // if true the next leading space is omitted
defaultScriptType := "text/javascript"
defaultStyleType := "text/css"
defaultInlineStyleType := "text/css;inline=1"
attrMinifyBuffer := buffer.NewWriter(make([]byte, 0, 64))
attrByteBuffer := make([]byte, 0, 64)
attrIntBuffer := make([]int, 0, maxAttrLookup)
attrTokenBuffer := make([]*html.Token, 0, maxAttrLookup)
l := html.NewLexer(r)
tb := html.NewTokenBuffer(l)
for {
t := *tb.Shift()
SWITCH:
switch t.TokenType {
case html.ErrorToken:
if l.Err() == io.EOF {
return nil
}
return l.Err()
case html.DoctypeToken:
if _, err := w.Write([]byte("<!doctype html>")); err != nil {
return err
}
case html.CommentToken:
// TODO: ensure that nested comments are handled properly (lexer doesn't handle this!)
var comment []byte
if bytes.HasPrefix(t.Data, []byte("[if")) {
comment = append(append([]byte("<!--"), t.Data...), []byte("-->")...)
} else if bytes.HasSuffix(t.Data, []byte("--")) {
// only occurs when mixed up with conditional comments
comment = append(append([]byte("<!"), t.Data...), '>')
}
if _, err := w.Write(comment); err != nil {
return err
}
case html.TextToken:
// CSS and JS minifiers for inline code
if rawTag != 0 {
if rawTag == html.Style || rawTag == html.Script || rawTag == html.Iframe || rawTag == html.Svg || rawTag == html.Math {
var mediatype string
if rawTag == html.Iframe {
mediatype = "text/html"
} else if len(rawTagMediatype) > 0 {
mediatype = string(rawTagMediatype)
} else if rawTag == html.Script {
mediatype = defaultScriptType
} else if rawTag == html.Style {
mediatype = defaultStyleType
} else if rawTag == html.Svg {
mediatype = "image/svg+xml"
} else if rawTag == html.Math {
mediatype = "application/mathml+xml"
}
// ignore CDATA
if trimmedData := parse.Trim(t.Data, parse.IsWhitespace); len(trimmedData) > 12 && bytes.Equal(trimmedData[:9], []byte("<![CDATA[")) && bytes.Equal(trimmedData[len(trimmedData)-3:], []byte("]]>")) {
t.Data = trimmedData[9 : len(trimmedData)-3]
}
if err := m.Minify(mediatype, w, buffer.NewReader(t.Data)); err != nil {
if _, err := w.Write(t.Data); err != nil {
return err
}
}
} else if _, err := w.Write(t.Data); err != nil {
return err
}
if !nonPhrasingTagMap[rawTag] && rawTag != html.Script {
omitSpace = len(t.Data) > 0 && t.Data[len(t.Data)-1] == ' '
}
} else {
t.Data = parse.ReplaceMultiple(t.Data, parse.IsWhitespace, ' ')
// whitespace removal; trim left
if omitSpace && t.Data[0] == ' ' {
t.Data = t.Data[1:]
}
// whitespace removal; trim right
omitSpace = false
if len(t.Data) == 0 {
omitSpace = true
} else if t.Data[len(t.Data)-1] == ' ' {
omitSpace = true
i := 0
for {
next := tb.Peek(i)
// trim if EOF, text token with leading whitespace or block token
if next.TokenType == html.ErrorToken {
t.Data = t.Data[:len(t.Data)-1]
omitSpace = false
break
} else if next.TokenType == html.TextToken {
// remove if the text token starts with a whitespace
if len(next.Data) > 0 && parse.IsWhitespace(next.Data[0]) {
t.Data = t.Data[:len(t.Data)-1]
omitSpace = false
}
break
} else if next.TokenType == html.StartTagToken || next.TokenType == html.EndTagToken {
// remove when followed up by a block tag
if nonPhrasingTagMap[next.Hash] {
t.Data = t.Data[:len(t.Data)-1]
omitSpace = false
break
} else if next.TokenType == html.StartTagToken {
break
}
}
i++
}
}
if _, err := w.Write(t.Data); err != nil {
return err
}
}
case html.StartTagToken, html.EndTagToken:
rawTag = 0
hasAttributes := false
if t.TokenType == html.StartTagToken {
if next := tb.Peek(0); next.TokenType == html.AttributeToken {
hasAttributes = true
}
if rawTagMap[t.Hash] {
// ignore empty script and style tags
if !hasAttributes && (t.Hash == html.Script || t.Hash == html.Style) {
if next := tb.Peek(1); next.TokenType == html.EndTagToken {
tb.Shift()
tb.Shift()
break
}
}
rawTag = t.Hash
rawTagMediatype = []byte{}
}
}
if nonPhrasingTagMap[t.Hash] {
omitSpace = true // omit spaces after block elements
}
// remove superfluous ending tags
if !hasAttributes && (t.Hash == html.Html || t.Hash == html.Head || t.Hash == html.Body || t.Hash == html.Colgroup) {
break
} else if t.TokenType == html.EndTagToken {
if t.Hash == html.Thead || t.Hash == html.Tbody || t.Hash == html.Tfoot || t.Hash == html.Tr || t.Hash == html.Th || t.Hash == html.Td ||
t.Hash == html.Optgroup || t.Hash == html.Option || t.Hash == html.Dd || t.Hash == html.Dt ||
t.Hash == html.Li || t.Hash == html.Rb || t.Hash == html.Rt || t.Hash == html.Rtc || t.Hash == html.Rp {
break
} else if t.Hash == html.P {
i := 0
for {
next := tb.Peek(i)
i++
// continue if text token is empty or whitespace
if next.TokenType == html.TextToken && parse.IsAllWhitespace(next.Data) {
continue
}
if next.TokenType == html.ErrorToken || next.TokenType == html.EndTagToken && next.Hash != html.A || next.TokenType == html.StartTagToken && nonPhrasingTagMap[next.Hash] {
break SWITCH
}
break
}
}
}
// write tag
if t.TokenType == html.EndTagToken {
if _, err := w.Write(endBytes); err != nil {
return err
}
} else {
if _, err := w.Write(ltBytes); err != nil {
return err
}
}
if _, err := w.Write(t.Data); err != nil {
return err
}
if hasAttributes {
// rewrite attributes with interdependent conditions
if t.Hash == html.A {
if attr := getAttributes(tb, &attrIntBuffer, &attrTokenBuffer, html.Id, html.Name, html.Rel, html.Href); attr != nil {
if id := attr[0]; id != nil {
if name := attr[1]; name != nil && parse.Equal(id.AttrVal, name.AttrVal) {
name.Data = nil
}
}
// TODO: omit http or https according to URL, specified through options
// if rel := attr[2]; rel == nil || !parse.EqualFold(rel.AttrVal, externalBytes) {
// if href := attr[3]; href != nil {
// if len(href.AttrVal) > 5 && parse.EqualFold(href.AttrVal[:4], []byte{'h', 't', 't', 'p'}) {
// if href.AttrVal[4] == ':' {
// href.AttrVal = href.AttrVal[5:]
// } else if (href.AttrVal[4] == 's' || href.AttrVal[4] == 'S') && href.AttrVal[5] == ':' {
// href.AttrVal = href.AttrVal[6:]
// }
// }
// }
// }
}
} else if t.Hash == html.Meta {
if attr := getAttributes(tb, &attrIntBuffer, &attrTokenBuffer, html.Content, html.Http_Equiv, html.Charset, html.Name); attr != nil {
if content := attr[0]; content != nil {
if httpEquiv := attr[1]; httpEquiv != nil {
content.AttrVal = minify.ContentType(content.AttrVal)
if charset := attr[2]; charset == nil && parse.EqualFold(httpEquiv.AttrVal, []byte("content-type")) && parse.Equal(content.AttrVal, []byte("text/html;charset=utf-8")) {
httpEquiv.Data = nil
content.Data = []byte("charset")
content.Hash = html.Charset
content.AttrVal = []byte("utf-8")
} else if parse.EqualFold(httpEquiv.AttrVal, []byte("content-style-type")) {
defaultStyleType = string(content.AttrVal)
defaultInlineStyleType = defaultStyleType + ";inline=1"
} else if parse.EqualFold(httpEquiv.AttrVal, []byte("content-script-type")) {
defaultScriptType = string(content.AttrVal)
}
}
if name := attr[3]; name != nil {
if parse.EqualFold(name.AttrVal, []byte("keywords")) {
content.AttrVal = bytes.Replace(content.AttrVal, []byte(", "), []byte(","), -1)
} else if parse.EqualFold(name.AttrVal, []byte("viewport")) {
content.AttrVal = bytes.Replace(content.AttrVal, []byte(" "), []byte(""), -1)
}
}
}
}
} else if t.Hash == html.Script {
if attr := getAttributes(tb, &attrIntBuffer, &attrTokenBuffer, html.Src, html.Charset); attr != nil {
if src := attr[0]; src != nil {
if charset := attr[1]; charset != nil {
charset.Data = nil
}
}
}
}
// write attributes
for {
attr := *tb.Shift()
if attr.TokenType != html.AttributeToken {
break
} else if attr.Data == nil {
continue // removed attribute
}
val := attr.AttrVal
if len(val) > 1 && (val[0] == '"' || val[0] == '\'') {
val = parse.Trim(val[1:len(val)-1], parse.IsWhitespace)
}
if len(val) == 0 && (attr.Hash == html.Class ||
attr.Hash == html.Dir ||
attr.Hash == html.Id ||
attr.Hash == html.Lang ||
attr.Hash == html.Name ||
attr.Hash == html.Title ||
attr.Hash == html.Action && t.Hash == html.Form ||
attr.Hash == html.Value && t.Hash == html.Input) {
continue // omit empty attribute values
}
if caseInsensitiveAttrMap[attr.Hash] {
val = parse.ToLower(val)
if attr.Hash == html.Enctype || attr.Hash == html.Codetype || attr.Hash == html.Accept || attr.Hash == html.Type && (t.Hash == html.A || t.Hash == html.Link || t.Hash == html.Object || t.Hash == html.Param || t.Hash == html.Script || t.Hash == html.Style || t.Hash == html.Source) {
val = minify.ContentType(val)
}
}
if rawTag != 0 && attr.Hash == html.Type {
rawTagMediatype = val
}
// default attribute values can be ommited
if attr.Hash == html.Type && (t.Hash == html.Script && parse.Equal(val, []byte("text/javascript")) ||
t.Hash == html.Style && parse.Equal(val, []byte("text/css")) ||
t.Hash == html.Link && parse.Equal(val, []byte("text/css")) ||
t.Hash == html.Input && parse.Equal(val, []byte("text")) ||
t.Hash == html.Button && parse.Equal(val, []byte("submit"))) ||
attr.Hash == html.Language && t.Hash == html.Script ||
attr.Hash == html.Method && parse.Equal(val, []byte("get")) ||
attr.Hash == html.Enctype && parse.Equal(val, []byte("application/x-www-form-urlencoded")) ||
attr.Hash == html.Colspan && parse.Equal(val, []byte("1")) ||
attr.Hash == html.Rowspan && parse.Equal(val, []byte("1")) ||
attr.Hash == html.Shape && parse.Equal(val, []byte("rect")) ||
attr.Hash == html.Span && parse.Equal(val, []byte("1")) ||
attr.Hash == html.Clear && parse.Equal(val, []byte("none")) ||
attr.Hash == html.Frameborder && parse.Equal(val, []byte("1")) ||
attr.Hash == html.Scrolling && parse.Equal(val, []byte("auto")) ||
attr.Hash == html.Valuetype && parse.Equal(val, []byte("data")) ||
attr.Hash == html.Media && t.Hash == html.Style && parse.Equal(val, []byte("all")) {
continue
}
// CSS and JS minifiers for attribute inline code
if attr.Hash == html.Style {
attrMinifyBuffer.Reset()
if m.Minify(defaultInlineStyleType, attrMinifyBuffer, buffer.NewReader(val)) == nil {
val = attrMinifyBuffer.Bytes()
}
if len(val) == 0 {
continue
}
} else if len(attr.Data) > 2 && attr.Data[0] == 'o' && attr.Data[1] == 'n' {
if len(val) >= 11 && parse.EqualFold(val[:11], []byte("javascript:")) {
val = val[11:]
}
attrMinifyBuffer.Reset()
if m.Minify(defaultScriptType, attrMinifyBuffer, buffer.NewReader(val)) == nil {
val = attrMinifyBuffer.Bytes()
}
if len(val) == 0 {
continue
}
} else if len(val) > 5 && urlAttrMap[attr.Hash] { // anchors are already handled
// TODO: omit http or https according to URL, specified through options
//if t.Hash != html.A {
// if parse.EqualFold(val[:4], []byte{'h', 't', 't', 'p'}) {
// if val[4] == ':' {
// val = val[5:]
// } else if (val[4] == 's' || val[4] == 'S') && val[5] == ':' {
// val = val[6:]
// }
// }
// } else
if parse.EqualFold(val[:5], []byte{'d', 'a', 't', 'a', ':'}) {
val = minify.DataURI(m, val)
}
}
if _, err := w.Write(spaceBytes); err != nil {
return err
}
if _, err := w.Write(attr.Data); err != nil {
return err
}
if len(val) > 0 && !booleanAttrMap[attr.Hash] {
if _, err := w.Write(isBytes); err != nil {
return err
}
// no quotes if possible, else prefer single or double depending on which occurs more often in value
val = html.EscapeAttrVal(&attrByteBuffer, attr.AttrVal, val)
if _, err := w.Write(val); err != nil {
return err
}
}
}
}
if _, err := w.Write(gtBytes); err != nil {
return err
}
}
}
}