471 lines
10 KiB
Go
471 lines
10 KiB
Go
package minify // import "github.com/tdewolff/minify"
|
|
|
|
import (
|
|
"bytes"
|
|
"encoding/base64"
|
|
"net/url"
|
|
|
|
"github.com/tdewolff/parse/v2"
|
|
"github.com/tdewolff/parse/v2/strconv"
|
|
)
|
|
|
|
// Epsilon is the closest number to zero that is not considered to be zero.
|
|
var Epsilon = 0.00001
|
|
|
|
// Mediatype minifies a given mediatype by removing all whitespace.
|
|
func Mediatype(b []byte) []byte {
|
|
j := 0
|
|
start := 0
|
|
inString := false
|
|
for i, c := range b {
|
|
if !inString && parse.IsWhitespace(c) {
|
|
if start != 0 {
|
|
j += copy(b[j:], b[start:i])
|
|
} else {
|
|
j += i
|
|
}
|
|
start = i + 1
|
|
} else if c == '"' {
|
|
inString = !inString
|
|
}
|
|
}
|
|
if start != 0 {
|
|
j += copy(b[j:], b[start:])
|
|
return parse.ToLower(b[:j])
|
|
}
|
|
return parse.ToLower(b)
|
|
}
|
|
|
|
// DataURI minifies a data URI and calls a minifier by the specified mediatype. Specifications: https://www.ietf.org/rfc/rfc2397.txt.
|
|
func DataURI(m *M, dataURI []byte) []byte {
|
|
if mediatype, data, err := parse.DataURI(dataURI); err == nil {
|
|
dataURI, _ = m.Bytes(string(mediatype), data)
|
|
base64Len := len(";base64") + base64.StdEncoding.EncodedLen(len(dataURI))
|
|
asciiLen := len(dataURI)
|
|
for _, c := range dataURI {
|
|
if 'A' <= c && c <= 'Z' || 'a' <= c && c <= 'z' || '0' <= c && c <= '9' || c == '-' || c == '_' || c == '.' || c == '~' || c == ' ' {
|
|
asciiLen++
|
|
} else {
|
|
asciiLen += 2
|
|
}
|
|
if asciiLen > base64Len {
|
|
break
|
|
}
|
|
}
|
|
if asciiLen > base64Len {
|
|
encoded := make([]byte, base64Len-len(";base64"))
|
|
base64.StdEncoding.Encode(encoded, dataURI)
|
|
dataURI = encoded
|
|
mediatype = append(mediatype, []byte(";base64")...)
|
|
} else {
|
|
dataURI = []byte(url.QueryEscape(string(dataURI)))
|
|
dataURI = bytes.Replace(dataURI, []byte("\""), []byte("\\\""), -1)
|
|
}
|
|
if len("text/plain") <= len(mediatype) && parse.EqualFold(mediatype[:len("text/plain")], []byte("text/plain")) {
|
|
mediatype = mediatype[len("text/plain"):]
|
|
}
|
|
for i := 0; i+len(";charset=us-ascii") <= len(mediatype); i++ {
|
|
// must start with semicolon and be followed by end of mediatype or semicolon
|
|
if mediatype[i] == ';' && parse.EqualFold(mediatype[i+1:i+len(";charset=us-ascii")], []byte("charset=us-ascii")) && (i+len(";charset=us-ascii") >= len(mediatype) || mediatype[i+len(";charset=us-ascii")] == ';') {
|
|
mediatype = append(mediatype[:i], mediatype[i+len(";charset=us-ascii"):]...)
|
|
break
|
|
}
|
|
}
|
|
dataURI = append(append(append([]byte("data:"), mediatype...), ','), dataURI...)
|
|
}
|
|
return dataURI
|
|
}
|
|
|
|
const MaxInt = int(^uint(0) >> 1)
|
|
const MinInt = -MaxInt - 1
|
|
|
|
// Decimal minifies a given byte slice containing a number (see parse.Number) and removes superfluous characters.
|
|
// It does not parse or output exponents.
|
|
func Decimal(num []byte, prec int) []byte {
|
|
// omit first + and register mantissa start and end, whether it's negative and the exponent
|
|
neg := false
|
|
start := 0
|
|
dot := -1
|
|
end := len(num)
|
|
if 0 < end && (num[0] == '+' || num[0] == '-') {
|
|
if num[0] == '-' {
|
|
neg = true
|
|
}
|
|
start++
|
|
}
|
|
for i, c := range num[start:] {
|
|
if c == '.' {
|
|
dot = start + i
|
|
break
|
|
}
|
|
}
|
|
if dot == -1 {
|
|
dot = end
|
|
}
|
|
|
|
// trim leading zeros but leave at least one digit
|
|
for start < end-1 && num[start] == '0' {
|
|
start++
|
|
}
|
|
// trim trailing zeros
|
|
i := end - 1
|
|
for ; i > dot; i-- {
|
|
if num[i] != '0' {
|
|
end = i + 1
|
|
break
|
|
}
|
|
}
|
|
if i == dot {
|
|
end = dot
|
|
if start == end {
|
|
num[start] = '0'
|
|
return num[start : start+1]
|
|
}
|
|
} else if start == end-1 && num[start] == '0' {
|
|
return num[start:end]
|
|
}
|
|
|
|
// apply precision
|
|
if prec > -1 && dot+1+prec < end {
|
|
end = dot + 1 + prec
|
|
inc := num[end] >= '5'
|
|
if inc || num[end-1] == '0' {
|
|
// process either an increase from a lesser significant decimal (>= 5)
|
|
// or remove trailing zeros after the dot, or both
|
|
for i := end - 1; i > start; i-- {
|
|
if i == dot {
|
|
end--
|
|
} else if inc {
|
|
if num[i] == '9' {
|
|
if i > dot {
|
|
end--
|
|
} else {
|
|
num[i] = '0'
|
|
break
|
|
}
|
|
} else {
|
|
num[i]++
|
|
inc = false
|
|
break
|
|
}
|
|
} else if i > dot && num[i] == '0' {
|
|
end--
|
|
} else {
|
|
break
|
|
}
|
|
}
|
|
}
|
|
if dot == start && end == start+1 {
|
|
if inc {
|
|
num[start] = '1'
|
|
} else {
|
|
num[start] = '0'
|
|
}
|
|
} else {
|
|
if dot+1 == end {
|
|
end--
|
|
}
|
|
if inc {
|
|
if num[start] == '9' {
|
|
num[start] = '0'
|
|
copy(num[start+1:], num[start:end])
|
|
end++
|
|
num[start] = '1'
|
|
} else {
|
|
num[start]++
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if neg {
|
|
start--
|
|
num[start] = '-'
|
|
}
|
|
return num[start:end]
|
|
}
|
|
|
|
// Number minifies a given byte slice containing a number (see parse.Number) and removes superfluous characters.
|
|
func Number(num []byte, prec int) []byte {
|
|
// omit first + and register mantissa start and end, whether it's negative and the exponent
|
|
neg := false
|
|
start := 0
|
|
dot := -1
|
|
end := len(num)
|
|
origExp := 0
|
|
if 0 < end && (num[0] == '+' || num[0] == '-') {
|
|
if num[0] == '-' {
|
|
neg = true
|
|
}
|
|
start++
|
|
}
|
|
for i, c := range num[start:] {
|
|
if c == '.' {
|
|
dot = start + i
|
|
} else if c == 'e' || c == 'E' {
|
|
end = start + i
|
|
i += start + 1
|
|
if i < len(num) && num[i] == '+' {
|
|
i++
|
|
}
|
|
if tmpOrigExp, n := strconv.ParseInt(num[i:]); n > 0 && tmpOrigExp >= int64(MinInt) && tmpOrigExp <= int64(MaxInt) {
|
|
// range checks for when int is 32 bit
|
|
origExp = int(tmpOrigExp)
|
|
} else {
|
|
return num
|
|
}
|
|
break
|
|
}
|
|
}
|
|
if dot == -1 {
|
|
dot = end
|
|
}
|
|
|
|
// trim leading zeros but leave at least one digit
|
|
for start < end-1 && num[start] == '0' {
|
|
start++
|
|
}
|
|
// trim trailing zeros
|
|
i := end - 1
|
|
for ; i > dot; i-- {
|
|
if num[i] != '0' {
|
|
end = i + 1
|
|
break
|
|
}
|
|
}
|
|
if i == dot {
|
|
end = dot
|
|
if start == end {
|
|
num[start] = '0'
|
|
return num[start : start+1]
|
|
}
|
|
} else if start == end-1 && num[start] == '0' {
|
|
return num[start:end]
|
|
}
|
|
|
|
// n is the number of significant digits
|
|
// normExp would be the exponent if it were normalised (0.1 <= f < 1)
|
|
n := 0
|
|
normExp := 0
|
|
if dot == start {
|
|
for i = dot + 1; i < end; i++ {
|
|
if num[i] != '0' {
|
|
n = end - i
|
|
normExp = dot - i + 1
|
|
break
|
|
}
|
|
}
|
|
} else if dot == end {
|
|
normExp = end - start
|
|
for i = end - 1; i >= start; i-- {
|
|
if num[i] != '0' {
|
|
n = i + 1 - start
|
|
end = i + 1
|
|
break
|
|
}
|
|
}
|
|
} else {
|
|
n = end - start - 1
|
|
normExp = dot - start
|
|
}
|
|
|
|
if origExp < 0 && (normExp < MinInt-origExp || normExp-n < MinInt-origExp) || origExp > 0 && (normExp > MaxInt-origExp || normExp-n > MaxInt-origExp) {
|
|
return num
|
|
}
|
|
normExp += origExp
|
|
|
|
// intExp would be the exponent if it were an integer
|
|
intExp := normExp - n
|
|
lenIntExp := 1
|
|
if intExp <= -10 || intExp >= 10 {
|
|
lenIntExp = strconv.LenInt(int64(intExp))
|
|
}
|
|
|
|
// there are three cases to consider when printing the number
|
|
// case 1: without decimals and with an exponent (large numbers)
|
|
// case 2: with decimals and without an exponent (around zero)
|
|
// case 3: without decimals and with a negative exponent (small numbers)
|
|
if normExp >= n {
|
|
// case 1
|
|
if dot < end {
|
|
if dot == start {
|
|
start = end - n
|
|
} else {
|
|
// TODO: copy the other part if shorter?
|
|
copy(num[dot:], num[dot+1:end])
|
|
end--
|
|
}
|
|
}
|
|
if normExp >= n+3 {
|
|
num[end] = 'e'
|
|
end++
|
|
for i := end + lenIntExp - 1; i >= end; i-- {
|
|
num[i] = byte(intExp%10) + '0'
|
|
intExp /= 10
|
|
}
|
|
end += lenIntExp
|
|
} else if normExp == n+2 {
|
|
num[end] = '0'
|
|
num[end+1] = '0'
|
|
end += 2
|
|
} else if normExp == n+1 {
|
|
num[end] = '0'
|
|
end++
|
|
}
|
|
} else if normExp >= -lenIntExp-1 {
|
|
// case 2
|
|
zeroes := -normExp
|
|
newDot := 0
|
|
if zeroes > 0 {
|
|
// dot placed at the front and add zeroes
|
|
newDot = end - n - zeroes - 1
|
|
if newDot != dot {
|
|
d := start - newDot
|
|
if d > 0 {
|
|
if dot < end {
|
|
// copy original digits behind the dot backwards
|
|
copy(num[dot+1+d:], num[dot+1:end])
|
|
if dot > start {
|
|
// copy original digits before the dot backwards
|
|
copy(num[start+d+1:], num[start:dot])
|
|
}
|
|
} else if dot > start {
|
|
// copy original digits before the dot backwards
|
|
copy(num[start+d:], num[start:dot])
|
|
}
|
|
newDot = start
|
|
end += d
|
|
} else {
|
|
start += -d
|
|
}
|
|
num[newDot] = '.'
|
|
for i := 0; i < zeroes; i++ {
|
|
num[newDot+1+i] = '0'
|
|
}
|
|
}
|
|
} else {
|
|
// placed in the middle
|
|
if dot == start {
|
|
// TODO: try if placing at the end reduces copying
|
|
// when there are zeroes after the dot
|
|
dot = end - n - 1
|
|
start = dot
|
|
} else if dot >= end {
|
|
// TODO: try if placing at the start reduces copying
|
|
// when input has no dot in it
|
|
dot = end
|
|
end++
|
|
}
|
|
newDot = start + normExp
|
|
if newDot > dot {
|
|
// copy digits forwards
|
|
copy(num[dot:], num[dot+1:newDot+1])
|
|
} else if newDot < dot {
|
|
// copy digits backwards
|
|
copy(num[newDot+1:], num[newDot:dot])
|
|
}
|
|
num[newDot] = '.'
|
|
}
|
|
|
|
// apply precision
|
|
dot = newDot
|
|
if prec > -1 && dot+1+prec < end {
|
|
end = dot + 1 + prec
|
|
inc := num[end] >= '5'
|
|
if inc || num[end-1] == '0' {
|
|
for i := end - 1; i > start; i-- {
|
|
if i == dot {
|
|
end--
|
|
} else if inc {
|
|
if num[i] == '9' {
|
|
if i > dot {
|
|
end--
|
|
} else {
|
|
num[i] = '0'
|
|
break
|
|
}
|
|
} else {
|
|
num[i]++
|
|
inc = false
|
|
break
|
|
}
|
|
} else if i > dot && num[i] == '0' {
|
|
end--
|
|
} else {
|
|
break
|
|
}
|
|
}
|
|
}
|
|
if dot == start && end == start+1 {
|
|
if inc {
|
|
num[start] = '1'
|
|
} else {
|
|
num[start] = '0'
|
|
}
|
|
} else {
|
|
if dot+1 == end {
|
|
end--
|
|
}
|
|
if inc {
|
|
if num[start] == '9' {
|
|
num[start] = '0'
|
|
copy(num[start+1:], num[start:end])
|
|
end++
|
|
num[start] = '1'
|
|
} else {
|
|
num[start]++
|
|
}
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
// case 3
|
|
|
|
// find new end, considering moving numbers to the front, removing the dot and increasing the length of the exponent
|
|
newEnd := end
|
|
if dot == start {
|
|
newEnd = start + n
|
|
} else {
|
|
newEnd--
|
|
}
|
|
newEnd += 2 + lenIntExp
|
|
|
|
exp := intExp
|
|
lenExp := lenIntExp
|
|
if newEnd < len(num) {
|
|
// it saves space to convert the decimal to an integer and decrease the exponent
|
|
if dot < end {
|
|
if dot == start {
|
|
copy(num[start:], num[end-n:end])
|
|
end = start + n
|
|
} else {
|
|
copy(num[dot:], num[dot+1:end])
|
|
end--
|
|
}
|
|
}
|
|
} else {
|
|
// it does not save space and will panic, so we revert to the original representation
|
|
exp = origExp
|
|
lenExp = 1
|
|
if origExp <= -10 || origExp >= 10 {
|
|
lenExp = strconv.LenInt(int64(origExp))
|
|
}
|
|
}
|
|
num[end] = 'e'
|
|
num[end+1] = '-'
|
|
end += 2
|
|
exp = -exp
|
|
for i := end + lenExp - 1; i >= end; i-- {
|
|
num[i] = byte(exp%10) + '0'
|
|
exp /= 10
|
|
}
|
|
end += lenExp
|
|
}
|
|
|
|
if neg {
|
|
start--
|
|
num[start] = '-'
|
|
}
|
|
return num[start:end]
|
|
}
|