642 lines
10 KiB
Go
642 lines
10 KiB
Go
package brotli
|
|
|
|
const (
|
|
transformIdentity = 0
|
|
transformOmitLast1 = 1
|
|
transformOmitLast2 = 2
|
|
transformOmitLast3 = 3
|
|
transformOmitLast4 = 4
|
|
transformOmitLast5 = 5
|
|
transformOmitLast6 = 6
|
|
transformOmitLast7 = 7
|
|
transformOmitLast8 = 8
|
|
transformOmitLast9 = 9
|
|
transformUppercaseFirst = 10
|
|
transformUppercaseAll = 11
|
|
transformOmitFirst1 = 12
|
|
transformOmitFirst2 = 13
|
|
transformOmitFirst3 = 14
|
|
transformOmitFirst4 = 15
|
|
transformOmitFirst5 = 16
|
|
transformOmitFirst6 = 17
|
|
transformOmitFirst7 = 18
|
|
transformOmitFirst8 = 19
|
|
transformOmitFirst9 = 20
|
|
transformShiftFirst = 21
|
|
transformShiftAll = 22 + iota - 22
|
|
numTransformTypes
|
|
)
|
|
|
|
const transformsMaxCutOff = transformOmitLast9
|
|
|
|
type transforms struct {
|
|
prefix_suffix_size uint16
|
|
prefix_suffix []byte
|
|
prefix_suffix_map []uint16
|
|
num_transforms uint32
|
|
transforms []byte
|
|
params []byte
|
|
cutOffTransforms [transformsMaxCutOff + 1]int16
|
|
}
|
|
|
|
func transformPrefixId(t *transforms, I int) byte {
|
|
return t.transforms[(I*3)+0]
|
|
}
|
|
|
|
func transformType(t *transforms, I int) byte {
|
|
return t.transforms[(I*3)+1]
|
|
}
|
|
|
|
func transformSuffixId(t *transforms, I int) byte {
|
|
return t.transforms[(I*3)+2]
|
|
}
|
|
|
|
func transformPrefix(t *transforms, I int) []byte {
|
|
return t.prefix_suffix[t.prefix_suffix_map[transformPrefixId(t, I)]:]
|
|
}
|
|
|
|
func transformSuffix(t *transforms, I int) []byte {
|
|
return t.prefix_suffix[t.prefix_suffix_map[transformSuffixId(t, I)]:]
|
|
}
|
|
|
|
/* RFC 7932 transforms string data */
|
|
const kPrefixSuffix string = "\001 \002, \010 of the \004 of \002s \001.\005 and \004 " + "in \001\"\004 to \002\">\001\n\002. \001]\005 for \003 a \006 " + "that \001'\006 with \006 from \004 by \001(\006. T" + "he \004 on \004 as \004 is \004ing \002\n\t\001:\003ed " + "\002=\"\004 at \003ly \001,\002='\005.com/\007. This \005" + " not \003er \003al \004ful \004ive \005less \004es" + "t \004ize \002\xc2\xa0\004ous \005 the \002e \000"
|
|
|
|
var kPrefixSuffixMap = [50]uint16{
|
|
0x00,
|
|
0x02,
|
|
0x05,
|
|
0x0E,
|
|
0x13,
|
|
0x16,
|
|
0x18,
|
|
0x1E,
|
|
0x23,
|
|
0x25,
|
|
0x2A,
|
|
0x2D,
|
|
0x2F,
|
|
0x32,
|
|
0x34,
|
|
0x3A,
|
|
0x3E,
|
|
0x45,
|
|
0x47,
|
|
0x4E,
|
|
0x55,
|
|
0x5A,
|
|
0x5C,
|
|
0x63,
|
|
0x68,
|
|
0x6D,
|
|
0x72,
|
|
0x77,
|
|
0x7A,
|
|
0x7C,
|
|
0x80,
|
|
0x83,
|
|
0x88,
|
|
0x8C,
|
|
0x8E,
|
|
0x91,
|
|
0x97,
|
|
0x9F,
|
|
0xA5,
|
|
0xA9,
|
|
0xAD,
|
|
0xB2,
|
|
0xB7,
|
|
0xBD,
|
|
0xC2,
|
|
0xC7,
|
|
0xCA,
|
|
0xCF,
|
|
0xD5,
|
|
0xD8,
|
|
}
|
|
|
|
/* RFC 7932 transforms */
|
|
var kTransformsData = []byte{
|
|
49,
|
|
transformIdentity,
|
|
49,
|
|
49,
|
|
transformIdentity,
|
|
0,
|
|
0,
|
|
transformIdentity,
|
|
0,
|
|
49,
|
|
transformOmitFirst1,
|
|
49,
|
|
49,
|
|
transformUppercaseFirst,
|
|
0,
|
|
49,
|
|
transformIdentity,
|
|
47,
|
|
0,
|
|
transformIdentity,
|
|
49,
|
|
4,
|
|
transformIdentity,
|
|
0,
|
|
49,
|
|
transformIdentity,
|
|
3,
|
|
49,
|
|
transformUppercaseFirst,
|
|
49,
|
|
49,
|
|
transformIdentity,
|
|
6,
|
|
49,
|
|
transformOmitFirst2,
|
|
49,
|
|
49,
|
|
transformOmitLast1,
|
|
49,
|
|
1,
|
|
transformIdentity,
|
|
0,
|
|
49,
|
|
transformIdentity,
|
|
1,
|
|
0,
|
|
transformUppercaseFirst,
|
|
0,
|
|
49,
|
|
transformIdentity,
|
|
7,
|
|
49,
|
|
transformIdentity,
|
|
9,
|
|
48,
|
|
transformIdentity,
|
|
0,
|
|
49,
|
|
transformIdentity,
|
|
8,
|
|
49,
|
|
transformIdentity,
|
|
5,
|
|
49,
|
|
transformIdentity,
|
|
10,
|
|
49,
|
|
transformIdentity,
|
|
11,
|
|
49,
|
|
transformOmitLast3,
|
|
49,
|
|
49,
|
|
transformIdentity,
|
|
13,
|
|
49,
|
|
transformIdentity,
|
|
14,
|
|
49,
|
|
transformOmitFirst3,
|
|
49,
|
|
49,
|
|
transformOmitLast2,
|
|
49,
|
|
49,
|
|
transformIdentity,
|
|
15,
|
|
49,
|
|
transformIdentity,
|
|
16,
|
|
0,
|
|
transformUppercaseFirst,
|
|
49,
|
|
49,
|
|
transformIdentity,
|
|
12,
|
|
5,
|
|
transformIdentity,
|
|
49,
|
|
0,
|
|
transformIdentity,
|
|
1,
|
|
49,
|
|
transformOmitFirst4,
|
|
49,
|
|
49,
|
|
transformIdentity,
|
|
18,
|
|
49,
|
|
transformIdentity,
|
|
17,
|
|
49,
|
|
transformIdentity,
|
|
19,
|
|
49,
|
|
transformIdentity,
|
|
20,
|
|
49,
|
|
transformOmitFirst5,
|
|
49,
|
|
49,
|
|
transformOmitFirst6,
|
|
49,
|
|
47,
|
|
transformIdentity,
|
|
49,
|
|
49,
|
|
transformOmitLast4,
|
|
49,
|
|
49,
|
|
transformIdentity,
|
|
22,
|
|
49,
|
|
transformUppercaseAll,
|
|
49,
|
|
49,
|
|
transformIdentity,
|
|
23,
|
|
49,
|
|
transformIdentity,
|
|
24,
|
|
49,
|
|
transformIdentity,
|
|
25,
|
|
49,
|
|
transformOmitLast7,
|
|
49,
|
|
49,
|
|
transformOmitLast1,
|
|
26,
|
|
49,
|
|
transformIdentity,
|
|
27,
|
|
49,
|
|
transformIdentity,
|
|
28,
|
|
0,
|
|
transformIdentity,
|
|
12,
|
|
49,
|
|
transformIdentity,
|
|
29,
|
|
49,
|
|
transformOmitFirst9,
|
|
49,
|
|
49,
|
|
transformOmitFirst7,
|
|
49,
|
|
49,
|
|
transformOmitLast6,
|
|
49,
|
|
49,
|
|
transformIdentity,
|
|
21,
|
|
49,
|
|
transformUppercaseFirst,
|
|
1,
|
|
49,
|
|
transformOmitLast8,
|
|
49,
|
|
49,
|
|
transformIdentity,
|
|
31,
|
|
49,
|
|
transformIdentity,
|
|
32,
|
|
47,
|
|
transformIdentity,
|
|
3,
|
|
49,
|
|
transformOmitLast5,
|
|
49,
|
|
49,
|
|
transformOmitLast9,
|
|
49,
|
|
0,
|
|
transformUppercaseFirst,
|
|
1,
|
|
49,
|
|
transformUppercaseFirst,
|
|
8,
|
|
5,
|
|
transformIdentity,
|
|
21,
|
|
49,
|
|
transformUppercaseAll,
|
|
0,
|
|
49,
|
|
transformUppercaseFirst,
|
|
10,
|
|
49,
|
|
transformIdentity,
|
|
30,
|
|
0,
|
|
transformIdentity,
|
|
5,
|
|
35,
|
|
transformIdentity,
|
|
49,
|
|
47,
|
|
transformIdentity,
|
|
2,
|
|
49,
|
|
transformUppercaseFirst,
|
|
17,
|
|
49,
|
|
transformIdentity,
|
|
36,
|
|
49,
|
|
transformIdentity,
|
|
33,
|
|
5,
|
|
transformIdentity,
|
|
0,
|
|
49,
|
|
transformUppercaseFirst,
|
|
21,
|
|
49,
|
|
transformUppercaseFirst,
|
|
5,
|
|
49,
|
|
transformIdentity,
|
|
37,
|
|
0,
|
|
transformIdentity,
|
|
30,
|
|
49,
|
|
transformIdentity,
|
|
38,
|
|
0,
|
|
transformUppercaseAll,
|
|
0,
|
|
49,
|
|
transformIdentity,
|
|
39,
|
|
0,
|
|
transformUppercaseAll,
|
|
49,
|
|
49,
|
|
transformIdentity,
|
|
34,
|
|
49,
|
|
transformUppercaseAll,
|
|
8,
|
|
49,
|
|
transformUppercaseFirst,
|
|
12,
|
|
0,
|
|
transformIdentity,
|
|
21,
|
|
49,
|
|
transformIdentity,
|
|
40,
|
|
0,
|
|
transformUppercaseFirst,
|
|
12,
|
|
49,
|
|
transformIdentity,
|
|
41,
|
|
49,
|
|
transformIdentity,
|
|
42,
|
|
49,
|
|
transformUppercaseAll,
|
|
17,
|
|
49,
|
|
transformIdentity,
|
|
43,
|
|
0,
|
|
transformUppercaseFirst,
|
|
5,
|
|
49,
|
|
transformUppercaseAll,
|
|
10,
|
|
0,
|
|
transformIdentity,
|
|
34,
|
|
49,
|
|
transformUppercaseFirst,
|
|
33,
|
|
49,
|
|
transformIdentity,
|
|
44,
|
|
49,
|
|
transformUppercaseAll,
|
|
5,
|
|
45,
|
|
transformIdentity,
|
|
49,
|
|
0,
|
|
transformIdentity,
|
|
33,
|
|
49,
|
|
transformUppercaseFirst,
|
|
30,
|
|
49,
|
|
transformUppercaseAll,
|
|
30,
|
|
49,
|
|
transformIdentity,
|
|
46,
|
|
49,
|
|
transformUppercaseAll,
|
|
1,
|
|
49,
|
|
transformUppercaseFirst,
|
|
34,
|
|
0,
|
|
transformUppercaseFirst,
|
|
33,
|
|
0,
|
|
transformUppercaseAll,
|
|
30,
|
|
0,
|
|
transformUppercaseAll,
|
|
1,
|
|
49,
|
|
transformUppercaseAll,
|
|
33,
|
|
49,
|
|
transformUppercaseAll,
|
|
21,
|
|
49,
|
|
transformUppercaseAll,
|
|
12,
|
|
0,
|
|
transformUppercaseAll,
|
|
5,
|
|
49,
|
|
transformUppercaseAll,
|
|
34,
|
|
0,
|
|
transformUppercaseAll,
|
|
12,
|
|
0,
|
|
transformUppercaseFirst,
|
|
30,
|
|
0,
|
|
transformUppercaseAll,
|
|
34,
|
|
0,
|
|
transformUppercaseFirst,
|
|
34,
|
|
}
|
|
|
|
var kBrotliTransforms = transforms{
|
|
217,
|
|
[]byte(kPrefixSuffix),
|
|
kPrefixSuffixMap[:],
|
|
121,
|
|
kTransformsData,
|
|
nil, /* no extra parameters */
|
|
[transformsMaxCutOff + 1]int16{0, 12, 27, 23, 42, 63, 56, 48, 59, 64},
|
|
}
|
|
|
|
func getTransforms() *transforms {
|
|
return &kBrotliTransforms
|
|
}
|
|
|
|
func toUpperCase(p []byte) int {
|
|
if p[0] < 0xC0 {
|
|
if p[0] >= 'a' && p[0] <= 'z' {
|
|
p[0] ^= 32
|
|
}
|
|
|
|
return 1
|
|
}
|
|
|
|
/* An overly simplified uppercasing model for UTF-8. */
|
|
if p[0] < 0xE0 {
|
|
p[1] ^= 32
|
|
return 2
|
|
}
|
|
|
|
/* An arbitrary transform for three byte characters. */
|
|
p[2] ^= 5
|
|
|
|
return 3
|
|
}
|
|
|
|
func shiftTransform(word []byte, word_len int, parameter uint16) int {
|
|
/* Limited sign extension: scalar < (1 << 24). */
|
|
var scalar uint32 = (uint32(parameter) & 0x7FFF) + (0x1000000 - (uint32(parameter) & 0x8000))
|
|
if word[0] < 0x80 {
|
|
/* 1-byte rune / 0sssssss / 7 bit scalar (ASCII). */
|
|
scalar += uint32(word[0])
|
|
|
|
word[0] = byte(scalar & 0x7F)
|
|
return 1
|
|
} else if word[0] < 0xC0 {
|
|
/* Continuation / 10AAAAAA. */
|
|
return 1
|
|
} else if word[0] < 0xE0 {
|
|
/* 2-byte rune / 110sssss AAssssss / 11 bit scalar. */
|
|
if word_len < 2 {
|
|
return 1
|
|
}
|
|
scalar += uint32(word[1]&0x3F | (word[0]&0x1F)<<6)
|
|
word[0] = byte(0xC0 | (scalar>>6)&0x1F)
|
|
word[1] = byte(uint32(word[1]&0xC0) | scalar&0x3F)
|
|
return 2
|
|
} else if word[0] < 0xF0 {
|
|
/* 3-byte rune / 1110ssss AAssssss BBssssss / 16 bit scalar. */
|
|
if word_len < 3 {
|
|
return word_len
|
|
}
|
|
scalar += uint32(word[2])&0x3F | uint32(word[1]&0x3F)<<6 | uint32(word[0]&0x0F)<<12
|
|
word[0] = byte(0xE0 | (scalar>>12)&0x0F)
|
|
word[1] = byte(uint32(word[1]&0xC0) | (scalar>>6)&0x3F)
|
|
word[2] = byte(uint32(word[2]&0xC0) | scalar&0x3F)
|
|
return 3
|
|
} else if word[0] < 0xF8 {
|
|
/* 4-byte rune / 11110sss AAssssss BBssssss CCssssss / 21 bit scalar. */
|
|
if word_len < 4 {
|
|
return word_len
|
|
}
|
|
scalar += uint32(word[3])&0x3F | uint32(word[2]&0x3F)<<6 | uint32(word[1]&0x3F)<<12 | uint32(word[0]&0x07)<<18
|
|
word[0] = byte(0xF0 | (scalar>>18)&0x07)
|
|
word[1] = byte(uint32(word[1]&0xC0) | (scalar>>12)&0x3F)
|
|
word[2] = byte(uint32(word[2]&0xC0) | (scalar>>6)&0x3F)
|
|
word[3] = byte(uint32(word[3]&0xC0) | scalar&0x3F)
|
|
return 4
|
|
}
|
|
|
|
return 1
|
|
}
|
|
|
|
func transformDictionaryWord(dst []byte, word []byte, len int, trans *transforms, transform_idx int) int {
|
|
var idx int = 0
|
|
var prefix []byte = transformPrefix(trans, transform_idx)
|
|
var type_ byte = transformType(trans, transform_idx)
|
|
var suffix []byte = transformSuffix(trans, transform_idx)
|
|
{
|
|
var prefix_len int = int(prefix[0])
|
|
prefix = prefix[1:]
|
|
for {
|
|
tmp1 := prefix_len
|
|
prefix_len--
|
|
if tmp1 == 0 {
|
|
break
|
|
}
|
|
dst[idx] = prefix[0]
|
|
idx++
|
|
prefix = prefix[1:]
|
|
}
|
|
}
|
|
{
|
|
var t int = int(type_)
|
|
var i int = 0
|
|
if t <= transformOmitLast9 {
|
|
len -= t
|
|
} else if t >= transformOmitFirst1 && t <= transformOmitFirst9 {
|
|
var skip int = t - (transformOmitFirst1 - 1)
|
|
word = word[skip:]
|
|
len -= skip
|
|
}
|
|
|
|
for i < len {
|
|
dst[idx] = word[i]
|
|
idx++
|
|
i++
|
|
}
|
|
if t == transformUppercaseFirst {
|
|
toUpperCase(dst[idx-len:])
|
|
} else if t == transformUppercaseAll {
|
|
var uppercase []byte = dst
|
|
uppercase = uppercase[idx-len:]
|
|
for len > 0 {
|
|
var step int = toUpperCase(uppercase)
|
|
uppercase = uppercase[step:]
|
|
len -= step
|
|
}
|
|
} else if t == transformShiftFirst {
|
|
var param uint16 = uint16(trans.params[transform_idx*2]) + uint16(trans.params[transform_idx*2+1])<<8
|
|
shiftTransform(dst[idx-len:], int(len), param)
|
|
} else if t == transformShiftAll {
|
|
var param uint16 = uint16(trans.params[transform_idx*2]) + uint16(trans.params[transform_idx*2+1])<<8
|
|
var shift []byte = dst
|
|
shift = shift[idx-len:]
|
|
for len > 0 {
|
|
var step int = shiftTransform(shift, int(len), param)
|
|
shift = shift[step:]
|
|
len -= step
|
|
}
|
|
}
|
|
}
|
|
{
|
|
var suffix_len int = int(suffix[0])
|
|
suffix = suffix[1:]
|
|
for {
|
|
tmp2 := suffix_len
|
|
suffix_len--
|
|
if tmp2 == 0 {
|
|
break
|
|
}
|
|
dst[idx] = suffix[0]
|
|
idx++
|
|
suffix = suffix[1:]
|
|
}
|
|
return idx
|
|
}
|
|
}
|