513 lines
9.0 KiB
Go
513 lines
9.0 KiB
Go
/**
|
|
* Copyright 2014 Paul Querna
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*
|
|
*/
|
|
|
|
package v1
|
|
|
|
import (
|
|
"fmt"
|
|
"io"
|
|
"unicode"
|
|
"unicode/utf16"
|
|
)
|
|
|
|
const sliceStringMask = cIJC | cNFP
|
|
|
|
type ffReader struct {
|
|
s []byte
|
|
i int
|
|
l int
|
|
}
|
|
|
|
func newffReader(d []byte) *ffReader {
|
|
return &ffReader{
|
|
s: d,
|
|
i: 0,
|
|
l: len(d),
|
|
}
|
|
}
|
|
|
|
func (r *ffReader) Slice(start, stop int) []byte {
|
|
return r.s[start:stop]
|
|
}
|
|
|
|
func (r *ffReader) Pos() int {
|
|
return r.i
|
|
}
|
|
|
|
// Reset the reader, and add new input.
|
|
func (r *ffReader) Reset(d []byte) {
|
|
r.s = d
|
|
r.i = 0
|
|
r.l = len(d)
|
|
}
|
|
|
|
// Calcuates the Position with line and line offset,
|
|
// because this isn't counted for performance reasons,
|
|
// it will iterate the buffer from the beginning, and should
|
|
// only be used in error-paths.
|
|
func (r *ffReader) PosWithLine() (int, int) {
|
|
currentLine := 1
|
|
currentChar := 0
|
|
|
|
for i := 0; i < r.i; i++ {
|
|
c := r.s[i]
|
|
currentChar++
|
|
if c == '\n' {
|
|
currentLine++
|
|
currentChar = 0
|
|
}
|
|
}
|
|
|
|
return currentLine, currentChar
|
|
}
|
|
|
|
func (r *ffReader) ReadByteNoWS() (byte, error) {
|
|
if r.i >= r.l {
|
|
return 0, io.EOF
|
|
}
|
|
|
|
j := r.i
|
|
|
|
for {
|
|
c := r.s[j]
|
|
j++
|
|
|
|
// inline whitespace parsing gives another ~8% performance boost
|
|
// for many kinds of nicely indented JSON.
|
|
// ... and using a [255]bool instead of multiple ifs, gives another 2%
|
|
/*
|
|
if c != '\t' &&
|
|
c != '\n' &&
|
|
c != '\v' &&
|
|
c != '\f' &&
|
|
c != '\r' &&
|
|
c != ' ' {
|
|
r.i = j
|
|
return c, nil
|
|
}
|
|
*/
|
|
if whitespaceLookupTable[c] == false {
|
|
r.i = j
|
|
return c, nil
|
|
}
|
|
|
|
if j >= r.l {
|
|
return 0, io.EOF
|
|
}
|
|
}
|
|
}
|
|
|
|
func (r *ffReader) ReadByte() (byte, error) {
|
|
if r.i >= r.l {
|
|
return 0, io.EOF
|
|
}
|
|
|
|
r.i++
|
|
|
|
return r.s[r.i-1], nil
|
|
}
|
|
|
|
func (r *ffReader) UnreadByte() error {
|
|
if r.i <= 0 {
|
|
panic("ffReader.UnreadByte: at beginning of slice")
|
|
}
|
|
r.i--
|
|
return nil
|
|
}
|
|
|
|
func (r *ffReader) readU4(j int) (rune, error) {
|
|
|
|
var u4 [4]byte
|
|
for i := 0; i < 4; i++ {
|
|
if j >= r.l {
|
|
return -1, io.EOF
|
|
}
|
|
c := r.s[j]
|
|
if byteLookupTable[c]&cVHC != 0 {
|
|
u4[i] = c
|
|
j++
|
|
continue
|
|
} else {
|
|
// TODO(pquerna): handle errors better. layering violation.
|
|
return -1, fmt.Errorf("lex_string_invalid_hex_char: %v %v", c, string(u4[:]))
|
|
}
|
|
}
|
|
|
|
// TODO(pquerna): utf16.IsSurrogate
|
|
rr, err := ParseUint(u4[:], 16, 64)
|
|
if err != nil {
|
|
return -1, err
|
|
}
|
|
return rune(rr), nil
|
|
}
|
|
|
|
func (r *ffReader) handleEscaped(c byte, j int, out DecodingBuffer) (int, error) {
|
|
if j >= r.l {
|
|
return 0, io.EOF
|
|
}
|
|
|
|
c = r.s[j]
|
|
j++
|
|
|
|
if c == 'u' {
|
|
ru, err := r.readU4(j)
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
|
|
if utf16.IsSurrogate(ru) {
|
|
ru2, err := r.readU4(j + 6)
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
out.Write(r.s[r.i : j-2])
|
|
r.i = j + 10
|
|
j = r.i
|
|
rval := utf16.DecodeRune(ru, ru2)
|
|
if rval != unicode.ReplacementChar {
|
|
out.WriteRune(rval)
|
|
} else {
|
|
return 0, fmt.Errorf("lex_string_invalid_unicode_surrogate: %v %v", ru, ru2)
|
|
}
|
|
} else {
|
|
out.Write(r.s[r.i : j-2])
|
|
r.i = j + 4
|
|
j = r.i
|
|
out.WriteRune(ru)
|
|
}
|
|
return j, nil
|
|
} else if byteLookupTable[c]&cVEC == 0 {
|
|
return 0, fmt.Errorf("lex_string_invalid_escaped_char: %v", c)
|
|
} else {
|
|
out.Write(r.s[r.i : j-2])
|
|
r.i = j
|
|
j = r.i
|
|
|
|
switch c {
|
|
case '"':
|
|
out.WriteByte('"')
|
|
case '\\':
|
|
out.WriteByte('\\')
|
|
case '/':
|
|
out.WriteByte('/')
|
|
case 'b':
|
|
out.WriteByte('\b')
|
|
case 'f':
|
|
out.WriteByte('\f')
|
|
case 'n':
|
|
out.WriteByte('\n')
|
|
case 'r':
|
|
out.WriteByte('\r')
|
|
case 't':
|
|
out.WriteByte('\t')
|
|
}
|
|
}
|
|
|
|
return j, nil
|
|
}
|
|
|
|
func (r *ffReader) SliceString(out DecodingBuffer) error {
|
|
var c byte
|
|
// TODO(pquerna): string_with_escapes? de-escape here?
|
|
j := r.i
|
|
|
|
for {
|
|
if j >= r.l {
|
|
return io.EOF
|
|
}
|
|
|
|
j, c = scanString(r.s, j)
|
|
|
|
if c == '"' {
|
|
if j != r.i {
|
|
out.Write(r.s[r.i : j-1])
|
|
r.i = j
|
|
}
|
|
return nil
|
|
} else if c == '\\' {
|
|
var err error
|
|
j, err = r.handleEscaped(c, j, out)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
} else if byteLookupTable[c]&cIJC != 0 {
|
|
return fmt.Errorf("lex_string_invalid_json_char: %v", c)
|
|
}
|
|
continue
|
|
}
|
|
}
|
|
|
|
// TODO(pquerna): consider combining wibth the normal byte mask.
|
|
var whitespaceLookupTable [256]bool = [256]bool{
|
|
false, /* 0 */
|
|
false, /* 1 */
|
|
false, /* 2 */
|
|
false, /* 3 */
|
|
false, /* 4 */
|
|
false, /* 5 */
|
|
false, /* 6 */
|
|
false, /* 7 */
|
|
false, /* 8 */
|
|
true, /* 9 */
|
|
true, /* 10 */
|
|
true, /* 11 */
|
|
true, /* 12 */
|
|
true, /* 13 */
|
|
false, /* 14 */
|
|
false, /* 15 */
|
|
false, /* 16 */
|
|
false, /* 17 */
|
|
false, /* 18 */
|
|
false, /* 19 */
|
|
false, /* 20 */
|
|
false, /* 21 */
|
|
false, /* 22 */
|
|
false, /* 23 */
|
|
false, /* 24 */
|
|
false, /* 25 */
|
|
false, /* 26 */
|
|
false, /* 27 */
|
|
false, /* 28 */
|
|
false, /* 29 */
|
|
false, /* 30 */
|
|
false, /* 31 */
|
|
true, /* 32 */
|
|
false, /* 33 */
|
|
false, /* 34 */
|
|
false, /* 35 */
|
|
false, /* 36 */
|
|
false, /* 37 */
|
|
false, /* 38 */
|
|
false, /* 39 */
|
|
false, /* 40 */
|
|
false, /* 41 */
|
|
false, /* 42 */
|
|
false, /* 43 */
|
|
false, /* 44 */
|
|
false, /* 45 */
|
|
false, /* 46 */
|
|
false, /* 47 */
|
|
false, /* 48 */
|
|
false, /* 49 */
|
|
false, /* 50 */
|
|
false, /* 51 */
|
|
false, /* 52 */
|
|
false, /* 53 */
|
|
false, /* 54 */
|
|
false, /* 55 */
|
|
false, /* 56 */
|
|
false, /* 57 */
|
|
false, /* 58 */
|
|
false, /* 59 */
|
|
false, /* 60 */
|
|
false, /* 61 */
|
|
false, /* 62 */
|
|
false, /* 63 */
|
|
false, /* 64 */
|
|
false, /* 65 */
|
|
false, /* 66 */
|
|
false, /* 67 */
|
|
false, /* 68 */
|
|
false, /* 69 */
|
|
false, /* 70 */
|
|
false, /* 71 */
|
|
false, /* 72 */
|
|
false, /* 73 */
|
|
false, /* 74 */
|
|
false, /* 75 */
|
|
false, /* 76 */
|
|
false, /* 77 */
|
|
false, /* 78 */
|
|
false, /* 79 */
|
|
false, /* 80 */
|
|
false, /* 81 */
|
|
false, /* 82 */
|
|
false, /* 83 */
|
|
false, /* 84 */
|
|
false, /* 85 */
|
|
false, /* 86 */
|
|
false, /* 87 */
|
|
false, /* 88 */
|
|
false, /* 89 */
|
|
false, /* 90 */
|
|
false, /* 91 */
|
|
false, /* 92 */
|
|
false, /* 93 */
|
|
false, /* 94 */
|
|
false, /* 95 */
|
|
false, /* 96 */
|
|
false, /* 97 */
|
|
false, /* 98 */
|
|
false, /* 99 */
|
|
false, /* 100 */
|
|
false, /* 101 */
|
|
false, /* 102 */
|
|
false, /* 103 */
|
|
false, /* 104 */
|
|
false, /* 105 */
|
|
false, /* 106 */
|
|
false, /* 107 */
|
|
false, /* 108 */
|
|
false, /* 109 */
|
|
false, /* 110 */
|
|
false, /* 111 */
|
|
false, /* 112 */
|
|
false, /* 113 */
|
|
false, /* 114 */
|
|
false, /* 115 */
|
|
false, /* 116 */
|
|
false, /* 117 */
|
|
false, /* 118 */
|
|
false, /* 119 */
|
|
false, /* 120 */
|
|
false, /* 121 */
|
|
false, /* 122 */
|
|
false, /* 123 */
|
|
false, /* 124 */
|
|
false, /* 125 */
|
|
false, /* 126 */
|
|
false, /* 127 */
|
|
false, /* 128 */
|
|
false, /* 129 */
|
|
false, /* 130 */
|
|
false, /* 131 */
|
|
false, /* 132 */
|
|
false, /* 133 */
|
|
false, /* 134 */
|
|
false, /* 135 */
|
|
false, /* 136 */
|
|
false, /* 137 */
|
|
false, /* 138 */
|
|
false, /* 139 */
|
|
false, /* 140 */
|
|
false, /* 141 */
|
|
false, /* 142 */
|
|
false, /* 143 */
|
|
false, /* 144 */
|
|
false, /* 145 */
|
|
false, /* 146 */
|
|
false, /* 147 */
|
|
false, /* 148 */
|
|
false, /* 149 */
|
|
false, /* 150 */
|
|
false, /* 151 */
|
|
false, /* 152 */
|
|
false, /* 153 */
|
|
false, /* 154 */
|
|
false, /* 155 */
|
|
false, /* 156 */
|
|
false, /* 157 */
|
|
false, /* 158 */
|
|
false, /* 159 */
|
|
false, /* 160 */
|
|
false, /* 161 */
|
|
false, /* 162 */
|
|
false, /* 163 */
|
|
false, /* 164 */
|
|
false, /* 165 */
|
|
false, /* 166 */
|
|
false, /* 167 */
|
|
false, /* 168 */
|
|
false, /* 169 */
|
|
false, /* 170 */
|
|
false, /* 171 */
|
|
false, /* 172 */
|
|
false, /* 173 */
|
|
false, /* 174 */
|
|
false, /* 175 */
|
|
false, /* 176 */
|
|
false, /* 177 */
|
|
false, /* 178 */
|
|
false, /* 179 */
|
|
false, /* 180 */
|
|
false, /* 181 */
|
|
false, /* 182 */
|
|
false, /* 183 */
|
|
false, /* 184 */
|
|
false, /* 185 */
|
|
false, /* 186 */
|
|
false, /* 187 */
|
|
false, /* 188 */
|
|
false, /* 189 */
|
|
false, /* 190 */
|
|
false, /* 191 */
|
|
false, /* 192 */
|
|
false, /* 193 */
|
|
false, /* 194 */
|
|
false, /* 195 */
|
|
false, /* 196 */
|
|
false, /* 197 */
|
|
false, /* 198 */
|
|
false, /* 199 */
|
|
false, /* 200 */
|
|
false, /* 201 */
|
|
false, /* 202 */
|
|
false, /* 203 */
|
|
false, /* 204 */
|
|
false, /* 205 */
|
|
false, /* 206 */
|
|
false, /* 207 */
|
|
false, /* 208 */
|
|
false, /* 209 */
|
|
false, /* 210 */
|
|
false, /* 211 */
|
|
false, /* 212 */
|
|
false, /* 213 */
|
|
false, /* 214 */
|
|
false, /* 215 */
|
|
false, /* 216 */
|
|
false, /* 217 */
|
|
false, /* 218 */
|
|
false, /* 219 */
|
|
false, /* 220 */
|
|
false, /* 221 */
|
|
false, /* 222 */
|
|
false, /* 223 */
|
|
false, /* 224 */
|
|
false, /* 225 */
|
|
false, /* 226 */
|
|
false, /* 227 */
|
|
false, /* 228 */
|
|
false, /* 229 */
|
|
false, /* 230 */
|
|
false, /* 231 */
|
|
false, /* 232 */
|
|
false, /* 233 */
|
|
false, /* 234 */
|
|
false, /* 235 */
|
|
false, /* 236 */
|
|
false, /* 237 */
|
|
false, /* 238 */
|
|
false, /* 239 */
|
|
false, /* 240 */
|
|
false, /* 241 */
|
|
false, /* 242 */
|
|
false, /* 243 */
|
|
false, /* 244 */
|
|
false, /* 245 */
|
|
false, /* 246 */
|
|
false, /* 247 */
|
|
false, /* 248 */
|
|
false, /* 249 */
|
|
false, /* 250 */
|
|
false, /* 251 */
|
|
false, /* 252 */
|
|
false, /* 253 */
|
|
false, /* 254 */
|
|
false, /* 255 */
|
|
}
|