/usr/share/gocode/src/golang.org/x/text/internal/triegen/print.go is in golang-golang-x-text-dev 0.0~git20170627.0.6353ef0-1ubuntu2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 | // Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package triegen
import (
"bytes"
"fmt"
"io"
"strings"
"text/template"
)
// print writes all the data structures as well as the code necessary to use the
// trie to w.
func (b *builder) print(w io.Writer) error {
b.Stats.NValueEntries = len(b.ValueBlocks) * blockSize
b.Stats.NValueBytes = len(b.ValueBlocks) * blockSize * b.ValueSize
b.Stats.NIndexEntries = len(b.IndexBlocks) * blockSize
b.Stats.NIndexBytes = len(b.IndexBlocks) * blockSize * b.IndexSize
b.Stats.NHandleBytes = len(b.Trie) * 2 * b.IndexSize
// If we only have one root trie, all starter blocks are at position 0 and
// we can access the arrays directly.
if len(b.Trie) == 1 {
// At this point we cannot refer to the generated tables directly.
b.ASCIIBlock = b.Name + "Values"
b.StarterBlock = b.Name + "Index"
} else {
// Otherwise we need to have explicit starter indexes in the trie
// structure.
b.ASCIIBlock = "t.ascii"
b.StarterBlock = "t.utf8Start"
}
b.SourceType = "[]byte"
if err := lookupGen.Execute(w, b); err != nil {
return err
}
b.SourceType = "string"
if err := lookupGen.Execute(w, b); err != nil {
return err
}
if err := trieGen.Execute(w, b); err != nil {
return err
}
for _, c := range b.Compactions {
if err := c.c.Print(w); err != nil {
return err
}
}
return nil
}
func printValues(n int, values []uint64) string {
w := &bytes.Buffer{}
boff := n * blockSize
fmt.Fprintf(w, "\t// Block %#x, offset %#x", n, boff)
var newline bool
for i, v := range values {
if i%6 == 0 {
newline = true
}
if v != 0 {
if newline {
fmt.Fprintf(w, "\n")
newline = false
}
fmt.Fprintf(w, "\t%#02x:%#04x, ", boff+i, v)
}
}
return w.String()
}
func printIndex(b *builder, nr int, n *node) string {
w := &bytes.Buffer{}
boff := nr * blockSize
fmt.Fprintf(w, "\t// Block %#x, offset %#x", nr, boff)
var newline bool
for i, c := range n.children {
if i%8 == 0 {
newline = true
}
if c != nil {
v := b.Compactions[c.index.compaction].Offset + uint32(c.index.index)
if v != 0 {
if newline {
fmt.Fprintf(w, "\n")
newline = false
}
fmt.Fprintf(w, "\t%#02x:%#02x, ", boff+i, v)
}
}
}
return w.String()
}
var (
trieGen = template.Must(template.New("trie").Funcs(template.FuncMap{
"printValues": printValues,
"printIndex": printIndex,
"title": strings.Title,
"dec": func(x int) int { return x - 1 },
"psize": func(n int) string {
return fmt.Sprintf("%d bytes (%.2f KiB)", n, float64(n)/1024)
},
}).Parse(trieTemplate))
lookupGen = template.Must(template.New("lookup").Parse(lookupTemplate))
)
// TODO: consider the return type of lookup. It could be uint64, even if the
// internal value type is smaller. We will have to verify this with the
// performance of unicode/norm, which is very sensitive to such changes.
const trieTemplate = `{{$b := .}}{{$multi := gt (len .Trie) 1}}
// {{.Name}}Trie. Total size: {{psize .Size}}. Checksum: {{printf "%08x" .Checksum}}.
type {{.Name}}Trie struct { {{if $multi}}
ascii []{{.ValueType}} // index for ASCII bytes
utf8Start []{{.IndexType}} // index for UTF-8 bytes >= 0xC0
{{end}}}
func new{{title .Name}}Trie(i int) *{{.Name}}Trie { {{if $multi}}
h := {{.Name}}TrieHandles[i]
return &{{.Name}}Trie{ {{.Name}}Values[uint32(h.ascii)<<6:], {{.Name}}Index[uint32(h.multi)<<6:] }
}
type {{.Name}}TrieHandle struct {
ascii, multi {{.IndexType}}
}
// {{.Name}}TrieHandles: {{len .Trie}} handles, {{.Stats.NHandleBytes}} bytes
var {{.Name}}TrieHandles = [{{len .Trie}}]{{.Name}}TrieHandle{
{{range .Trie}} { {{.ASCIIIndex}}, {{.StarterIndex}} }, // {{printf "%08x" .Checksum}}: {{.Name}}
{{end}}}{{else}}
return &{{.Name}}Trie{}
}
{{end}}
// lookupValue determines the type of block n and looks up the value for b.
func (t *{{.Name}}Trie) lookupValue(n uint32, b byte) {{.ValueType}}{{$last := dec (len .Compactions)}} {
switch { {{range $i, $c := .Compactions}}
{{if eq $i $last}}default{{else}}case n < {{$c.Cutoff}}{{end}}:{{if ne $i 0}}
n -= {{$c.Offset}}{{end}}
return {{print $b.ValueType}}({{$c.Handler}}){{end}}
}
}
// {{.Name}}Values: {{len .ValueBlocks}} blocks, {{.Stats.NValueEntries}} entries, {{.Stats.NValueBytes}} bytes
// The third block is the zero block.
var {{.Name}}Values = [{{.Stats.NValueEntries}}]{{.ValueType}} {
{{range $i, $v := .ValueBlocks}}{{printValues $i $v}}
{{end}}}
// {{.Name}}Index: {{len .IndexBlocks}} blocks, {{.Stats.NIndexEntries}} entries, {{.Stats.NIndexBytes}} bytes
// Block 0 is the zero block.
var {{.Name}}Index = [{{.Stats.NIndexEntries}}]{{.IndexType}} {
{{range $i, $v := .IndexBlocks}}{{printIndex $b $i $v}}
{{end}}}
`
// TODO: consider allowing zero-length strings after evaluating performance with
// unicode/norm.
const lookupTemplate = `
// lookup{{if eq .SourceType "string"}}String{{end}} returns the trie value for the first UTF-8 encoding in s and
// the width in bytes of this encoding. The size will be 0 if s does not
// hold enough bytes to complete the encoding. len(s) must be greater than 0.
func (t *{{.Name}}Trie) lookup{{if eq .SourceType "string"}}String{{end}}(s {{.SourceType}}) (v {{.ValueType}}, sz int) {
c0 := s[0]
switch {
case c0 < 0x80: // is ASCII
return {{.ASCIIBlock}}[c0], 1
case c0 < 0xC2:
return 0, 1 // Illegal UTF-8: not a starter, not ASCII.
case c0 < 0xE0: // 2-byte UTF-8
if len(s) < 2 {
return 0, 0
}
i := {{.StarterBlock}}[c0]
c1 := s[1]
if c1 < 0x80 || 0xC0 <= c1 {
return 0, 1 // Illegal UTF-8: not a continuation byte.
}
return t.lookupValue(uint32(i), c1), 2
case c0 < 0xF0: // 3-byte UTF-8
if len(s) < 3 {
return 0, 0
}
i := {{.StarterBlock}}[c0]
c1 := s[1]
if c1 < 0x80 || 0xC0 <= c1 {
return 0, 1 // Illegal UTF-8: not a continuation byte.
}
o := uint32(i)<<6 + uint32(c1)
i = {{.Name}}Index[o]
c2 := s[2]
if c2 < 0x80 || 0xC0 <= c2 {
return 0, 2 // Illegal UTF-8: not a continuation byte.
}
return t.lookupValue(uint32(i), c2), 3
case c0 < 0xF8: // 4-byte UTF-8
if len(s) < 4 {
return 0, 0
}
i := {{.StarterBlock}}[c0]
c1 := s[1]
if c1 < 0x80 || 0xC0 <= c1 {
return 0, 1 // Illegal UTF-8: not a continuation byte.
}
o := uint32(i)<<6 + uint32(c1)
i = {{.Name}}Index[o]
c2 := s[2]
if c2 < 0x80 || 0xC0 <= c2 {
return 0, 2 // Illegal UTF-8: not a continuation byte.
}
o = uint32(i)<<6 + uint32(c2)
i = {{.Name}}Index[o]
c3 := s[3]
if c3 < 0x80 || 0xC0 <= c3 {
return 0, 3 // Illegal UTF-8: not a continuation byte.
}
return t.lookupValue(uint32(i), c3), 4
}
// Illegal rune
return 0, 1
}
// lookup{{if eq .SourceType "string"}}String{{end}}Unsafe returns the trie value for the first UTF-8 encoding in s.
// s must start with a full and valid UTF-8 encoded rune.
func (t *{{.Name}}Trie) lookup{{if eq .SourceType "string"}}String{{end}}Unsafe(s {{.SourceType}}) {{.ValueType}} {
c0 := s[0]
if c0 < 0x80 { // is ASCII
return {{.ASCIIBlock}}[c0]
}
i := {{.StarterBlock}}[c0]
if c0 < 0xE0 { // 2-byte UTF-8
return t.lookupValue(uint32(i), s[1])
}
i = {{.Name}}Index[uint32(i)<<6+uint32(s[1])]
if c0 < 0xF0 { // 3-byte UTF-8
return t.lookupValue(uint32(i), s[2])
}
i = {{.Name}}Index[uint32(i)<<6+uint32(s[2])]
if c0 < 0xF8 { // 4-byte UTF-8
return t.lookupValue(uint32(i), s[3])
}
return 0
}
`
|