/usr/share/gocode/src/github.com/cznic/strutil/strutil.go is in golang-github-cznic-strutil-dev 0.0~git20150430.0.1eb03e3-1.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 | // Copyright (c) 2014 The sortutil 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 strutil collects utils supplemental to the standard strings package.
package strutil
import (
"bytes"
"encoding/base32"
"encoding/base64"
"fmt"
"io"
"reflect"
"sort"
"strconv"
"strings"
"sync"
)
// Base32ExtDecode decodes base32 extended (RFC 4648) text to binary data.
func Base32ExtDecode(text []byte) (data []byte, err error) {
n := base32.HexEncoding.DecodedLen(len(text))
data = make([]byte, n)
decoder := base32.NewDecoder(base32.HexEncoding, bytes.NewBuffer(text))
if n, err = decoder.Read(data); err != nil {
n = 0
}
data = data[:n]
return
}
// Base32ExtEncode encodes binary data to base32 extended (RFC 4648) encoded text.
func Base32ExtEncode(data []byte) (text []byte) {
n := base32.HexEncoding.EncodedLen(len(data))
buf := bytes.NewBuffer(make([]byte, 0, n))
encoder := base32.NewEncoder(base32.HexEncoding, buf)
encoder.Write(data)
encoder.Close()
if buf.Len() != n {
panic("internal error")
}
return buf.Bytes()
}
// Base64Decode decodes base64 text to binary data.
func Base64Decode(text []byte) (data []byte, err error) {
n := base64.StdEncoding.DecodedLen(len(text))
data = make([]byte, n)
decoder := base64.NewDecoder(base64.StdEncoding, bytes.NewBuffer(text))
if n, err = decoder.Read(data); err != nil {
n = 0
}
data = data[:n]
return
}
// Base64Encode encodes binary data to base64 encoded text.
func Base64Encode(data []byte) (text []byte) {
n := base64.StdEncoding.EncodedLen(len(data))
buf := bytes.NewBuffer(make([]byte, 0, n))
encoder := base64.NewEncoder(base64.StdEncoding, buf)
encoder.Write(data)
encoder.Close()
if buf.Len() != n {
panic("internal error")
}
return buf.Bytes()
}
// Formatter is an io.Writer extended by a fmt.Printf like function Format
type Formatter interface {
io.Writer
Format(format string, args ...interface{}) (n int, errno error)
}
type indentFormatter struct {
io.Writer
indent []byte
indentLevel int
state int
}
const (
st0 = iota
stBOL
stPERC
stBOLPERC
)
// IndentFormatter returns a new Formatter which interprets %i and %u in the
// Format() format string as indent and undent commands. The commands can
// nest. The Formatter writes to io.Writer 'w' and inserts one 'indent'
// string per current indent level value.
// Behaviour of commands reaching negative indent levels is undefined.
// IndentFormatter(os.Stdout, "\t").Format("abc%d%%e%i\nx\ny\n%uz\n", 3)
// output:
// abc3%e
// x
// y
// z
// The Go quoted string literal form of the above is:
// "abc%%e\n\tx\n\tx\nz\n"
// The commands can be scattered between separate invocations of Format(),
// i.e. the formatter keeps track of the indent level and knows if it is
// positioned on start of a line and should emit indentation(s).
// The same output as above can be produced by e.g.:
// f := IndentFormatter(os.Stdout, " ")
// f.Format("abc%d%%e%i\nx\n", 3)
// f.Format("y\n%uz\n")
func IndentFormatter(w io.Writer, indent string) Formatter {
return &indentFormatter{w, []byte(indent), 0, stBOL}
}
func (f *indentFormatter) format(flat bool, format string, args ...interface{}) (n int, errno error) {
buf := []byte{}
for i := 0; i < len(format); i++ {
c := format[i]
switch f.state {
case st0:
switch c {
case '\n':
cc := c
if flat && f.indentLevel != 0 {
cc = ' '
}
buf = append(buf, cc)
f.state = stBOL
case '%':
f.state = stPERC
default:
buf = append(buf, c)
}
case stBOL:
switch c {
case '\n':
cc := c
if flat && f.indentLevel != 0 {
cc = ' '
}
buf = append(buf, cc)
case '%':
f.state = stBOLPERC
default:
if !flat {
for i := 0; i < f.indentLevel; i++ {
buf = append(buf, f.indent...)
}
}
buf = append(buf, c)
f.state = st0
}
case stBOLPERC:
switch c {
case 'i':
f.indentLevel++
f.state = stBOL
case 'u':
f.indentLevel--
f.state = stBOL
default:
if !flat {
for i := 0; i < f.indentLevel; i++ {
buf = append(buf, f.indent...)
}
}
buf = append(buf, '%', c)
f.state = st0
}
case stPERC:
switch c {
case 'i':
f.indentLevel++
f.state = st0
case 'u':
f.indentLevel--
f.state = st0
default:
buf = append(buf, '%', c)
f.state = st0
}
default:
panic("unexpected state")
}
}
switch f.state {
case stPERC, stBOLPERC:
buf = append(buf, '%')
}
return f.Write([]byte(fmt.Sprintf(string(buf), args...)))
}
func (f *indentFormatter) Format(format string, args ...interface{}) (n int, errno error) {
return f.format(false, format, args...)
}
type flatFormatter indentFormatter
// FlatFormatter returns a newly created Formatter with the same functionality as the one returned
// by IndentFormatter except it allows a newline in the 'format' string argument of Format
// to pass through iff indent level is currently zero.
//
// If indent level is non-zero then such new lines are changed to a space character.
// There is no indent string, the %i and %u format verbs are used solely to determine the indent level.
//
// The FlatFormatter is intended for flattening of normally nested structure textual representation to
// a one top level structure per line form.
// FlatFormatter(os.Stdout, " ").Format("abc%d%%e%i\nx\ny\n%uz\n", 3)
// output in the form of a Go quoted string literal:
// "abc3%%e x y z\n"
func FlatFormatter(w io.Writer) Formatter {
return (*flatFormatter)(IndentFormatter(w, "").(*indentFormatter))
}
func (f *flatFormatter) Format(format string, args ...interface{}) (n int, errno error) {
return (*indentFormatter)(f).format(true, format, args...)
}
// Pool handles aligning of strings having equal values to the same string instance.
// Intended use is to conserve some memory e.g. where a large number of identically valued strings
// with non identical backing arrays may exists in several semantically distinct instances of some structs.
// Pool is *not* concurrent access safe. It doesn't handle common prefix/suffix aligning,
// e.g. having s1 == "abc" and s2 == "bc", s2 is not automatically aligned as s1[1:].
type Pool struct {
pool map[string]string
}
// NewPool returns a newly created Pool.
func NewPool() *Pool {
return &Pool{map[string]string{}}
}
// Align returns a string with the same value as its argument. It guarantees that
// all aligned strings share a single instance in memory.
func (p *Pool) Align(s string) string {
if a, ok := p.pool[s]; ok {
return a
}
s = StrPack(s)
p.pool[s] = s
return s
}
// Count returns the number of items in the pool.
func (p *Pool) Count() int {
return len(p.pool)
}
// GoPool is a concurrent access safe version of Pool.
type GoPool struct {
pool map[string]string
rwm *sync.RWMutex
}
// NewGoPool returns a newly created GoPool.
func NewGoPool() (p *GoPool) {
return &GoPool{map[string]string{}, &sync.RWMutex{}}
}
// Align returns a string with the same value as its argument. It guarantees that
// all aligned strings share a single instance in memory.
func (p *GoPool) Align(s string) (y string) {
if s != "" {
p.rwm.RLock() // R++
if a, ok := p.pool[s]; ok { // found
p.rwm.RUnlock() // R--
return a
}
p.rwm.RUnlock() // R--
// not found but with a race condition, retry within a write lock
p.rwm.Lock() // W++
defer p.rwm.Unlock() // W--
if a, ok := p.pool[s]; ok { // done in a race
return a
}
// we won
s = StrPack(s)
p.pool[s] = s
return s
}
return
}
// Count returns the number of items in the pool.
func (p *GoPool) Count() int {
return len(p.pool)
}
// Dict is a string <-> id bijection. Dict is *not* concurrent access safe for assigning new ids
// to strings not yet contained in the bijection.
// Id for an empty string is guaranteed to be 0,
// thus Id for any non empty string is guaranteed to be non zero.
type Dict struct {
si map[string]int
is []string
}
// NewDict returns a newly created Dict.
func NewDict() (d *Dict) {
d = &Dict{map[string]int{}, []string{}}
d.Id("")
return
}
// Count returns the number of items in the dict.
func (d *Dict) Count() int {
return len(d.is)
}
// Id maps string s to its numeric identificator.
func (d *Dict) Id(s string) (y int) {
if y, ok := d.si[s]; ok {
return y
}
s = StrPack(s)
y = len(d.is)
d.si[s] = y
d.is = append(d.is, s)
return
}
// S maps an id to its string value and ok == true. Id values not contained in the bijection
// return "", false.
func (d *Dict) S(id int) (s string, ok bool) {
if id >= len(d.is) {
return "", false
}
return d.is[id], true
}
// GoDict is a concurrent access safe version of Dict.
type GoDict struct {
si map[string]int
is []string
rwm *sync.RWMutex
}
// NewGoDict returns a newly created GoDict.
func NewGoDict() (d *GoDict) {
d = &GoDict{map[string]int{}, []string{}, &sync.RWMutex{}}
d.Id("")
return
}
// Count returns the number of items in the dict.
func (d *GoDict) Count() int {
return len(d.is)
}
// Id maps string s to its numeric identificator. The implementation honors getting
// an existing id at the cost of assigning a new one.
func (d *GoDict) Id(s string) (y int) {
d.rwm.RLock() // R++
if y, ok := d.si[s]; ok { // found
d.rwm.RUnlock() // R--
return y
}
d.rwm.RUnlock() // R--
// not found but with a race condition
d.rwm.Lock() // W++ recheck with write lock
defer d.rwm.Unlock() // W--
if y, ok := d.si[s]; ok { // some other goroutine won already
return y
}
// a race free not found state => insert the string
s = StrPack(s)
y = len(d.is)
d.si[s] = y
d.is = append(d.is, s)
return
}
// S maps an id to its string value and ok == true. Id values not contained in the bijection
// return "", false.
func (d *GoDict) S(id int) (s string, ok bool) {
d.rwm.RLock() // R++
defer d.rwm.RUnlock() // R--
if id >= len(d.is) {
return "", false
}
return d.is[id], true
}
// StrPack returns a new instance of s which is tightly packed in memory.
// It is intended for avoiding the situation where having a live reference
// to a string slice over an unreferenced biger underlying string keeps the biger one
// in memory anyway - it can't be GCed.
func StrPack(s string) string {
return string([]byte(s))
}
// JoinFields returns strings in flds joined by sep. Flds may contain arbitrary
// bytes, including the sep as they are safely escaped. JoinFields panics if
// sep is the backslash character or if len(sep) != 1.
func JoinFields(flds []string, sep string) string {
if len(sep) != 1 || sep == "\\" {
panic("invalid separator")
}
a := make([]string, len(flds))
for i, v := range flds {
v = strings.Replace(v, "\\", "\\0", -1)
a[i] = strings.Replace(v, sep, "\\1", -1)
}
return strings.Join(a, sep)
}
// SplitFields splits s, which must be produced by JoinFields using the same
// sep, into flds. SplitFields panics if sep is the backslash character or if
// len(sep) != 1.
func SplitFields(s, sep string) (flds []string) {
if len(sep) != 1 || sep == "\\" {
panic("invalid separator")
}
a := strings.Split(s, sep)
r := make([]string, len(a))
for i, v := range a {
v = strings.Replace(v, "\\1", sep, -1)
r[i] = strings.Replace(v, "\\0", "\\", -1)
}
return r
}
// PrettyPrintHooks allow to customize the result of PrettyPrint for types
// listed in the map value.
type PrettyPrintHooks map[reflect.Type]func(f Formatter, v interface{}, prefix, suffix string)
// PrettyString returns the output of PrettyPrint as a string.
func PrettyString(v interface{}, prefix, suffix string, hooks PrettyPrintHooks) string {
var b bytes.Buffer
PrettyPrint(&b, v, prefix, suffix, hooks)
return b.String()
}
// PrettyPrint pretty prints v to w. Zero values and unexported struct fields
// are omitted.
func PrettyPrint(w io.Writer, v interface{}, prefix, suffix string, hooks PrettyPrintHooks) {
if v == nil {
return
}
f := IndentFormatter(w, "· ")
defer func() {
if e := recover(); e != nil {
f.Format("\npanic: %v", e)
}
}()
prettyPrint(nil, f, prefix, suffix, v, hooks)
}
func prettyPrint(protect map[interface{}]struct{}, sf Formatter, prefix, suffix string, v interface{}, hooks PrettyPrintHooks) {
if v == nil {
return
}
rt := reflect.TypeOf(v)
if handler := hooks[rt]; handler != nil {
handler(sf, v, prefix, suffix)
return
}
rv := reflect.ValueOf(v)
switch rt.Kind() {
case reflect.Slice:
if rv.Len() == 0 {
return
}
sf.Format("%s[]%T{ // len %d%i\n", prefix, rv.Index(0).Interface(), rv.Len())
for i := 0; i < rv.Len(); i++ {
prettyPrint(protect, sf, fmt.Sprintf("%d: ", i), ",\n", rv.Index(i).Interface(), hooks)
}
suffix = strings.Replace(suffix, "%", "%%", -1)
sf.Format("%u}" + suffix)
case reflect.Array:
if reflect.Zero(rt).Interface() == rv.Interface() {
return
}
sf.Format("%s[%d]%T{%i\n", prefix, rv.Len(), rv.Index(0).Interface())
for i := 0; i < rv.Len(); i++ {
prettyPrint(protect, sf, fmt.Sprintf("%d: ", i), ",\n", rv.Index(i).Interface(), hooks)
}
suffix = strings.Replace(suffix, "%", "%%", -1)
sf.Format("%u}" + suffix)
case reflect.Struct:
if rt.NumField() == 0 {
return
}
if reflect.DeepEqual(reflect.Zero(rt).Interface(), rv.Interface()) {
return
}
sf.Format("%s%T{%i\n", prefix, v)
for i := 0; i < rt.NumField(); i++ {
f := rv.Field(i)
if !f.CanInterface() {
continue
}
prettyPrint(protect, sf, fmt.Sprintf("%s: ", rt.Field(i).Name), ",\n", f.Interface(), hooks)
}
suffix = strings.Replace(suffix, "%", "%%", -1)
sf.Format("%u}" + suffix)
case reflect.Ptr:
if rv.IsNil() {
return
}
rvi := rv.Interface()
if _, ok := protect[rvi]; ok {
suffix = strings.Replace(suffix, "%", "%%", -1)
sf.Format("%s&%T{ /* recursive/repetitive pointee not shown */ }"+suffix, prefix, rv.Elem().Interface())
return
}
if protect == nil {
protect = map[interface{}]struct{}{}
}
protect[rvi] = struct{}{}
prettyPrint(protect, sf, prefix+"&", suffix, rv.Elem().Interface(), hooks)
case reflect.Int, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Int8:
if v := rv.Int(); v != 0 {
suffix = strings.Replace(suffix, "%", "%%", -1)
sf.Format("%s%v"+suffix, prefix, v)
}
case reflect.Uint, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uint8:
if v := rv.Uint(); v != 0 {
suffix = strings.Replace(suffix, "%", "%%", -1)
sf.Format("%s%v"+suffix, prefix, v)
}
case reflect.Float32, reflect.Float64:
if v := rv.Float(); v != 0 {
suffix = strings.Replace(suffix, "%", "%%", -1)
sf.Format("%s%v"+suffix, prefix, v)
}
case reflect.Complex64, reflect.Complex128:
if v := rv.Complex(); v != 0 {
suffix = strings.Replace(suffix, "%", "%%", -1)
sf.Format("%s%v"+suffix, prefix, v)
}
case reflect.Uintptr:
if v := rv.Uint(); v != 0 {
suffix = strings.Replace(suffix, "%", "%%", -1)
sf.Format("%s%v"+suffix, prefix, v)
}
case reflect.UnsafePointer:
s := fmt.Sprintf("%p", rv.Interface())
if s == "0x0" {
return
}
suffix = strings.Replace(suffix, "%", "%%", -1)
sf.Format("%s%s"+suffix, prefix, s)
case reflect.Bool:
if v := rv.Bool(); v {
suffix = strings.Replace(suffix, "%", "%%", -1)
sf.Format("%s%v"+suffix, prefix, rv.Bool())
}
case reflect.String:
s := rv.Interface().(string)
if s == "" {
return
}
suffix = strings.Replace(suffix, "%", "%%", -1)
sf.Format("%s%q"+suffix, prefix, s)
case reflect.Chan:
if reflect.Zero(rt).Interface() == rv.Interface() {
return
}
c := rv.Cap()
s := ""
if c != 0 {
s = fmt.Sprintf("// capacity: %d", c)
}
suffix = strings.Replace(suffix, "%", "%%", -1)
sf.Format("%s%s %s%s"+suffix, prefix, rt.ChanDir(), rt.Elem().Name(), s)
case reflect.Func:
if rv.IsNil() {
return
}
var in, out []string
for i := 0; i < rt.NumIn(); i++ {
x := reflect.Zero(rt.In(i))
in = append(in, fmt.Sprintf("%T", x.Interface()))
}
if rt.IsVariadic() {
i := len(in) - 1
in[i] = "..." + in[i][2:]
}
for i := 0; i < rt.NumOut(); i++ {
out = append(out, rt.Out(i).Name())
}
s := "(" + strings.Join(in, ", ") + ")"
t := strings.Join(out, ", ")
if len(out) > 1 {
t = "(" + t + ")"
}
if t != "" {
t = " " + t
}
suffix = strings.Replace(suffix, "%", "%%", -1)
sf.Format("%sfunc%s%s { ... }"+suffix, prefix, s, t)
case reflect.Map:
keys := rv.MapKeys()
if len(keys) == 0 {
return
}
var buf bytes.Buffer
nf := IndentFormatter(&buf, "· ")
var skeys []string
for i, k := range keys {
prettyPrint(protect, nf, "", "", k.Interface(), hooks)
skeys = append(skeys, fmt.Sprintf("%s%10d", buf.Bytes(), i))
buf.Reset()
}
sort.Strings(skeys)
sf.Format("%s%T{%i\n", prefix, v)
for _, k := range skeys {
si := strings.TrimSpace(k[len(k)-10:])
k = k[:len(k)-10]
n, _ := strconv.ParseUint(si, 10, 64)
mv := rv.MapIndex(keys[n])
prettyPrint(protect, sf, fmt.Sprintf("%s: ", k), ",\n", mv.Interface(), hooks)
}
suffix = strings.Replace(suffix, "%", "%%", -1)
sf.Format("%u}" + suffix)
}
}
|