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GeezerVison is showing github.com — gitconfig/edit.go at master · git-bug/gitconfig Expand file tree/ Copy pathedit.goMore file actions 621 lines (581 loc) · 18.9 KB / Copy pathedit.goFile metadata and controls621 lines (581 loc) · 18.9 KB 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 package gitconfig import ( "errors" "slices" "strings" ) // Edits are computed on the items of the file as splices of its bytes, in // the places and the format git's own edits use. The result is parsed again // and checked against the expected entries before it replaces the file, so // that no edit can change anything but what it was asked to. // errUnsafeEdit is returned, wrapped in a *KeyError, if an edit would have // changed other entries than its own. It is a bug of this package if it // ever happens. var errUnsafeEdit = errors.New("gitconfig: internal error: the edit would change other entries") // splice replaces data[start:end] with text. type splice struct { start, end int text string } // prepare checks that the file is open and validates key for an edit. It // returns the key in canonical form, with its section and name as the // caller spelled them, for new lines and headers; the subsection of the // canonical form is already spelled as given. func (f *File) prepare(key string) (k Key, section, name string, err error) { if err := f.checkOpen(key); err != nil { return Key{}, "", "", err } k, ok := parseKey(key) if !ok || k.Section == "" { return Key{}, "", "", &KeyError{Key: key, Err: ErrInvalidKey} } section = key[:strings.IndexByte(key, '.')] name = key[strings.LastIndexByte(key, '.')+1:] return k, section, name, nil } // prepareValue is prepare for an edit that writes value. func (f *File) prepareValue(key, value string) (k Key, section, name string, err error) { k, section, name, err = f.prepare(key) if err != nil { return Key{}, "", "", err } if strings.IndexByte(value, 0) >= 0 { return Key{}, "", "", &KeyError{Key: key, Err: ErrInvalidValue} } return k, section, name, nil } func (f *File) checkOpen(key string) error { if f.closed { return &KeyError{Key: key, Err: ErrClosed} } return nil } // entriesOf returns the indexes of the entries of key. func (f *File) entriesOf(k Key) []int { var idx []int sk := k.sectionKey() for i, it := range f.items { if it.kind == itemEntry && f.secOf(it) == sk && f.nameOf(it) == k.Name { idx = append(idx, i) } } return idx } // flatEntry is an entry as the checks of an edit compare them, origin left // out. Unlike Config, the checks include the entries before any header, // with the zero sec: an edit must not change them either. They never match // the edited key or section, which always has a section name. type flatEntry struct { sec sectionKey name string value string implicit bool } func (e flatEntry) is(k Key) bool { return e.sec == k.sectionKey() && e.name == k.Name } // flatCursor walks the entries of a parsed file, without copying them out: // the checks of an edit compare two whole files. type flatCursor struct { p *parsed i int keep func(flatEntry) bool } // next returns the next entry keep accepts, or false at the end. func (c *flatCursor) next() (flatEntry, bool) { for c.i < len(c.p.items) { it := c.p.items[c.i] c.i++ if it.kind != itemEntry { continue } e := flatEntry{c.p.secOf(it), c.p.nameOf(it), c.p.valueOf(it), it.implicit} if c.keep == nil || c.keep(e) { return e, true } } return flatEntry{}, false } // sameEntries reports whether the entries of before that keepBefore accepts, // changed by conv, are the entries of after that keepAfter accepts. A nil // function keeps every entry, or changes none. func sameEntries(before, after *parsed, keepBefore, keepAfter func(flatEntry) bool, conv func(flatEntry) flatEntry) bool { b := flatCursor{p: before, keep: keepBefore} a := flatCursor{p: after, keep: keepAfter} for { eb, okB := b.next() ea, okA := a.next() if okB != okA { return false } if !okB { return true } if conv != nil { eb = conv(eb) } if eb != ea { return false } } } // apply splices the bytes of the file, parses the result, and keeps it if // check accepts the entries before and after the edit. func (f *File) apply(key string, splices []splice, check func(before, after *parsed) bool) error { // The splices never overlap; they are applied in order of position. slices.SortFunc(splices, func(a, b splice) int { return a.start - b.start }) // The file must stay one that Parse and Load accept: an edited file // beyond the byte limit is never built. size := len(f.data) for _, s := range splices { size += len(s.text) - (s.end - s.start) } if size > maxLoadBytes { return &KeyError{Key: key, Err: ErrLoadLimit} } data := make([]byte, 0, size) at := 0 for _, s := range splices { data = append(data, f.data[at:s.start]...) data = append(data, s.text...) at = s.end } data = append(data, f.data[at:]...) p, err := parseFile(f.name, data) if errors.Is(err, ErrLoadLimit) { // The file must stay one that Parse and Load accept. return &KeyError{Key: key, Err: ErrLoadLimit} } if err != nil || !check(&f.parsed, &p) { return &KeyError{Key: key, Err: errUnsafeEdit} } f.data = data f.parsed = p f.snap = nil return nil } // checkKey returns a check that the entries of other keys are unchanged and // that k has the values want after the edit. Only the first implicitOK of // them may be implicit: those an edit keeps (Add) may be, a value it writes // never is. func checkKey(k Key, want []string, implicitOK int) func(before, after *parsed) bool { return func(before, after *parsed) bool { other := func(e flatEntry) bool { return !e.is(k) } if !sameEntries(before, after, other, other, nil) { return false } got := flatCursor{p: after, keep: func(e flatEntry) bool { return e.is(k) }} for i := 0; ; i++ { e, ok := got.next() if !ok { return i == len(want) } if i == len(want) || e.value != want[i] || e.implicit && i >= implicitOK { return false } } } } // Layout helpers. A token is a header or an entry; the whitespace before a // token on its line is its own. // ownStart returns where the token at i starts, its whitespace included. func (f *File) ownStart(i int) int { if i > 0 && f.items[i-1].kind == itemSpace { return int(f.items[i-1].start) } return int(f.items[i].start) } // firstOnLine reports whether the token at i is the first of its line. func (f *File) firstOnLine(i int) bool { j := i - 1 if j >= 0 && f.items[j].kind == itemSpace { j-- } return j < 0 || f.items[j].kind == itemNewline || f.items[j].kind == itemBOM } // newlineAfter returns the index of the first newline after item i, or -1 // if the file ends first. func (f *File) newlineAfter(i int) int { for j := i + 1; j < len(f.items); j++ { if f.items[j].kind == itemNewline { return j } } return -1 } // lineEnd returns the end of the line of item i, its newline included. func (f *File) lineEnd(i int) int { if n := f.newlineAfter(i); n >= 0 { return int(f.items[n].end) } return len(f.data) } // terminator returns what must be written at the end of the file before a // new line can start there. func (f *File) terminator() string { if len(f.items) == 0 { return "" } last := f.items[len(f.items)-1] switch { case last.kind == itemNewline || last.kind == itemBOM: return "" case last.kind == itemEntry && last.open == continued: // A blank line ends the value. return "\n" case last.kind == itemEntry && last.open == backslashEOF: // The first newline completes the continuation, the blank line // after it ends the value. return "\n\n" } return "\n" } // formatEntry returns the line git writes for an entry. func formatEntry(name, value string) string { return "\t" + name + " = " + quoteValue(value) + "\n" } // quoteValue quotes and escapes a value as git writes it: in quotes if it // starts or ends with a space or contains '#', ';' or a CR; backslash, // double quote, tab and newline escaped. // // Unquoted, an edge space would be trimmed, '#' and ';' would start a // comment, and a CR could be trimmed or read as part of a CRLF. Tabs need // no quotes: they are escaped. func quoteValue(v string) string { var sb strings.Builder quote := strings.HasPrefix(v, " ") || strings.HasSuffix(v, " ") || strings.ContainsAny(v, "#;\r") if quote { sb.WriteByte('"') } for i := 0; i < len(v); i++ { switch c := v[i]; c { case '\\', '"': sb.WriteByte('\\') sb.WriteByte(c) case '\t': sb.WriteString(`\t`) case '\n': sb.WriteString(`\n`) default: sb.WriteByte(c) } } if quote { sb.WriteByte('"') } return sb.String() } // formatHeader returns a section header as git writes it. func formatHeader(section, sub string, hasSub bool) string { if !hasSub { return "[" + section + "]" } r := strings.NewReplacer(`\`, `\\`, `"`, `\"`) return "[" + section + " \"" + r.Replace(sub) + "\"]" } // replaceEntry returns the splice that rewrites the entry at i. func (f *File) replaceEntry(i int, name, value string) splice { line := formatEntry(name, value) if !f.firstOnLine(i) { // After a header on the same line: the line is split. line = "\n" + line } return splice{f.ownStart(i), f.entryLineEnd(i), line} } // removeEntry returns the splice that removes the entry at i: its line, or // the rest of the line after a header, which then ends with a newline. func (f *File) removeEntry(i int) splice { text := "" if !f.firstOnLine(i) { text = "\n" } return splice{f.ownStart(i), f.entryLineEnd(i), text} } // entryLineEnd returns where the line of the entry at i ends for git when it // removes or rewrites it: after its newline, and after the CR of the next // line if that line is a blank CRLF line (git turns it into a blank LF line). func (f *File) entryLineEnd(i int) int { n := f.newlineAfter(i) if n < 0 { return len(f.data) } end := int(f.items[n].end) if n+1 < len(f.items) && f.items[n+1].kind == itemNewline && f.items[n+1].end-f.items[n+1].start == 2 { end++ } return end } // unsetEntries returns the splices that remove the entries at idx, all of // the same key, with the headers of their section where nothing remains in // them, as git does. git decides for each entry on the file as it is before // the edit: // // - Headers of the same section that follow each other count as one. // - Looking back from the entry, the headers go only if one of them is // reached before any other entry or a header of another section. // - Looking forward, past the other removed entries, an entry before the // next header of another section keeps them. // - A comment between the previous entry or header of another section and // that next header keeps them too, except the comments at the end of the // removed entries' lines. // // The region removed then starts after the previous entry's line, or right // after the previous header or a BOM (the rest of its line becomes a // newline), and ends at the next header, its indentation included. func (f *File) unsetEntries(idx []int) []splice { // Comments at the end of a removed entry's line play no part. trailing := make(map[int]bool) for _, i := range idx { for j := i + 1; j < len(f.items) && f.items[j].kind != itemNewline; j++ { if f.items[j].kind == itemComment { trailing[j] = true } } } // comments[j] counts the comments of items[:j] that play a part. comments := make([]int, len(f.items)+1) for j, it := range f.items { comments[j+1] = comments[j] if it.kind == itemComment && !trailing[j] { comments[j+1]++ } } // From the last entry back, so that a forward scan reaching a removed // entry can stop where that entry's own scan did. forward := make(map[int]int, len(idx)) splices := make([]splice, len(idx)) for n := len(idx) - 1; n >= 0; n-- { splices[n] = f.unsetEntry(idx[n], forward, comments) } // Merge the regions that overlap: a region may hold other entries. slices.SortFunc(splices, func(a, b splice) int { return a.start - b.start }) var merged []splice for _, sp := range splices { if n := len(merged); n > 0 && sp.start < merged[n-1].end { merged[n-1].end = max(merged[n-1].end, sp.end) continue } merged = append(merged, sp) } return merged } // unsetEntry returns the splice that removes the entry at i. forward holds // where the forward scan of each removed entry after i stopped; the scan of // i is added to it. comments counts the comments that play a part, as // unsetEntries computes it. func (f *File) unsetEntry(i int, forward map[int]int, comments []int) splice { sec := f.items[i].sec sameHeader := func(it item) bool { return it.kind == itemHeader && f.secOf(it) == f.secs[sec] } // Scan back to the previous entry or header of another section, b; // headers tells whether a header of the entry's section was passed. headers := false b := i - 1 for ; b >= 0; b-- { it := f.items[b] if it.kind == itemEntry || it.kind == itemHeader && !sameHeader(it) { break } if sameHeader(it) { headers = true } } // Scan forward to the next entry or header of another section, fw. fw := i + 1 for ; fw < len(f.items); fw++ { if end, ok := forward[fw]; ok { // A removed entry: the scan goes on as its own did. fw = end break } it := f.items[fw] if it.kind == itemEntry || it.kind == itemHeader && !sameHeader(it) { break } } forward[i] = fw if !headers || fw < len(f.items) && f.items[fw].kind == itemEntry { // The section keeps other entries: remove the entry's line only. return f.removeEntry(i) } // The section's headers go too: remove from after b up to fw. start, text := 0, "" switch { case b < 0: if len(f.items) > 0 && f.items[0].kind == itemBOM { // git ends the line after a BOM as after a header. start, text = int(f.items[0].end), "\n" } case f.items[b].kind == itemEntry: start = f.lineEnd(b) default: start, text = int(f.items[b].end), "\n" } end := len(f.data) if fw < len(f.items) { end = int(f.items[fw].start) } // The region is items[from:fw]: start and end are item boundaries. from, _ := slices.BinarySearchFunc(f.items, start, func(it item, start int) int { return int(it.start) - start }) if comments[fw]-comments[from] > 0 { return f.removeEntry(i) } return splice{start, end, text} } // insert returns the splice that adds a new entry for k, at the end of the // last section that matches, or in a new section at the end of the file. func (f *File) insert(k Key, section, name, value string) splice { line := formatEntry(name, value) headers := f.headersOf(k.sectionKey()) if len(headers) == 0 { return splice{len(f.data), len(f.data), f.terminator() + formatHeader(section, k.Subsection, k.HasSubsection) + "\n" + line} } // Insert after the last entry of the last matching section, or after // its header if it has none. h := headers[len(headers)-1] last := h for i := h + 1; i < len(f.items) && f.items[i].kind != itemHeader; i++ { if f.items[i].kind == itemEntry { last = i } } if f.items[last].kind == itemEntry { if n := f.newlineAfter(last); n >= 0 { end := int(f.items[n].end) if f.entryLineEnd(last) != end { // git's end of the entry takes the CR of a blank CRLF // line: the new line goes after that blank line. end = int(f.items[n+1].end) } return splice{end, end, line} } return splice{len(f.data), len(f.data), f.terminator() + line} } // After a header: right after its newline, or splitting its line. if last+1 < len(f.items) && f.items[last+1].kind == itemNewline { end := int(f.items[last+1].end) return splice{end, end, line} } end := int(f.items[last].end) return splice{end, end, "\n" + line} } // prepareSection checks that the file is open and validates the name of a // section given to a section edit, and its subsections. func (f *File) prepareSection(section string, subs ...string) error { if err := f.checkOpen(section); err != nil { return err } if err := sectionArg(section); err != nil { return err } for _, sub := range subs { if !validSubsection(sub) { return &KeyError{Key: sub, Err: ErrInvalidKey} } } return nil } // sectionArg validates the name of a section given to a section edit. func sectionArg(section string) error { if section == "" || !validSection(section) { return &KeyError{Key: section, Err: ErrInvalidKey} } return nil } // headersOf returns the indexes of the headers of sk. func (f *File) headersOf(sk sectionKey) []int { var idx []int for i, it := range f.items { if it.kind == itemHeader && f.secOf(it) == sk { idx = append(idx, i) } } return idx } // removeSection removes every header of sk and what follows it up to the // next header, whose own whitespace is kept. func (f *File) removeSection(name string, sk sectionKey) (bool, error) { headers := f.headersOf(sk) if len(headers) == 0 { return false, nil } var splices []splice for _, h := range headers { end := len(f.data) for j := h + 1; j < len(f.items); j++ { if f.items[j].kind == itemHeader { end = f.ownStart(j) break } } splices = append(splices, splice{f.ownStart(h), end, ""}) } err := f.apply(name, splices, func(before, after *parsed) bool { return sameEntries(before, after, func(e flatEntry) bool { return e.sec != sk }, nil, nil) }) return err == nil, err } // renameSection rewrites every header of sk as header, and checks that the // entries of sk now have section to. func (f *File) renameSection(name string, sk, to sectionKey, header string) error { headers := f.headersOf(sk) if len(headers) == 0 { return &KeyError{Key: name, Err: ErrNotFound} } // Renaming many headers to a long name multiplies the size of the file: // bound the result before building it. Each header grows by the // difference of the spellings, and a rewritten line by at most "\n\t". grow := 0 for _, h := range headers { grow += len(header) - int(f.items[h].end-f.items[h].start) + 2 } if len(f.data)+grow > maxLoadBytes { return &KeyError{Key: name, Err: ErrLoadLimit} } // A header that does not start its line follows another header on the // same line ("[b] [a]") and is rewritten in place. A header that starts // its line has the whole line rewritten, the other headers of sk on it // included. var splices []splice done := -1 // headers up to this index are rewritten with their line for _, h := range headers { if h <= done { continue } if !f.firstOnLine(h) { splices = append(splices, splice{int(f.items[h].start), int(f.items[h].end), header}) continue } // git rewrites the line: the header alone, then the rest of the // line, if any, on a line of its own. rest := h + 1 for rest < len(f.items) && f.items[rest].kind == itemSpace { rest++ } end := len(f.items) if n := f.newlineAfter(h); n >= 0 { end = n + 1 } var text strings.Builder text.WriteString(header + "\n") if rest < end && f.items[rest].kind != itemNewline { text.WriteByte('\t') for _, it := range f.items[rest:end] { if it.kind == itemHeader && f.secOf(it) == sk { text.WriteString(header) } else { text.Write(f.data[it.start:it.end]) } } } splices = append(splices, splice{f.ownStart(h), f.lineEnd(h), text.String()}) done = end - 1 } return f.apply(name, splices, func(before, after *parsed) bool { return sameEntries(before, after, nil, nil, func(e flatEntry) flatEntry { if e.sec == sk { e.sec = to } return e }) }) } |
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