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Implement CacheDB for source packages in apt-ftparchive
[apt.git] / methods / rred.cc
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1// Copyright (c) 2014 Anthony Towns
2//
3// This program is free software; you can redistribute it and/or modify
4// it under the terms of the GNU General Public License as published by
5// the Free Software Foundation; either version 2 of the License, or
6// (at your option) any later version.
7
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8#include <config.h>
9
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10#include <apt-pkg/fileutl.h>
11#include <apt-pkg/error.h>
12#include <apt-pkg/acquire-method.h>
13#include <apt-pkg/strutl.h>
14#include <apt-pkg/hashes.h>
472ff00e 15#include <apt-pkg/configuration.h>
2e178d1c 16
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17#include <stddef.h>
18#include <iostream>
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19#include <string>
20#include <list>
21#include <vector>
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22
23#include <assert.h>
24#include <stdio.h>
25#include <stdlib.h>
26#include <string.h>
2e178d1c 27#include <sys/stat.h>
246bbb61 28#include <sys/time.h>
dbd5418b 29
2e178d1c 30#include <apti18n.h>
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31
32#define BLOCK_SIZE (512*1024)
33
34class MemBlock {
35 char *start;
36 size_t size;
37 char *free;
38 struct MemBlock *next;
39
25d99f3b 40 MemBlock(size_t size) : size(size), next(NULL)
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41 {
42 free = start = new char[size];
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43 }
44
45 size_t avail(void) { return size - (free - start); }
46
47 public:
48
49 MemBlock(void) {
50 free = start = new char[BLOCK_SIZE];
51 size = BLOCK_SIZE;
52 next = NULL;
53 }
54
55 ~MemBlock() {
56 delete [] start;
57 delete next;
58 }
59
60 void clear(void) {
61 free = start;
62 if (next)
63 next->clear();
64 }
65
66 char *add_easy(char *src, size_t len, char *last)
67 {
68 if (last) {
69 for (MemBlock *k = this; k; k = k->next) {
70 if (k->free == last) {
71 if (len <= k->avail()) {
72 char *n = k->add(src, len);
73 assert(last == n);
74 if (last == n)
75 return NULL;
76 return n;
77 } else {
78 break;
79 }
80 } else if (last >= start && last < free) {
81 break;
82 }
83 }
84 }
85 return add(src, len);
86 }
87
88 char *add(char *src, size_t len) {
89 if (len > avail()) {
90 if (!next) {
91 if (len > BLOCK_SIZE) {
92 next = new MemBlock(len);
93 } else {
94 next = new MemBlock;
95 }
96 }
97 return next->add(src, len);
98 }
99 char *dst = free;
100 free += len;
101 memcpy(dst, src, len);
102 return dst;
103 }
2e178d1c 104};
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105
106struct Change {
107 /* Ordering:
108 *
109 * 1. write out <offset> lines unchanged
110 * 2. skip <del_cnt> lines from source
111 * 3. write out <add_cnt> lines (<add>/<add_len>)
112 */
113 size_t offset;
114 size_t del_cnt;
115 size_t add_cnt; /* lines */
116 size_t add_len; /* bytes */
117 char *add;
118
119 Change(int off)
120 {
121 offset = off;
122 del_cnt = add_cnt = add_len = 0;
123 add = NULL;
124 }
125
126 /* actually, don't write <lines> lines from <add> */
127 void skip_lines(size_t lines)
128 {
129 while (lines > 0) {
130 char *s = (char*) memchr(add, '\n', add_len);
131 assert(s != NULL);
132 s++;
133 add_len -= (s - add);
134 add_cnt--;
135 lines--;
136 if (add_len == 0) {
137 add = NULL;
138 assert(add_cnt == 0);
139 assert(lines == 0);
140 } else {
141 add = s;
142 assert(add_cnt > 0);
143 }
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144 }
145 }
bb1293d9 146};
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147
148class FileChanges {
149 std::list<struct Change> changes;
150 std::list<struct Change>::iterator where;
151 size_t pos; // line number is as far left of iterator as possible
152
153 bool pos_is_okay(void)
154 {
155#ifdef POSDEBUG
156 size_t cpos = 0;
157 std::list<struct Change>::iterator x;
25d99f3b 158 for (x = changes.begin(); x != where; ++x) {
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159 assert(x != changes.end());
160 cpos += x->offset + x->add_cnt;
161 }
162 return cpos == pos;
bb1293d9 163#else
dbd5418b 164 return true;
bb1293d9 165#endif
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166 }
167
168 public:
169 FileChanges() {
170 where = changes.end();
171 pos = 0;
172 }
173
174 std::list<struct Change>::iterator begin(void) { return changes.begin(); }
175 std::list<struct Change>::iterator end(void) { return changes.end(); }
176
177 std::list<struct Change>::reverse_iterator rbegin(void) { return changes.rbegin(); }
178 std::list<struct Change>::reverse_iterator rend(void) { return changes.rend(); }
179
180 void add_change(Change c) {
181 assert(pos_is_okay());
182 go_to_change_for(c.offset);
183 assert(pos + where->offset == c.offset);
184 if (c.del_cnt > 0)
185 delete_lines(c.del_cnt);
186 assert(pos + where->offset == c.offset);
187 if (c.add_len > 0) {
188 assert(pos_is_okay());
189 if (where->add_len > 0)
190 new_change();
191 assert(where->add_len == 0 && where->add_cnt == 0);
192
193 where->add_len = c.add_len;
194 where->add_cnt = c.add_cnt;
195 where->add = c.add;
196 }
197 assert(pos_is_okay());
198 merge();
199 assert(pos_is_okay());
200 }
201
202 private:
203 void merge(void)
204 {
205 while (where->offset == 0 && where != changes.begin()) {
206 left();
207 }
208 std::list<struct Change>::iterator next = where;
25d99f3b 209 ++next;
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210
211 while (next != changes.end() && next->offset == 0) {
212 where->del_cnt += next->del_cnt;
213 next->del_cnt = 0;
214 if (next->add == NULL) {
215 next = changes.erase(next);
216 } else if (where->add == NULL) {
217 where->add = next->add;
218 where->add_len = next->add_len;
219 where->add_cnt = next->add_cnt;
220 next = changes.erase(next);
221 } else {
25d99f3b 222 ++next;
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223 }
224 }
225 }
226
227 void go_to_change_for(size_t line)
47d2bc78 228 {
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229 while(where != changes.end()) {
230 if (line < pos) {
231 left();
232 continue;
233 }
234 if (pos + where->offset + where->add_cnt <= line) {
235 right();
236 continue;
237 }
238 // line is somewhere in this slot
239 if (line < pos + where->offset) {
240 break;
241 } else if (line == pos + where->offset) {
242 return;
243 } else {
244 split(line - pos);
245 right();
246 return;
47d2bc78 247 }
bb1293d9 248 }
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249 /* it goes before this patch */
250 insert(line-pos);
251 }
252
253 void new_change(void) { insert(where->offset); }
254
255 void insert(size_t offset)
256 {
257 assert(pos_is_okay());
258 assert(where == changes.end() || offset <= where->offset);
259 if (where != changes.end())
260 where->offset -= offset;
261 changes.insert(where, Change(offset));
25d99f3b 262 --where;
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263 assert(pos_is_okay());
264 }
265
266 void split(size_t offset)
267 {
268 assert(pos_is_okay());
269
270 assert(where->offset < offset);
271 assert(offset < where->offset + where->add_cnt);
272
273 size_t keep_lines = offset - where->offset;
274
275 Change before(*where);
47d2bc78 276
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277 where->del_cnt = 0;
278 where->offset = 0;
279 where->skip_lines(keep_lines);
280
281 before.add_cnt = keep_lines;
282 before.add_len -= where->add_len;
283
284 changes.insert(where, before);
25d99f3b 285 --where;
dbd5418b 286 assert(pos_is_okay());
3de9ff77 287 }
dbd5418b 288
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289 void delete_lines(size_t cnt)
290 {
291 std::list<struct Change>::iterator x = where;
292 assert(pos_is_okay());
293 while (cnt > 0)
294 {
295 size_t del;
296 del = x->add_cnt;
297 if (del > cnt)
298 del = cnt;
299 x->skip_lines(del);
300 cnt -= del;
301
25d99f3b 302 ++x;
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303 if (x == changes.end()) {
304 del = cnt;
305 } else {
306 del = x->offset;
307 if (del > cnt)
308 del = cnt;
309 x->offset -= del;
310 }
311 where->del_cnt += del;
312 cnt -= del;
313 }
314 assert(pos_is_okay());
315 }
47d2bc78 316
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317 void left(void) {
318 assert(pos_is_okay());
25d99f3b 319 --where;
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320 pos -= where->offset + where->add_cnt;
321 assert(pos_is_okay());
322 }
47d2bc78 323
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324 void right(void) {
325 assert(pos_is_okay());
326 pos += where->offset + where->add_cnt;
25d99f3b 327 ++where;
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328 assert(pos_is_okay());
329 }
330};
331
332class Patch {
333 FileChanges filechanges;
334 MemBlock add_text;
335
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336 static bool retry_fwrite(char *b, size_t l, FILE *f, Hashes *hash)
337 {
338 size_t r = 1;
339 while (r > 0 && l > 0)
340 {
341 r = fwrite(b, 1, l, f);
342 if (hash)
343 hash->Add((unsigned char*)b, r);
344 l -= r;
345 b += r;
346 }
347 return l == 0;
348 }
349
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350 static void dump_rest(FILE *o, FILE *i, Hashes *hash)
351 {
352 char buffer[BLOCK_SIZE];
353 size_t l;
354 while (0 < (l = fread(buffer, 1, sizeof(buffer), i))) {
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355 if (!retry_fwrite(buffer, l, o, hash))
356 break;
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357 }
358 }
359
360 static void dump_lines(FILE *o, FILE *i, size_t n, Hashes *hash)
361 {
362 char buffer[BLOCK_SIZE];
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363 while (n > 0) {
364 if (fgets(buffer, sizeof(buffer), i) == 0)
365 buffer[0] = '\0';
25d99f3b 366 size_t const l = strlen(buffer);
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367 if (l == 0 || buffer[l-1] == '\n')
368 n--;
2fd754cf 369 retry_fwrite(buffer, l, o, hash);
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370 }
371 }
372
373 static void skip_lines(FILE *i, int n)
374 {
375 char buffer[BLOCK_SIZE];
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376 while (n > 0) {
377 if (fgets(buffer, sizeof(buffer), i) == 0)
378 buffer[0] = '\0';
25d99f3b 379 size_t const l = strlen(buffer);
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380 if (l == 0 || buffer[l-1] == '\n')
381 n--;
382 }
383 }
384
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385 static void dump_mem(FILE *o, char *p, size_t s, Hashes *hash) {
386 retry_fwrite(p, s, o, hash);
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387 }
388
389 public:
390
50bd6fd3 391 void read_diff(FileFd &f)
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392 {
393 char buffer[BLOCK_SIZE];
394 bool cmdwanted = true;
395
396 Change ch(0);
50bd6fd3 397 while(f.ReadLine(buffer, sizeof(buffer)))
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398 {
399 if (cmdwanted) {
400 char *m, *c;
401 size_t s, e;
402 s = strtol(buffer, &m, 10);
403 if (m == buffer) {
404 s = e = ch.offset + ch.add_cnt;
405 c = buffer;
406 } else if (*m == ',') {
407 m++;
408 e = strtol(m, &c, 10);
409 } else {
410 e = s;
411 c = m;
412 }
413 switch(*c) {
414 case 'a':
415 cmdwanted = false;
416 ch.add = NULL;
417 ch.add_cnt = 0;
418 ch.add_len = 0;
419 ch.offset = s;
420 ch.del_cnt = 0;
421 break;
422 case 'c':
423 cmdwanted = false;
424 ch.add = NULL;
425 ch.add_cnt = 0;
426 ch.add_len = 0;
427 ch.offset = s - 1;
428 ch.del_cnt = e - s + 1;
429 break;
430 case 'd':
431 ch.offset = s - 1;
432 ch.del_cnt = e - s + 1;
433 ch.add = NULL;
434 ch.add_cnt = 0;
435 ch.add_len = 0;
436 filechanges.add_change(ch);
437 break;
438 }
2fd754cf 439 } else { /* !cmdwanted */
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440 if (buffer[0] == '.' && buffer[1] == '\n') {
441 cmdwanted = true;
442 filechanges.add_change(ch);
443 } else {
444 char *last = NULL;
445 char *add;
446 size_t l;
447 if (ch.add)
448 last = ch.add + ch.add_len;
449 l = strlen(buffer);
450 add = add_text.add_easy(buffer, l, last);
451 if (!add) {
452 ch.add_len += l;
453 ch.add_cnt++;
454 } else {
455 if (ch.add) {
456 filechanges.add_change(ch);
457 ch.del_cnt = 0;
458 }
459 ch.offset += ch.add_cnt;
460 ch.add = add;
461 ch.add_len = l;
462 ch.add_cnt = 1;
463 }
464 }
465 }
466 }
467 }
468
469 void write_diff(FILE *f)
470 {
6298ff8b 471 unsigned long long line = 0;
dbd5418b 472 std::list<struct Change>::reverse_iterator ch;
25d99f3b 473 for (ch = filechanges.rbegin(); ch != filechanges.rend(); ++ch) {
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474 line += ch->offset + ch->del_cnt;
475 }
476
25d99f3b 477 for (ch = filechanges.rbegin(); ch != filechanges.rend(); ++ch) {
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478 std::list<struct Change>::reverse_iterator mg_i, mg_e = ch;
479 while (ch->del_cnt == 0 && ch->offset == 0)
25d99f3b 480 ++ch;
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481 line -= ch->del_cnt;
482 if (ch->add_cnt > 0) {
483 if (ch->del_cnt == 0) {
6298ff8b 484 fprintf(f, "%llua\n", line);
dbd5418b 485 } else if (ch->del_cnt == 1) {
6298ff8b 486 fprintf(f, "%lluc\n", line+1);
dbd5418b 487 } else {
6298ff8b 488 fprintf(f, "%llu,%lluc\n", line+1, line+ch->del_cnt);
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489 }
490
491 mg_i = ch;
492 do {
493 dump_mem(f, mg_i->add, mg_i->add_len, NULL);
494 } while (mg_i-- != mg_e);
495
496 fprintf(f, ".\n");
497 } else if (ch->del_cnt == 1) {
6298ff8b 498 fprintf(f, "%llud\n", line+1);
dbd5418b 499 } else if (ch->del_cnt > 1) {
6298ff8b 500 fprintf(f, "%llu,%llud\n", line+1, line+ch->del_cnt);
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501 }
502 line -= ch->offset;
503 }
504 }
47d2bc78 505
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506 void apply_against_file(FILE *out, FILE *in, Hashes *hash = NULL)
507 {
508 std::list<struct Change>::iterator ch;
25d99f3b 509 for (ch = filechanges.begin(); ch != filechanges.end(); ++ch) {
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510 dump_lines(out, in, ch->offset, hash);
511 skip_lines(in, ch->del_cnt);
512 dump_mem(out, ch->add, ch->add_len, hash);
513 }
514 dump_rest(out, in, hash);
47d2bc78 515 }
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516};
517
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518class RredMethod : public pkgAcqMethod {
519 private:
520 bool Debug;
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521
522 protected:
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523 virtual bool Fetch(FetchItem *Itm) {
524 Debug = _config->FindB("Debug::pkgAcquire::RRed", false);
525 URI Get = Itm->Uri;
526 std::string Path = Get.Host + Get.Path; // rred:/path - no host
527
528 FetchResult Res;
529 Res.Filename = Itm->DestFile;
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530 if (Itm->Uri.empty())
531 {
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532 Path = Itm->DestFile;
533 Itm->DestFile.append(".result");
534 } else
535 URIStart(Res);
536
50bd6fd3 537 std::vector<std::string> patchpaths;
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538 Patch patch;
539
50bd6fd3 540 if (FileExists(Path + ".ed") == true)
dbd5418b 541 patchpaths.push_back(Path + ".ed");
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542 else
543 {
544 _error->PushToStack();
545 std::vector<std::string> patches = GetListOfFilesInDir(flNotFile(Path), "gz", true, false);
546 _error->RevertToStack();
547
548 std::string const baseName = Path + ".ed.";
549 for (std::vector<std::string>::const_iterator p = patches.begin();
550 p != patches.end(); ++p)
551 if (p->compare(0, baseName.length(), baseName) == 0)
552 patchpaths.push_back(*p);
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553 }
554
555 std::string patch_name;
556 for (std::vector<std::string>::iterator I = patchpaths.begin();
557 I != patchpaths.end();
25d99f3b 558 ++I)
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559 {
560 patch_name = *I;
561 if (Debug == true)
562 std::clog << "Patching " << Path << " with " << patch_name
563 << std::endl;
564
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565 FileFd p;
566 // all patches are compressed, even if the name doesn't reflect it
567 if (p.Open(patch_name, FileFd::ReadOnly, FileFd::Gzip) == false) {
568 std::cerr << "Could not open patch file " << patch_name << std::endl;
569 _error->DumpErrors(std::cerr);
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570 abort();
571 }
572 patch.read_diff(p);
50bd6fd3 573 p.Close();
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574 }
575
576 if (Debug == true)
577 std::clog << "Applying patches against " << Path
578 << " and writing results to " << Itm->DestFile
579 << std::endl;
580
581 FILE *inp = fopen(Path.c_str(), "r");
582 FILE *out = fopen(Itm->DestFile.c_str(), "w");
583
584 Hashes hash;
585
586 patch.apply_against_file(out, inp, &hash);
587
588 fclose(out);
589 fclose(inp);
590
591 if (Debug == true) {
592 std::clog << "rred: finished file patching of " << Path << "." << std::endl;
593 }
594
595 struct stat bufbase, bufpatch;
596 if (stat(Path.c_str(), &bufbase) != 0 ||
597 stat(patch_name.c_str(), &bufpatch) != 0)
598 return _error->Errno("stat", _("Failed to stat"));
599
246bbb61 600 struct timeval times[2];
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601 times[0].tv_sec = bufbase.st_atime;
602 times[1].tv_sec = bufpatch.st_mtime;
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603 times[0].tv_usec = times[1].tv_usec = 0;
604 if (utimes(Itm->DestFile.c_str(), times) != 0)
605 return _error->Errno("utimes",_("Failed to set modification time"));
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606
607 if (stat(Itm->DestFile.c_str(), &bufbase) != 0)
608 return _error->Errno("stat", _("Failed to stat"));
609
610 Res.LastModified = bufbase.st_mtime;
611 Res.Size = bufbase.st_size;
612 Res.TakeHashes(hash);
613 URIDone(Res);
614
615 return true;
616 }
617
618 public:
25d99f3b 619 RredMethod() : pkgAcqMethod("2.0",SingleInstance | SendConfig), Debug(false) {}
bb1293d9 620};
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621
622int main(int argc, char **argv)
623{
624 int i;
625 bool just_diff = true;
626 Patch patch;
627
628 if (argc <= 1) {
629 RredMethod Mth;
630 return Mth.Run();
631 }
632
633 if (argc > 1 && strcmp(argv[1], "-f") == 0) {
634 just_diff = false;
635 i = 2;
636 } else {
637 i = 1;
638 }
639
640 for (; i < argc; i++) {
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641 FileFd p;
642 if (p.Open(argv[i], FileFd::ReadOnly) == false) {
643 _error->DumpErrors(std::cerr);
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644 exit(1);
645 }
646 patch.read_diff(p);
647 }
648
649 if (just_diff) {
650 patch.write_diff(stdout);
651 } else {
652 FILE *out, *inp;
653 out = stdout;
654 inp = stdin;
655
656 patch.apply_against_file(out, inp);
657 }
658 return 0;
2e178d1c 659}