op public repos

Blob

Date:: Fri Dec 31 09:33:01 2021 UTC
Message:: wrap overlong lines
Actions:: History | Blame | Raw File
1 /*
2  * Copyright (c) 2018, 2019 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/queue.h>
18 #include <sys/tree.h>
19 #include <sys/stat.h>
20 
21 #include <errno.h>
22 #include <dirent.h>
23 #include <fcntl.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <sha1.h>
28 #include <endian.h>
29 #include <limits.h>
30 #include <unistd.h>
31 #include <uuid.h>
32 
33 #include "got_error.h"
34 #include "got_object.h"
35 #include "got_path.h"
36 
37 #include "got_lib_fileindex.h"
38 #include "got_lib_worktree.h"
39 
40 /* got_fileindex_entry flags */
41 #define GOT_FILEIDX_F_PATH_LEN		0x00000fff
42 #define GOT_FILEIDX_F_STAGE		0x0000f000
43 #define GOT_FILEIDX_F_STAGE_SHIFT	12
44 #define GOT_FILEIDX_F_NOT_FLUSHED	0x00010000
45 #define GOT_FILEIDX_F_NO_BLOB		0x00020000
46 #define GOT_FILEIDX_F_NO_COMMIT		0x00040000
47 #define GOT_FILEIDX_F_NO_FILE_ON_DISK	0x00080000
48 #define GOT_FILEIDX_F_REMOVE_ON_FLUSH	0x00100000
49 #define GOT_FILEIDX_F_SKIPPED		0x00200000
50 
51 struct got_fileindex {
52 	struct got_fileindex_tree entries;
53 	int nentries; /* Does not include entries marked for removal. */
54 #define GOT_FILEIDX_MAX_ENTRIES INT_MAX
55 };
56 
57 mode_t
58 got_fileindex_entry_perms_get(struct got_fileindex_entry *ie)
59 {
60 	return ((ie->mode & GOT_FILEIDX_MODE_PERMS) >>
61 	    GOT_FILEIDX_MODE_PERMS_SHIFT);
62 }
63 
64 static void
65 fileindex_entry_perms_set(struct got_fileindex_entry *ie, mode_t mode)
66 {
67 	ie->mode &= ~GOT_FILEIDX_MODE_PERMS;
68 	ie->mode |= ((mode << GOT_FILEIDX_MODE_PERMS_SHIFT) &
69 	    GOT_FILEIDX_MODE_PERMS);
70 }
71 
72 mode_t
73 got_fileindex_perms_to_st(struct got_fileindex_entry *ie)
74 {
75 	mode_t perms = got_fileindex_entry_perms_get(ie);
76 	int type = got_fileindex_entry_filetype_get(ie);
77 	uint32_t ftype;
78 
79 	if (type == GOT_FILEIDX_MODE_REGULAR_FILE ||
80 	    type == GOT_FILEIDX_MODE_BAD_SYMLINK)
81 		ftype = S_IFREG;
82 	else
83 		ftype = S_IFLNK;
84 
85 	return (ftype | (perms & (S_IRWXU | S_IRWXG | S_IRWXO)));
86 }
87 
88 const struct got_error *
89 got_fileindex_entry_update(struct got_fileindex_entry *ie,
90     int wt_fd, const char *ondisk_path, uint8_t *blob_sha1,
91     uint8_t *commit_sha1, int update_timestamps)
92 {
93 	struct stat sb;
94 
95 	if (fstatat(wt_fd, ondisk_path, &sb, AT_SYMLINK_NOFOLLOW) != 0) {
96 		if (!((ie->flags & GOT_FILEIDX_F_NO_FILE_ON_DISK) &&
97 		    errno == ENOENT))
98 			return got_error_from_errno2("fstatat", ondisk_path);
99 		sb.st_mode = GOT_DEFAULT_FILE_MODE;
100 	} else {
101 		if (sb.st_mode & S_IFDIR)
102 			return got_error_set_errno(EISDIR, ondisk_path);
103 		ie->flags &= ~GOT_FILEIDX_F_NO_FILE_ON_DISK;
104 	}
105 
106 
107 	if ((ie->flags & GOT_FILEIDX_F_NO_FILE_ON_DISK) == 0) {
108 		if (update_timestamps) {
109 			ie->ctime_sec = sb.st_ctim.tv_sec;
110 			ie->ctime_nsec = sb.st_ctim.tv_nsec;
111 			ie->mtime_sec = sb.st_mtim.tv_sec;
112 			ie->mtime_nsec = sb.st_mtim.tv_nsec;
113 		}
114 		ie->uid = sb.st_uid;
115 		ie->gid = sb.st_gid;
116 		ie->size = (sb.st_size & 0xffffffff);
117 		if (S_ISLNK(sb.st_mode)) {
118 			got_fileindex_entry_filetype_set(ie,
119 			    GOT_FILEIDX_MODE_SYMLINK);
120 			fileindex_entry_perms_set(ie, 0);
121 		} else {
122 			got_fileindex_entry_filetype_set(ie,
123 			    GOT_FILEIDX_MODE_REGULAR_FILE);
124 			fileindex_entry_perms_set(ie,
125 			    sb.st_mode & (S_IRWXU | S_IRWXG | S_IRWXO));
126 		}
127 	}
128 
129 	if (blob_sha1) {
130 		memcpy(ie->blob_sha1, blob_sha1, SHA1_DIGEST_LENGTH);
131 		ie->flags &= ~GOT_FILEIDX_F_NO_BLOB;
132 	} else
133 		ie->flags |= GOT_FILEIDX_F_NO_BLOB;
134 
135 	if (commit_sha1) {
136 		memcpy(ie->commit_sha1, commit_sha1, SHA1_DIGEST_LENGTH);
137 		ie->flags &= ~GOT_FILEIDX_F_NO_COMMIT;
138 	} else
139 		ie->flags |= GOT_FILEIDX_F_NO_COMMIT;
140 
141 	return NULL;
142 }
143 
144 void
145 got_fileindex_entry_mark_deleted_from_disk(struct got_fileindex_entry *ie)
146 {
147 	ie->flags |= GOT_FILEIDX_F_NO_FILE_ON_DISK;
148 }
149 
150 void
151 got_fileindex_entry_mark_skipped(struct got_fileindex_entry *ie)
152 {
153 	ie->flags |= GOT_FILEIDX_F_SKIPPED;
154 }
155 
156 const struct got_error *
157 got_fileindex_entry_alloc(struct got_fileindex_entry **ie,
158     const char *relpath)
159 {
160 	size_t len;
161 
162 	*ie = calloc(1, sizeof(**ie));
163 	if (*ie == NULL)
164 		return got_error_from_errno("calloc");
165 
166 	(*ie)->path = strdup(relpath);
167 	if ((*ie)->path == NULL) {
168 		const struct got_error *err = got_error_from_errno("strdup");
169 		free(*ie);
170 		*ie = NULL;
171 		return err;
172 	}
173 
174 	len = strlen(relpath);
175 	if (len > GOT_FILEIDX_F_PATH_LEN)
176 		len = GOT_FILEIDX_F_PATH_LEN;
177 	(*ie)->flags |= len;
178 
179 	return NULL;
180 }
181 
182 void
183 got_fileindex_entry_free(struct got_fileindex_entry *ie)
184 {
185 	free(ie->path);
186 	free(ie);
187 }
188 
189 size_t
190 got_fileindex_entry_path_len(const struct got_fileindex_entry *ie)
191 {
192 	return (size_t)(ie->flags & GOT_FILEIDX_F_PATH_LEN);
193 }
194 
195 uint32_t
196 got_fileindex_entry_stage_get(const struct got_fileindex_entry *ie)
197 {
198 	return ((ie->flags & GOT_FILEIDX_F_STAGE) >> GOT_FILEIDX_F_STAGE_SHIFT);
199 }
200 
201 void
202 got_fileindex_entry_stage_set(struct got_fileindex_entry *ie, uint32_t stage)
203 {
204 	ie->flags &= ~GOT_FILEIDX_F_STAGE;
205 	ie->flags |= ((stage << GOT_FILEIDX_F_STAGE_SHIFT) &
206 	    GOT_FILEIDX_F_STAGE);
207 }
208 
209 int
210 got_fileindex_entry_filetype_get(struct got_fileindex_entry *ie)
211 {
212 	return (ie->mode & GOT_FILEIDX_MODE_FILE_TYPE_ONDISK);
213 }
214 
215 void
216 got_fileindex_entry_filetype_set(struct got_fileindex_entry *ie, int type)
217 {
218 	ie->mode &= ~GOT_FILEIDX_MODE_FILE_TYPE_ONDISK;
219 	ie->mode |= (type & GOT_FILEIDX_MODE_FILE_TYPE_ONDISK);
220 }
221 
222 void
223 got_fileindex_entry_staged_filetype_set(struct got_fileindex_entry *ie,
224     int type)
225 {
226 	ie->mode &= ~GOT_FILEIDX_MODE_FILE_TYPE_STAGED;
227 	ie->mode |= ((type << GOT_FILEIDX_MODE_FILE_TYPE_STAGED_SHIFT) &
228 	    GOT_FILEIDX_MODE_FILE_TYPE_STAGED);
229 }
230 
231 int
232 got_fileindex_entry_staged_filetype_get(struct got_fileindex_entry *ie)
233 {
234 	return (ie->mode & GOT_FILEIDX_MODE_FILE_TYPE_STAGED) >>
235 	    GOT_FILEIDX_MODE_FILE_TYPE_STAGED_SHIFT;
236 }
237 
238 int
239 got_fileindex_entry_has_blob(struct got_fileindex_entry *ie)
240 {
241 	return (ie->flags & GOT_FILEIDX_F_NO_BLOB) == 0;
242 }
243 
244 int
245 got_fileindex_entry_has_commit(struct got_fileindex_entry *ie)
246 {
247 	return (ie->flags & GOT_FILEIDX_F_NO_COMMIT) == 0;
248 }
249 
250 int
251 got_fileindex_entry_has_file_on_disk(struct got_fileindex_entry *ie)
252 {
253 	return (ie->flags & GOT_FILEIDX_F_NO_FILE_ON_DISK) == 0;
254 }
255 
256 int
257 got_fileindex_entry_was_skipped(struct got_fileindex_entry *ie)
258 {
259 	return (ie->flags & GOT_FILEIDX_F_SKIPPED) != 0;
260 }
261 
262 static const struct got_error *
263 add_entry(struct got_fileindex *fileindex, struct got_fileindex_entry *ie)
264 {
265 	if (fileindex->nentries >= GOT_FILEIDX_MAX_ENTRIES)
266 		return got_error(GOT_ERR_NO_SPACE);
267 
268 	RB_INSERT(got_fileindex_tree, &fileindex->entries, ie);
269 	fileindex->nentries++;
270 	return NULL;
271 }
272 
273 const struct got_error *
274 got_fileindex_entry_add(struct got_fileindex *fileindex,
275     struct got_fileindex_entry *ie)
276 {
277 	/* Flag this entry until it gets written out to disk. */
278 	ie->flags |= GOT_FILEIDX_F_NOT_FLUSHED;
279 
280 	return add_entry(fileindex, ie);
281 }
282 
283 void
284 got_fileindex_entry_remove(struct got_fileindex *fileindex,
285     struct got_fileindex_entry *ie)
286 {
287 	/*
288 	 * Removing an entry from the RB tree immediately breaks
289 	 * in-progress iterations over file index entries.
290 	 * So flag this entry for removal and remove it once the index
291 	 * is written out to disk. Meanwhile, pretend this entry no longer
292 	 * exists if we get queried for it again before then.
293 	 */
294 	ie->flags |= GOT_FILEIDX_F_REMOVE_ON_FLUSH;
295 	fileindex->nentries--;
296 }
297 
298 struct got_fileindex_entry *
299 got_fileindex_entry_get(struct got_fileindex *fileindex, const char *path,
300     size_t path_len)
301 {
302 	struct got_fileindex_entry *ie;
303 	struct got_fileindex_entry key;
304 	memset(&key, 0, sizeof(key));
305 	key.path = (char *)path;
306 	key.flags = (path_len & GOT_FILEIDX_F_PATH_LEN);
307 	ie = RB_FIND(got_fileindex_tree, &fileindex->entries, &key);
308 	if (ie && (ie->flags & GOT_FILEIDX_F_REMOVE_ON_FLUSH))
309 		return NULL;
310 	return ie;
311 }
312 
313 const struct got_error *
314 got_fileindex_for_each_entry_safe(struct got_fileindex *fileindex,
315     got_fileindex_cb cb, void *cb_arg)
316 {
317 	const struct got_error *err;
318 	struct got_fileindex_entry *ie, *tmp;
319 
320 	RB_FOREACH_SAFE(ie, got_fileindex_tree, &fileindex->entries, tmp) {
321 		if (ie->flags & GOT_FILEIDX_F_REMOVE_ON_FLUSH)
322 			continue;
323 		err = (*cb)(cb_arg, ie);
324 		if (err)
325 			return err;
326 	}
327 	return NULL;
328 }
329 
330 struct got_fileindex *
331 got_fileindex_alloc(void)
332 {
333 	struct got_fileindex *fileindex;
334 
335 	fileindex = calloc(1, sizeof(*fileindex));
336 	if (fileindex == NULL)
337 		return NULL;
338 
339 	RB_INIT(&fileindex->entries);
340 	return fileindex;
341 }
342 
343 void
344 got_fileindex_free(struct got_fileindex *fileindex)
345 {
346 	struct got_fileindex_entry *ie;
347 
348 	while ((ie = RB_MIN(got_fileindex_tree, &fileindex->entries))) {
349 		RB_REMOVE(got_fileindex_tree, &fileindex->entries, ie);
350 		got_fileindex_entry_free(ie);
351 	}
352 	free(fileindex);
353 }
354 
355 static const struct got_error *
356 write_fileindex_val64(SHA1_CTX *ctx, uint64_t val, FILE *outfile)
357 {
358 	size_t n;
359 
360 	val = htobe64(val);
361 	SHA1Update(ctx, (uint8_t *)&val, sizeof(val));
362 	n = fwrite(&val, 1, sizeof(val), outfile);
363 	if (n != sizeof(val))
364 		return got_ferror(outfile, GOT_ERR_IO);
365 	return NULL;
366 }
367 
368 static const struct got_error *
369 write_fileindex_val32(SHA1_CTX *ctx, uint32_t val, FILE *outfile)
370 {
371 	size_t n;
372 
373 	val = htobe32(val);
374 	SHA1Update(ctx, (uint8_t *)&val, sizeof(val));
375 	n = fwrite(&val, 1, sizeof(val), outfile);
376 	if (n != sizeof(val))
377 		return got_ferror(outfile, GOT_ERR_IO);
378 	return NULL;
379 }
380 
381 static const struct got_error *
382 write_fileindex_val16(SHA1_CTX *ctx, uint16_t val, FILE *outfile)
383 {
384 	size_t n;
385 
386 	val = htobe16(val);
387 	SHA1Update(ctx, (uint8_t *)&val, sizeof(val));
388 	n = fwrite(&val, 1, sizeof(val), outfile);
389 	if (n != sizeof(val))
390 		return got_ferror(outfile, GOT_ERR_IO);
391 	return NULL;
392 }
393 
394 static const struct got_error *
395 write_fileindex_path(SHA1_CTX *ctx, const char *path, FILE *outfile)
396 {
397 	size_t n, len, pad = 0;
398 	static const uint8_t zero[8] = { 0 };
399 
400 	len = strlen(path);
401 	while ((len + pad) % 8 != 0)
402 		pad++;
403 	if (pad == 0)
404 		pad = 8; /* NUL-terminate */
405 
406 	SHA1Update(ctx, path, len);
407 	n = fwrite(path, 1, len, outfile);
408 	if (n != len)
409 		return got_ferror(outfile, GOT_ERR_IO);
410 	SHA1Update(ctx, zero, pad);
411 	n = fwrite(zero, 1, pad, outfile);
412 	if (n != pad)
413 		return got_ferror(outfile, GOT_ERR_IO);
414 	return NULL;
415 }
416 
417 static const struct got_error *
418 write_fileindex_entry(SHA1_CTX *ctx, struct got_fileindex_entry *ie,
419     FILE *outfile)
420 {
421 	const struct got_error *err;
422 	size_t n;
423 	uint32_t stage;
424 
425 	err = write_fileindex_val64(ctx, ie->ctime_sec, outfile);
426 	if (err)
427 		return err;
428 	err = write_fileindex_val64(ctx, ie->ctime_nsec, outfile);
429 	if (err)
430 		return err;
431 	err = write_fileindex_val64(ctx, ie->mtime_sec, outfile);
432 	if (err)
433 		return err;
434 	err = write_fileindex_val64(ctx, ie->mtime_nsec, outfile);
435 	if (err)
436 		return err;
437 
438 	err = write_fileindex_val32(ctx, ie->uid, outfile);
439 	if (err)
440 		return err;
441 	err = write_fileindex_val32(ctx, ie->gid, outfile);
442 	if (err)
443 		return err;
444 	err = write_fileindex_val32(ctx, ie->size, outfile);
445 	if (err)
446 		return err;
447 
448 	err = write_fileindex_val16(ctx, ie->mode, outfile);
449 	if (err)
450 		return err;
451 
452 	SHA1Update(ctx, ie->blob_sha1, SHA1_DIGEST_LENGTH);
453 	n = fwrite(ie->blob_sha1, 1, SHA1_DIGEST_LENGTH, outfile);
454 	if (n != SHA1_DIGEST_LENGTH)
455 		return got_ferror(outfile, GOT_ERR_IO);
456 
457 	SHA1Update(ctx, ie->commit_sha1, SHA1_DIGEST_LENGTH);
458 	n = fwrite(ie->commit_sha1, 1, SHA1_DIGEST_LENGTH, outfile);
459 	if (n != SHA1_DIGEST_LENGTH)
460 		return got_ferror(outfile, GOT_ERR_IO);
461 
462 	err = write_fileindex_val32(ctx, ie->flags, outfile);
463 	if (err)
464 		return err;
465 
466 	err = write_fileindex_path(ctx, ie->path, outfile);
467 	if (err)
468 		return err;
469 
470 	stage = got_fileindex_entry_stage_get(ie);
471 	if (stage == GOT_FILEIDX_STAGE_MODIFY ||
472 	    stage == GOT_FILEIDX_STAGE_ADD) {
473 		SHA1Update(ctx, ie->staged_blob_sha1, SHA1_DIGEST_LENGTH);
474 		n = fwrite(ie->staged_blob_sha1, 1, SHA1_DIGEST_LENGTH,
475 		    outfile);
476 		if (n != SHA1_DIGEST_LENGTH)
477 			return got_ferror(outfile, GOT_ERR_IO);
478 	}
479 
480 	return NULL;
481 }
482 
483 const struct got_error *
484 got_fileindex_write(struct got_fileindex *fileindex, FILE *outfile)
485 {
486 	const struct got_error *err = NULL;
487 	struct got_fileindex_hdr hdr;
488 	SHA1_CTX ctx;
489 	uint8_t sha1[SHA1_DIGEST_LENGTH];
490 	size_t n;
491 	struct got_fileindex_entry *ie, *tmp;
492 
493 	SHA1Init(&ctx);
494 
495 	hdr.signature = htobe32(GOT_FILE_INDEX_SIGNATURE);
496 	hdr.version = htobe32(GOT_FILE_INDEX_VERSION);
497 	hdr.nentries = htobe32(fileindex->nentries);
498 
499 	SHA1Update(&ctx, (uint8_t *)&hdr.signature, sizeof(hdr.signature));
500 	SHA1Update(&ctx, (uint8_t *)&hdr.version, sizeof(hdr.version));
501 	SHA1Update(&ctx, (uint8_t *)&hdr.nentries, sizeof(hdr.nentries));
502 	n = fwrite(&hdr.signature, 1, sizeof(hdr.signature), outfile);
503 	if (n != sizeof(hdr.signature))
504 		return got_ferror(outfile, GOT_ERR_IO);
505 	n = fwrite(&hdr.version, 1, sizeof(hdr.version), outfile);
506 	if (n != sizeof(hdr.version))
507 		return got_ferror(outfile, GOT_ERR_IO);
508 	n = fwrite(&hdr.nentries, 1, sizeof(hdr.nentries), outfile);
509 	if (n != sizeof(hdr.nentries))
510 		return got_ferror(outfile, GOT_ERR_IO);
511 
512 	RB_FOREACH_SAFE(ie, got_fileindex_tree, &fileindex->entries, tmp) {
513 		ie->flags &= ~GOT_FILEIDX_F_NOT_FLUSHED;
514 		ie->flags &= ~GOT_FILEIDX_F_SKIPPED;
515 		if (ie->flags & GOT_FILEIDX_F_REMOVE_ON_FLUSH) {
516 			RB_REMOVE(got_fileindex_tree, &fileindex->entries, ie);
517 			got_fileindex_entry_free(ie);
518 			continue;
519 		}
520 		err = write_fileindex_entry(&ctx, ie, outfile);
521 		if (err)
522 			return err;
523 	}
524 
525 	SHA1Final(sha1, &ctx);
526 	n = fwrite(sha1, 1, sizeof(sha1), outfile);
527 	if (n != sizeof(sha1))
528 		return got_ferror(outfile, GOT_ERR_IO);
529 
530 	if (fflush(outfile) != 0)
531 		return got_error_from_errno("fflush");
532 
533 	return NULL;
534 }
535 
536 static const struct got_error *
537 read_fileindex_val64(uint64_t *val, SHA1_CTX *ctx, FILE *infile)
538 {
539 	size_t n;
540 
541 	n = fread(val, 1, sizeof(*val), infile);
542 	if (n != sizeof(*val))
543 		return got_ferror(infile, GOT_ERR_FILEIDX_BAD);
544 	SHA1Update(ctx, (uint8_t *)val, sizeof(*val));
545 	*val = be64toh(*val);
546 	return NULL;
547 }
548 
549 static const struct got_error *
550 read_fileindex_val32(uint32_t *val, SHA1_CTX *ctx, FILE *infile)
551 {
552 	size_t n;
553 
554 	n = fread(val, 1, sizeof(*val), infile);
555 	if (n != sizeof(*val))
556 		return got_ferror(infile, GOT_ERR_FILEIDX_BAD);
557 	SHA1Update(ctx, (uint8_t *)val, sizeof(*val));
558 	*val = be32toh(*val);
559 	return NULL;
560 }
561 
562 static const struct got_error *
563 read_fileindex_val16(uint16_t *val, SHA1_CTX *ctx, FILE *infile)
564 {
565 	size_t n;
566 
567 	n = fread(val, 1, sizeof(*val), infile);
568 	if (n != sizeof(*val))
569 		return got_ferror(infile, GOT_ERR_FILEIDX_BAD);
570 	SHA1Update(ctx, (uint8_t *)val, sizeof(*val));
571 	*val = be16toh(*val);
572 	return NULL;
573 }
574 
575 static const struct got_error *
576 read_fileindex_path(char **path, SHA1_CTX *ctx, FILE *infile)
577 {
578 	const struct got_error *err = NULL;
579 	const size_t chunk_size = 8;
580 	size_t n, len = 0, totlen = chunk_size;
581 
582 	*path = malloc(totlen);
583 	if (*path == NULL)
584 		return got_error_from_errno("malloc");
585 
586 	do {
587 		if (len + chunk_size > totlen) {
588 			char *p = reallocarray(*path, totlen + chunk_size, 1);
589 			if (p == NULL) {
590 				err = got_error_from_errno("reallocarray");
591 				break;
592 			}
593 			totlen += chunk_size;
594 			*path = p;
595 		}
596 		n = fread(*path + len, 1, chunk_size, infile);
597 		if (n != chunk_size) {
598 			err = got_ferror(infile, GOT_ERR_FILEIDX_BAD);
599 			break;
600 		}
601 		SHA1Update(ctx, *path + len, chunk_size);
602 		len += chunk_size;
603 	} while (memchr(*path + len - chunk_size, '\0', chunk_size) == NULL);
604 
605 	if (err) {
606 		free(*path);
607 		*path = NULL;
608 	}
609 	return err;
610 }
611 
612 static const struct got_error *
613 read_fileindex_entry(struct got_fileindex_entry **iep, SHA1_CTX *ctx,
614     FILE *infile, uint32_t version)
615 {
616 	const struct got_error *err;
617 	struct got_fileindex_entry *ie;
618 	size_t n;
619 
620 	*iep = NULL;
621 
622 	ie = calloc(1, sizeof(*ie));
623 	if (ie == NULL)
624 		return got_error_from_errno("calloc");
625 
626 	err = read_fileindex_val64(&ie->ctime_sec, ctx, infile);
627 	if (err)
628 		goto done;
629 	err = read_fileindex_val64(&ie->ctime_nsec, ctx, infile);
630 	if (err)
631 		goto done;
632 	err = read_fileindex_val64(&ie->mtime_sec, ctx, infile);
633 	if (err)
634 		goto done;
635 	err = read_fileindex_val64(&ie->mtime_nsec, ctx, infile);
636 	if (err)
637 		goto done;
638 
639 	err = read_fileindex_val32(&ie->uid, ctx, infile);
640 	if (err)
641 		goto done;
642 	err = read_fileindex_val32(&ie->gid, ctx, infile);
643 	if (err)
644 		goto done;
645 	err = read_fileindex_val32(&ie->size, ctx, infile);
646 	if (err)
647 		goto done;
648 
649 	err = read_fileindex_val16(&ie->mode, ctx, infile);
650 	if (err)
651 		goto done;
652 
653 	n = fread(ie->blob_sha1, 1, SHA1_DIGEST_LENGTH, infile);
654 	if (n != SHA1_DIGEST_LENGTH) {
655 		err = got_ferror(infile, GOT_ERR_FILEIDX_BAD);
656 		goto done;
657 	}
658 	SHA1Update(ctx, ie->blob_sha1, SHA1_DIGEST_LENGTH);
659 
660 	n = fread(ie->commit_sha1, 1, SHA1_DIGEST_LENGTH, infile);
661 	if (n != SHA1_DIGEST_LENGTH) {
662 		err = got_ferror(infile, GOT_ERR_FILEIDX_BAD);
663 		goto done;
664 	}
665 	SHA1Update(ctx, ie->commit_sha1, SHA1_DIGEST_LENGTH);
666 
667 	err = read_fileindex_val32(&ie->flags, ctx, infile);
668 	if (err)
669 		goto done;
670 
671 	err = read_fileindex_path(&ie->path, ctx, infile);
672 	if (err)
673 		goto done;
674 
675 	if (version >= 2) {
676 		uint32_t stage = got_fileindex_entry_stage_get(ie);
677 		if (stage == GOT_FILEIDX_STAGE_MODIFY ||
678 		    stage == GOT_FILEIDX_STAGE_ADD) {
679 			n = fread(ie->staged_blob_sha1, 1, SHA1_DIGEST_LENGTH,
680 			    infile);
681 			if (n != SHA1_DIGEST_LENGTH) {
682 				err = got_ferror(infile, GOT_ERR_FILEIDX_BAD);
683 				goto done;
684 			}
685 			SHA1Update(ctx, ie->staged_blob_sha1, SHA1_DIGEST_LENGTH);
686 		}
687 	} else {
688 		/* GOT_FILE_INDEX_VERSION 1 does not support staging. */
689 		ie->flags &= ~GOT_FILEIDX_F_STAGE;
690 	}
691 
692 done:
693 	if (err)
694 		got_fileindex_entry_free(ie);
695 	else
696 		*iep = ie;
697 	return err;
698 }
699 
700 const struct got_error *
701 got_fileindex_read(struct got_fileindex *fileindex, FILE *infile)
702 {
703 	const struct got_error *err = NULL;
704 	struct got_fileindex_hdr hdr;
705 	SHA1_CTX ctx;
706 	struct got_fileindex_entry *ie;
707 	uint8_t sha1_expected[SHA1_DIGEST_LENGTH];
708 	uint8_t sha1[SHA1_DIGEST_LENGTH];
709 	size_t n;
710 	int i;
711 
712 	SHA1Init(&ctx);
713 
714 	n = fread(&hdr.signature, 1, sizeof(hdr.signature), infile);
715 	if (n != sizeof(hdr.signature)) {
716 		if (n == 0) /* EOF */
717 			return NULL;
718 		return got_ferror(infile, GOT_ERR_FILEIDX_BAD);
719 	}
720 	n = fread(&hdr.version, 1, sizeof(hdr.version), infile);
721 	if (n != sizeof(hdr.version)) {
722 		if (n == 0) /* EOF */
723 			return NULL;
724 		return got_ferror(infile, GOT_ERR_FILEIDX_BAD);
725 	}
726 	n = fread(&hdr.nentries, 1, sizeof(hdr.nentries), infile);
727 	if (n != sizeof(hdr.nentries)) {
728 		if (n == 0) /* EOF */
729 			return NULL;
730 		return got_ferror(infile, GOT_ERR_FILEIDX_BAD);
731 	}
732 
733 	SHA1Update(&ctx, (uint8_t *)&hdr.signature, sizeof(hdr.signature));
734 	SHA1Update(&ctx, (uint8_t *)&hdr.version, sizeof(hdr.version));
735 	SHA1Update(&ctx, (uint8_t *)&hdr.nentries, sizeof(hdr.nentries));
736 
737 	hdr.signature = be32toh(hdr.signature);
738 	hdr.version = be32toh(hdr.version);
739 	hdr.nentries = be32toh(hdr.nentries);
740 
741 	if (hdr.signature != GOT_FILE_INDEX_SIGNATURE)
742 		return got_error(GOT_ERR_FILEIDX_SIG);
743 	if (hdr.version > GOT_FILE_INDEX_VERSION)
744 		return got_error(GOT_ERR_FILEIDX_VER);
745 
746 	for (i = 0; i < hdr.nentries; i++) {
747 		err = read_fileindex_entry(&ie, &ctx, infile, hdr.version);
748 		if (err)
749 			return err;
750 		err = add_entry(fileindex, ie);
751 		if (err)
752 			return err;
753 	}
754 
755 	n = fread(sha1_expected, 1, sizeof(sha1_expected), infile);
756 	if (n != sizeof(sha1_expected))
757 		return got_ferror(infile, GOT_ERR_FILEIDX_BAD);
758 	SHA1Final(sha1, &ctx);
759 	if (memcmp(sha1, sha1_expected, SHA1_DIGEST_LENGTH) != 0)
760 		return got_error(GOT_ERR_FILEIDX_CSUM);
761 
762 	return NULL;
763 }
764 
765 static struct got_fileindex_entry *
766 walk_fileindex(struct got_fileindex *fileindex, struct got_fileindex_entry *ie)
767 {
768 	struct got_fileindex_entry *next;
769 
770 	next = RB_NEXT(got_fileindex_tree, &fileindex->entries, ie);
771 
772 	/* Skip entries which were added or removed by diff callbacks. */
773 	while (next && (next->flags & (GOT_FILEIDX_F_NOT_FLUSHED |
774 	    GOT_FILEIDX_F_REMOVE_ON_FLUSH)))
775 		next = RB_NEXT(got_fileindex_tree, &fileindex->entries, next);
776 
777 	return next;
778 }
779 
780 static const struct got_error *
781 diff_fileindex_tree(struct got_fileindex *, struct got_fileindex_entry **ie,
782     struct got_tree_object *tree, const char *, const char *,
783     struct got_repository *, struct got_fileindex_diff_tree_cb *, void *);
784 
785 static const struct got_error *
786 walk_tree(struct got_tree_entry **next, struct got_fileindex *fileindex,
787     struct got_fileindex_entry **ie, struct got_tree_object *tree, int *tidx,
788     const char *path, const char *entry_name, struct got_repository *repo,
789     struct got_fileindex_diff_tree_cb *cb, void *cb_arg)
790 {
791 	const struct got_error *err = NULL;
792 	struct got_tree_entry *te = got_object_tree_get_entry(tree, *tidx);
793 
794 	if (!got_object_tree_entry_is_submodule(te) &&
795 	    S_ISDIR(got_tree_entry_get_mode(te))) {
796 		char *subpath;
797 		struct got_tree_object *subtree;
798 
799 		if (asprintf(&subpath, "%s%s%s", path,
800 		    path[0] == '\0' ? "" : "/",
801 		    got_tree_entry_get_name(te)) == -1)
802 			return got_error_from_errno("asprintf");
803 
804 		err = got_object_open_as_tree(&subtree, repo,
805 		    got_tree_entry_get_id(te));
806 		if (err) {
807 			free(subpath);
808 			return err;
809 		}
810 
811 		err = diff_fileindex_tree(fileindex, ie, subtree, subpath,
812 		    entry_name, repo, cb, cb_arg);
813 		free(subpath);
814 		got_object_tree_close(subtree);
815 		if (err)
816 			return err;
817 	}
818 
819 	(*tidx)++;
820 	*next = got_object_tree_get_entry(tree, *tidx);
821 	return NULL;
822 }
823 
824 static const struct got_error *
825 diff_fileindex_tree(struct got_fileindex *fileindex,
826     struct got_fileindex_entry **ie, struct got_tree_object *tree,
827     const char *path, const char *entry_name, struct got_repository *repo,
828     struct got_fileindex_diff_tree_cb *cb, void *cb_arg)
829 {
830 	const struct got_error *err = NULL;
831 	struct got_tree_entry *te = NULL;
832 	size_t path_len = strlen(path);
833 	struct got_fileindex_entry *next;
834 	int tidx = 0;
835 
836 	te = got_object_tree_get_entry(tree, tidx);
837 	while ((*ie && got_path_is_child((*ie)->path, path, path_len)) || te) {
838 		if (te && *ie) {
839 			char *te_path;
840 			const char *te_name = got_tree_entry_get_name(te);
841 			int cmp;
842 			if (asprintf(&te_path, "%s/%s", path, te_name) == -1) {
843 				err = got_error_from_errno("asprintf");
844 				break;
845 			}
846 			cmp = got_path_cmp((*ie)->path, te_path,
847 			    got_fileindex_entry_path_len(*ie), strlen(te_path));
848 			free(te_path);
849 			if (cmp == 0) {
850 				if (got_path_is_child((*ie)->path, path,
851 				    path_len) &&
852 				    !got_object_tree_entry_is_submodule(te) &&
853 				    (entry_name == NULL ||
854 				    strcmp(te_name, entry_name) == 0)) {
855 					err = cb->diff_old_new(cb_arg, *ie, te,
856 					    path);
857 					if (err || entry_name)
858 						break;
859 				}
860 				*ie = walk_fileindex(fileindex, *ie);
861 				err = walk_tree(&te, fileindex, ie, tree, &tidx,
862 				    path, entry_name, repo, cb, cb_arg);
863 			} else if (cmp < 0) {
864 				next = walk_fileindex(fileindex, *ie);
865 				if (got_path_is_child((*ie)->path, path,
866 				    path_len) && entry_name == NULL) {
867 					err = cb->diff_old(cb_arg, *ie, path);
868 					if (err || entry_name)
869 						break;
870 				}
871 				*ie = next;
872 			} else {
873 				if ((entry_name == NULL ||
874 				    strcmp(te_name, entry_name) == 0)) {
875 					err = cb->diff_new(cb_arg, te, path);
876 					if (err || entry_name)
877 						break;
878 				}
879 				err = walk_tree(&te, fileindex, ie, tree, &tidx,
880 				    path, entry_name, repo, cb, cb_arg);
881 			}
882 			if (err)
883 				break;
884 		} else if (*ie) {
885 			next = walk_fileindex(fileindex, *ie);
886 			if (got_path_is_child((*ie)->path, path, path_len) &&
887 			    (entry_name == NULL ||
888 			    (te && strcmp(got_tree_entry_get_name(te),
889 			    entry_name) == 0))) {
890 				err = cb->diff_old(cb_arg, *ie, path);
891 				if (err || entry_name)
892 					break;
893 			}
894 			*ie = next;
895 		} else if (te) {
896 			if (!got_object_tree_entry_is_submodule(te) &&
897 			    (entry_name == NULL ||
898 			    strcmp(got_tree_entry_get_name(te), entry_name)
899 			    == 0)) {
900 				err = cb->diff_new(cb_arg, te, path);
901 				if (err || entry_name)
902 					break;
903 			}
904 			err = walk_tree(&te, fileindex, ie, tree, &tidx, path,
905 			    entry_name, repo, cb, cb_arg);
906 			if (err)
907 				break;
908 		}
909 	}
910 
911 	return err;
912 }
913 
914 const struct got_error *
915 got_fileindex_diff_tree(struct got_fileindex *fileindex,
916     struct got_tree_object *tree, const char *path, const char *entry_name,
917     struct got_repository *repo,
918     struct got_fileindex_diff_tree_cb *cb, void *cb_arg)
919 {
920 	struct got_fileindex_entry *ie;
921 	ie = RB_MIN(got_fileindex_tree, &fileindex->entries);
922 	while (ie && !got_path_is_child(ie->path, path, strlen(path)))
923 		ie = walk_fileindex(fileindex, ie);
924 	return diff_fileindex_tree(fileindex, &ie, tree, path, entry_name, repo,
925 	    cb, cb_arg);
926 }
927 
928 static const struct got_error *
929 diff_fileindex_dir(struct got_fileindex *, struct got_fileindex_entry **,
930     struct got_pathlist_head *, int, const char *, const char *,
931     struct got_repository *, struct got_fileindex_diff_dir_cb *, void *);
932 
933 static const struct got_error *
934 read_dirlist(struct got_pathlist_head *dirlist, DIR *dir, const char *path)
935 {
936 	const struct got_error *err = NULL;
937 	struct got_pathlist_entry *new = NULL;
938 	struct dirent *dep = NULL;
939 	struct dirent *de = NULL;
940 
941 	for (;;) {
942 		de = malloc(sizeof(struct dirent) + NAME_MAX + 1);
943 		if (de == NULL) {
944 			err = got_error_from_errno("malloc");
945 			break;
946 		}
947 
948 		if (readdir_r(dir, de, &dep) != 0) {
949 			err = got_error_from_errno("readdir_r");
950 			free(de);
951 			break;
952 		}
953 		if (dep == NULL) {
954 			free(de);
955 			break;
956 		}
957 
958 		if (strcmp(de->d_name, ".") == 0 ||
959 		    strcmp(de->d_name, "..") == 0 ||
960 		    (path[0] == '\0' &&
961 		    strcmp(de->d_name, GOT_WORKTREE_GOT_DIR) == 0)) {
962 			free(de);
963 			continue;
964 		}
965 
966 		err = got_pathlist_insert(&new, dirlist, de->d_name, de);
967 		if (err) {
968 			free(de);
969 			break;
970 		}
971 		if (new == NULL) {
972 			err = got_error(GOT_ERR_DIR_DUP_ENTRY);
973 			free(de);
974 			break;
975 		}
976 	}
977 
978 	return err;
979 }
980 
981 void
982 free_dirlist(struct got_pathlist_head *dirlist)
983 {
984 	struct got_pathlist_entry *dle;
985 
986 	TAILQ_FOREACH(dle, dirlist, entry)
987 		free(dle->data);
988 	got_pathlist_free(dirlist);
989 }
990 
991 static int
992 have_tracked_file_in_dir(struct got_fileindex *fileindex, const char *path)
993 {
994 	struct got_fileindex_entry *ie;
995 	size_t path_len = strlen(path);
996 	int cmp;
997 
998 	ie = RB_ROOT(&fileindex->entries);
999 	while (ie) {
1000 		if (got_path_is_child(ie->path, path, path_len))
1001 			return 1;
1002 		cmp = got_path_cmp(path, ie->path, path_len,
1003 		    got_fileindex_entry_path_len(ie));
1004 		if (cmp < 0)
1005 			ie = RB_LEFT(ie, entry);
1006 		else if (cmp > 0)
1007 			ie = RB_RIGHT(ie, entry);
1008 		else
1009 			break;
1010 	}
1011 
1012 	return 0;
1013 }
1014 
1015 static const struct got_error *
1016 walk_dir(struct got_pathlist_entry **next, struct got_fileindex *fileindex,
1017     struct got_fileindex_entry **ie, struct got_pathlist_entry *dle, int fd,
1018     const char *path, const char *rootpath, struct got_repository *repo,
1019     int ignore, struct got_fileindex_diff_dir_cb *cb, void *cb_arg)
1020 {
1021 	const struct got_error *err = NULL;
1022 	struct dirent *de = dle->data;
1023 	DIR *subdir = NULL;
1024 	int subdirfd = -1;
1025 	int type;
1026 
1027 	*next = NULL;
1028 
1029 	if (de->d_type == DT_UNKNOWN) {
1030 		/* Occurs on NFS mounts without "readdir plus" RPC. */
1031 		char *dir_path;
1032 		if (asprintf(&dir_path, "%s/%s", rootpath, path) == -1)
1033 			return got_error_from_errno("asprintf");
1034 		err = got_path_dirent_type(&type, dir_path, de);
1035 		free(dir_path);
1036 		if (err)
1037 			return err;
1038 	} else
1039 		type = de->d_type;
1040 
1041 	/* Must traverse ignored directories if they contain tracked files. */
1042 	if (type == DT_DIR && ignore &&
1043 	    have_tracked_file_in_dir(fileindex, path))
1044 		ignore = 0;
1045 
1046 	if (type == DT_DIR && !ignore) {
1047 		char *subpath;
1048 		char *subdirpath;
1049 		struct got_pathlist_head subdirlist;
1050 
1051 		TAILQ_INIT(&subdirlist);
1052 
1053 		if (asprintf(&subpath, "%s%s%s", path,
1054 		    path[0] == '\0' ? "" : "/", de->d_name) == -1)
1055 			return got_error_from_errno("asprintf");
1056 
1057 		if (asprintf(&subdirpath, "%s/%s", rootpath, subpath) == -1) {
1058 			free(subpath);
1059 			return got_error_from_errno("asprintf");
1060 		}
1061 
1062 		subdirfd = openat(fd, de->d_name,
1063 		    O_RDONLY | O_NOFOLLOW | O_DIRECTORY | O_CLOEXEC);
1064 		if (subdirfd == -1) {
1065 			if (errno == EACCES) {
1066 				*next = TAILQ_NEXT(dle, entry);
1067 				return NULL;
1068 			}
1069 			err = got_error_from_errno2("openat", subdirpath);
1070 			free(subpath);
1071 			free(subdirpath);
1072 			return err;
1073 		}
1074 
1075 		subdir = fdopendir(subdirfd);
1076 		if (subdir == NULL)
1077 			return got_error_from_errno2("fdopendir", path);
1078 		subdirfd = -1;
1079 		err = read_dirlist(&subdirlist, subdir, subdirpath);
1080 		if (err) {
1081 			free(subpath);
1082 			free(subdirpath);
1083 			closedir(subdir);
1084 			return err;
1085 		}
1086 		err = diff_fileindex_dir(fileindex, ie, &subdirlist,
1087 		    dirfd(subdir), rootpath, subpath, repo, cb, cb_arg);
1088 		if (subdir && closedir(subdir) == -1 && err == NULL)
1089 			err = got_error_from_errno2("closedir", subdirpath);
1090 		free(subpath);
1091 		free(subdirpath);
1092 		free_dirlist(&subdirlist);
1093 		if (err)
1094 			return err;
1095 	}
1096 
1097 	*next = TAILQ_NEXT(dle, entry);
1098 	return NULL;
1099 }
1100 
1101 static const struct got_error *
1102 diff_fileindex_dir(struct got_fileindex *fileindex,
1103     struct got_fileindex_entry **ie, struct got_pathlist_head *dirlist,
1104     int dirfd, const char *rootpath, const char *path,
1105     struct got_repository *repo,
1106     struct got_fileindex_diff_dir_cb *cb, void *cb_arg)
1107 {
1108 	const struct got_error *err = NULL;
1109 	struct dirent *de = NULL;
1110 	size_t path_len = strlen(path);
1111 	struct got_pathlist_entry *dle;
1112 	int ignore;
1113 
1114 	if (cb->diff_traverse) {
1115 		err = cb->diff_traverse(cb_arg, path, dirfd);
1116 		if (err)
1117 			return err;
1118 	}
1119 
1120 	dle = TAILQ_FIRST(dirlist);
1121 	while ((*ie && got_path_is_child((*ie)->path, path, path_len)) || dle) {
1122 		if (dle && *ie) {
1123 			char *de_path;
1124 			int cmp;
1125 			de = dle->data;
1126 			if (asprintf(&de_path, "%s/%s", path,
1127 			    de->d_name) == -1) {
1128 				err = got_error_from_errno("asprintf");
1129 				break;
1130 			}
1131 			cmp = got_path_cmp((*ie)->path, de_path,
1132 			    got_fileindex_entry_path_len(*ie),
1133 			    strlen(path) + 1 + de->d_namlen);
1134 			free(de_path);
1135 			if (cmp == 0) {
1136 				err = cb->diff_old_new(cb_arg, *ie, de, path,
1137 				    dirfd);
1138 				if (err)
1139 					break;
1140 				*ie = walk_fileindex(fileindex, *ie);
1141 				err = walk_dir(&dle, fileindex, ie, dle, dirfd,
1142 				    path, rootpath, repo, 0, cb, cb_arg);
1143 			} else if (cmp < 0 ) {
1144 				err = cb->diff_old(cb_arg, *ie, path);
1145 				if (err)
1146 					break;
1147 				*ie = walk_fileindex(fileindex, *ie);
1148 			} else {
1149 				err = cb->diff_new(&ignore, cb_arg, de, path,
1150 				    dirfd);
1151 				if (err)
1152 					break;
1153 				err = walk_dir(&dle, fileindex, ie, dle, dirfd,
1154 				    path, rootpath, repo, ignore, cb, cb_arg);
1155 			}
1156 			if (err)
1157 				break;
1158 		} else if (*ie) {
1159 			err = cb->diff_old(cb_arg, *ie, path);
1160 			if (err)
1161 				break;
1162 			*ie = walk_fileindex(fileindex, *ie);
1163 		} else if (dle) {
1164 			de = dle->data;
1165 			err = cb->diff_new(&ignore, cb_arg, de, path, dirfd);
1166 			if (err)
1167 				break;
1168 			err = walk_dir(&dle, fileindex, ie, dle, dirfd, path,
1169 			    rootpath, repo, ignore, cb, cb_arg);
1170 			if (err)
1171 				break;
1172 		}
1173 	}
1174 
1175 	return err;
1176 }
1177 
1178 const struct got_error *
1179 got_fileindex_diff_dir(struct got_fileindex *fileindex, int fd,
1180     const char *rootpath, const char *path, struct got_repository *repo,
1181     struct got_fileindex_diff_dir_cb *cb, void *cb_arg)
1182 {
1183 	const struct got_error *err;
1184 	struct got_fileindex_entry *ie;
1185 	struct got_pathlist_head dirlist;
1186 	int fd2;
1187 	DIR *dir;
1188 
1189 	TAILQ_INIT(&dirlist);
1190 
1191 	/* 
1192 	 * Duplicate the file descriptor so we can call closedir() below
1193 	 * without closing the file descriptor passed in by our caller.
1194 	 */
1195 	fd2 = dup(fd);
1196 	if (fd2 == -1)
1197 		return got_error_from_errno2("dup", path);
1198 	if (lseek(fd2, 0, SEEK_SET) == -1) {
1199 		err = got_error_from_errno2("lseek", path);
1200 		close(fd2);
1201 		return err;
1202 	}
1203 	dir = fdopendir(fd2);
1204 	if (dir == NULL) {
1205 		err = got_error_from_errno2("fdopendir", path);
1206 		close(fd2);
1207 		return err;
1208 	}
1209 	err = read_dirlist(&dirlist, dir, path);
1210 	if (err) {
1211 		closedir(dir);
1212 		return err;
1213 	}
1214 
1215 	ie = RB_MIN(got_fileindex_tree, &fileindex->entries);
1216 	while (ie && !got_path_is_child(ie->path, path, strlen(path)))
1217 		ie = walk_fileindex(fileindex, ie);
1218 	err = diff_fileindex_dir(fileindex, &ie, &dirlist, dirfd(dir),
1219 	    rootpath, path, repo, cb, cb_arg);
1220 
1221 	if (closedir(dir) == -1 && err == NULL)
1222 		err = got_error_from_errno2("closedir", path);
1223 	free_dirlist(&dirlist);
1224 	return err;
1225 }
1226 
1227 RB_GENERATE(got_fileindex_tree, got_fileindex_entry, entry, got_fileindex_cmp);