1 /*
2  * Copyright (c) 2020 Ori Bernstein
3  * Copyright (c) 2021 Stefan Sperling <stsp@openbsd.org>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 #include <sys/types.h>
19 #include <sys/queue.h>
20 #include <sys/tree.h>
21 #include <sys/uio.h>
22 #include <sys/stat.h>
23 #include <sys/time.h>
24 #include <sys/mman.h>
25 
26 #include <endian.h>
27 #include <errno.h>
28 #include <stdint.h>
29 #include <imsg.h>
30 #include <inttypes.h>
31 #include <poll.h>
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <string.h>
35 #include <sha1.h>
36 #include <time.h>
37 #include <unistd.h>
38 #include <limits.h>
39 #include <zlib.h>
40 
41 #include "got_error.h"
42 #include "got_cancel.h"
43 #include "got_object.h"
44 #include "got_path.h"
45 #include "got_reference.h"
46 #include "got_repository_admin.h"
47 
48 #include "got_lib_deltify.h"
49 #include "got_lib_delta.h"
50 #include "got_lib_object.h"
51 #include "got_lib_object_idset.h"
52 #include "got_lib_object_cache.h"
53 #include "got_lib_deflate.h"
54 #include "got_lib_ratelimit.h"
55 #include "got_lib_pack.h"
56 #include "got_lib_pack_create.h"
57 #include "got_lib_repository.h"
58 #include "got_lib_inflate.h"
59 #include "got_lib_poll.h"
60 
61 #include "murmurhash2.h"
62 
63 #ifndef MIN
64 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
65 #endif
66 
67 #ifndef MAX
68 #define	MAX(_a,_b) ((_a) > (_b) ? (_a) : (_b))
69 #endif
70 
71 #ifndef nitems
72 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
73 #endif
74 
75 static const struct got_error *
76 alloc_meta(struct got_pack_meta **new, struct got_object_id *id,
77     const char *path, int obj_type, time_t mtime, uint32_t seed)
78 {
79 	struct got_pack_meta *m;
80 
81 	*new = NULL;
82 
83 	m = calloc(1, sizeof(*m));
84 	if (m == NULL)
85 		return got_error_from_errno("calloc");
86 
87 	memcpy(&m->id, id, sizeof(m->id));
88 
89 	m->path_hash = murmurhash2(path, strlen(path), seed);
90 	m->obj_type = obj_type;
91 	m->mtime = mtime;
92 	*new = m;
93 	return NULL;
94 }
95 
96 static void
97 clear_meta(struct got_pack_meta *meta)
98 {
99 	if (meta == NULL)
100 		return;
101 	meta->path_hash = 0;
102 	free(meta->delta_buf);
103 	meta->delta_buf = NULL;
104 	free(meta->base_obj_id);
105 	meta->base_obj_id = NULL;
106 	meta->reused_delta_offset = 0;
107 }
108 
109 static void
110 free_nmeta(struct got_pack_meta **meta, int nmeta)
111 {
112 	int i;
113 
114 	for (i = 0; i < nmeta; i++)
115 		clear_meta(meta[i]);
116 	free(meta);
117 }
118 
119 static int
120 delta_order_cmp(const void *pa, const void *pb)
121 {
122 	struct got_pack_meta *a, *b;
123 
124 	a = *(struct got_pack_meta **)pa;
125 	b = *(struct got_pack_meta **)pb;
126 
127 	if (a->obj_type != b->obj_type)
128 		return a->obj_type - b->obj_type;
129 	if (a->path_hash < b->path_hash)
130 		return -1;
131 	if (a->path_hash > b->path_hash)
132 		return 1;
133 	if (a->mtime < b->mtime)
134 		return -1;
135 	if (a->mtime > b->mtime)
136 		return 1;
137 	return got_object_id_cmp(&a->id, &b->id);
138 }
139 
140 static off_t
141 delta_size(struct got_delta_instruction *deltas, int ndeltas)
142 {
143 	int i;
144 	off_t size = 32;
145 	for (i = 0; i < ndeltas; i++) {
146 		if (deltas[i].copy)
147 			size += GOT_DELTA_SIZE_SHIFT;
148 		else
149 			size += deltas[i].len + 1;
150 	}
151 	return size;
152 }
153 
154 static const struct got_error *
155 append(unsigned char **p, size_t *len, off_t *sz, void *seg, int nseg)
156 {
157 	char *n;
158 
159 	if (*len + nseg >= *sz) {
160 		while (*len + nseg >= *sz)
161 			*sz += *sz / 2;
162 		n = realloc(*p, *sz);
163 		if (n == NULL)
164 			return got_error_from_errno("realloc");
165 		*p = n;
166 	}
167 	memcpy(*p + *len, seg, nseg);
168 	*len += nseg;
169 	return NULL;
170 }
171 
172 static const struct got_error *
173 encode_delta_in_mem(struct got_pack_meta *m, struct got_raw_object *o,
174     struct got_delta_instruction *deltas, int ndeltas,
175     off_t delta_size, off_t base_size)
176 {
177 	const struct got_error *err;
178 	unsigned char buf[16], *bp;
179 	int i, j;
180 	size_t len = 0, compressed_len;
181 	off_t bufsize = delta_size;
182 	off_t n;
183 	struct got_delta_instruction *d;
184 	uint8_t *delta_buf;
185 
186 	delta_buf = malloc(bufsize);
187 	if (delta_buf == NULL)
188 		return got_error_from_errno("malloc");
189 
190 	/* base object size */
191 	buf[0] = base_size & GOT_DELTA_SIZE_VAL_MASK;
192 	n = base_size >> GOT_DELTA_SIZE_SHIFT;
193 	for (i = 1; n > 0; i++) {
194 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
195 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
196 		n >>= GOT_DELTA_SIZE_SHIFT;
197 	}
198 	err = append(&delta_buf, &len, &bufsize, buf, i);
199 	if (err)
200 		goto done;
201 
202 	/* target object size */
203 	buf[0] = o->size & GOT_DELTA_SIZE_VAL_MASK;
204 	n = o->size >> GOT_DELTA_SIZE_SHIFT;
205 	for (i = 1; n > 0; i++) {
206 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
207 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
208 		n >>= GOT_DELTA_SIZE_SHIFT;
209 	}
210 	err = append(&delta_buf, &len, &bufsize, buf, i);
211 	if (err)
212 		goto done;
213 
214 	for (j = 0; j < ndeltas; j++) {
215 		d = &deltas[j];
216 		if (d->copy) {
217 			n = d->offset;
218 			bp = &buf[1];
219 			buf[0] = GOT_DELTA_BASE_COPY;
220 			for (i = 0; i < 4; i++) {
221 				/* DELTA_COPY_OFF1 ... DELTA_COPY_OFF4 */
222 				buf[0] |= 1 << i;
223 				*bp++ = n & 0xff;
224 				n >>= 8;
225 				if (n == 0)
226 					break;
227 			}
228 
229 			n = d->len;
230 			if (n != GOT_DELTA_COPY_DEFAULT_LEN) {
231 				/* DELTA_COPY_LEN1 ... DELTA_COPY_LEN3 */
232 				for (i = 0; i < 3 && n > 0; i++) {
233 					buf[0] |= 1 << (i + 4);
234 					*bp++ = n & 0xff;
235 					n >>= 8;
236 				}
237 			}
238 			err = append(&delta_buf, &len, &bufsize,
239 			    buf, bp - buf);
240 			if (err)
241 				goto done;
242 		} else if (o->f == NULL) {
243 			n = 0;
244 			while (n != d->len) {
245 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
246 				err = append(&delta_buf, &len, &bufsize,
247 				    buf, 1);
248 				if (err)
249 					goto done;
250 				err = append(&delta_buf, &len, &bufsize,
251 				    o->data + o->hdrlen + d->offset + n,
252 				    buf[0]);
253 				if (err)
254 					goto done;
255 				n += buf[0];
256 			}
257 		} else {
258 			char content[128];
259 			size_t r;
260 			if (fseeko(o->f, o->hdrlen + d->offset, SEEK_SET) == -1) {
261 				err = got_error_from_errno("fseeko");
262 				goto done;
263 			}
264 			n = 0;
265 			while (n != d->len) {
266 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
267 				err = append(&delta_buf, &len, &bufsize,
268 				    buf, 1);
269 				if (err)
270 					goto done;
271 				r = fread(content, 1, buf[0], o->f);
272 				if (r != buf[0]) {
273 					err = got_ferror(o->f, GOT_ERR_IO);
274 					goto done;
275 				}
276 				err = append(&delta_buf, &len, &bufsize,
277 				    content, buf[0]);
278 				if (err)
279 					goto done;
280 				n += buf[0];
281 			}
282 		}
283 	}
284 
285 	err = got_deflate_to_mem_mmap(&m->delta_buf, &compressed_len,
286 	    NULL, NULL, delta_buf, 0, len);
287 	if (err)
288 		goto done;
289 
290 	m->delta_len = len;
291 	m->delta_compressed_len = compressed_len;
292 done:
293 	free(delta_buf);
294 	return err;
295 }
296 
297 static const struct got_error *
298 encode_delta(struct got_pack_meta *m, struct got_raw_object *o,
299     struct got_delta_instruction *deltas, int ndeltas,
300     off_t base_size, FILE *f)
301 {
302 	const struct got_error *err;
303 	unsigned char buf[16], *bp;
304 	int i, j;
305 	off_t n;
306 	struct got_deflate_buf zb;
307 	struct got_delta_instruction *d;
308 	off_t delta_len = 0, compressed_len = 0;
309 
310 	err = got_deflate_init(&zb, NULL, GOT_DEFLATE_BUFSIZE);
311 	if (err)
312 		return err;
313 
314 	/* base object size */
315 	buf[0] = base_size & GOT_DELTA_SIZE_VAL_MASK;
316 	n = base_size >> GOT_DELTA_SIZE_SHIFT;
317 	for (i = 1; n > 0; i++) {
318 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
319 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
320 		n >>= GOT_DELTA_SIZE_SHIFT;
321 	}
322 
323 	err = got_deflate_append_to_file_mmap(&zb, &compressed_len,
324 	    buf, 0, i, f, NULL);
325 	if (err)
326 		goto done;
327 	delta_len += i;
328 
329 	/* target object size */
330 	buf[0] = o->size & GOT_DELTA_SIZE_VAL_MASK;
331 	n = o->size >> GOT_DELTA_SIZE_SHIFT;
332 	for (i = 1; n > 0; i++) {
333 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
334 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
335 		n >>= GOT_DELTA_SIZE_SHIFT;
336 	}
337 
338 	err = got_deflate_append_to_file_mmap(&zb, &compressed_len,
339 	    buf, 0, i, f, NULL);
340 	if (err)
341 		goto done;
342 	delta_len += i;
343 
344 	for (j = 0; j < ndeltas; j++) {
345 		d = &deltas[j];
346 		if (d->copy) {
347 			n = d->offset;
348 			bp = &buf[1];
349 			buf[0] = GOT_DELTA_BASE_COPY;
350 			for (i = 0; i < 4; i++) {
351 				/* DELTA_COPY_OFF1 ... DELTA_COPY_OFF4 */
352 				buf[0] |= 1 << i;
353 				*bp++ = n & 0xff;
354 				n >>= 8;
355 				if (n == 0)
356 					break;
357 			}
358 			n = d->len;
359 			if (n != GOT_DELTA_COPY_DEFAULT_LEN) {
360 				/* DELTA_COPY_LEN1 ... DELTA_COPY_LEN3 */
361 				for (i = 0; i < 3 && n > 0; i++) {
362 					buf[0] |= 1 << (i + 4);
363 					*bp++ = n & 0xff;
364 					n >>= 8;
365 				}
366 			}
367 			err = got_deflate_append_to_file_mmap(&zb,
368 			    &compressed_len, buf, 0, bp - buf, f, NULL);
369 			if (err)
370 				goto done;
371 			delta_len += (bp - buf);
372 		} else if (o->f == NULL) {
373 			n = 0;
374 			while (n != d->len) {
375 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
376 				err = got_deflate_append_to_file_mmap(&zb,
377 				    &compressed_len, buf, 0, 1, f, NULL);
378 				if (err)
379 					goto done;
380 				delta_len++;
381 				err = got_deflate_append_to_file_mmap(&zb,
382 				    &compressed_len,
383 				    o->data + o->hdrlen + d->offset + n, 0,
384 				    buf[0], f, NULL);
385 				if (err)
386 					goto done;
387 				delta_len += buf[0];
388 				n += buf[0];
389 			}
390 		} else {
391 			char content[128];
392 			size_t r;
393 			if (fseeko(o->f, o->hdrlen + d->offset, SEEK_SET) == -1) {
394 				err = got_error_from_errno("fseeko");
395 				goto done;
396 			}
397 			n = 0;
398 			while (n != d->len) {
399 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
400 				err = got_deflate_append_to_file_mmap(&zb,
401 				    &compressed_len, buf, 0, 1, f, NULL);
402 				if (err)
403 					goto done;
404 				delta_len++;
405 				r = fread(content, 1, buf[0], o->f);
406 				if (r != buf[0]) {
407 					err = got_ferror(o->f, GOT_ERR_IO);
408 					goto done;
409 				}
410 				err = got_deflate_append_to_file_mmap(&zb,
411 				    &compressed_len, content, 0, buf[0], f,
412 				    NULL);
413 				if (err)
414 					goto done;
415 				delta_len += buf[0];
416 				n += buf[0];
417 			}
418 		}
419 	}
420 
421 	err = got_deflate_flush(&zb, f, NULL, &compressed_len);
422 	if (err)
423 		goto done;
424 
425 	/* sanity check */
426 	if (compressed_len != ftello(f) - m->delta_offset) {
427 		err = got_error(GOT_ERR_COMPRESSION);
428 		goto done;
429 	}
430 
431 	m->delta_len = delta_len;
432 	m->delta_compressed_len = compressed_len;
433 done:
434 	got_deflate_end(&zb);
435 	return err;
436 }
437 
438 const struct got_error *
439 got_pack_report_progress(got_pack_progress_cb progress_cb, void *progress_arg,
440     struct got_ratelimit *rl, int ncolored, int nfound, int ntrees,
441     off_t packfile_size, int ncommits, int nobj_total, int obj_deltify,
442     int nobj_written)
443 {
444 	const struct got_error *err;
445 	int elapsed;
446 
447 	if (progress_cb == NULL)
448 		return NULL;
449 
450 	err = got_ratelimit_check(&elapsed, rl);
451 	if (err || !elapsed)
452 		return err;
453 
454 	return progress_cb(progress_arg, ncolored, nfound, ntrees,
455 	    packfile_size, ncommits, nobj_total, obj_deltify, nobj_written);
456 }
457 
458 const struct got_error *
459 got_pack_add_meta(struct got_pack_meta *m, struct got_pack_metavec *v)
460 {
461 	if (v->nmeta == v->metasz){
462 		size_t newsize = 2 * v->metasz;
463 		struct got_pack_meta **new;
464 		new = reallocarray(v->meta, newsize, sizeof(*new));
465 		if (new == NULL)
466 			return got_error_from_errno("reallocarray");
467 		v->meta = new;
468 		v->metasz = newsize;
469 	}
470 
471 	v->meta[v->nmeta++] = m;
472 	return NULL;
473 }
474 
475 const struct got_error *
476 got_pack_find_pack_for_reuse(struct got_packidx **best_packidx,
477     struct got_repository *repo)
478 {
479 	const struct got_error *err = NULL;
480 	struct got_pathlist_entry *pe;
481 	const char *best_packidx_path = NULL;
482 	int nobj_max = 0;
483 
484 	*best_packidx = NULL;
485 
486 	TAILQ_FOREACH(pe, &repo->packidx_paths, entry) {
487 		const char *path_packidx = pe->path;
488 		struct got_packidx *packidx;
489 		int nobj;
490 
491 		err = got_repo_get_packidx(&packidx, path_packidx, repo);
492 		if (err)
493 			break;
494 
495 		nobj = be32toh(packidx->hdr.fanout_table[0xff]);
496 		if (nobj > nobj_max) {
497 			best_packidx_path = path_packidx;
498 			nobj_max = nobj;
499 		}
500 	}
501 
502 	if (best_packidx_path) {
503 		err = got_repo_get_packidx(best_packidx, best_packidx_path,
504 		    repo);
505 	}
506 
507 	return err;
508 }
509 
510 const struct got_error *
511 got_pack_cache_pack_for_packidx(struct got_pack **pack,
512     struct got_packidx *packidx, struct got_repository *repo)
513 {
514 	const struct got_error *err;
515 	char *path_packfile = NULL;
516 
517 	err = got_packidx_get_packfile_path(&path_packfile,
518 	    packidx->path_packidx);
519 	if (err)
520 		return err;
521 
522 	*pack = got_repo_get_cached_pack(repo, path_packfile);
523 	if (*pack == NULL) {
524 		err = got_repo_cache_pack(pack, repo, path_packfile, packidx);
525 		if (err)
526 			goto done;
527 	}
528 done:
529 	free(path_packfile);
530 	return err;
531 }
532 
533 static const struct got_error *
534 pick_deltas(struct got_pack_meta **meta, int nmeta, int ncolored,
535     int nfound, int ntrees, int ncommits, int nreused, FILE *delta_cache,
536     struct got_repository *repo,
537     got_pack_progress_cb progress_cb, void *progress_arg,
538     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
539 {
540 	const struct got_error *err = NULL;
541 	struct got_pack_meta *m = NULL, *base = NULL;
542 	struct got_raw_object *raw = NULL, *base_raw = NULL;
543 	struct got_delta_instruction *deltas = NULL, *best_deltas = NULL;
544 	int i, j, ndeltas, best_ndeltas;
545 	off_t size, best_size;
546 	const int max_base_candidates = 3;
547 	size_t delta_memsize = 0;
548 	const size_t max_delta_memsize = 4 * GOT_DELTA_RESULT_SIZE_CACHED_MAX;
549 	int outfd = -1;
550 	uint32_t delta_seed;
551 
552 	delta_seed = arc4random();
553 
554 	qsort(meta, nmeta, sizeof(struct got_pack_meta *), delta_order_cmp);
555 	for (i = 0; i < nmeta; i++) {
556 		if (cancel_cb) {
557 			err = (*cancel_cb)(cancel_arg);
558 			if (err)
559 				break;
560 		}
561 		err = got_pack_report_progress(progress_cb, progress_arg, rl,
562 		    ncolored, nfound, ntrees, 0L, ncommits, nreused + nmeta,
563 		    nreused + i, 0);
564 		if (err)
565 			goto done;
566 		m = meta[i];
567 
568 		if (m->obj_type == GOT_OBJ_TYPE_COMMIT ||
569 		    m->obj_type == GOT_OBJ_TYPE_TAG)
570 			continue;
571 
572 		err = got_object_raw_open(&raw, &outfd, repo, &m->id);
573 		if (err)
574 			goto done;
575 		m->size = raw->size;
576 
577 		if (raw->f == NULL) {
578 			err = got_deltify_init_mem(&m->dtab, raw->data,
579 			    raw->hdrlen, raw->size + raw->hdrlen, delta_seed);
580 		} else {
581 			err = got_deltify_init(&m->dtab, raw->f, raw->hdrlen,
582 			    raw->size + raw->hdrlen, delta_seed);
583 		}
584 		if (err)
585 			goto done;
586 
587 		if (i > max_base_candidates) {
588 			struct got_pack_meta *n = NULL;
589 			n = meta[i - (max_base_candidates + 1)];
590 			got_deltify_free(n->dtab);
591 			n->dtab = NULL;
592 		}
593 
594 		best_size = raw->size;
595 		best_ndeltas = 0;
596 		for (j = MAX(0, i - max_base_candidates); j < i; j++) {
597 			if (cancel_cb) {
598 				err = (*cancel_cb)(cancel_arg);
599 				if (err)
600 					goto done;
601 			}
602 			base = meta[j];
603 			/* long chains make unpacking slow, avoid such bases */
604 			if (base->nchain >= 128 ||
605 			    base->obj_type != m->obj_type)
606 				continue;
607 
608 			err = got_object_raw_open(&base_raw, &outfd, repo,
609 			    &base->id);
610 			if (err)
611 				goto done;
612 
613 			if (raw->f == NULL && base_raw->f == NULL) {
614 				err = got_deltify_mem_mem(&deltas, &ndeltas,
615 				    raw->data, raw->hdrlen,
616 				    raw->size + raw->hdrlen, delta_seed,
617 				    base->dtab, base_raw->data,
618 				    base_raw->hdrlen,
619 				    base_raw->size + base_raw->hdrlen);
620 			} else if (raw->f == NULL) {
621 				err = got_deltify_mem_file(&deltas, &ndeltas,
622 				    raw->data, raw->hdrlen,
623 				    raw->size + raw->hdrlen, delta_seed,
624 				    base->dtab, base_raw->f,
625 				    base_raw->hdrlen,
626 				    base_raw->size + base_raw->hdrlen);
627 			} else if (base_raw->f == NULL) {
628 				err = got_deltify_file_mem(&deltas, &ndeltas,
629 				    raw->f, raw->hdrlen,
630 				    raw->size + raw->hdrlen, delta_seed,
631 				    base->dtab, base_raw->data,
632 				    base_raw->hdrlen,
633 				    base_raw->size + base_raw->hdrlen);
634 			} else {
635 				err = got_deltify(&deltas, &ndeltas,
636 				    raw->f, raw->hdrlen,
637 				    raw->size + raw->hdrlen, delta_seed,
638 				    base->dtab, base_raw->f, base_raw->hdrlen,
639 				    base_raw->size + base_raw->hdrlen);
640 			}
641 			got_object_raw_close(base_raw);
642 			base_raw = NULL;
643 			if (err)
644 				goto done;
645 
646 			size = delta_size(deltas, ndeltas);
647 			if (size + 32 < best_size){
648 				/*
649 				 * if we already picked a best delta,
650 				 * replace it.
651 				 */
652 				best_size = size;
653 				free(best_deltas);
654 				best_deltas = deltas;
655 				best_ndeltas = ndeltas;
656 				deltas = NULL;
657 				m->nchain = base->nchain + 1;
658 				m->prev = base;
659 				m->head = base->head;
660 				if (m->head == NULL)
661 					m->head = base;
662 			} else {
663 				free(deltas);
664 				deltas = NULL;
665 				ndeltas = 0;
666 			}
667 		}
668 
669 		if (best_ndeltas > 0) {
670 			if (best_size <= GOT_DELTA_RESULT_SIZE_CACHED_MAX &&
671 			    delta_memsize + best_size <= max_delta_memsize) {
672 				delta_memsize += best_size;
673 				err = encode_delta_in_mem(m, raw, best_deltas,
674 				    best_ndeltas, best_size, m->prev->size);
675 			} else {
676 				m->delta_offset = ftello(delta_cache);
677 				err = encode_delta(m, raw, best_deltas,
678 				    best_ndeltas, m->prev->size, delta_cache);
679 			}
680 			free(best_deltas);
681 			best_deltas = NULL;
682 			best_ndeltas = 0;
683 			if (err)
684 				goto done;
685 		}
686 
687 		got_object_raw_close(raw);
688 		raw = NULL;
689 	}
690 done:
691 	for (i = MAX(0, nmeta - max_base_candidates); i < nmeta; i++) {
692 		got_deltify_free(meta[i]->dtab);
693 		meta[i]->dtab = NULL;
694 	}
695 	if (raw)
696 		got_object_raw_close(raw);
697 	if (base_raw)
698 		got_object_raw_close(base_raw);
699 	if (outfd != -1 && close(outfd) == -1 && err == NULL)
700 		err = got_error_from_errno("close");
701 	free(deltas);
702 	free(best_deltas);
703 	return err;
704 }
705 
706 static const struct got_error *
707 search_packidx(int *found, struct got_object_id *id,
708     struct got_repository *repo)
709 {
710 	const struct got_error *err = NULL;
711 	struct got_packidx *packidx = NULL;
712 	int idx;
713 
714 	*found = 0;
715 
716 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
717 	if (err == NULL)
718 		*found = 1; /* object is already packed */
719 	else if (err->code == GOT_ERR_NO_OBJ)
720 		err = NULL;
721 	return err;
722 }
723 
724 const struct got_error *
725 got_pack_add_object(int want_meta, struct got_object_idset *idset,
726     struct got_object_id *id, const char *path, int obj_type,
727     time_t mtime, uint32_t seed, int loose_obj_only,
728     struct got_repository *repo, int *ncolored, int *nfound, int *ntrees,
729     got_pack_progress_cb progress_cb, void *progress_arg,
730     struct got_ratelimit *rl)
731 {
732 	const struct got_error *err;
733 	struct got_pack_meta *m = NULL;
734 
735 	if (loose_obj_only) {
736 		int is_packed;
737 		err = search_packidx(&is_packed, id, repo);
738 		if (err)
739 			return err;
740 		if (is_packed && want_meta)
741 			return NULL;
742 	}
743 
744 	if (want_meta) {
745 		err = alloc_meta(&m, id, path, obj_type, mtime, seed);
746 		if (err)
747 			return err;
748 
749 		(*nfound)++;
750 		err = got_pack_report_progress(progress_cb, progress_arg, rl,
751 		    *ncolored, *nfound, *ntrees, 0L, 0, 0, 0, 0);
752 		if (err) {
753 			clear_meta(m);
754 			free(m);
755 			return err;
756 		}
757 	}
758 
759 	err = got_object_idset_add(idset, id, m);
760 	if (err) {
761 		clear_meta(m);
762 		free(m);
763 	}
764 	return err;
765 }
766 
767 const struct got_error *
768 got_pack_load_tree_entries(struct got_object_id_queue *ids, int want_meta,
769     struct got_object_idset *idset, struct got_object_idset *idset_exclude,
770     struct got_tree_object *tree,
771     const char *dpath, time_t mtime, uint32_t seed, struct got_repository *repo,
772     int loose_obj_only, int *ncolored, int *nfound, int *ntrees,
773     got_pack_progress_cb progress_cb, void *progress_arg,
774     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
775 {
776 	const struct got_error *err;
777 	char *p = NULL;
778 	int i;
779 
780 	(*ntrees)++;
781 	err = got_pack_report_progress(progress_cb, progress_arg, rl,
782 	    *ncolored, *nfound, *ntrees, 0L, 0, 0, 0, 0);
783 	if (err)
784 		return err;
785 
786 	for (i = 0; i < got_object_tree_get_nentries(tree); i++) {
787 		struct got_tree_entry *e = got_object_tree_get_entry(tree, i);
788 		struct got_object_id *id = got_tree_entry_get_id(e);
789 		mode_t mode = got_tree_entry_get_mode(e);
790 
791 		if (cancel_cb) {
792 			err = (*cancel_cb)(cancel_arg);
793 			if (err)
794 				break;
795 		}
796 
797 		if (got_object_tree_entry_is_submodule(e) ||
798 		    got_object_idset_contains(idset, id) ||
799 		    got_object_idset_contains(idset_exclude, id))
800 			continue;
801 
802 		/*
803 		 * If got-read-pack is crawling trees for us then
804 		 * we are only here to collect blob IDs.
805 		 */
806 		if (ids == NULL && S_ISDIR(mode))
807 			continue;
808 
809 		if (asprintf(&p, "%s%s%s", dpath,
810 		    got_path_is_root_dir(dpath) ? "" : "/",
811 		    got_tree_entry_get_name(e)) == -1) {
812 			err = got_error_from_errno("asprintf");
813 			break;
814 		}
815 
816 		if (S_ISDIR(mode)) {
817 			struct got_object_qid *qid;
818 			err = got_object_qid_alloc(&qid, id);
819 			if (err)
820 				break;
821 			qid->data = p;
822 			p = NULL;
823 			STAILQ_INSERT_TAIL(ids, qid, entry);
824 		} else if (S_ISREG(mode) || S_ISLNK(mode)) {
825 			err = got_pack_add_object(want_meta,
826 			    want_meta ? idset : idset_exclude, id, p,
827 			    GOT_OBJ_TYPE_BLOB, mtime, seed, loose_obj_only,
828 			    repo, ncolored, nfound, ntrees,
829 			    progress_cb, progress_arg, rl);
830 			if (err)
831 				break;
832 			free(p);
833 			p = NULL;
834 		} else {
835 			free(p);
836 			p = NULL;
837 		}
838 	}
839 
840 	free(p);
841 	return err;
842 }
843 
844 const struct got_error *
845 got_pack_load_tree(int want_meta, struct got_object_idset *idset,
846     struct got_object_idset *idset_exclude,
847     struct got_object_id *tree_id, const char *dpath, time_t mtime,
848     uint32_t seed, struct got_repository *repo, int loose_obj_only,
849     int *ncolored, int *nfound, int *ntrees,
850     got_pack_progress_cb progress_cb, void *progress_arg,
851     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
852 {
853 	const struct got_error *err = NULL;
854 	struct got_object_id_queue tree_ids;
855 	struct got_object_qid *qid;
856 	struct got_tree_object *tree = NULL;
857 
858 	if (got_object_idset_contains(idset, tree_id) ||
859 	    got_object_idset_contains(idset_exclude, tree_id))
860 		return NULL;
861 
862 	err = got_object_qid_alloc(&qid, tree_id);
863 	if (err)
864 		return err;
865 	qid->data = strdup(dpath);
866 	if (qid->data == NULL) {
867 		err = got_error_from_errno("strdup");
868 		got_object_qid_free(qid);
869 		return err;
870 	}
871 
872 	STAILQ_INIT(&tree_ids);
873 	STAILQ_INSERT_TAIL(&tree_ids, qid, entry);
874 
875 	while (!STAILQ_EMPTY(&tree_ids)) {
876 		const char *path;
877 		if (cancel_cb) {
878 			err = (*cancel_cb)(cancel_arg);
879 			if (err)
880 				break;
881 		}
882 
883 		qid = STAILQ_FIRST(&tree_ids);
884 		STAILQ_REMOVE_HEAD(&tree_ids, entry);
885 		path = qid->data;
886 
887 		if (got_object_idset_contains(idset, &qid->id) ||
888 		    got_object_idset_contains(idset_exclude, &qid->id)) {
889 			free(qid->data);
890 			got_object_qid_free(qid);
891 			continue;
892 		}
893 
894 		err = got_pack_add_object(want_meta,
895 		    want_meta ? idset : idset_exclude,
896 		    &qid->id, path, GOT_OBJ_TYPE_TREE,
897 		    mtime, seed, loose_obj_only, repo,
898 		    ncolored, nfound, ntrees, progress_cb, progress_arg, rl);
899 		if (err) {
900 			free(qid->data);
901 			got_object_qid_free(qid);
902 			break;
903 		}
904 
905 		err = got_object_open_as_tree(&tree, repo, &qid->id);
906 		if (err) {
907 			free(qid->data);
908 			got_object_qid_free(qid);
909 			break;
910 		}
911 
912 		err = got_pack_load_tree_entries(&tree_ids, want_meta, idset,
913 		    idset_exclude, tree, path, mtime, seed, repo,
914 		    loose_obj_only, ncolored, nfound, ntrees,
915 		    progress_cb, progress_arg, rl,
916 		    cancel_cb, cancel_arg);
917 		free(qid->data);
918 		got_object_qid_free(qid);
919 		if (err)
920 			break;
921 
922 		got_object_tree_close(tree);
923 		tree = NULL;
924 	}
925 
926 	STAILQ_FOREACH(qid, &tree_ids, entry)
927 		free(qid->data);
928 	got_object_id_queue_free(&tree_ids);
929 	if (tree)
930 		got_object_tree_close(tree);
931 	return err;
932 }
933 
934 static const struct got_error *
935 load_commit(int want_meta, struct got_object_idset *idset,
936     struct got_object_idset *idset_exclude,
937     struct got_object_id *id, struct got_repository *repo, uint32_t seed,
938     int loose_obj_only, int *ncolored, int *nfound, int *ntrees,
939     got_pack_progress_cb progress_cb, void *progress_arg,
940     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
941 {
942 	const struct got_error *err;
943 	struct got_commit_object *commit;
944 
945 	if (got_object_idset_contains(idset, id) ||
946 	    got_object_idset_contains(idset_exclude, id))
947 		return NULL;
948 
949 	if (loose_obj_only) {
950 		int is_packed;
951 		err = search_packidx(&is_packed, id, repo);
952 		if (err)
953 			return err;
954 		if (is_packed && want_meta)
955 			return NULL;
956 	}
957 
958 	err = got_object_open_as_commit(&commit, repo, id);
959 	if (err)
960 		return err;
961 
962 	err = got_pack_add_object(want_meta,
963 	    want_meta ? idset : idset_exclude, id, "", GOT_OBJ_TYPE_COMMIT,
964 	    got_object_commit_get_committer_time(commit), seed,
965 	    loose_obj_only, repo,
966 	    ncolored, nfound, ntrees, progress_cb, progress_arg, rl);
967 	if (err)
968 		goto done;
969 
970 	err = got_pack_load_tree(want_meta, idset, idset_exclude,
971 	    got_object_commit_get_tree_id(commit),
972 	    "", got_object_commit_get_committer_time(commit), seed,
973 	    repo, loose_obj_only, ncolored, nfound, ntrees,
974 	    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
975 done:
976 	got_object_commit_close(commit);
977 	return err;
978 }
979 
980 static const struct got_error *
981 load_tag(int want_meta, struct got_object_idset *idset,
982     struct got_object_idset *idset_exclude,
983     struct got_object_id *id, struct got_repository *repo, uint32_t seed,
984     int loose_obj_only, int *ncolored, int *nfound, int *ntrees,
985     got_pack_progress_cb progress_cb, void *progress_arg,
986     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
987 {
988 	const struct got_error *err;
989 	struct got_tag_object *tag = NULL;
990 
991 	if (got_object_idset_contains(idset, id) ||
992 	    got_object_idset_contains(idset_exclude, id))
993 		return NULL;
994 
995 	if (loose_obj_only) {
996 		int is_packed;
997 		err = search_packidx(&is_packed, id, repo);
998 		if (err)
999 			return err;
1000 		if (is_packed && want_meta)
1001 			return NULL;
1002 	}
1003 
1004 	err = got_object_open_as_tag(&tag, repo, id);
1005 	if (err)
1006 		return err;
1007 
1008 	err = got_pack_add_object(want_meta,
1009 	    want_meta ? idset : idset_exclude, id, "", GOT_OBJ_TYPE_TAG,
1010 	    got_object_tag_get_tagger_time(tag), seed, loose_obj_only, repo,
1011 	    ncolored, nfound, ntrees, progress_cb, progress_arg, rl);
1012 	if (err)
1013 		goto done;
1014 
1015 	switch (got_object_tag_get_object_type(tag)) {
1016 	case GOT_OBJ_TYPE_COMMIT:
1017 		err = load_commit(want_meta, idset, idset_exclude,
1018 		    got_object_tag_get_object_id(tag), repo, seed,
1019 		    loose_obj_only, ncolored, nfound, ntrees,
1020 		    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1021 		break;
1022 	case GOT_OBJ_TYPE_TREE:
1023 		err = got_pack_load_tree(want_meta, idset, idset_exclude,
1024 		    got_object_tag_get_object_id(tag), "",
1025 		    got_object_tag_get_tagger_time(tag), seed, repo,
1026 		    loose_obj_only, ncolored, nfound, ntrees,
1027 		    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1028 		break;
1029 	default:
1030 		break;
1031 	}
1032 
1033 done:
1034 	got_object_tag_close(tag);
1035 	return err;
1036 }
1037 
1038 const struct got_error *
1039 got_pack_paint_commit(struct got_object_qid *qid, intptr_t color)
1040 {
1041 	if (color < 0 || color >= COLOR_MAX)
1042 		return got_error(GOT_ERR_RANGE);
1043 
1044 	qid->data = (void *)color;
1045 	return NULL;
1046 }
1047 
1048 const struct got_error *
1049 got_pack_queue_commit_id(struct got_object_id_queue *ids,
1050     struct got_object_id *id, intptr_t color, struct got_repository *repo)
1051 {
1052 	const struct got_error *err;
1053 	struct got_object_qid *qid;
1054 
1055 	err = got_object_qid_alloc(&qid, id);
1056 	if (err)
1057 		return err;
1058 
1059 	STAILQ_INSERT_TAIL(ids, qid, entry);
1060 	return got_pack_paint_commit(qid, color);
1061 }
1062 
1063 struct append_id_arg {
1064 	struct got_object_id **array;
1065 	int idx;
1066 	struct got_object_idset *drop;
1067 	struct got_object_idset *skip;
1068 };
1069 
1070 static const struct got_error *
1071 append_id(struct got_object_id *id, void *data, void *arg)
1072 {
1073 	struct append_id_arg *a = arg;
1074 
1075 	if (got_object_idset_contains(a->skip, id) ||
1076 	    got_object_idset_contains(a->drop, id))
1077 		return NULL;
1078 
1079 	a->array[++a->idx] = got_object_id_dup(id);
1080 	if (a->array[a->idx] == NULL)
1081 		return got_error_from_errno("got_object_id_dup");
1082 
1083 	return NULL;
1084 }
1085 
1086 static const struct got_error *
1087 queue_commit_or_tag_id(struct got_object_id *id, intptr_t color,
1088     struct got_object_id_queue *ids, struct got_repository *repo)
1089 {
1090 	const struct got_error *err;
1091 	struct got_tag_object *tag = NULL;
1092 	int obj_type;
1093 
1094 	err = got_object_get_type(&obj_type, repo, id);
1095 	if (err)
1096 		return err;
1097 
1098 	if (obj_type == GOT_OBJ_TYPE_TAG) {
1099 		err = got_object_open_as_tag(&tag, repo, id);
1100 		if (err)
1101 			return err;
1102 		obj_type = got_object_tag_get_object_type(tag);
1103 		id = got_object_tag_get_object_id(tag);
1104 	}
1105 
1106 	if (obj_type == GOT_OBJ_TYPE_COMMIT) {
1107 		err = got_pack_queue_commit_id(ids, id, color, repo);
1108 		if (err)
1109 			goto done;
1110 	}
1111 done:
1112 	if (tag)
1113 		got_object_tag_close(tag);
1114 	return err;
1115 }
1116 
1117 const struct got_error *
1118 got_pack_find_pack_for_commit_painting(struct got_packidx **best_packidx,
1119     struct got_object_id_queue *ids, int nids, struct got_repository *repo)
1120 {
1121 	const struct got_error *err = NULL;
1122 	struct got_pathlist_entry *pe;
1123 	const char *best_packidx_path = NULL;
1124 	int nobj_max = 0;
1125 	int ncommits_max = 0;
1126 
1127 	*best_packidx = NULL;
1128 
1129 	/*
1130 	 * Find the largest pack which contains at least some of the
1131 	 * commits we are interested in.
1132 	 */
1133 	TAILQ_FOREACH(pe, &repo->packidx_paths, entry) {
1134 		const char *path_packidx = pe->path;
1135 		struct got_packidx *packidx;
1136 		int nobj, idx, ncommits = 0;
1137 		struct got_object_qid *qid;
1138 
1139 		err = got_repo_get_packidx(&packidx, path_packidx, repo);
1140 		if (err)
1141 			break;
1142 
1143 		nobj = be32toh(packidx->hdr.fanout_table[0xff]);
1144 		if (nobj <= nobj_max)
1145 			continue;
1146 
1147 		STAILQ_FOREACH(qid, ids, entry) {
1148 			idx = got_packidx_get_object_idx(packidx, &qid->id);
1149 			if (idx != -1)
1150 				ncommits++;
1151 		}
1152 		if (ncommits > ncommits_max) {
1153 			best_packidx_path = path_packidx;
1154 			nobj_max = nobj;
1155 			ncommits_max = ncommits;
1156 		}
1157 	}
1158 
1159 	if (best_packidx_path && err == NULL) {
1160 		err = got_repo_get_packidx(best_packidx, best_packidx_path,
1161 		    repo);
1162 	}
1163 
1164 	return err;
1165 }
1166 
1167 static const struct got_error *
1168 findtwixt(struct got_object_id ***res, int *nres, int *ncolored,
1169     struct got_object_id **head, int nhead,
1170     struct got_object_id **tail, int ntail,
1171     struct got_repository *repo,
1172     got_pack_progress_cb progress_cb, void *progress_arg,
1173     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1174 {
1175 	const struct got_error *err = NULL;
1176 	struct got_object_id_queue ids;
1177 	struct got_object_idset *keep, *drop, *skip = NULL;
1178 	int i, nkeep;
1179 
1180 	STAILQ_INIT(&ids);
1181 	*res = NULL;
1182 	*nres = 0;
1183 	*ncolored = 0;
1184 
1185 	keep = got_object_idset_alloc();
1186 	if (keep == NULL)
1187 		return got_error_from_errno("got_object_idset_alloc");
1188 
1189 	drop = got_object_idset_alloc();
1190 	if (drop == NULL) {
1191 		err = got_error_from_errno("got_object_idset_alloc");
1192 		goto done;
1193 	}
1194 
1195 	skip = got_object_idset_alloc();
1196 	if (skip == NULL) {
1197 		err = got_error_from_errno("got_object_idset_alloc");
1198 		goto done;
1199 	}
1200 
1201 	for (i = 0; i < nhead; i++) {
1202 		struct got_object_id *id = head[i];
1203 		if (id == NULL)
1204 			continue;
1205 		err = queue_commit_or_tag_id(id, COLOR_KEEP, &ids, repo);
1206 		if (err)
1207 			goto done;
1208 	}
1209 
1210 	for (i = 0; i < ntail; i++) {
1211 		struct got_object_id *id = tail[i];
1212 		if (id == NULL)
1213 			continue;
1214 		err = queue_commit_or_tag_id(id, COLOR_DROP, &ids, repo);
1215 		if (err)
1216 			goto done;
1217 	}
1218 
1219 	err = got_pack_paint_commits(ncolored, &ids, nhead + ntail,
1220 	    keep, drop, skip, repo, progress_cb, progress_arg, rl,
1221 	    cancel_cb, cancel_arg);
1222 	if (err)
1223 		goto done;
1224 
1225 	nkeep = got_object_idset_num_elements(keep);
1226 	if (nkeep > 0) {
1227 		struct append_id_arg arg;
1228 		arg.array = calloc(nkeep, sizeof(struct got_object_id *));
1229 		if (arg.array == NULL) {
1230 			err = got_error_from_errno("calloc");
1231 			goto done;
1232 		}
1233 		arg.idx = -1;
1234 		arg.skip = skip;
1235 		arg.drop = drop;
1236 		err = got_object_idset_for_each(keep, append_id, &arg);
1237 		if (err) {
1238 			free(arg.array);
1239 			goto done;
1240 		}
1241 		*res = arg.array;
1242 		*nres = arg.idx + 1;
1243 	}
1244 done:
1245 	got_object_idset_free(keep);
1246 	got_object_idset_free(drop);
1247 	if (skip)
1248 		got_object_idset_free(skip);
1249 	got_object_id_queue_free(&ids);
1250 	return err;
1251 }
1252 
1253 static const struct got_error *
1254 find_pack_for_enumeration(struct got_packidx **best_packidx,
1255     struct got_object_id **ids, int nids, struct got_repository *repo)
1256 {
1257 	const struct got_error *err = NULL;
1258 	struct got_pathlist_entry *pe;
1259 	const char *best_packidx_path = NULL;
1260 	int nobj_max = 0;
1261 	int ncommits_max = 0;
1262 
1263 	*best_packidx = NULL;
1264 
1265 	/*
1266 	 * Find the largest pack which contains at least some of the
1267 	 * commits and tags we are interested in.
1268 	 */
1269 	TAILQ_FOREACH(pe, &repo->packidx_paths, entry) {
1270 		const char *path_packidx = pe->path;
1271 		struct got_packidx *packidx;
1272 		int nobj, i, idx, ncommits = 0;
1273 
1274 		err = got_repo_get_packidx(&packidx, path_packidx, repo);
1275 		if (err)
1276 			break;
1277 
1278 		nobj = be32toh(packidx->hdr.fanout_table[0xff]);
1279 		if (nobj <= nobj_max)
1280 			continue;
1281 
1282 		for (i = 0; i < nids; i++) {
1283 			idx = got_packidx_get_object_idx(packidx, ids[i]);
1284 			if (idx != -1)
1285 				ncommits++;
1286 		}
1287 		if (ncommits > ncommits_max) {
1288 			best_packidx_path = path_packidx;
1289 			nobj_max = nobj;
1290 			ncommits_max = ncommits;
1291 		}
1292 	}
1293 
1294 	if (best_packidx_path && err == NULL) {
1295 		err = got_repo_get_packidx(best_packidx, best_packidx_path,
1296 		    repo);
1297 	}
1298 
1299 	return err;
1300 }
1301 
1302 static const struct got_error *
1303 load_object_ids(int *ncolored, int *nfound, int *ntrees,
1304     struct got_object_idset *idset, struct got_object_id **theirs, int ntheirs,
1305     struct got_object_id **ours, int nours, struct got_repository *repo,
1306     uint32_t seed, int loose_obj_only, got_pack_progress_cb progress_cb,
1307     void *progress_arg, struct got_ratelimit *rl, got_cancel_cb cancel_cb,
1308     void *cancel_arg)
1309 {
1310 	const struct got_error *err = NULL;
1311 	struct got_object_id **ids = NULL;
1312 	struct got_packidx *packidx = NULL;
1313 	int i, nobj = 0, obj_type, found_all_objects = 0;
1314 	struct got_object_idset *idset_exclude;
1315 
1316 	idset_exclude = got_object_idset_alloc();
1317 	if (idset_exclude == NULL)
1318 		return got_error_from_errno("got_object_idset_alloc");
1319 
1320 	*ncolored = 0;
1321 	*nfound = 0;
1322 	*ntrees = 0;
1323 
1324 	err = findtwixt(&ids, &nobj, ncolored, ours, nours, theirs, ntheirs,
1325 	    repo, progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1326 	if (err)
1327 		goto done;
1328 
1329 	err = find_pack_for_enumeration(&packidx, theirs, ntheirs, repo);
1330 	if (err)
1331 		goto done;
1332 	if (packidx) {
1333 		err = got_pack_load_packed_object_ids(&found_all_objects,
1334 		    theirs, ntheirs, NULL, 0, 0, seed, idset, idset_exclude,
1335 		    loose_obj_only, repo, packidx, ncolored, nfound, ntrees,
1336 		    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1337 		if (err)
1338 			goto done;
1339 	}
1340 
1341 	for (i = 0; i < ntheirs; i++) {
1342 		struct got_object_id *id = theirs[i];
1343 		if (id == NULL)
1344 			continue;
1345 		err = got_object_get_type(&obj_type, repo, id);
1346 		if (err)
1347 			return err;
1348 		if (obj_type == GOT_OBJ_TYPE_COMMIT) {
1349 			if (!found_all_objects) {
1350 				err = load_commit(0, idset, idset_exclude,
1351 				    id, repo, seed, loose_obj_only,
1352 				    ncolored, nfound, ntrees,
1353 				    progress_cb, progress_arg, rl,
1354 				    cancel_cb, cancel_arg);
1355 				if (err)
1356 					goto done;
1357 			}
1358 		} else if (obj_type == GOT_OBJ_TYPE_TAG) {
1359 			err = load_tag(0, idset, idset_exclude, id, repo,
1360 			    seed, loose_obj_only, ncolored, nfound, ntrees,
1361 			    progress_cb, progress_arg, rl,
1362 			    cancel_cb, cancel_arg);
1363 			if (err)
1364 				goto done;
1365 		}
1366 	}
1367 
1368 	found_all_objects = 0;
1369 	err = find_pack_for_enumeration(&packidx, ids, nobj, repo);
1370 	if (err)
1371 		goto done;
1372 	if (packidx) {
1373 		err = got_pack_load_packed_object_ids(&found_all_objects, ids,
1374 		    nobj, theirs, ntheirs, 1, seed, idset, idset_exclude,
1375 		    loose_obj_only, repo, packidx, ncolored, nfound, ntrees,
1376 		    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1377 		if (err)
1378 			goto done;
1379 	}
1380 
1381 	if (!found_all_objects) {
1382 		for (i = 0; i < nobj; i++) {
1383 			err = load_commit(1, idset, idset_exclude, ids[i],
1384 			    repo, seed, loose_obj_only, ncolored, nfound,
1385 			    ntrees, progress_cb, progress_arg, rl,
1386 			    cancel_cb, cancel_arg);
1387 			if (err)
1388 				goto done;
1389 		}
1390 	}
1391 
1392 	for (i = 0; i < nours; i++) {
1393 		struct got_object_id *id = ours[i];
1394 		struct got_pack_meta *m;
1395 		if (id == NULL)
1396 			continue;
1397 		m = got_object_idset_get(idset, id);
1398 		if (m == NULL) {
1399 			err = got_object_get_type(&obj_type, repo, id);
1400 			if (err)
1401 				goto done;
1402 		} else
1403 			obj_type = m->obj_type;
1404 		if (obj_type != GOT_OBJ_TYPE_TAG)
1405 			continue;
1406 		err = load_tag(1, idset, idset_exclude, id, repo,
1407 		    seed, loose_obj_only, ncolored, nfound, ntrees,
1408 		    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1409 		if (err)
1410 			goto done;
1411 	}
1412 done:
1413 	for (i = 0; i < nobj; i++) {
1414 		free(ids[i]);
1415 	}
1416 	free(ids);
1417 	got_object_idset_free(idset_exclude);
1418 	return err;
1419 }
1420 
1421 static const struct got_error *
1422 hwrite(int fd, const void *buf, off_t len, SHA1_CTX *ctx)
1423 {
1424 	SHA1Update(ctx, buf, len);
1425 	return got_poll_write_full(fd, buf, len);
1426 }
1427 
1428 static const struct got_error *
1429 hcopy(FILE *fsrc, int fd_dst, off_t len, SHA1_CTX *ctx)
1430 {
1431 	const struct got_error *err;
1432 	unsigned char buf[65536];
1433 	off_t remain = len;
1434 	size_t n;
1435 
1436 	while (remain > 0) {
1437 		size_t copylen = MIN(sizeof(buf), remain);
1438 		n = fread(buf, 1, copylen, fsrc);
1439 		if (n != copylen)
1440 			return got_ferror(fsrc, GOT_ERR_IO);
1441 		SHA1Update(ctx, buf, copylen);
1442 		err = got_poll_write_full(fd_dst, buf, copylen);
1443 		if (err)
1444 			return err;
1445 		remain -= copylen;
1446 	}
1447 
1448 	return NULL;
1449 }
1450 
1451 static const struct got_error *
1452 hcopy_mmap(uint8_t *src, off_t src_offset, size_t src_size,
1453     int fd, off_t len, SHA1_CTX *ctx)
1454 {
1455 	if (src_offset + len > src_size)
1456 		return got_error(GOT_ERR_RANGE);
1457 
1458 	SHA1Update(ctx, src + src_offset, len);
1459 	return got_poll_write_full(fd, src + src_offset, len);
1460 }
1461 
1462 static void
1463 putbe32(char *b, uint32_t n)
1464 {
1465 	b[0] = n >> 24;
1466 	b[1] = n >> 16;
1467 	b[2] = n >> 8;
1468 	b[3] = n >> 0;
1469 }
1470 
1471 static int
1472 write_order_cmp(const void *pa, const void *pb)
1473 {
1474 	struct got_pack_meta *a, *b, *ahd, *bhd;
1475 
1476 	a = *(struct got_pack_meta **)pa;
1477 	b = *(struct got_pack_meta **)pb;
1478 	ahd = (a->head == NULL) ? a : a->head;
1479 	bhd = (b->head == NULL) ? b : b->head;
1480 	if (bhd->mtime < ahd->mtime)
1481 		return -1;
1482 	if (bhd->mtime > ahd->mtime)
1483 		return 1;
1484 	if (bhd < ahd)
1485 		return -1;
1486 	if (bhd > ahd)
1487 		return 1;
1488 	if (a->nchain != b->nchain)
1489 		return a->nchain - b->nchain;
1490 	if (a->mtime < b->mtime)
1491 		return -1;
1492 	if (a->mtime > b->mtime)
1493 		return 1;
1494 	return got_object_id_cmp(&a->id, &b->id);
1495 }
1496 
1497 static int
1498 reuse_write_order_cmp(const void *pa, const void *pb)
1499 {
1500 	struct got_pack_meta *a, *b;
1501 
1502 	a = *(struct got_pack_meta **)pa;
1503 	b = *(struct got_pack_meta **)pb;
1504 
1505 	if (a->reused_delta_offset < b->reused_delta_offset)
1506 		return -1;
1507 	if (a->reused_delta_offset > b->reused_delta_offset)
1508 		return 1;
1509 	return 0;
1510 }
1511 
1512 static const struct got_error *
1513 packhdr(int *hdrlen, char *hdr, size_t bufsize, int obj_type, size_t len)
1514 {
1515 	size_t i;
1516 
1517 	*hdrlen = 0;
1518 
1519 	hdr[0] = obj_type << 4;
1520 	hdr[0] |= len & 0xf;
1521 	len >>= 4;
1522 	for (i = 1; len != 0; i++){
1523 		if (i >= bufsize)
1524 			return got_error(GOT_ERR_NO_SPACE);
1525 		hdr[i - 1] |= GOT_DELTA_SIZE_MORE;
1526 		hdr[i] = len & GOT_DELTA_SIZE_VAL_MASK;
1527 		len >>= GOT_DELTA_SIZE_SHIFT;
1528 	}
1529 
1530 	*hdrlen = i;
1531 	return NULL;
1532 }
1533 
1534 static int
1535 packoff(char *hdr, off_t off)
1536 {
1537 	int i, j;
1538 	char rbuf[8];
1539 
1540 	rbuf[0] = off & GOT_DELTA_SIZE_VAL_MASK;
1541 	for (i = 1; (off >>= GOT_DELTA_SIZE_SHIFT) != 0; i++) {
1542 		rbuf[i] = (--off & GOT_DELTA_SIZE_VAL_MASK) |
1543 		    GOT_DELTA_SIZE_MORE;
1544 	}
1545 
1546 	j = 0;
1547 	while (i > 0)
1548 		hdr[j++] = rbuf[--i];
1549 	return j;
1550 }
1551 
1552 static const struct got_error *
1553 deltahdr(off_t *packfile_size, SHA1_CTX *ctx, int packfd,
1554     struct got_pack_meta *m)
1555 {
1556 	const struct got_error *err;
1557 	char buf[32];
1558 	int nh;
1559 
1560 	if (m->prev->off != 0) {
1561 		err = packhdr(&nh, buf, sizeof(buf),
1562 		    GOT_OBJ_TYPE_OFFSET_DELTA, m->delta_len);
1563 		if (err)
1564 			return err;
1565 		nh += packoff(buf + nh, m->off - m->prev->off);
1566 		err = hwrite(packfd, buf, nh, ctx);
1567 		if (err)
1568 			return err;
1569 		*packfile_size += nh;
1570 	} else {
1571 		err = packhdr(&nh, buf, sizeof(buf),
1572 		    GOT_OBJ_TYPE_REF_DELTA, m->delta_len);
1573 		if (err)
1574 			return err;
1575 		err = hwrite(packfd, buf, nh, ctx);
1576 		if (err)
1577 			return err;
1578 		*packfile_size += nh;
1579 		err = hwrite(packfd, m->prev->id.sha1,
1580 		    sizeof(m->prev->id.sha1), ctx);
1581 		if (err)
1582 			return err;
1583 		*packfile_size += sizeof(m->prev->id.sha1);
1584 	}
1585 
1586 	return NULL;
1587 }
1588 
1589 static const struct got_error *
1590 write_packed_object(off_t *packfile_size, int packfd,
1591     FILE *delta_cache, uint8_t *delta_cache_map, size_t delta_cache_size,
1592     struct got_pack_meta *m, int *outfd, SHA1_CTX *ctx,
1593     struct got_repository *repo)
1594 {
1595 	const struct got_error *err = NULL;
1596 	struct got_deflate_checksum csum;
1597 	char buf[32];
1598 	int nh;
1599 	struct got_raw_object *raw = NULL;
1600 	off_t outlen;
1601 
1602 	csum.output_sha1 = ctx;
1603 	csum.output_crc = NULL;
1604 
1605 	m->off = *packfile_size;
1606 	if (m->delta_len == 0) {
1607 		err = got_object_raw_open(&raw, outfd, repo, &m->id);
1608 		if (err)
1609 			goto done;
1610 		err = packhdr(&nh, buf, sizeof(buf),
1611 		    m->obj_type, raw->size);
1612 		if (err)
1613 			goto done;
1614 		err = hwrite(packfd, buf, nh, ctx);
1615 		if (err)
1616 			goto done;
1617 		*packfile_size += nh;
1618 		if (raw->f == NULL) {
1619 			err = got_deflate_to_fd_mmap(&outlen,
1620 			    raw->data + raw->hdrlen, 0, raw->size,
1621 			    packfd, &csum);
1622 			if (err)
1623 				goto done;
1624 		} else {
1625 			if (fseeko(raw->f, raw->hdrlen, SEEK_SET)
1626 			    == -1) {
1627 				err = got_error_from_errno("fseeko");
1628 				goto done;
1629 			}
1630 			err = got_deflate_to_fd(&outlen, raw->f,
1631 			    raw->size, packfd, &csum);
1632 			if (err)
1633 				goto done;
1634 		}
1635 		*packfile_size += outlen;
1636 		got_object_raw_close(raw);
1637 		raw = NULL;
1638 	} else if (m->delta_buf) {
1639 		err = deltahdr(packfile_size, ctx, packfd, m);
1640 		if (err)
1641 			goto done;
1642 		err = hwrite(packfd, m->delta_buf,
1643 		    m->delta_compressed_len, ctx);
1644 		if (err)
1645 			goto done;
1646 		*packfile_size += m->delta_compressed_len;
1647 		free(m->delta_buf);
1648 		m->delta_buf = NULL;
1649 	} else if (delta_cache_map) {
1650 		err = deltahdr(packfile_size, ctx, packfd, m);
1651 		if (err)
1652 			goto done;
1653 		err = hcopy_mmap(delta_cache_map, m->delta_offset,
1654 		    delta_cache_size, packfd, m->delta_compressed_len,
1655 		    ctx);
1656 		if (err)
1657 			goto done;
1658 		*packfile_size += m->delta_compressed_len;
1659 	} else {
1660 		if (fseeko(delta_cache, m->delta_offset, SEEK_SET)
1661 		    == -1) {
1662 			err = got_error_from_errno("fseeko");
1663 			goto done;
1664 		}
1665 		err = deltahdr(packfile_size, ctx, packfd, m);
1666 		if (err)
1667 			goto done;
1668 		err = hcopy(delta_cache, packfd,
1669 		    m->delta_compressed_len, ctx);
1670 		if (err)
1671 			goto done;
1672 		*packfile_size += m->delta_compressed_len;
1673 	}
1674 done:
1675 	if (raw)
1676 		got_object_raw_close(raw);
1677 	return err;
1678 }
1679 
1680 static const struct got_error *
1681 genpack(uint8_t *pack_sha1, int packfd, FILE *delta_cache,
1682     struct got_pack_meta **deltify, int ndeltify,
1683     struct got_pack_meta **reuse, int nreuse,
1684     int ncolored, int nfound, int ntrees, int nours,
1685     struct got_repository *repo,
1686     got_pack_progress_cb progress_cb, void *progress_arg,
1687     struct got_ratelimit *rl,
1688     got_cancel_cb cancel_cb, void *cancel_arg)
1689 {
1690 	const struct got_error *err = NULL;
1691 	int i;
1692 	SHA1_CTX ctx;
1693 	struct got_pack_meta *m;
1694 	char buf[32];
1695 	off_t packfile_size = 0;
1696 	int outfd = -1;
1697 	int delta_cache_fd = -1;
1698 	uint8_t *delta_cache_map = NULL;
1699 	size_t delta_cache_size = 0;
1700 
1701 	SHA1Init(&ctx);
1702 
1703 #ifndef GOT_PACK_NO_MMAP
1704 	delta_cache_fd = dup(fileno(delta_cache));
1705 	if (delta_cache_fd != -1) {
1706 		struct stat sb;
1707 		if (fstat(delta_cache_fd, &sb) == -1) {
1708 			err = got_error_from_errno("fstat");
1709 			goto done;
1710 		}
1711 		if (sb.st_size > 0 && sb.st_size <= SIZE_MAX) {
1712 			delta_cache_map = mmap(NULL, sb.st_size,
1713 			    PROT_READ, MAP_PRIVATE, delta_cache_fd, 0);
1714 			if (delta_cache_map == MAP_FAILED) {
1715 				if (errno != ENOMEM) {
1716 					err = got_error_from_errno("mmap");
1717 					goto done;
1718 				}
1719 				delta_cache_map = NULL; /* fallback on stdio */
1720 			} else
1721 				delta_cache_size = (size_t)sb.st_size;
1722 		}
1723 	}
1724 #endif
1725 	err = hwrite(packfd, "PACK", 4, &ctx);
1726 	if (err)
1727 		goto done;
1728 	putbe32(buf, GOT_PACKFILE_VERSION);
1729 	err = hwrite(packfd, buf, 4, &ctx);
1730 	if (err)
1731 		goto done;
1732 	putbe32(buf, ndeltify + nreuse);
1733 	err = hwrite(packfd, buf, 4, &ctx);
1734 	if (err)
1735 		goto done;
1736 
1737 	qsort(deltify, ndeltify, sizeof(struct got_pack_meta *),
1738 	    write_order_cmp);
1739 	for (i = 0; i < ndeltify; i++) {
1740 		err = got_pack_report_progress(progress_cb, progress_arg, rl,
1741 		    ncolored, nfound, ntrees, packfile_size, nours,
1742 		    ndeltify + nreuse, ndeltify + nreuse, i);
1743 		if (err)
1744 			goto done;
1745 		m = deltify[i];
1746 		err = write_packed_object(&packfile_size, packfd,
1747 		    delta_cache, delta_cache_map, delta_cache_size,
1748 		    m, &outfd, &ctx, repo);
1749 		if (err)
1750 			goto done;
1751 	}
1752 
1753 	qsort(reuse, nreuse, sizeof(struct got_pack_meta *),
1754 	    reuse_write_order_cmp);
1755 	for (i = 0; i < nreuse; i++) {
1756 		err = got_pack_report_progress(progress_cb, progress_arg, rl,
1757 		    ncolored, nfound, ntrees, packfile_size, nours,
1758 		    ndeltify + nreuse, ndeltify + nreuse, ndeltify + i);
1759 		if (err)
1760 			goto done;
1761 		m = reuse[i];
1762 		err = write_packed_object(&packfile_size, packfd,
1763 		    delta_cache, delta_cache_map, delta_cache_size,
1764 		    m, &outfd, &ctx, repo);
1765 		if (err)
1766 			goto done;
1767 	}
1768 
1769 	SHA1Final(pack_sha1, &ctx);
1770 	err = got_poll_write_full(packfd, pack_sha1, SHA1_DIGEST_LENGTH);
1771 	if (err)
1772 		goto done;
1773 	packfile_size += SHA1_DIGEST_LENGTH;
1774 	packfile_size += sizeof(struct got_packfile_hdr);
1775 	if (progress_cb) {
1776 		err = progress_cb(progress_arg, ncolored, nfound, ntrees,
1777 		    packfile_size, nours, ndeltify + nreuse,
1778 		    ndeltify + nreuse, ndeltify + nreuse);
1779 		if (err)
1780 			goto done;
1781 	}
1782 done:
1783 	if (outfd != -1 && close(outfd) == -1 && err == NULL)
1784 		err = got_error_from_errno("close");
1785 	if (delta_cache_map && munmap(delta_cache_map, delta_cache_size) == -1)
1786 		err = got_error_from_errno("munmap");
1787 	if (delta_cache_fd != -1 && close(delta_cache_fd) == -1 && err == NULL)
1788 		err = got_error_from_errno("close");
1789 	return err;
1790 }
1791 
1792 static const struct got_error *
1793 add_meta_idset_cb(struct got_object_id *id, void *data, void *arg)
1794 {
1795 	struct got_pack_meta *m = data;
1796 	struct got_pack_metavec *v = arg;
1797 
1798 	if (m->reused_delta_offset != 0)
1799 		return NULL;
1800 
1801 	return got_pack_add_meta(m, v);
1802 }
1803 
1804 const struct got_error *
1805 got_pack_create(uint8_t *packsha1, int packfd, FILE *delta_cache,
1806     struct got_object_id **theirs, int ntheirs,
1807     struct got_object_id **ours, int nours,
1808     struct got_repository *repo, int loose_obj_only, int allow_empty,
1809     got_pack_progress_cb progress_cb, void *progress_arg,
1810     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1811 {
1812 	const struct got_error *err;
1813 	int delta_cache_fd = -1;
1814 	struct got_object_idset *idset;
1815 	struct got_pack_metavec deltify, reuse;
1816 	int ncolored = 0, nfound = 0, ntrees = 0;
1817 	size_t ndeltify;
1818 	uint32_t seed;
1819 
1820 	seed = arc4random();
1821 
1822 	memset(&deltify, 0, sizeof(deltify));
1823 	memset(&reuse, 0, sizeof(reuse));
1824 
1825 	idset = got_object_idset_alloc();
1826 	if (idset == NULL)
1827 		return got_error_from_errno("got_object_idset_alloc");
1828 
1829 	err = load_object_ids(&ncolored, &nfound, &ntrees, idset, theirs,
1830 	    ntheirs, ours, nours, repo, seed, loose_obj_only,
1831 	    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1832 	if (err)
1833 		goto done;
1834 
1835 	if (progress_cb) {
1836 		err = progress_cb(progress_arg, ncolored, nfound, ntrees,
1837 		    0L, nours, got_object_idset_num_elements(idset), 0, 0);
1838 		if (err)
1839 			goto done;
1840 	}
1841 
1842 	if (got_object_idset_num_elements(idset) == 0 && !allow_empty) {
1843 		err = got_error(GOT_ERR_CANNOT_PACK);
1844 		goto done;
1845 	}
1846 
1847 	delta_cache_fd = dup(fileno(delta_cache));
1848 	if (delta_cache_fd == -1) {
1849 		err = got_error_from_errno("dup");
1850 		goto done;
1851 	}
1852 
1853 	reuse.metasz = 64;
1854 	reuse.meta = calloc(reuse.metasz,
1855 	    sizeof(struct got_pack_meta *));
1856 	if (reuse.meta == NULL) {
1857 		err = got_error_from_errno("calloc");
1858 		goto done;
1859 	}
1860 
1861 	err = got_pack_search_deltas(&reuse, idset, delta_cache_fd,
1862 	    ncolored, nfound, ntrees, nours,
1863 	    repo, progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1864 	if (err)
1865 		goto done;
1866 
1867 	if (fseeko(delta_cache, 0L, SEEK_END) == -1) {
1868 		err = got_error_from_errno("fseeko");
1869 		goto done;
1870 	}
1871 
1872 	ndeltify = got_object_idset_num_elements(idset) - reuse.nmeta;
1873 	if (ndeltify > 0) {
1874 		deltify.meta = calloc(ndeltify, sizeof(struct got_pack_meta *));
1875 		if (deltify.meta == NULL) {
1876 			err = got_error_from_errno("calloc");
1877 			goto done;
1878 		}
1879 		deltify.metasz = ndeltify;
1880 
1881 		err = got_object_idset_for_each(idset, add_meta_idset_cb,
1882 		    &deltify);
1883 		if (err)
1884 			goto done;
1885 		if (deltify.nmeta > 0) {
1886 			err = pick_deltas(deltify.meta, deltify.nmeta,
1887 			    ncolored, nfound, ntrees, nours, reuse.nmeta,
1888 			    delta_cache, repo, progress_cb, progress_arg, rl,
1889 			    cancel_cb, cancel_arg);
1890 			if (err)
1891 				goto done;
1892 		}
1893 	}
1894 
1895 	if (fflush(delta_cache) == EOF) {
1896 		err = got_error_from_errno("fflush");
1897 		goto done;
1898 	}
1899 
1900 	if (progress_cb) {
1901 		/*
1902 		 * Report a 1-byte packfile write to indicate we are about
1903 		 * to start sending packfile data. gotd(8) needs this.
1904 		 */
1905 		err = progress_cb(progress_arg, ncolored, nfound, ntrees,
1906 		    1 /* packfile_size */, nours,
1907 		    got_object_idset_num_elements(idset),
1908 		    deltify.nmeta + reuse.nmeta, 0);
1909 		if (err)
1910 			goto done;
1911 	}
1912 
1913 	err = genpack(packsha1, packfd, delta_cache, deltify.meta,
1914 	    deltify.nmeta, reuse.meta, reuse.nmeta, ncolored, nfound, ntrees,
1915 	    nours, repo, progress_cb, progress_arg, rl,
1916 	    cancel_cb, cancel_arg);
1917 	if (err)
1918 		goto done;
1919 done:
1920 	free_nmeta(deltify.meta, deltify.nmeta);
1921 	free_nmeta(reuse.meta, reuse.nmeta);
1922 	got_object_idset_free(idset);
1923 	if (delta_cache_fd != -1 && close(delta_cache_fd) == -1 && err == NULL)
1924 		err = got_error_from_errno("close");
1925 	return err;
1926 }