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 "got_compat.h"
19 
20 #include <sys/types.h>
21 #include <sys/queue.h>
22 #include <sys/uio.h>
23 #include <sys/stat.h>
24 #include <sys/time.h>
25 #include <sys/mman.h>
26 
27 #include <errno.h>
28 #include <stdint.h>
29 #include <inttypes.h>
30 #include <poll.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <time.h>
35 #include <unistd.h>
36 #include <limits.h>
37 #include <zlib.h>
38 
39 #include "got_error.h"
40 #include "got_cancel.h"
41 #include "got_object.h"
42 #include "got_path.h"
43 #include "got_reference.h"
44 #include "got_repository_admin.h"
45 
46 #include "got_lib_deltify.h"
47 #include "got_lib_delta.h"
48 #include "got_lib_hash.h"
49 #include "got_lib_object.h"
50 #include "got_lib_object_idset.h"
51 #include "got_lib_object_cache.h"
52 #include "got_lib_deflate.h"
53 #include "got_lib_ratelimit.h"
54 #include "got_lib_pack.h"
55 #include "got_lib_pack_create.h"
56 #include "got_lib_repository.h"
57 #include "got_lib_inflate.h"
58 #include "got_lib_poll.h"
59 
60 #include "murmurhash2.h"
61 
62 #ifndef MIN
63 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
64 #endif
65 
66 #ifndef MAX
67 #define	MAX(_a,_b) ((_a) > (_b) ? (_a) : (_b))
68 #endif
69 
70 #ifndef nitems
71 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
72 #endif
73 
74 static const struct got_error *
75 alloc_meta(struct got_pack_meta **new, struct got_object_id *id,
76     const char *path, int obj_type, time_t mtime, uint32_t seed)
77 {
78 	struct got_pack_meta *m;
79 
80 	*new = NULL;
81 
82 	m = calloc(1, sizeof(*m));
83 	if (m == NULL)
84 		return got_error_from_errno("calloc");
85 
86 	memcpy(&m->id, id, sizeof(m->id));
87 
88 	m->path_hash = murmurhash2(path, strlen(path), seed);
89 	m->obj_type = obj_type;
90 	m->mtime = mtime;
91 	*new = m;
92 	return NULL;
93 }
94 
95 static void
96 clear_meta(struct got_pack_meta *meta)
97 {
98 	if (meta == NULL)
99 		return;
100 	meta->path_hash = 0;
101 	free(meta->delta_buf);
102 	meta->delta_buf = NULL;
103 	free(meta->base_obj_id);
104 	meta->base_obj_id = NULL;
105 	meta->reused_delta_offset = 0;
106 }
107 
108 static void
109 free_nmeta(struct got_pack_meta **meta, int nmeta)
110 {
111 	int i;
112 
113 	for (i = 0; i < nmeta; i++)
114 		clear_meta(meta[i]);
115 	free(meta);
116 }
117 
118 static int
119 delta_order_cmp(const void *pa, const void *pb)
120 {
121 	struct got_pack_meta *a, *b;
122 
123 	a = *(struct got_pack_meta **)pa;
124 	b = *(struct got_pack_meta **)pb;
125 
126 	if (a->obj_type != b->obj_type)
127 		return a->obj_type - b->obj_type;
128 	if (a->path_hash < b->path_hash)
129 		return -1;
130 	if (a->path_hash > b->path_hash)
131 		return 1;
132 	if (a->mtime < b->mtime)
133 		return -1;
134 	if (a->mtime > b->mtime)
135 		return 1;
136 	return got_object_id_cmp(&a->id, &b->id);
137 }
138 
139 static off_t
140 delta_size(struct got_delta_instruction *deltas, int ndeltas)
141 {
142 	int i;
143 	off_t size = 32;
144 	for (i = 0; i < ndeltas; i++) {
145 		if (deltas[i].copy)
146 			size += GOT_DELTA_SIZE_SHIFT;
147 		else
148 			size += deltas[i].len + 1;
149 	}
150 	return size;
151 }
152 
153 static const struct got_error *
154 append(unsigned char **p, size_t *len, off_t *sz, void *seg, int nseg)
155 {
156 	char *n;
157 
158 	if (*len + nseg >= *sz) {
159 		while (*len + nseg >= *sz)
160 			*sz += *sz / 2;
161 		n = realloc(*p, *sz);
162 		if (n == NULL)
163 			return got_error_from_errno("realloc");
164 		*p = n;
165 	}
166 	memcpy(*p + *len, seg, nseg);
167 	*len += nseg;
168 	return NULL;
169 }
170 
171 static const struct got_error *
172 encode_delta_in_mem(struct got_pack_meta *m, struct got_raw_object *o,
173     struct got_delta_instruction *deltas, int ndeltas,
174     off_t delta_size, off_t base_size)
175 {
176 	const struct got_error *err;
177 	unsigned char buf[16], *bp;
178 	int i, j;
179 	size_t len = 0, compressed_len;
180 	off_t bufsize = delta_size;
181 	off_t n;
182 	struct got_delta_instruction *d;
183 	uint8_t *delta_buf;
184 
185 	delta_buf = malloc(bufsize);
186 	if (delta_buf == NULL)
187 		return got_error_from_errno("malloc");
188 
189 	/* base object size */
190 	buf[0] = base_size & GOT_DELTA_SIZE_VAL_MASK;
191 	n = base_size >> GOT_DELTA_SIZE_SHIFT;
192 	for (i = 1; n > 0; i++) {
193 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
194 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
195 		n >>= GOT_DELTA_SIZE_SHIFT;
196 	}
197 	err = append(&delta_buf, &len, &bufsize, buf, i);
198 	if (err)
199 		goto done;
200 
201 	/* target object size */
202 	buf[0] = o->size & GOT_DELTA_SIZE_VAL_MASK;
203 	n = o->size >> GOT_DELTA_SIZE_SHIFT;
204 	for (i = 1; n > 0; i++) {
205 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
206 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
207 		n >>= GOT_DELTA_SIZE_SHIFT;
208 	}
209 	err = append(&delta_buf, &len, &bufsize, buf, i);
210 	if (err)
211 		goto done;
212 
213 	for (j = 0; j < ndeltas; j++) {
214 		d = &deltas[j];
215 		if (d->copy) {
216 			n = d->offset;
217 			bp = &buf[1];
218 			buf[0] = GOT_DELTA_BASE_COPY;
219 			for (i = 0; i < 4; i++) {
220 				/* DELTA_COPY_OFF1 ... DELTA_COPY_OFF4 */
221 				buf[0] |= 1 << i;
222 				*bp++ = n & 0xff;
223 				n >>= 8;
224 				if (n == 0)
225 					break;
226 			}
227 
228 			n = d->len;
229 			if (n != GOT_DELTA_COPY_DEFAULT_LEN) {
230 				/* DELTA_COPY_LEN1 ... DELTA_COPY_LEN3 */
231 				for (i = 0; i < 3 && n > 0; i++) {
232 					buf[0] |= 1 << (i + 4);
233 					*bp++ = n & 0xff;
234 					n >>= 8;
235 				}
236 			}
237 			err = append(&delta_buf, &len, &bufsize,
238 			    buf, bp - buf);
239 			if (err)
240 				goto done;
241 		} else if (o->f == NULL) {
242 			n = 0;
243 			while (n != d->len) {
244 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
245 				err = append(&delta_buf, &len, &bufsize,
246 				    buf, 1);
247 				if (err)
248 					goto done;
249 				err = append(&delta_buf, &len, &bufsize,
250 				    o->data + o->hdrlen + d->offset + n,
251 				    buf[0]);
252 				if (err)
253 					goto done;
254 				n += buf[0];
255 			}
256 		} else {
257 			char content[128];
258 			size_t r;
259 			if (fseeko(o->f, o->hdrlen + d->offset, SEEK_SET) == -1) {
260 				err = got_error_from_errno("fseeko");
261 				goto done;
262 			}
263 			n = 0;
264 			while (n != d->len) {
265 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
266 				err = append(&delta_buf, &len, &bufsize,
267 				    buf, 1);
268 				if (err)
269 					goto done;
270 				r = fread(content, 1, buf[0], o->f);
271 				if (r != buf[0]) {
272 					err = got_ferror(o->f, GOT_ERR_IO);
273 					goto done;
274 				}
275 				err = append(&delta_buf, &len, &bufsize,
276 				    content, buf[0]);
277 				if (err)
278 					goto done;
279 				n += buf[0];
280 			}
281 		}
282 	}
283 
284 	err = got_deflate_to_mem_mmap(&m->delta_buf, &compressed_len,
285 	    NULL, NULL, delta_buf, 0, len);
286 	if (err)
287 		goto done;
288 
289 	m->delta_len = len;
290 	m->delta_compressed_len = compressed_len;
291 done:
292 	free(delta_buf);
293 	return err;
294 }
295 
296 static const struct got_error *
297 encode_delta(struct got_pack_meta *m, struct got_raw_object *o,
298     struct got_delta_instruction *deltas, int ndeltas,
299     off_t base_size, FILE *f)
300 {
301 	const struct got_error *err;
302 	unsigned char buf[16], *bp;
303 	int i, j;
304 	off_t n;
305 	struct got_deflate_buf zb;
306 	struct got_delta_instruction *d;
307 	off_t delta_len = 0, compressed_len = 0;
308 
309 	err = got_deflate_init(&zb, NULL, GOT_DEFLATE_BUFSIZE);
310 	if (err)
311 		return err;
312 
313 	/* base object size */
314 	buf[0] = base_size & GOT_DELTA_SIZE_VAL_MASK;
315 	n = base_size >> GOT_DELTA_SIZE_SHIFT;
316 	for (i = 1; n > 0; i++) {
317 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
318 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
319 		n >>= GOT_DELTA_SIZE_SHIFT;
320 	}
321 
322 	err = got_deflate_append_to_file_mmap(&zb, &compressed_len,
323 	    buf, 0, i, f, NULL);
324 	if (err)
325 		goto done;
326 	delta_len += i;
327 
328 	/* target object size */
329 	buf[0] = o->size & GOT_DELTA_SIZE_VAL_MASK;
330 	n = o->size >> GOT_DELTA_SIZE_SHIFT;
331 	for (i = 1; n > 0; i++) {
332 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
333 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
334 		n >>= GOT_DELTA_SIZE_SHIFT;
335 	}
336 
337 	err = got_deflate_append_to_file_mmap(&zb, &compressed_len,
338 	    buf, 0, i, f, NULL);
339 	if (err)
340 		goto done;
341 	delta_len += i;
342 
343 	for (j = 0; j < ndeltas; j++) {
344 		d = &deltas[j];
345 		if (d->copy) {
346 			n = d->offset;
347 			bp = &buf[1];
348 			buf[0] = GOT_DELTA_BASE_COPY;
349 			for (i = 0; i < 4; i++) {
350 				/* DELTA_COPY_OFF1 ... DELTA_COPY_OFF4 */
351 				buf[0] |= 1 << i;
352 				*bp++ = n & 0xff;
353 				n >>= 8;
354 				if (n == 0)
355 					break;
356 			}
357 			n = d->len;
358 			if (n != GOT_DELTA_COPY_DEFAULT_LEN) {
359 				/* DELTA_COPY_LEN1 ... DELTA_COPY_LEN3 */
360 				for (i = 0; i < 3 && n > 0; i++) {
361 					buf[0] |= 1 << (i + 4);
362 					*bp++ = n & 0xff;
363 					n >>= 8;
364 				}
365 			}
366 			err = got_deflate_append_to_file_mmap(&zb,
367 			    &compressed_len, buf, 0, bp - buf, f, NULL);
368 			if (err)
369 				goto done;
370 			delta_len += (bp - buf);
371 		} else if (o->f == NULL) {
372 			n = 0;
373 			while (n != d->len) {
374 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
375 				err = got_deflate_append_to_file_mmap(&zb,
376 				    &compressed_len, buf, 0, 1, f, NULL);
377 				if (err)
378 					goto done;
379 				delta_len++;
380 				err = got_deflate_append_to_file_mmap(&zb,
381 				    &compressed_len,
382 				    o->data + o->hdrlen + d->offset + n, 0,
383 				    buf[0], f, NULL);
384 				if (err)
385 					goto done;
386 				delta_len += buf[0];
387 				n += buf[0];
388 			}
389 		} else {
390 			char content[128];
391 			size_t r;
392 			if (fseeko(o->f, o->hdrlen + d->offset, SEEK_SET) == -1) {
393 				err = got_error_from_errno("fseeko");
394 				goto done;
395 			}
396 			n = 0;
397 			while (n != d->len) {
398 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
399 				err = got_deflate_append_to_file_mmap(&zb,
400 				    &compressed_len, buf, 0, 1, f, NULL);
401 				if (err)
402 					goto done;
403 				delta_len++;
404 				r = fread(content, 1, buf[0], o->f);
405 				if (r != buf[0]) {
406 					err = got_ferror(o->f, GOT_ERR_IO);
407 					goto done;
408 				}
409 				err = got_deflate_append_to_file_mmap(&zb,
410 				    &compressed_len, content, 0, buf[0], f,
411 				    NULL);
412 				if (err)
413 					goto done;
414 				delta_len += buf[0];
415 				n += buf[0];
416 			}
417 		}
418 	}
419 
420 	err = got_deflate_flush(&zb, f, NULL, &compressed_len);
421 	if (err)
422 		goto done;
423 
424 	/* sanity check */
425 	if (compressed_len != ftello(f) - m->delta_offset) {
426 		err = got_error(GOT_ERR_COMPRESSION);
427 		goto done;
428 	}
429 
430 	m->delta_len = delta_len;
431 	m->delta_compressed_len = compressed_len;
432 done:
433 	got_deflate_end(&zb);
434 	return err;
435 }
436 
437 const struct got_error *
438 got_pack_report_progress(got_pack_progress_cb progress_cb, void *progress_arg,
439     struct got_ratelimit *rl, int ncolored, int nfound, int ntrees,
440     off_t packfile_size, int ncommits, int nobj_total, int obj_deltify,
441     int nobj_written)
442 {
443 	const struct got_error *err;
444 	int elapsed;
445 
446 	if (progress_cb == NULL)
447 		return NULL;
448 
449 	err = got_ratelimit_check(&elapsed, rl);
450 	if (err || !elapsed)
451 		return err;
452 
453 	return progress_cb(progress_arg, ncolored, nfound, ntrees,
454 	    packfile_size, ncommits, nobj_total, obj_deltify, nobj_written);
455 }
456 
457 const struct got_error *
458 got_pack_add_meta(struct got_pack_meta *m, struct got_pack_metavec *v)
459 {
460 	if (v->nmeta == v->metasz){
461 		size_t newsize = 2 * v->metasz;
462 		struct got_pack_meta **new;
463 		new = reallocarray(v->meta, newsize, sizeof(*new));
464 		if (new == NULL)
465 			return got_error_from_errno("reallocarray");
466 		v->meta = new;
467 		v->metasz = newsize;
468 	}
469 
470 	v->meta[v->nmeta++] = m;
471 	return NULL;
472 }
473 
474 const struct got_error *
475 got_pack_find_pack_for_reuse(struct got_packidx **best_packidx,
476     struct got_repository *repo)
477 {
478 	const struct got_error *err = NULL;
479 	struct got_pathlist_entry *pe;
480 	const char *best_packidx_path = NULL;
481 	int nobj_max = 0;
482 
483 	*best_packidx = NULL;
484 
485 	TAILQ_FOREACH(pe, &repo->packidx_paths, entry) {
486 		const char *path_packidx = pe->path;
487 		struct got_packidx *packidx;
488 		int nobj;
489 
490 		err = got_repo_get_packidx(&packidx, path_packidx, repo);
491 		if (err)
492 			break;
493 
494 		nobj = be32toh(packidx->hdr.fanout_table[0xff]);
495 		if (nobj > nobj_max) {
496 			best_packidx_path = path_packidx;
497 			nobj_max = nobj;
498 		}
499 	}
500 
501 	if (best_packidx_path) {
502 		err = got_repo_get_packidx(best_packidx, best_packidx_path,
503 		    repo);
504 	}
505 
506 	return err;
507 }
508 
509 const struct got_error *
510 got_pack_cache_pack_for_packidx(struct got_pack **pack,
511     struct got_packidx *packidx, struct got_repository *repo)
512 {
513 	const struct got_error *err;
514 	char *path_packfile = NULL;
515 
516 	err = got_packidx_get_packfile_path(&path_packfile,
517 	    packidx->path_packidx);
518 	if (err)
519 		return err;
520 
521 	*pack = got_repo_get_cached_pack(repo, path_packfile);
522 	if (*pack == NULL) {
523 		err = got_repo_cache_pack(pack, repo, path_packfile, packidx);
524 		if (err)
525 			goto done;
526 	}
527 done:
528 	free(path_packfile);
529 	return err;
530 }
531 
532 static const struct got_error *
533 pick_deltas(struct got_pack_meta **meta, int nmeta, int ncolored,
534     int nfound, int ntrees, int ncommits, int nreused, FILE *delta_cache,
535     struct got_repository *repo,
536     got_pack_progress_cb progress_cb, void *progress_arg,
537     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
538 {
539 	const struct got_error *err = NULL;
540 	struct got_pack_meta *m = NULL, *base = NULL;
541 	struct got_raw_object *raw = NULL, *base_raw = NULL;
542 	struct got_delta_instruction *deltas = NULL, *best_deltas = NULL;
543 	int i, j, ndeltas, best_ndeltas;
544 	off_t size, best_size;
545 	const int max_base_candidates = 3;
546 	size_t delta_memsize = 0;
547 	const size_t max_delta_memsize = 4 * GOT_DELTA_RESULT_SIZE_CACHED_MAX;
548 	int outfd = -1;
549 	uint32_t delta_seed;
550 
551 	delta_seed = arc4random();
552 
553 	qsort(meta, nmeta, sizeof(struct got_pack_meta *), delta_order_cmp);
554 	for (i = 0; i < nmeta; i++) {
555 		if (cancel_cb) {
556 			err = (*cancel_cb)(cancel_arg);
557 			if (err)
558 				break;
559 		}
560 		err = got_pack_report_progress(progress_cb, progress_arg, rl,
561 		    ncolored, nfound, ntrees, 0L, ncommits, nreused + nmeta,
562 		    nreused + i, 0);
563 		if (err)
564 			goto done;
565 		m = meta[i];
566 
567 		if (m->obj_type == GOT_OBJ_TYPE_COMMIT ||
568 		    m->obj_type == GOT_OBJ_TYPE_TAG)
569 			continue;
570 
571 		err = got_object_raw_open(&raw, &outfd, repo, &m->id);
572 		if (err)
573 			goto done;
574 		m->size = raw->size;
575 
576 		if (raw->f == NULL) {
577 			err = got_deltify_init_mem(&m->dtab, raw->data,
578 			    raw->hdrlen, raw->size + raw->hdrlen, delta_seed);
579 		} else {
580 			err = got_deltify_init(&m->dtab, raw->f, raw->hdrlen,
581 			    raw->size + raw->hdrlen, delta_seed);
582 		}
583 		if (err)
584 			goto done;
585 
586 		if (i > max_base_candidates) {
587 			struct got_pack_meta *n = NULL;
588 			n = meta[i - (max_base_candidates + 1)];
589 			got_deltify_free(n->dtab);
590 			n->dtab = NULL;
591 		}
592 
593 		best_size = raw->size;
594 		best_ndeltas = 0;
595 		for (j = MAX(0, i - max_base_candidates); j < i; j++) {
596 			if (cancel_cb) {
597 				err = (*cancel_cb)(cancel_arg);
598 				if (err)
599 					goto done;
600 			}
601 			base = meta[j];
602 			/* long chains make unpacking slow, avoid such bases */
603 			if (base->nchain >= 128 ||
604 			    base->obj_type != m->obj_type)
605 				continue;
606 
607 			err = got_object_raw_open(&base_raw, &outfd, repo,
608 			    &base->id);
609 			if (err)
610 				goto done;
611 
612 			if (raw->f == NULL && base_raw->f == NULL) {
613 				err = got_deltify_mem_mem(&deltas, &ndeltas,
614 				    raw->data, raw->hdrlen,
615 				    raw->size + raw->hdrlen, delta_seed,
616 				    base->dtab, base_raw->data,
617 				    base_raw->hdrlen,
618 				    base_raw->size + base_raw->hdrlen);
619 			} else if (raw->f == NULL) {
620 				err = got_deltify_mem_file(&deltas, &ndeltas,
621 				    raw->data, raw->hdrlen,
622 				    raw->size + raw->hdrlen, delta_seed,
623 				    base->dtab, base_raw->f,
624 				    base_raw->hdrlen,
625 				    base_raw->size + base_raw->hdrlen);
626 			} else if (base_raw->f == NULL) {
627 				err = got_deltify_file_mem(&deltas, &ndeltas,
628 				    raw->f, raw->hdrlen,
629 				    raw->size + raw->hdrlen, delta_seed,
630 				    base->dtab, base_raw->data,
631 				    base_raw->hdrlen,
632 				    base_raw->size + base_raw->hdrlen);
633 			} else {
634 				err = got_deltify(&deltas, &ndeltas,
635 				    raw->f, raw->hdrlen,
636 				    raw->size + raw->hdrlen, delta_seed,
637 				    base->dtab, base_raw->f, base_raw->hdrlen,
638 				    base_raw->size + base_raw->hdrlen);
639 			}
640 			got_object_raw_close(base_raw);
641 			base_raw = NULL;
642 			if (err)
643 				goto done;
644 
645 			size = delta_size(deltas, ndeltas);
646 			if (size + 32 < best_size){
647 				/*
648 				 * if we already picked a best delta,
649 				 * replace it.
650 				 */
651 				best_size = size;
652 				free(best_deltas);
653 				best_deltas = deltas;
654 				best_ndeltas = ndeltas;
655 				deltas = NULL;
656 				m->nchain = base->nchain + 1;
657 				m->prev = base;
658 				m->head = base->head;
659 				if (m->head == NULL)
660 					m->head = base;
661 			} else {
662 				free(deltas);
663 				deltas = NULL;
664 				ndeltas = 0;
665 			}
666 		}
667 
668 		if (best_ndeltas > 0) {
669 			if (best_size <= GOT_DELTA_RESULT_SIZE_CACHED_MAX &&
670 			    delta_memsize + best_size <= max_delta_memsize) {
671 				delta_memsize += best_size;
672 				err = encode_delta_in_mem(m, raw, best_deltas,
673 				    best_ndeltas, best_size, m->prev->size);
674 			} else {
675 				m->delta_offset = ftello(delta_cache);
676 				err = encode_delta(m, raw, best_deltas,
677 				    best_ndeltas, m->prev->size, delta_cache);
678 			}
679 			free(best_deltas);
680 			best_deltas = NULL;
681 			best_ndeltas = 0;
682 			if (err)
683 				goto done;
684 		}
685 
686 		got_object_raw_close(raw);
687 		raw = NULL;
688 	}
689 done:
690 	for (i = MAX(0, nmeta - max_base_candidates); i < nmeta; i++) {
691 		got_deltify_free(meta[i]->dtab);
692 		meta[i]->dtab = NULL;
693 	}
694 	if (raw)
695 		got_object_raw_close(raw);
696 	if (base_raw)
697 		got_object_raw_close(base_raw);
698 	if (outfd != -1 && close(outfd) == -1 && err == NULL)
699 		err = got_error_from_errno("close");
700 	free(deltas);
701 	free(best_deltas);
702 	return err;
703 }
704 
705 static const struct got_error *
706 search_packidx(int *found, struct got_object_id *id,
707     struct got_repository *repo)
708 {
709 	const struct got_error *err = NULL;
710 	struct got_packidx *packidx = NULL;
711 	int idx;
712 
713 	*found = 0;
714 
715 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
716 	if (err == NULL)
717 		*found = 1; /* object is already packed */
718 	else if (err->code == GOT_ERR_NO_OBJ)
719 		err = NULL;
720 	return err;
721 }
722 
723 const struct got_error *
724 got_pack_add_object(int want_meta, struct got_object_idset *idset,
725     struct got_object_id *id, const char *path, int obj_type,
726     time_t mtime, uint32_t seed, int loose_obj_only,
727     struct got_repository *repo, int *ncolored, int *nfound, int *ntrees,
728     got_pack_progress_cb progress_cb, void *progress_arg,
729     struct got_ratelimit *rl)
730 {
731 	const struct got_error *err;
732 	struct got_pack_meta *m = NULL;
733 
734 	if (loose_obj_only) {
735 		int is_packed;
736 		err = search_packidx(&is_packed, id, repo);
737 		if (err)
738 			return err;
739 		if (is_packed && want_meta)
740 			return NULL;
741 	}
742 
743 	if (want_meta) {
744 		err = alloc_meta(&m, id, path, obj_type, mtime, seed);
745 		if (err)
746 			return err;
747 
748 		(*nfound)++;
749 		err = got_pack_report_progress(progress_cb, progress_arg, rl,
750 		    *ncolored, *nfound, *ntrees, 0L, 0, 0, 0, 0);
751 		if (err) {
752 			clear_meta(m);
753 			free(m);
754 			return err;
755 		}
756 	}
757 
758 	err = got_object_idset_add(idset, id, m);
759 	if (err) {
760 		clear_meta(m);
761 		free(m);
762 	}
763 	return err;
764 }
765 
766 const struct got_error *
767 got_pack_load_tree_entries(struct got_object_id_queue *ids, int want_meta,
768     struct got_object_idset *idset, struct got_object_idset *idset_exclude,
769     struct got_tree_object *tree,
770     const char *dpath, time_t mtime, uint32_t seed, struct got_repository *repo,
771     int loose_obj_only, int *ncolored, int *nfound, int *ntrees,
772     got_pack_progress_cb progress_cb, void *progress_arg,
773     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
774 {
775 	const struct got_error *err;
776 	char *p = NULL;
777 	int i;
778 
779 	(*ntrees)++;
780 	err = got_pack_report_progress(progress_cb, progress_arg, rl,
781 	    *ncolored, *nfound, *ntrees, 0L, 0, 0, 0, 0);
782 	if (err)
783 		return err;
784 
785 	for (i = 0; i < got_object_tree_get_nentries(tree); i++) {
786 		struct got_tree_entry *e = got_object_tree_get_entry(tree, i);
787 		struct got_object_id *id = got_tree_entry_get_id(e);
788 		mode_t mode = got_tree_entry_get_mode(e);
789 
790 		if (cancel_cb) {
791 			err = (*cancel_cb)(cancel_arg);
792 			if (err)
793 				break;
794 		}
795 
796 		if (got_object_tree_entry_is_submodule(e) ||
797 		    got_object_idset_contains(idset, id) ||
798 		    got_object_idset_contains(idset_exclude, id))
799 			continue;
800 
801 		/*
802 		 * If got-read-pack is crawling trees for us then
803 		 * we are only here to collect blob IDs.
804 		 */
805 		if (ids == NULL && S_ISDIR(mode))
806 			continue;
807 
808 		if (asprintf(&p, "%s%s%s", dpath,
809 		    got_path_is_root_dir(dpath) ? "" : "/",
810 		    got_tree_entry_get_name(e)) == -1) {
811 			err = got_error_from_errno("asprintf");
812 			break;
813 		}
814 
815 		if (S_ISDIR(mode)) {
816 			struct got_object_qid *qid;
817 			err = got_object_qid_alloc(&qid, id);
818 			if (err)
819 				break;
820 			qid->data = p;
821 			p = NULL;
822 			STAILQ_INSERT_TAIL(ids, qid, entry);
823 		} else if (S_ISREG(mode) || S_ISLNK(mode)) {
824 			err = got_pack_add_object(want_meta,
825 			    want_meta ? idset : idset_exclude, id, p,
826 			    GOT_OBJ_TYPE_BLOB, mtime, seed, loose_obj_only,
827 			    repo, ncolored, nfound, ntrees,
828 			    progress_cb, progress_arg, rl);
829 			if (err)
830 				break;
831 			free(p);
832 			p = NULL;
833 		} else {
834 			free(p);
835 			p = NULL;
836 		}
837 	}
838 
839 	free(p);
840 	return err;
841 }
842 
843 const struct got_error *
844 got_pack_load_tree(int want_meta, struct got_object_idset *idset,
845     struct got_object_idset *idset_exclude,
846     struct got_object_id *tree_id, const char *dpath, time_t mtime,
847     uint32_t seed, struct got_repository *repo, int loose_obj_only,
848     int *ncolored, int *nfound, int *ntrees,
849     got_pack_progress_cb progress_cb, void *progress_arg,
850     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
851 {
852 	const struct got_error *err = NULL;
853 	struct got_object_id_queue tree_ids;
854 	struct got_object_qid *qid;
855 	struct got_tree_object *tree = NULL;
856 
857 	if (got_object_idset_contains(idset, tree_id) ||
858 	    got_object_idset_contains(idset_exclude, tree_id))
859 		return NULL;
860 
861 	err = got_object_qid_alloc(&qid, tree_id);
862 	if (err)
863 		return err;
864 	qid->data = strdup(dpath);
865 	if (qid->data == NULL) {
866 		err = got_error_from_errno("strdup");
867 		got_object_qid_free(qid);
868 		return err;
869 	}
870 
871 	STAILQ_INIT(&tree_ids);
872 	STAILQ_INSERT_TAIL(&tree_ids, qid, entry);
873 
874 	while (!STAILQ_EMPTY(&tree_ids)) {
875 		const char *path;
876 		if (cancel_cb) {
877 			err = (*cancel_cb)(cancel_arg);
878 			if (err)
879 				break;
880 		}
881 
882 		qid = STAILQ_FIRST(&tree_ids);
883 		STAILQ_REMOVE_HEAD(&tree_ids, entry);
884 		path = qid->data;
885 
886 		if (got_object_idset_contains(idset, &qid->id) ||
887 		    got_object_idset_contains(idset_exclude, &qid->id)) {
888 			free(qid->data);
889 			got_object_qid_free(qid);
890 			continue;
891 		}
892 
893 		err = got_pack_add_object(want_meta,
894 		    want_meta ? idset : idset_exclude,
895 		    &qid->id, path, GOT_OBJ_TYPE_TREE,
896 		    mtime, seed, loose_obj_only, repo,
897 		    ncolored, nfound, ntrees, progress_cb, progress_arg, rl);
898 		if (err) {
899 			free(qid->data);
900 			got_object_qid_free(qid);
901 			break;
902 		}
903 
904 		err = got_object_open_as_tree(&tree, repo, &qid->id);
905 		if (err) {
906 			free(qid->data);
907 			got_object_qid_free(qid);
908 			break;
909 		}
910 
911 		err = got_pack_load_tree_entries(&tree_ids, want_meta, idset,
912 		    idset_exclude, tree, path, mtime, seed, repo,
913 		    loose_obj_only, ncolored, nfound, ntrees,
914 		    progress_cb, progress_arg, rl,
915 		    cancel_cb, cancel_arg);
916 		free(qid->data);
917 		got_object_qid_free(qid);
918 		if (err)
919 			break;
920 
921 		got_object_tree_close(tree);
922 		tree = NULL;
923 	}
924 
925 	STAILQ_FOREACH(qid, &tree_ids, entry)
926 		free(qid->data);
927 	got_object_id_queue_free(&tree_ids);
928 	if (tree)
929 		got_object_tree_close(tree);
930 	return err;
931 }
932 
933 static const struct got_error *
934 load_commit(int want_meta, struct got_object_idset *idset,
935     struct got_object_idset *idset_exclude,
936     struct got_object_id *id, struct got_repository *repo, uint32_t seed,
937     int loose_obj_only, int *ncolored, int *nfound, int *ntrees,
938     got_pack_progress_cb progress_cb, void *progress_arg,
939     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
940 {
941 	const struct got_error *err;
942 	struct got_commit_object *commit;
943 
944 	if (got_object_idset_contains(idset, id) ||
945 	    got_object_idset_contains(idset_exclude, id))
946 		return NULL;
947 
948 	if (loose_obj_only) {
949 		int is_packed;
950 		err = search_packidx(&is_packed, id, repo);
951 		if (err)
952 			return err;
953 		if (is_packed && want_meta)
954 			return NULL;
955 	}
956 
957 	err = got_object_open_as_commit(&commit, repo, id);
958 	if (err)
959 		return err;
960 
961 	err = got_pack_add_object(want_meta,
962 	    want_meta ? idset : idset_exclude, id, "", GOT_OBJ_TYPE_COMMIT,
963 	    got_object_commit_get_committer_time(commit), seed,
964 	    loose_obj_only, repo,
965 	    ncolored, nfound, ntrees, progress_cb, progress_arg, rl);
966 	if (err)
967 		goto done;
968 
969 	err = got_pack_load_tree(want_meta, idset, idset_exclude,
970 	    got_object_commit_get_tree_id(commit),
971 	    "", got_object_commit_get_committer_time(commit), seed,
972 	    repo, loose_obj_only, ncolored, nfound, ntrees,
973 	    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
974 done:
975 	got_object_commit_close(commit);
976 	return err;
977 }
978 
979 static const struct got_error *
980 load_tag(int want_meta, struct got_object_idset *idset,
981     struct got_object_idset *idset_exclude,
982     struct got_object_id *id, struct got_repository *repo, uint32_t seed,
983     int loose_obj_only, int *ncolored, int *nfound, int *ntrees,
984     got_pack_progress_cb progress_cb, void *progress_arg,
985     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
986 {
987 	const struct got_error *err;
988 	struct got_tag_object *tag = NULL;
989 
990 	if (got_object_idset_contains(idset, id) ||
991 	    got_object_idset_contains(idset_exclude, id))
992 		return NULL;
993 
994 	if (loose_obj_only) {
995 		int is_packed;
996 		err = search_packidx(&is_packed, id, repo);
997 		if (err)
998 			return err;
999 		if (is_packed && want_meta)
1000 			return NULL;
1001 	}
1002 
1003 	err = got_object_open_as_tag(&tag, repo, id);
1004 	if (err)
1005 		return err;
1006 
1007 	err = got_pack_add_object(want_meta,
1008 	    want_meta ? idset : idset_exclude, id, "", GOT_OBJ_TYPE_TAG,
1009 	    got_object_tag_get_tagger_time(tag), seed, loose_obj_only, repo,
1010 	    ncolored, nfound, ntrees, progress_cb, progress_arg, rl);
1011 	if (err)
1012 		goto done;
1013 
1014 	switch (got_object_tag_get_object_type(tag)) {
1015 	case GOT_OBJ_TYPE_COMMIT:
1016 		err = load_commit(want_meta, idset, idset_exclude,
1017 		    got_object_tag_get_object_id(tag), repo, seed,
1018 		    loose_obj_only, ncolored, nfound, ntrees,
1019 		    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1020 		break;
1021 	case GOT_OBJ_TYPE_TREE:
1022 		err = got_pack_load_tree(want_meta, idset, idset_exclude,
1023 		    got_object_tag_get_object_id(tag), "",
1024 		    got_object_tag_get_tagger_time(tag), seed, repo,
1025 		    loose_obj_only, ncolored, nfound, ntrees,
1026 		    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1027 		break;
1028 	default:
1029 		break;
1030 	}
1031 
1032 done:
1033 	got_object_tag_close(tag);
1034 	return err;
1035 }
1036 
1037 const struct got_error *
1038 got_pack_paint_commit(struct got_object_qid *qid, intptr_t color)
1039 {
1040 	if (color < 0 || color >= COLOR_MAX)
1041 		return got_error(GOT_ERR_RANGE);
1042 
1043 	qid->data = (void *)color;
1044 	return NULL;
1045 }
1046 
1047 const struct got_error *
1048 got_pack_queue_commit_id(struct got_object_id_queue *ids,
1049     struct got_object_id *id, intptr_t color, struct got_repository *repo)
1050 {
1051 	const struct got_error *err;
1052 	struct got_object_qid *qid;
1053 
1054 	err = got_object_qid_alloc(&qid, id);
1055 	if (err)
1056 		return err;
1057 
1058 	STAILQ_INSERT_TAIL(ids, qid, entry);
1059 	return got_pack_paint_commit(qid, color);
1060 }
1061 
1062 struct append_id_arg {
1063 	struct got_object_id **array;
1064 	int idx;
1065 	struct got_object_idset *drop;
1066 	struct got_object_idset *skip;
1067 };
1068 
1069 static const struct got_error *
1070 append_id(struct got_object_id *id, void *data, void *arg)
1071 {
1072 	struct append_id_arg *a = arg;
1073 
1074 	if (got_object_idset_contains(a->skip, id) ||
1075 	    got_object_idset_contains(a->drop, id))
1076 		return NULL;
1077 
1078 	a->array[++a->idx] = got_object_id_dup(id);
1079 	if (a->array[a->idx] == NULL)
1080 		return got_error_from_errno("got_object_id_dup");
1081 
1082 	return NULL;
1083 }
1084 
1085 static const struct got_error *
1086 queue_commit_or_tag_id(struct got_object_id *id, intptr_t color,
1087     struct got_object_id_queue *ids, struct got_repository *repo)
1088 {
1089 	const struct got_error *err;
1090 	struct got_tag_object *tag = NULL;
1091 	int obj_type;
1092 
1093 	err = got_object_get_type(&obj_type, repo, id);
1094 	if (err)
1095 		return err;
1096 
1097 	if (obj_type == GOT_OBJ_TYPE_TAG) {
1098 		err = got_object_open_as_tag(&tag, repo, id);
1099 		if (err)
1100 			return err;
1101 		obj_type = got_object_tag_get_object_type(tag);
1102 		id = got_object_tag_get_object_id(tag);
1103 	}
1104 
1105 	if (obj_type == GOT_OBJ_TYPE_COMMIT) {
1106 		err = got_pack_queue_commit_id(ids, id, color, repo);
1107 		if (err)
1108 			goto done;
1109 	}
1110 done:
1111 	if (tag)
1112 		got_object_tag_close(tag);
1113 	return err;
1114 }
1115 
1116 const struct got_error *
1117 got_pack_find_pack_for_commit_painting(struct got_packidx **best_packidx,
1118     struct got_object_id_queue *ids, int nids, struct got_repository *repo)
1119 {
1120 	const struct got_error *err = NULL;
1121 	struct got_pathlist_entry *pe;
1122 	const char *best_packidx_path = NULL;
1123 	int nobj_max = 0;
1124 	int ncommits_max = 0;
1125 
1126 	*best_packidx = NULL;
1127 
1128 	/*
1129 	 * Find the largest pack which contains at least some of the
1130 	 * commits we are interested in.
1131 	 */
1132 	TAILQ_FOREACH(pe, &repo->packidx_paths, entry) {
1133 		const char *path_packidx = pe->path;
1134 		struct got_packidx *packidx;
1135 		int nobj, idx, ncommits = 0;
1136 		struct got_object_qid *qid;
1137 
1138 		err = got_repo_get_packidx(&packidx, path_packidx, repo);
1139 		if (err)
1140 			break;
1141 
1142 		nobj = be32toh(packidx->hdr.fanout_table[0xff]);
1143 		if (nobj <= nobj_max)
1144 			continue;
1145 
1146 		STAILQ_FOREACH(qid, ids, entry) {
1147 			idx = got_packidx_get_object_idx(packidx, &qid->id);
1148 			if (idx != -1)
1149 				ncommits++;
1150 		}
1151 		if (ncommits > ncommits_max) {
1152 			best_packidx_path = path_packidx;
1153 			nobj_max = nobj;
1154 			ncommits_max = ncommits;
1155 		}
1156 	}
1157 
1158 	if (best_packidx_path && err == NULL) {
1159 		err = got_repo_get_packidx(best_packidx, best_packidx_path,
1160 		    repo);
1161 	}
1162 
1163 	return err;
1164 }
1165 
1166 static const struct got_error *
1167 findtwixt(struct got_object_id ***res, int *nres, int *ncolored,
1168     struct got_object_id **head, int nhead,
1169     struct got_object_id **tail, int ntail,
1170     struct got_repository *repo,
1171     got_pack_progress_cb progress_cb, void *progress_arg,
1172     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1173 {
1174 	const struct got_error *err = NULL;
1175 	struct got_object_id_queue ids;
1176 	struct got_object_idset *keep, *drop, *skip = NULL;
1177 	int i, nkeep;
1178 
1179 	STAILQ_INIT(&ids);
1180 	*res = NULL;
1181 	*nres = 0;
1182 	*ncolored = 0;
1183 
1184 	keep = got_object_idset_alloc();
1185 	if (keep == NULL)
1186 		return got_error_from_errno("got_object_idset_alloc");
1187 
1188 	drop = got_object_idset_alloc();
1189 	if (drop == NULL) {
1190 		err = got_error_from_errno("got_object_idset_alloc");
1191 		goto done;
1192 	}
1193 
1194 	skip = got_object_idset_alloc();
1195 	if (skip == NULL) {
1196 		err = got_error_from_errno("got_object_idset_alloc");
1197 		goto done;
1198 	}
1199 
1200 	for (i = 0; i < nhead; i++) {
1201 		struct got_object_id *id = head[i];
1202 		if (id == NULL)
1203 			continue;
1204 		err = queue_commit_or_tag_id(id, COLOR_KEEP, &ids, repo);
1205 		if (err)
1206 			goto done;
1207 	}
1208 
1209 	for (i = 0; i < ntail; i++) {
1210 		struct got_object_id *id = tail[i];
1211 		if (id == NULL)
1212 			continue;
1213 		err = queue_commit_or_tag_id(id, COLOR_DROP, &ids, repo);
1214 		if (err)
1215 			goto done;
1216 	}
1217 
1218 	err = got_pack_paint_commits(ncolored, &ids, nhead + ntail,
1219 	    keep, drop, skip, repo, progress_cb, progress_arg, rl,
1220 	    cancel_cb, cancel_arg);
1221 	if (err)
1222 		goto done;
1223 
1224 	nkeep = got_object_idset_num_elements(keep);
1225 	if (nkeep > 0) {
1226 		struct append_id_arg arg;
1227 		arg.array = calloc(nkeep, sizeof(struct got_object_id *));
1228 		if (arg.array == NULL) {
1229 			err = got_error_from_errno("calloc");
1230 			goto done;
1231 		}
1232 		arg.idx = -1;
1233 		arg.skip = skip;
1234 		arg.drop = drop;
1235 		err = got_object_idset_for_each(keep, append_id, &arg);
1236 		if (err) {
1237 			free(arg.array);
1238 			goto done;
1239 		}
1240 		*res = arg.array;
1241 		*nres = arg.idx + 1;
1242 	}
1243 done:
1244 	got_object_idset_free(keep);
1245 	got_object_idset_free(drop);
1246 	if (skip)
1247 		got_object_idset_free(skip);
1248 	got_object_id_queue_free(&ids);
1249 	return err;
1250 }
1251 
1252 static const struct got_error *
1253 find_pack_for_enumeration(struct got_packidx **best_packidx,
1254     struct got_object_id **ids, int nids, struct got_repository *repo)
1255 {
1256 	const struct got_error *err = NULL;
1257 	struct got_pathlist_entry *pe;
1258 	const char *best_packidx_path = NULL;
1259 	int nobj_max = 0;
1260 	int ncommits_max = 0;
1261 
1262 	*best_packidx = NULL;
1263 
1264 	/*
1265 	 * Find the largest pack which contains at least some of the
1266 	 * commits and tags we are interested in.
1267 	 */
1268 	TAILQ_FOREACH(pe, &repo->packidx_paths, entry) {
1269 		const char *path_packidx = pe->path;
1270 		struct got_packidx *packidx;
1271 		int nobj, i, idx, ncommits = 0;
1272 
1273 		err = got_repo_get_packidx(&packidx, path_packidx, repo);
1274 		if (err)
1275 			break;
1276 
1277 		nobj = be32toh(packidx->hdr.fanout_table[0xff]);
1278 		if (nobj <= nobj_max)
1279 			continue;
1280 
1281 		for (i = 0; i < nids; i++) {
1282 			idx = got_packidx_get_object_idx(packidx, ids[i]);
1283 			if (idx != -1)
1284 				ncommits++;
1285 		}
1286 		if (ncommits > ncommits_max) {
1287 			best_packidx_path = path_packidx;
1288 			nobj_max = nobj;
1289 			ncommits_max = ncommits;
1290 		}
1291 	}
1292 
1293 	if (best_packidx_path && err == NULL) {
1294 		err = got_repo_get_packidx(best_packidx, best_packidx_path,
1295 		    repo);
1296 	}
1297 
1298 	return err;
1299 }
1300 
1301 static const struct got_error *
1302 load_object_ids(int *ncolored, int *nfound, int *ntrees,
1303     struct got_object_idset *idset, struct got_object_id **theirs, int ntheirs,
1304     struct got_object_id **ours, int nours, struct got_repository *repo,
1305     uint32_t seed, int loose_obj_only, got_pack_progress_cb progress_cb,
1306     void *progress_arg, struct got_ratelimit *rl, got_cancel_cb cancel_cb,
1307     void *cancel_arg)
1308 {
1309 	const struct got_error *err = NULL;
1310 	struct got_object_id **ids = NULL;
1311 	struct got_packidx *packidx = NULL;
1312 	int i, nobj = 0, obj_type, found_all_objects = 0;
1313 	struct got_object_idset *idset_exclude;
1314 
1315 	idset_exclude = got_object_idset_alloc();
1316 	if (idset_exclude == NULL)
1317 		return got_error_from_errno("got_object_idset_alloc");
1318 
1319 	*ncolored = 0;
1320 	*nfound = 0;
1321 	*ntrees = 0;
1322 
1323 	err = findtwixt(&ids, &nobj, ncolored, ours, nours, theirs, ntheirs,
1324 	    repo, progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1325 	if (err)
1326 		goto done;
1327 
1328 	err = find_pack_for_enumeration(&packidx, theirs, ntheirs, repo);
1329 	if (err)
1330 		goto done;
1331 	if (packidx) {
1332 		err = got_pack_load_packed_object_ids(&found_all_objects,
1333 		    theirs, ntheirs, NULL, 0, 0, seed, idset, idset_exclude,
1334 		    loose_obj_only, repo, packidx, ncolored, nfound, ntrees,
1335 		    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1336 		if (err)
1337 			goto done;
1338 	}
1339 
1340 	for (i = 0; i < ntheirs; i++) {
1341 		struct got_object_id *id = theirs[i];
1342 		if (id == NULL)
1343 			continue;
1344 		err = got_object_get_type(&obj_type, repo, id);
1345 		if (err)
1346 			return err;
1347 		if (obj_type == GOT_OBJ_TYPE_COMMIT) {
1348 			if (!found_all_objects) {
1349 				err = load_commit(0, idset, idset_exclude,
1350 				    id, repo, seed, loose_obj_only,
1351 				    ncolored, nfound, ntrees,
1352 				    progress_cb, progress_arg, rl,
1353 				    cancel_cb, cancel_arg);
1354 				if (err)
1355 					goto done;
1356 			}
1357 		} else if (obj_type == GOT_OBJ_TYPE_TAG) {
1358 			err = load_tag(0, idset, idset_exclude, id, repo,
1359 			    seed, loose_obj_only, ncolored, nfound, ntrees,
1360 			    progress_cb, progress_arg, rl,
1361 			    cancel_cb, cancel_arg);
1362 			if (err)
1363 				goto done;
1364 		}
1365 	}
1366 
1367 	found_all_objects = 0;
1368 	err = find_pack_for_enumeration(&packidx, ids, nobj, repo);
1369 	if (err)
1370 		goto done;
1371 	if (packidx) {
1372 		err = got_pack_load_packed_object_ids(&found_all_objects, ids,
1373 		    nobj, theirs, ntheirs, 1, seed, idset, idset_exclude,
1374 		    loose_obj_only, repo, packidx, ncolored, nfound, ntrees,
1375 		    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1376 		if (err)
1377 			goto done;
1378 	}
1379 
1380 	if (!found_all_objects) {
1381 		for (i = 0; i < nobj; i++) {
1382 			err = load_commit(1, idset, idset_exclude, ids[i],
1383 			    repo, seed, loose_obj_only, ncolored, nfound,
1384 			    ntrees, progress_cb, progress_arg, rl,
1385 			    cancel_cb, cancel_arg);
1386 			if (err)
1387 				goto done;
1388 		}
1389 	}
1390 
1391 	for (i = 0; i < nours; i++) {
1392 		struct got_object_id *id = ours[i];
1393 		struct got_pack_meta *m;
1394 		if (id == NULL)
1395 			continue;
1396 		m = got_object_idset_get(idset, id);
1397 		if (m == NULL) {
1398 			err = got_object_get_type(&obj_type, repo, id);
1399 			if (err)
1400 				goto done;
1401 		} else
1402 			obj_type = m->obj_type;
1403 		if (obj_type != GOT_OBJ_TYPE_TAG)
1404 			continue;
1405 		err = load_tag(1, idset, idset_exclude, id, repo,
1406 		    seed, loose_obj_only, ncolored, nfound, ntrees,
1407 		    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1408 		if (err)
1409 			goto done;
1410 	}
1411 done:
1412 	for (i = 0; i < nobj; i++) {
1413 		free(ids[i]);
1414 	}
1415 	free(ids);
1416 	got_object_idset_free(idset_exclude);
1417 	return err;
1418 }
1419 
1420 static const struct got_error *
1421 hwrite(int fd, const void *buf, off_t len, struct got_hash *ctx)
1422 {
1423 	got_hash_update(ctx, buf, len);
1424 	return got_poll_write_full(fd, buf, len);
1425 }
1426 
1427 static const struct got_error *
1428 hcopy(FILE *fsrc, int fd_dst, off_t len, struct got_hash *ctx)
1429 {
1430 	const struct got_error *err;
1431 	unsigned char buf[65536];
1432 	off_t remain = len;
1433 	size_t n;
1434 
1435 	while (remain > 0) {
1436 		size_t copylen = MIN(sizeof(buf), remain);
1437 		n = fread(buf, 1, copylen, fsrc);
1438 		if (n != copylen)
1439 			return got_ferror(fsrc, GOT_ERR_IO);
1440 		got_hash_update(ctx, buf, copylen);
1441 		err = got_poll_write_full(fd_dst, buf, copylen);
1442 		if (err)
1443 			return err;
1444 		remain -= copylen;
1445 	}
1446 
1447 	return NULL;
1448 }
1449 
1450 static const struct got_error *
1451 hcopy_mmap(uint8_t *src, off_t src_offset, size_t src_size,
1452     int fd, off_t len, struct got_hash *ctx)
1453 {
1454 	if (src_offset + len > src_size)
1455 		return got_error(GOT_ERR_RANGE);
1456 
1457 	got_hash_update(ctx, src + src_offset, len);
1458 	return got_poll_write_full(fd, src + src_offset, len);
1459 }
1460 
1461 static void
1462 putbe32(char *b, uint32_t n)
1463 {
1464 	b[0] = n >> 24;
1465 	b[1] = n >> 16;
1466 	b[2] = n >> 8;
1467 	b[3] = n >> 0;
1468 }
1469 
1470 static int
1471 write_order_cmp(const void *pa, const void *pb)
1472 {
1473 	struct got_pack_meta *a, *b, *ahd, *bhd;
1474 
1475 	a = *(struct got_pack_meta **)pa;
1476 	b = *(struct got_pack_meta **)pb;
1477 	ahd = (a->head == NULL) ? a : a->head;
1478 	bhd = (b->head == NULL) ? b : b->head;
1479 	if (bhd->mtime < ahd->mtime)
1480 		return -1;
1481 	if (bhd->mtime > ahd->mtime)
1482 		return 1;
1483 	if (bhd < ahd)
1484 		return -1;
1485 	if (bhd > ahd)
1486 		return 1;
1487 	if (a->nchain != b->nchain)
1488 		return a->nchain - b->nchain;
1489 	if (a->mtime < b->mtime)
1490 		return -1;
1491 	if (a->mtime > b->mtime)
1492 		return 1;
1493 	return got_object_id_cmp(&a->id, &b->id);
1494 }
1495 
1496 static int
1497 reuse_write_order_cmp(const void *pa, const void *pb)
1498 {
1499 	struct got_pack_meta *a, *b;
1500 
1501 	a = *(struct got_pack_meta **)pa;
1502 	b = *(struct got_pack_meta **)pb;
1503 
1504 	if (a->reused_delta_offset < b->reused_delta_offset)
1505 		return -1;
1506 	if (a->reused_delta_offset > b->reused_delta_offset)
1507 		return 1;
1508 	return 0;
1509 }
1510 
1511 static const struct got_error *
1512 packhdr(int *hdrlen, char *hdr, size_t bufsize, int obj_type, size_t len)
1513 {
1514 	size_t i;
1515 
1516 	*hdrlen = 0;
1517 
1518 	hdr[0] = obj_type << 4;
1519 	hdr[0] |= len & 0xf;
1520 	len >>= 4;
1521 	for (i = 1; len != 0; i++){
1522 		if (i >= bufsize)
1523 			return got_error(GOT_ERR_NO_SPACE);
1524 		hdr[i - 1] |= GOT_DELTA_SIZE_MORE;
1525 		hdr[i] = len & GOT_DELTA_SIZE_VAL_MASK;
1526 		len >>= GOT_DELTA_SIZE_SHIFT;
1527 	}
1528 
1529 	*hdrlen = i;
1530 	return NULL;
1531 }
1532 
1533 static int
1534 packoff(char *hdr, off_t off)
1535 {
1536 	int i, j;
1537 	char rbuf[8];
1538 
1539 	rbuf[0] = off & GOT_DELTA_SIZE_VAL_MASK;
1540 	for (i = 1; (off >>= GOT_DELTA_SIZE_SHIFT) != 0; i++) {
1541 		rbuf[i] = (--off & GOT_DELTA_SIZE_VAL_MASK) |
1542 		    GOT_DELTA_SIZE_MORE;
1543 	}
1544 
1545 	j = 0;
1546 	while (i > 0)
1547 		hdr[j++] = rbuf[--i];
1548 	return j;
1549 }
1550 
1551 static const struct got_error *
1552 deltahdr(off_t *packfile_size, struct got_hash *ctx, int packfd,
1553     int force_refdelta, struct got_pack_meta *m)
1554 {
1555 	const struct got_error *err;
1556 	char buf[32];
1557 	int nh;
1558 
1559 	if (m->prev->off != 0 && !force_refdelta) {
1560 		err = packhdr(&nh, buf, sizeof(buf),
1561 		    GOT_OBJ_TYPE_OFFSET_DELTA, m->delta_len);
1562 		if (err)
1563 			return err;
1564 		nh += packoff(buf + nh, m->off - m->prev->off);
1565 		err = hwrite(packfd, buf, nh, ctx);
1566 		if (err)
1567 			return err;
1568 		*packfile_size += nh;
1569 	} else {
1570 		err = packhdr(&nh, buf, sizeof(buf),
1571 		    GOT_OBJ_TYPE_REF_DELTA, m->delta_len);
1572 		if (err)
1573 			return err;
1574 		err = hwrite(packfd, buf, nh, ctx);
1575 		if (err)
1576 			return err;
1577 		*packfile_size += nh;
1578 		err = hwrite(packfd, m->prev->id.sha1,
1579 		    sizeof(m->prev->id.sha1), ctx);
1580 		if (err)
1581 			return err;
1582 		*packfile_size += sizeof(m->prev->id.sha1);
1583 	}
1584 
1585 	return NULL;
1586 }
1587 
1588 static const struct got_error *
1589 write_packed_object(off_t *packfile_size, int packfd,
1590     FILE *delta_cache, uint8_t *delta_cache_map, size_t delta_cache_size,
1591     struct got_pack_meta *m, int *outfd, struct got_hash *ctx,
1592     struct got_repository *repo, int force_refdelta)
1593 {
1594 	const struct got_error *err = NULL;
1595 	struct got_deflate_checksum csum;
1596 	char buf[32];
1597 	int nh;
1598 	struct got_raw_object *raw = NULL;
1599 	off_t outlen, delta_offset;
1600 
1601 	memset(&csum, 0, sizeof(csum));
1602 	csum.output_ctx = ctx;
1603 
1604 	if (m->reused_delta_offset)
1605 		delta_offset = m->reused_delta_offset;
1606 	else
1607 		delta_offset = m->delta_offset;
1608 
1609 	m->off = *packfile_size;
1610 	if (m->delta_len == 0) {
1611 		err = got_object_raw_open(&raw, outfd, repo, &m->id);
1612 		if (err)
1613 			goto done;
1614 		err = packhdr(&nh, buf, sizeof(buf),
1615 		    m->obj_type, raw->size);
1616 		if (err)
1617 			goto done;
1618 		err = hwrite(packfd, buf, nh, ctx);
1619 		if (err)
1620 			goto done;
1621 		*packfile_size += nh;
1622 		if (raw->f == NULL) {
1623 			err = got_deflate_to_fd_mmap(&outlen,
1624 			    raw->data + raw->hdrlen, 0, raw->size,
1625 			    packfd, &csum);
1626 			if (err)
1627 				goto done;
1628 		} else {
1629 			if (fseeko(raw->f, raw->hdrlen, SEEK_SET)
1630 			    == -1) {
1631 				err = got_error_from_errno("fseeko");
1632 				goto done;
1633 			}
1634 			err = got_deflate_to_fd(&outlen, raw->f,
1635 			    raw->size, packfd, &csum);
1636 			if (err)
1637 				goto done;
1638 		}
1639 		*packfile_size += outlen;
1640 		got_object_raw_close(raw);
1641 		raw = NULL;
1642 	} else if (m->delta_buf) {
1643 		err = deltahdr(packfile_size, ctx, packfd, force_refdelta, m);
1644 		if (err)
1645 			goto done;
1646 		err = hwrite(packfd, m->delta_buf,
1647 		    m->delta_compressed_len, ctx);
1648 		if (err)
1649 			goto done;
1650 		*packfile_size += m->delta_compressed_len;
1651 		free(m->delta_buf);
1652 		m->delta_buf = NULL;
1653 	} else if (delta_cache_map) {
1654 		err = deltahdr(packfile_size, ctx, packfd, force_refdelta, m);
1655 		if (err)
1656 			goto done;
1657 		err = hcopy_mmap(delta_cache_map, delta_offset,
1658 		    delta_cache_size, packfd, m->delta_compressed_len,
1659 		    ctx);
1660 		if (err)
1661 			goto done;
1662 		*packfile_size += m->delta_compressed_len;
1663 	} else {
1664 		if (fseeko(delta_cache, delta_offset, SEEK_SET) == -1) {
1665 			err = got_error_from_errno("fseeko");
1666 			goto done;
1667 		}
1668 		err = deltahdr(packfile_size, ctx, packfd, force_refdelta, m);
1669 		if (err)
1670 			goto done;
1671 		err = hcopy(delta_cache, packfd,
1672 		    m->delta_compressed_len, ctx);
1673 		if (err)
1674 			goto done;
1675 		*packfile_size += m->delta_compressed_len;
1676 	}
1677 done:
1678 	if (raw)
1679 		got_object_raw_close(raw);
1680 	return err;
1681 }
1682 
1683 static const struct got_error *
1684 genpack(uint8_t *pack_sha1, int packfd, struct got_pack *reuse_pack,
1685     FILE *delta_cache, struct got_pack_meta **deltify, int ndeltify,
1686     struct got_pack_meta **reuse, int nreuse,
1687     int ncolored, int nfound, int ntrees, int nours,
1688     struct got_repository *repo, int force_refdelta,
1689     got_pack_progress_cb progress_cb, void *progress_arg,
1690     struct got_ratelimit *rl,
1691     got_cancel_cb cancel_cb, void *cancel_arg)
1692 {
1693 	const struct got_error *err = NULL;
1694 	int i;
1695 	struct got_hash ctx;
1696 	struct got_pack_meta *m;
1697 	char buf[32];
1698 	off_t packfile_size = 0;
1699 	int outfd = -1;
1700 	int delta_cache_fd = -1;
1701 	uint8_t *delta_cache_map = NULL;
1702 	size_t delta_cache_size = 0;
1703 	FILE *packfile = NULL;
1704 
1705 	got_hash_init(&ctx, GOT_HASH_SHA1);
1706 
1707 #ifndef GOT_PACK_NO_MMAP
1708 	delta_cache_fd = dup(fileno(delta_cache));
1709 	if (delta_cache_fd != -1) {
1710 		struct stat sb;
1711 		if (fstat(delta_cache_fd, &sb) == -1) {
1712 			err = got_error_from_errno("fstat");
1713 			goto done;
1714 		}
1715 		if (sb.st_size > 0 && sb.st_size <= SIZE_MAX) {
1716 			delta_cache_map = mmap(NULL, sb.st_size,
1717 			    PROT_READ, MAP_PRIVATE, delta_cache_fd, 0);
1718 			if (delta_cache_map == MAP_FAILED) {
1719 				if (errno != ENOMEM) {
1720 					err = got_error_from_errno("mmap");
1721 					goto done;
1722 				}
1723 				delta_cache_map = NULL; /* fallback on stdio */
1724 			} else
1725 				delta_cache_size = (size_t)sb.st_size;
1726 		}
1727 	}
1728 #endif
1729 	err = hwrite(packfd, "PACK", 4, &ctx);
1730 	if (err)
1731 		goto done;
1732 	putbe32(buf, GOT_PACKFILE_VERSION);
1733 	err = hwrite(packfd, buf, 4, &ctx);
1734 	if (err)
1735 		goto done;
1736 	putbe32(buf, ndeltify + nreuse);
1737 	err = hwrite(packfd, buf, 4, &ctx);
1738 	if (err)
1739 		goto done;
1740 
1741 	qsort(deltify, ndeltify, sizeof(struct got_pack_meta *),
1742 	    write_order_cmp);
1743 	for (i = 0; i < ndeltify; i++) {
1744 		err = got_pack_report_progress(progress_cb, progress_arg, rl,
1745 		    ncolored, nfound, ntrees, packfile_size, nours,
1746 		    ndeltify + nreuse, ndeltify + nreuse, i);
1747 		if (err)
1748 			goto done;
1749 		m = deltify[i];
1750 		err = write_packed_object(&packfile_size, packfd,
1751 		    delta_cache, delta_cache_map, delta_cache_size,
1752 		    m, &outfd, &ctx, repo, force_refdelta);
1753 		if (err)
1754 			goto done;
1755 	}
1756 
1757 	qsort(reuse, nreuse, sizeof(struct got_pack_meta *),
1758 	    reuse_write_order_cmp);
1759 	if (nreuse > 0 && reuse_pack->map == NULL) {
1760 		int fd = dup(reuse_pack->fd);
1761 		if (fd == -1) {
1762 			err = got_error_from_errno("dup");
1763 			goto done;
1764 		}
1765 		packfile = fdopen(fd, "r");
1766 		if (packfile == NULL) {
1767 			err = got_error_from_errno("fdopen");
1768 			close(fd);
1769 			goto done;
1770 		}
1771 	}
1772 	for (i = 0; i < nreuse; i++) {
1773 		err = got_pack_report_progress(progress_cb, progress_arg, rl,
1774 		    ncolored, nfound, ntrees, packfile_size, nours,
1775 		    ndeltify + nreuse, ndeltify + nreuse, ndeltify + i);
1776 		if (err)
1777 			goto done;
1778 		m = reuse[i];
1779 		err = write_packed_object(&packfile_size, packfd,
1780 		    packfile, reuse_pack->map, reuse_pack->filesize,
1781 		    m, &outfd, &ctx, repo, force_refdelta);
1782 		if (err)
1783 			goto done;
1784 	}
1785 
1786 	got_hash_final(&ctx, pack_sha1);
1787 	err = got_poll_write_full(packfd, pack_sha1, SHA1_DIGEST_LENGTH);
1788 	if (err)
1789 		goto done;
1790 	packfile_size += SHA1_DIGEST_LENGTH;
1791 	packfile_size += sizeof(struct got_packfile_hdr);
1792 	if (progress_cb) {
1793 		err = progress_cb(progress_arg, ncolored, nfound, ntrees,
1794 		    packfile_size, nours, ndeltify + nreuse,
1795 		    ndeltify + nreuse, ndeltify + nreuse);
1796 		if (err)
1797 			goto done;
1798 	}
1799 done:
1800 	if (outfd != -1 && close(outfd) == -1 && err == NULL)
1801 		err = got_error_from_errno("close");
1802 	if (delta_cache_map && munmap(delta_cache_map, delta_cache_size) == -1)
1803 		err = got_error_from_errno("munmap");
1804 	if (delta_cache_fd != -1 && close(delta_cache_fd) == -1 && err == NULL)
1805 		err = got_error_from_errno("close");
1806 	if (packfile && fclose(packfile) == EOF && err == NULL)
1807 		err = got_error_from_errno("fclose");
1808 	return err;
1809 }
1810 
1811 static const struct got_error *
1812 add_meta_idset_cb(struct got_object_id *id, void *data, void *arg)
1813 {
1814 	struct got_pack_meta *m = data;
1815 	struct got_pack_metavec *v = arg;
1816 
1817 	if (m->reused_delta_offset != 0)
1818 		return NULL;
1819 
1820 	return got_pack_add_meta(m, v);
1821 }
1822 
1823 const struct got_error *
1824 got_pack_create(uint8_t *packsha1, int packfd, FILE *delta_cache,
1825     struct got_object_id **theirs, int ntheirs,
1826     struct got_object_id **ours, int nours,
1827     struct got_repository *repo, int loose_obj_only, int allow_empty,
1828     int force_refdelta, got_pack_progress_cb progress_cb, void *progress_arg,
1829     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1830 {
1831 	const struct got_error *err;
1832 	struct got_object_idset *idset;
1833 	struct got_packidx *reuse_packidx = NULL;
1834 	struct got_pack *reuse_pack = NULL;
1835 	struct got_pack_metavec deltify, reuse;
1836 	int ncolored = 0, nfound = 0, ntrees = 0;
1837 	size_t ndeltify;
1838 	uint32_t seed;
1839 
1840 	seed = arc4random();
1841 
1842 	memset(&deltify, 0, sizeof(deltify));
1843 	memset(&reuse, 0, sizeof(reuse));
1844 
1845 	idset = got_object_idset_alloc();
1846 	if (idset == NULL)
1847 		return got_error_from_errno("got_object_idset_alloc");
1848 
1849 	err = load_object_ids(&ncolored, &nfound, &ntrees, idset, theirs,
1850 	    ntheirs, ours, nours, repo, seed, loose_obj_only,
1851 	    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1852 	if (err)
1853 		goto done;
1854 
1855 	if (progress_cb) {
1856 		err = progress_cb(progress_arg, ncolored, nfound, ntrees,
1857 		    0L, nours, got_object_idset_num_elements(idset), 0, 0);
1858 		if (err)
1859 			goto done;
1860 	}
1861 
1862 	if (got_object_idset_num_elements(idset) == 0 && !allow_empty) {
1863 		err = got_error(GOT_ERR_CANNOT_PACK);
1864 		goto done;
1865 	}
1866 
1867 	reuse.metasz = 64;
1868 	reuse.meta = calloc(reuse.metasz,
1869 	    sizeof(struct got_pack_meta *));
1870 	if (reuse.meta == NULL) {
1871 		err = got_error_from_errno("calloc");
1872 		goto done;
1873 	}
1874 
1875 	err = got_pack_search_deltas(&reuse_packidx, &reuse_pack,
1876 	    &reuse, idset, ncolored, nfound, ntrees, nours,
1877 	    repo, progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1878 	if (err)
1879 		goto done;
1880 
1881 	if (reuse_packidx && reuse_pack) {
1882 		err = got_repo_pin_pack(repo, reuse_packidx, reuse_pack);
1883 		if (err)
1884 			goto done;
1885 	}
1886 
1887 	if (fseeko(delta_cache, 0L, SEEK_END) == -1) {
1888 		err = got_error_from_errno("fseeko");
1889 		goto done;
1890 	}
1891 
1892 	ndeltify = got_object_idset_num_elements(idset) - reuse.nmeta;
1893 	if (ndeltify > 0) {
1894 		deltify.meta = calloc(ndeltify, sizeof(struct got_pack_meta *));
1895 		if (deltify.meta == NULL) {
1896 			err = got_error_from_errno("calloc");
1897 			goto done;
1898 		}
1899 		deltify.metasz = ndeltify;
1900 
1901 		err = got_object_idset_for_each(idset, add_meta_idset_cb,
1902 		    &deltify);
1903 		if (err)
1904 			goto done;
1905 		if (deltify.nmeta > 0) {
1906 			err = pick_deltas(deltify.meta, deltify.nmeta,
1907 			    ncolored, nfound, ntrees, nours, reuse.nmeta,
1908 			    delta_cache, repo, progress_cb, progress_arg, rl,
1909 			    cancel_cb, cancel_arg);
1910 			if (err)
1911 				goto done;
1912 		}
1913 	}
1914 
1915 	if (fflush(delta_cache) == EOF) {
1916 		err = got_error_from_errno("fflush");
1917 		goto done;
1918 	}
1919 
1920 	if (progress_cb) {
1921 		/*
1922 		 * Report a 1-byte packfile write to indicate we are about
1923 		 * to start sending packfile data. gotd(8) needs this.
1924 		 */
1925 		err = progress_cb(progress_arg, ncolored, nfound, ntrees,
1926 		    1 /* packfile_size */, nours,
1927 		    got_object_idset_num_elements(idset),
1928 		    deltify.nmeta + reuse.nmeta, 0);
1929 		if (err)
1930 			goto done;
1931 	}
1932 
1933 	/* Pinned pack may have moved to different cache slot. */
1934 	reuse_pack = got_repo_get_pinned_pack(repo);
1935 
1936 	err = genpack(packsha1, packfd, reuse_pack, delta_cache, deltify.meta,
1937 	    deltify.nmeta, reuse.meta, reuse.nmeta, ncolored, nfound, ntrees,
1938 	    nours, repo, force_refdelta, progress_cb, progress_arg, rl,
1939 	    cancel_cb, cancel_arg);
1940 	if (err)
1941 		goto done;
1942 done:
1943 	free_nmeta(deltify.meta, deltify.nmeta);
1944 	free_nmeta(reuse.meta, reuse.nmeta);
1945 	got_object_idset_free(idset);
1946 	got_repo_unpin_pack(repo);
1947 	return err;
1948 }