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 
25 #include <stdint.h>
26 #include <imsg.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <string.h>
30 #include <sha1.h>
31 #include <time.h>
32 #include <limits.h>
33 #include <zlib.h>
34 
35 #include "got_error.h"
36 #include "got_cancel.h"
37 #include "got_object.h"
38 #include "got_path.h"
39 #include "got_reference.h"
40 #include "got_repository_admin.h"
41 #include "got_opentemp.h"
42 
43 #include "got_lib_deltify.h"
44 #include "got_lib_delta.h"
45 #include "got_lib_object.h"
46 #include "got_lib_object_idset.h"
47 #include "got_lib_object_cache.h"
48 #include "got_lib_deflate.h"
49 #include "got_lib_pack.h"
50 #include "got_lib_privsep.h"
51 #include "got_lib_repository.h"
52 #include "got_lib_ratelimit.h"
53 
54 #ifndef MIN
55 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
56 #endif
57 
58 #ifndef MAX
59 #define	MAX(_a,_b) ((_a) > (_b) ? (_a) : (_b))
60 #endif
61 
62 struct got_pack_meta {
63 	struct got_object_id id;
64 	char	*path;
65 	int	obj_type;
66 	off_t	size;
67 	time_t	mtime;
68 
69 	/* The best delta we picked */
70 	struct got_pack_meta *head;
71 	struct got_pack_meta *prev;
72 	unsigned char *delta_buf; /* if not encoded in delta cache file */
73 	off_t	delta_offset;	/* offset in delta cache file */
74 	off_t	delta_len;	/* encoded delta length */
75 	int	nchain;
76 
77 	/* Only used for delta window */
78 	struct got_delta_table *dtab;
79 
80 	/* Only used for writing offset deltas */
81 	off_t	off;
82 };
83 
84 struct got_pack_metavec {
85 	struct got_pack_meta **meta;
86 	int nmeta;
87 	int metasz;
88 };
89 
90 static const struct got_error *
91 alloc_meta(struct got_pack_meta **new, struct got_object_id *id,
92     const char *path, int obj_type, time_t mtime)
93 {
94 	const struct got_error *err = NULL;
95 	struct got_pack_meta *m;
96 
97 	*new = NULL;
98 
99 	m = calloc(1, sizeof(*m));
100 	if (m == NULL)
101 		return got_error_from_errno("calloc");
102 
103 	memcpy(&m->id, id, sizeof(m->id));
104 
105 	m->path = strdup(path);
106 	if (m->path == NULL) {
107 		err = got_error_from_errno("strdup");
108 		free(m);
109 		return err;
110 	}
111 
112 	m->obj_type = obj_type;
113 	m->mtime = mtime;
114 	*new = m;
115 	return NULL;
116 }
117 
118 static void
119 clear_meta(struct got_pack_meta *meta)
120 {
121 	if (meta == NULL)
122 		return;
123 	free(meta->path);
124 	meta->path = NULL;
125 	free(meta->delta_buf);
126 	meta->delta_buf = NULL;
127 }
128 
129 static void
130 free_nmeta(struct got_pack_meta **meta, int nmeta)
131 {
132 	int i;
133 
134 	for (i = 0; i < nmeta; i++)
135 		clear_meta(meta[i]);
136 	free(meta);
137 }
138 
139 static int
140 delta_order_cmp(const void *pa, const void *pb)
141 {
142 	struct got_pack_meta *a, *b;
143 	int cmp;
144 
145 	a = *(struct got_pack_meta **)pa;
146 	b = *(struct got_pack_meta **)pb;
147 
148 	if (a->obj_type != b->obj_type)
149 		return a->obj_type - b->obj_type;
150 	cmp = strcmp(a->path, b->path);
151 	if (cmp != 0)
152 		return cmp;
153 	if (a->mtime != b->mtime)
154 		return a->mtime - b->mtime;
155 	return got_object_id_cmp(&a->id, &b->id);
156 }
157 
158 static off_t
159 delta_size(struct got_delta_instruction *deltas, int ndeltas)
160 {
161 	int i;
162 	off_t size = 32;
163 	for (i = 0; i < ndeltas; i++) {
164 		if (deltas[i].copy)
165 			size += GOT_DELTA_SIZE_SHIFT;
166 		else
167 			size += deltas[i].len + 1;
168 	}
169 	return size;
170 }
171 
172 static const struct got_error *
173 append(unsigned char **p, size_t *len, off_t *sz, void *seg, int nseg)
174 {
175 	char *n;
176 
177 	if (*len + nseg >= *sz) {
178 		while (*len + nseg >= *sz)
179 			*sz += *sz / 2;
180 		n = realloc(*p, *sz);
181 		if (n == NULL)
182 			return got_error_from_errno("realloc");
183 		*p = n;
184 	}
185 	memcpy(*p + *len, seg, nseg);
186 	*len += nseg;
187 	return NULL;
188 }
189 
190 static const struct got_error *
191 encode_delta_in_mem(struct got_pack_meta *m, struct got_raw_object *o,
192     struct got_delta_instruction *deltas, int ndeltas,
193     off_t delta_size, off_t base_size)
194 {
195 	const struct got_error *err;
196 	unsigned char buf[16], *bp;
197 	int i, j;
198 	size_t len = 0;
199 	off_t n;
200 	struct got_delta_instruction *d;
201 
202 	m->delta_buf = malloc(delta_size);
203 	if (m->delta_buf == NULL)
204 		return got_error_from_errno("calloc");
205 
206 	/* base object size */
207 	buf[0] = base_size & GOT_DELTA_SIZE_VAL_MASK;
208 	n = base_size >> GOT_DELTA_SIZE_SHIFT;
209 	for (i = 1; n > 0; i++) {
210 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
211 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
212 		n >>= GOT_DELTA_SIZE_SHIFT;
213 	}
214 	err = append(&m->delta_buf, &len, &delta_size, buf, i);
215 	if (err)
216 		return err;
217 
218 	/* target object size */
219 	buf[0] = o->size & GOT_DELTA_SIZE_VAL_MASK;
220 	n = o->size >> GOT_DELTA_SIZE_SHIFT;
221 	for (i = 1; n > 0; i++) {
222 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
223 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
224 		n >>= GOT_DELTA_SIZE_SHIFT;
225 	}
226 	err = append(&m->delta_buf, &len, &delta_size, buf, i);
227 	if (err)
228 		return err;
229 
230 	for (j = 0; j < ndeltas; j++) {
231 		d = &deltas[j];
232 		if (d->copy) {
233 			n = d->offset;
234 			bp = &buf[1];
235 			buf[0] = GOT_DELTA_BASE_COPY;
236 			for (i = 0; i < 4; i++) {
237 				/* DELTA_COPY_OFF1 ... DELTA_COPY_OFF4 */
238 				buf[0] |= 1 << i;
239 				*bp++ = n & 0xff;
240 				n >>= 8;
241 				if (n == 0)
242 					break;
243 			}
244 
245 			n = d->len;
246 			if (n != GOT_DELTA_COPY_DEFAULT_LEN) {
247 				/* DELTA_COPY_LEN1 ... DELTA_COPY_LEN3 */
248 				for (i = 0; i < 3 && n > 0; i++) {
249 					buf[0] |= 1 << (i + 4);
250 					*bp++ = n & 0xff;
251 					n >>= 8;
252 				}
253 			}
254 			err = append(&m->delta_buf, &len, &delta_size,
255 			    buf, bp - buf);
256 			if (err)
257 				return err;
258 		} else if (o->f == NULL) {
259 			n = 0;
260 			while (n != d->len) {
261 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
262 				err = append(&m->delta_buf, &len, &delta_size,
263 				    buf, 1);
264 				if (err)
265 					return err;
266 				err = append(&m->delta_buf, &len, &delta_size,
267 				    o->data + o->hdrlen + d->offset + n,
268 				    buf[0]);
269 				if (err)
270 					return err;
271 				n += buf[0];
272 			}
273 		} else {
274 			char content[128];
275 			size_t r;
276 			if (fseeko(o->f, o->hdrlen + d->offset, SEEK_SET) == -1)
277 				return got_error_from_errno("fseeko");
278 			n = 0;
279 			while (n != d->len) {
280 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
281 				err = append(&m->delta_buf, &len, &delta_size,
282 				    buf, 1);
283 				if (err)
284 					return err;
285 				r = fread(content, 1, buf[0], o->f);
286 				if (r != buf[0])
287 					return got_ferror(o->f, GOT_ERR_IO);
288 				err = append(&m->delta_buf, &len, &delta_size,
289 				    content, buf[0]);
290 				if (err)
291 					return err;
292 				n += buf[0];
293 			}
294 		}
295 	}
296 
297 	m->delta_len = len;
298 	return NULL;
299 }
300 
301 static const struct got_error *
302 encode_delta(struct got_pack_meta *m, struct got_raw_object *o,
303     struct got_delta_instruction *deltas, int ndeltas,
304     off_t base_size, FILE *f)
305 {
306 	unsigned char buf[16], *bp;
307 	int i, j;
308 	off_t n;
309 	size_t w;
310 	struct got_delta_instruction *d;
311 
312 	/* base object size */
313 	buf[0] = base_size & GOT_DELTA_SIZE_VAL_MASK;
314 	n = base_size >> GOT_DELTA_SIZE_SHIFT;
315 	for (i = 1; n > 0; i++) {
316 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
317 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
318 		n >>= GOT_DELTA_SIZE_SHIFT;
319 	}
320 	w = fwrite(buf, 1, i, f);
321 	if (w != i)
322 		return got_ferror(f, GOT_ERR_IO);
323 
324 	/* target object size */
325 	buf[0] = o->size & GOT_DELTA_SIZE_VAL_MASK;
326 	n = o->size >> GOT_DELTA_SIZE_SHIFT;
327 	for (i = 1; n > 0; i++) {
328 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
329 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
330 		n >>= GOT_DELTA_SIZE_SHIFT;
331 	}
332 	w = fwrite(buf, 1, i, f);
333 	if (w != i)
334 		return got_ferror(f, GOT_ERR_IO);
335 
336 	for (j = 0; j < ndeltas; j++) {
337 		d = &deltas[j];
338 		if (d->copy) {
339 			n = d->offset;
340 			bp = &buf[1];
341 			buf[0] = GOT_DELTA_BASE_COPY;
342 			for (i = 0; i < 4; i++) {
343 				/* DELTA_COPY_OFF1 ... DELTA_COPY_OFF4 */
344 				buf[0] |= 1 << i;
345 				*bp++ = n & 0xff;
346 				n >>= 8;
347 				if (n == 0)
348 					break;
349 			}
350 
351 			n = d->len;
352 			if (n != GOT_DELTA_COPY_DEFAULT_LEN) {
353 				/* DELTA_COPY_LEN1 ... DELTA_COPY_LEN3 */
354 				for (i = 0; i < 3 && n > 0; i++) {
355 					buf[0] |= 1 << (i + 4);
356 					*bp++ = n & 0xff;
357 					n >>= 8;
358 				}
359 			}
360 			w = fwrite(buf, 1, bp - buf, f);
361 			if (w != bp - buf)
362 				return got_ferror(f, GOT_ERR_IO);
363 		} else if (o->f == NULL) {
364 			n = 0;
365 			while (n != d->len) {
366 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
367 				w = fwrite(buf, 1, 1, f);
368 				if (w != 1)
369 					return got_ferror(f, GOT_ERR_IO);
370 				w = fwrite(o->data + o->hdrlen + d->offset + n,
371 				    1, buf[0], f);
372 				if (w != buf[0])
373 					return got_ferror(f, GOT_ERR_IO);
374 				n += buf[0];
375 			}
376 		} else {
377 			char content[128];
378 			size_t r;
379 			if (fseeko(o->f, o->hdrlen + d->offset, SEEK_SET) == -1)
380 				return got_error_from_errno("fseeko");
381 			n = 0;
382 			while (n != d->len) {
383 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
384 				w = fwrite(buf, 1, 1, f);
385 				if (w != 1)
386 					return got_ferror(f, GOT_ERR_IO);
387 				r = fread(content, 1, buf[0], o->f);
388 				if (r != buf[0])
389 					return got_ferror(o->f, GOT_ERR_IO);
390 				w = fwrite(content, 1, buf[0], f);
391 				if (w != buf[0])
392 					return got_ferror(f, GOT_ERR_IO);
393 				n += buf[0];
394 			}
395 		}
396 	}
397 
398 	m->delta_len = ftello(f) - m->delta_offset;
399 	return NULL;
400 }
401 
402 static const struct got_error *
403 report_progress(got_pack_progress_cb progress_cb, void *progress_arg,
404     struct got_ratelimit *rl, off_t packfile_size, int ncommits,
405     int nobj_total, int obj_deltify, int nobj_written)
406 {
407 	const struct got_error *err;
408 	int elapsed;
409 
410 	if (progress_cb == NULL)
411 		return NULL;
412 
413 	err = got_ratelimit_check(&elapsed, rl);
414 	if (err || !elapsed)
415 		return err;
416 
417 	return progress_cb(progress_arg, packfile_size, ncommits,
418 	    nobj_total, obj_deltify, nobj_written);
419 }
420 
421 static const struct got_error *
422 pick_deltas(struct got_pack_meta **meta, int nmeta, int nours,
423     FILE *delta_cache, struct got_repository *repo,
424     got_pack_progress_cb progress_cb, void *progress_arg,
425     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
426 {
427 	const struct got_error *err = NULL;
428 	struct got_pack_meta *m = NULL, *base = NULL;
429 	struct got_raw_object *raw = NULL, *base_raw = NULL;
430 	struct got_delta_instruction *deltas = NULL, *best_deltas = NULL;
431 	int i, j, ndeltas, best_ndeltas;
432 	off_t size, best_size;
433 	const int max_base_candidates = 3;
434 	int outfd = -1;
435 
436 	qsort(meta, nmeta, sizeof(struct got_pack_meta *), delta_order_cmp);
437 	for (i = 0; i < nmeta; i++) {
438 		if (cancel_cb) {
439 			err = (*cancel_cb)(cancel_arg);
440 			if (err)
441 				break;
442 		}
443 		err = report_progress(progress_cb, progress_arg, rl,
444 		    0L, nours, nmeta, i, 0);
445 		if (err)
446 			goto done;
447 		m = meta[i];
448 
449 		if (m->obj_type == GOT_OBJ_TYPE_COMMIT ||
450 		    m->obj_type == GOT_OBJ_TYPE_TAG)
451 			continue;
452 
453 		err = got_object_raw_open(&raw, &outfd, repo, &m->id);
454 		if (err)
455 			goto done;
456 		m->size = raw->size;
457 
458 		if (raw->f == NULL) {
459 			err = got_deltify_init_mem(&m->dtab, raw->data,
460 			    raw->hdrlen, raw->size + raw->hdrlen);
461 		} else {
462 			err = got_deltify_init(&m->dtab, raw->f, raw->hdrlen,
463 			    raw->size + raw->hdrlen);
464 		}
465 		if (err)
466 			goto done;
467 
468 		if (i > max_base_candidates) {
469 			struct got_pack_meta *n = NULL;
470 			n = meta[i - (max_base_candidates + 1)];
471 			got_deltify_free(n->dtab);
472 			n->dtab = NULL;
473 		}
474 
475 		best_size = raw->size;
476 		best_ndeltas = 0;
477 		for (j = MAX(0, i - max_base_candidates); j < i; j++) {
478 			if (cancel_cb) {
479 				err = (*cancel_cb)(cancel_arg);
480 				if (err)
481 					goto done;
482 			}
483 			base = meta[j];
484 			/* long chains make unpacking slow, avoid such bases */
485 			if (base->nchain >= 128 ||
486 			    base->obj_type != m->obj_type)
487 				continue;
488 
489 			err = got_object_raw_open(&base_raw, &outfd, repo,
490 			    &base->id);
491 			if (err)
492 				goto done;
493 			if (raw->f == NULL && base_raw->f == NULL) {
494 				err = got_deltify_mem_mem(&deltas, &ndeltas,
495 				    raw->data, raw->hdrlen,
496 				    raw->size + raw->hdrlen,
497 				    base->dtab, base_raw->data,
498 				    base_raw->hdrlen,
499 				    base_raw->size + base_raw->hdrlen);
500 			} else if (raw->f == NULL) {
501 				err = got_deltify_mem_file(&deltas, &ndeltas,
502 				    raw->data, raw->hdrlen,
503 				    raw->size + raw->hdrlen,
504 				    base->dtab, base_raw->f,
505 				    base_raw->hdrlen,
506 				    base_raw->size + base_raw->hdrlen);
507 			} else if (base_raw->f == NULL) {
508 				err = got_deltify_file_mem(&deltas, &ndeltas,
509 				    raw->f, raw->hdrlen,
510 				    raw->size + raw->hdrlen,
511 				    base->dtab, base_raw->data,
512 				    base_raw->hdrlen,
513 				    base_raw->size + base_raw->hdrlen);
514 			} else {
515 				err = got_deltify(&deltas, &ndeltas,
516 				    raw->f, raw->hdrlen,
517 				    raw->size + raw->hdrlen,
518 				    base->dtab, base_raw->f, base_raw->hdrlen,
519 				    base_raw->size + base_raw->hdrlen);
520 			}
521 			got_object_raw_close(base_raw);
522 			base_raw = NULL;
523 			if (err)
524 				goto done;
525 
526 			size = delta_size(deltas, ndeltas);
527 			if (size + 32 < best_size){
528 				/*
529 				 * if we already picked a best delta,
530 				 * replace it.
531 				 */
532 				best_size = size;
533 				free(best_deltas);
534 				best_deltas = deltas;
535 				best_ndeltas = ndeltas;
536 				deltas = NULL;
537 				m->nchain = base->nchain + 1;
538 				m->prev = base;
539 				m->head = base->head;
540 				if (m->head == NULL)
541 					m->head = base;
542 			} else {
543 				free(deltas);
544 				deltas = NULL;
545 				ndeltas = 0;
546 			}
547 		}
548 
549 		if (best_ndeltas > 0) {
550 			if (best_size <= GOT_DELTA_RESULT_SIZE_CACHED_MAX) {
551 				err = encode_delta_in_mem(m, raw, best_deltas,
552 				    best_ndeltas, best_size, m->prev->size);
553 			} else {
554 				m->delta_offset = ftello(delta_cache);
555 				err = encode_delta(m, raw, best_deltas,
556 				    best_ndeltas, m->prev->size, delta_cache);
557 			}
558 			free(best_deltas);
559 			best_deltas = NULL;
560 			best_ndeltas = 0;
561 			if (err)
562 				goto done;
563 		}
564 
565 		got_object_raw_close(raw);
566 		raw = NULL;
567 	}
568 done:
569 	for (i = MAX(0, nmeta - max_base_candidates); i < nmeta; i++) {
570 		got_deltify_free(meta[i]->dtab);
571 		meta[i]->dtab = NULL;
572 	}
573 	if (raw)
574 		got_object_raw_close(raw);
575 	if (base_raw)
576 		got_object_raw_close(base_raw);
577 	if (outfd != -1 && close(outfd) == -1 && err == NULL)
578 		err = got_error_from_errno("close");
579 	free(deltas);
580 	free(best_deltas);
581 	return err;
582 }
583 
584 static const struct got_error *
585 search_packidx(int *found, struct got_object_id *id,
586     struct got_repository *repo)
587 {
588 	const struct got_error *err = NULL;
589 	struct got_packidx *packidx = NULL;
590 	int idx;
591 
592 	*found = 0;
593 
594 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
595 	if (err == NULL)
596 		*found = 1; /* object is already packed */
597 	else if (err->code == GOT_ERR_NO_OBJ)
598 		err = NULL;
599 	return err;
600 }
601 
602 static const int obj_types[] = {
603 	GOT_OBJ_TYPE_ANY,
604 	GOT_OBJ_TYPE_COMMIT,
605 	GOT_OBJ_TYPE_TREE,
606 	GOT_OBJ_TYPE_BLOB,
607 	GOT_OBJ_TYPE_TAG,
608 	GOT_OBJ_TYPE_OFFSET_DELTA,
609 	GOT_OBJ_TYPE_REF_DELTA
610 };
611 
612 static const struct got_error *
613 add_meta(struct got_pack_metavec *v, struct got_object_idset *idset,
614     struct got_object_id *id, const char *path, int obj_type,
615     time_t mtime, int loose_obj_only, struct got_repository *repo)
616 {
617 	const struct got_error *err;
618 	struct got_pack_meta *m;
619 
620 	if (loose_obj_only) {
621 		int is_packed;
622 		err = search_packidx(&is_packed, id, repo);
623 		if (err)
624 			return err;
625 		if (is_packed)
626 			return NULL;
627 	}
628 
629 	err = got_object_idset_add(idset, id, (void *)&obj_types[obj_type]);
630 	if (err)
631 		return err;
632 
633 	if (v == NULL)
634 		return NULL;
635 
636 	err = alloc_meta(&m, id, path, obj_type, mtime);
637 	if (err)
638 		goto done;
639 
640 	if (v->nmeta == v->metasz){
641 		size_t newsize = 2 * v->metasz;
642 		struct got_pack_meta **new;
643 		new = reallocarray(v->meta, newsize, sizeof(*new));
644 		if (new == NULL) {
645 			err = got_error_from_errno("reallocarray");
646 			goto done;
647 		}
648 		v->meta = new;
649 		v->metasz = newsize; 
650 	}
651 done:
652 	if (err) {
653 		clear_meta(m);
654 		free(m);
655 	} else
656 		v->meta[v->nmeta++] = m;
657 
658 	return err;
659 }
660 
661 static const struct got_error *
662 load_tree_entries(struct got_object_id_queue *ids, struct got_pack_metavec *v,
663     struct got_object_idset *idset, struct got_object_id *tree_id,
664     const char *dpath, time_t mtime, struct got_repository *repo,
665     int loose_obj_only, got_cancel_cb cancel_cb, void *cancel_arg)
666 {
667 	const struct got_error *err;
668 	struct got_tree_object *tree;
669 	char *p = NULL;
670 	int i;
671 
672 	err = got_object_open_as_tree(&tree, repo, tree_id);
673 	if (err)
674 		return err;
675 
676 	for (i = 0; i < got_object_tree_get_nentries(tree); i++) {
677 		struct got_tree_entry *e = got_object_tree_get_entry(tree, i);
678 		struct got_object_id *id = got_tree_entry_get_id(e);
679 		mode_t mode = got_tree_entry_get_mode(e);
680 
681 		if (cancel_cb) {
682 			err = (*cancel_cb)(cancel_arg);
683 			if (err)
684 				break;
685 		}
686 
687 		if (got_object_tree_entry_is_submodule(e) ||
688 		    got_object_idset_contains(idset, id))
689 			continue;
690 		
691 		if (asprintf(&p, "%s%s%s", dpath, dpath[0] != '\0' ? "/" : "",
692 		    got_tree_entry_get_name(e)) == -1) {
693 			err = got_error_from_errno("asprintf");
694 			break;
695 		}
696 
697 		if (S_ISDIR(mode)) {
698 			struct got_object_qid *qid;
699 			err = got_object_qid_alloc(&qid, id);
700 			if (err)
701 				break;
702 			STAILQ_INSERT_TAIL(ids, qid, entry);
703 		} else if (S_ISREG(mode) || S_ISLNK(mode)) {
704 			err = add_meta(v, idset, id, p, GOT_OBJ_TYPE_BLOB,
705 			    mtime, loose_obj_only, repo);
706 			if (err)
707 				break;
708 		}
709 		free(p);
710 		p = NULL;
711 	}
712 
713 	got_object_tree_close(tree);
714 	free(p);
715 	return err;
716 }
717 
718 static const struct got_error *
719 load_tree(struct got_pack_metavec *v, struct got_object_idset *idset,
720     struct got_object_id *tree_id, const char *dpath, time_t mtime,
721     int loose_obj_only, struct got_repository *repo,
722     got_cancel_cb cancel_cb, void *cancel_arg)
723 {
724 	const struct got_error *err = NULL;
725 	struct got_object_id_queue tree_ids;
726 	struct got_object_qid *qid;
727 
728 	if (got_object_idset_contains(idset, tree_id))
729 		return NULL;
730 
731 	err = got_object_qid_alloc(&qid, tree_id);
732 	if (err)
733 		return err;
734 
735 	STAILQ_INIT(&tree_ids);
736 	STAILQ_INSERT_TAIL(&tree_ids, qid, entry);
737 
738 	while (!STAILQ_EMPTY(&tree_ids)) {
739 		if (cancel_cb) {
740 			err = (*cancel_cb)(cancel_arg);
741 			if (err)
742 				break;
743 		}
744 
745 		qid = STAILQ_FIRST(&tree_ids);
746 		STAILQ_REMOVE_HEAD(&tree_ids, entry);
747 
748 		if (got_object_idset_contains(idset, qid->id)) {
749 			got_object_qid_free(qid);
750 			continue;
751 		}
752 
753 		err = add_meta(v, idset, qid->id, dpath, GOT_OBJ_TYPE_TREE,
754 		    mtime, loose_obj_only, repo);
755 		if (err) {
756 			got_object_qid_free(qid);
757 			break;
758 		}
759 
760 		err = load_tree_entries(&tree_ids, v, idset, qid->id, dpath,
761 		    mtime, repo, loose_obj_only, cancel_cb, cancel_arg);
762 		got_object_qid_free(qid);
763 		if (err)
764 			break;
765 	}
766 
767 	got_object_id_queue_free(&tree_ids);
768 	return err;
769 }
770 
771 static const struct got_error *
772 load_commit(struct got_pack_metavec *v, struct got_object_idset *idset,
773     struct got_object_id *id, struct got_repository *repo, int loose_obj_only,
774     got_cancel_cb cancel_cb, void *cancel_arg)
775 {
776 	const struct got_error *err;
777 	struct got_commit_object *commit;
778 
779 	if (got_object_idset_contains(idset, id))
780 		return NULL;
781 
782 	if (loose_obj_only) {
783 		int is_packed;
784 		err = search_packidx(&is_packed, id, repo);
785 		if (err)
786 			return err;
787 		if (is_packed)
788 			return NULL;
789 	}
790 
791 	err = got_object_open_as_commit(&commit, repo, id);
792 	if (err)
793 		return err;
794 
795 	err = add_meta(v, idset, id, "", GOT_OBJ_TYPE_COMMIT,
796 	    got_object_commit_get_committer_time(commit),
797 	    loose_obj_only, repo);
798 	if (err)
799 		goto done;
800 
801 	err = load_tree(v, idset, got_object_commit_get_tree_id(commit),
802 	    "", got_object_commit_get_committer_time(commit),
803 	    loose_obj_only, repo, cancel_cb, cancel_arg);
804 done:
805 	got_object_commit_close(commit);
806 	return err;
807 }
808 
809 static const struct got_error *
810 load_tag(struct got_pack_metavec *v, struct got_object_idset *idset,
811     struct got_object_id *id, struct got_repository *repo, int loose_obj_only,
812     got_cancel_cb cancel_cb, void *cancel_arg)
813 {
814 	const struct got_error *err;
815 	struct got_tag_object *tag = NULL;
816 
817 	if (got_object_idset_contains(idset, id))
818 		return NULL;
819 
820 	if (loose_obj_only) {
821 		int is_packed;
822 		err = search_packidx(&is_packed, id, repo);
823 		if (err)
824 			return err;
825 		if (is_packed)
826 			return NULL;
827 	}
828 
829 	err = got_object_open_as_tag(&tag, repo, id);
830 	if (err)
831 		return err;
832 
833 	err = add_meta(v, idset, id, "", GOT_OBJ_TYPE_TAG,
834 	    got_object_tag_get_tagger_time(tag),
835 	    loose_obj_only, repo);
836 	if (err)
837 		goto done;
838 
839 	switch (got_object_tag_get_object_type(tag)) {
840 	case GOT_OBJ_TYPE_COMMIT:
841 		err = load_commit(v, idset,
842 		    got_object_tag_get_object_id(tag), repo,
843 		    loose_obj_only, cancel_cb, cancel_arg);
844 		break;
845 	case GOT_OBJ_TYPE_TREE:
846 		err = load_tree(v, idset, got_object_tag_get_object_id(tag),
847 		    "", got_object_tag_get_tagger_time(tag),
848 		    loose_obj_only, repo, cancel_cb, cancel_arg);
849 		break;
850 	default:
851 		break;
852 	}
853 
854 done:
855 	got_object_tag_close(tag);
856 	return err;
857 }
858 
859 enum findtwixt_color {
860 	COLOR_KEEP = 0,
861 	COLOR_DROP,
862 	COLOR_BLANK,
863 };
864 static const int findtwixt_colors[] = {
865 	COLOR_KEEP,
866 	COLOR_DROP,
867 	COLOR_BLANK
868 };
869 
870 static const struct got_error *
871 queue_commit_id(struct got_object_id_queue *ids, struct got_object_id *id,
872     int color, struct got_repository *repo)
873 {
874 	const struct got_error *err;
875 	struct got_object_qid *qid;
876 
877 	err = got_object_qid_alloc(&qid, id);
878 	if (err)
879 		return err;
880 
881 	STAILQ_INSERT_TAIL(ids, qid, entry);
882 	qid->data = (void *)&findtwixt_colors[color];
883 	return NULL;
884 }
885 
886 static const struct got_error *
887 drop_commit(struct got_object_idset *keep, struct got_object_idset *drop,
888     struct got_object_id *id, struct got_repository *repo,
889     got_cancel_cb cancel_cb, void *cancel_arg)
890 {
891 	const struct got_error *err = NULL;
892 	struct got_commit_object *commit;
893 	const struct got_object_id_queue *parents;
894 	struct got_object_id_queue ids;
895 	struct got_object_qid *qid;
896 
897 	STAILQ_INIT(&ids);
898 
899 	err = got_object_qid_alloc(&qid, id);
900 	if (err)
901 		return err;
902 	STAILQ_INSERT_HEAD(&ids, qid, entry);
903 
904 	while (!STAILQ_EMPTY(&ids)) {
905 		if (cancel_cb) {
906 			err = (*cancel_cb)(cancel_arg);
907 			if (err)
908 				break;
909 		}
910 
911 		qid = STAILQ_FIRST(&ids);
912 		STAILQ_REMOVE_HEAD(&ids, entry);
913 
914 		if (got_object_idset_contains(drop, qid->id)) {
915 			got_object_qid_free(qid);
916 			continue;
917 		}
918 
919 		err = got_object_idset_add(drop, qid->id,
920 		    (void *)&obj_types[GOT_OBJ_TYPE_COMMIT]);
921 		if (err) {
922 			got_object_qid_free(qid);
923 			break;
924 		}
925 
926 		if (!got_object_idset_contains(keep, qid->id)) {
927 			got_object_qid_free(qid);
928 			continue;
929 		}
930 
931 		err = got_object_open_as_commit(&commit, repo, qid->id);
932 		got_object_qid_free(qid);
933 		if (err)
934 			break;
935 
936 		parents = got_object_commit_get_parent_ids(commit);
937 		if (parents) {
938 			err = got_object_id_queue_copy(parents, &ids);
939 			if (err) {
940 				got_object_commit_close(commit);
941 				break;
942 			}
943 		}
944 		got_object_commit_close(commit);
945 	}
946 
947 	got_object_id_queue_free(&ids);
948 	return err;
949 }
950 
951 struct append_id_arg {
952 	struct got_object_id **array;
953 	int idx;
954 };
955 
956 static const struct got_error *
957 append_id(struct got_object_id *id, void *data, void *arg)
958 {
959 	struct append_id_arg *a = arg;
960 
961 	a->array[a->idx] = got_object_id_dup(id);
962 	if (a->array[a->idx] == NULL)
963 		return got_error_from_errno("got_object_id_dup");
964 
965 	a->idx++;
966 	return NULL;
967 }
968 
969 static const struct got_error *
970 findtwixt(struct got_object_id ***res, int *nres,
971     struct got_object_id **head, int nhead,
972     struct got_object_id **tail, int ntail,
973     struct got_repository *repo,
974     got_cancel_cb cancel_cb, void *cancel_arg)
975 {
976 	const struct got_error *err = NULL;
977 	struct got_object_id_queue ids;
978 	struct got_object_idset *keep, *drop;
979 	struct got_object_qid *qid;
980 	int i, ncolor, nkeep, obj_type;
981 
982 	STAILQ_INIT(&ids);
983 	*res = NULL;
984 	*nres = 0;
985 
986 	keep = got_object_idset_alloc();
987 	if (keep == NULL)
988 		return got_error_from_errno("got_object_idset_alloc");
989 
990 	drop = got_object_idset_alloc();
991 	if (drop == NULL) {
992 		err = got_error_from_errno("got_object_idset_alloc");
993 		goto done;
994 	}
995 
996 	for (i = 0; i < nhead; i++) {
997 		struct got_object_id *id = head[i];
998 		if (id == NULL)
999 			continue;
1000 		err = got_object_get_type(&obj_type, repo, id);
1001 		if (err)
1002 			return err;
1003 		if (obj_type != GOT_OBJ_TYPE_COMMIT)
1004 			continue;
1005 		err = queue_commit_id(&ids, id, COLOR_KEEP, repo);
1006 		if (err)
1007 			goto done;
1008 	}		
1009 	for (i = 0; i < ntail; i++) {
1010 		struct got_object_id *id = tail[i];
1011 		if (id == NULL)
1012 			continue;
1013 		err = got_object_get_type(&obj_type, repo, id);
1014 		if (err)
1015 			return err;
1016 		if (obj_type != GOT_OBJ_TYPE_COMMIT)
1017 			continue;
1018 		err = queue_commit_id(&ids, id, COLOR_DROP, repo);
1019 		if (err)
1020 			goto done;
1021 	}
1022 
1023 	while (!STAILQ_EMPTY(&ids)) {
1024 		int qcolor;
1025 		qid = STAILQ_FIRST(&ids);
1026 		qcolor = *((int *)qid->data);
1027 
1028 		if (got_object_idset_contains(drop, qid->id))
1029 			ncolor = COLOR_DROP;
1030 		else if (got_object_idset_contains(keep, qid->id))
1031 			ncolor = COLOR_KEEP;
1032 		else
1033 			ncolor = COLOR_BLANK;
1034 
1035 		if (ncolor == COLOR_DROP || (ncolor == COLOR_KEEP &&
1036 		    qcolor == COLOR_KEEP)) {
1037 			STAILQ_REMOVE_HEAD(&ids, entry);
1038 			got_object_qid_free(qid);
1039 			continue;
1040 		}
1041 
1042 		if (ncolor == COLOR_KEEP && qcolor == COLOR_DROP) {
1043 			err = drop_commit(keep, drop, qid->id, repo,
1044 			    cancel_cb, cancel_arg);
1045 			if (err)
1046 				goto done;
1047 		} else if (ncolor == COLOR_BLANK) {
1048 			struct got_commit_object *commit;
1049 			struct got_object_id *id;
1050 			const struct got_object_id_queue *parents;
1051 			struct got_object_qid *pid;
1052 
1053 			id = got_object_id_dup(qid->id);
1054 			if (id == NULL) {
1055 				err = got_error_from_errno("got_object_id_dup");
1056 				goto done;
1057 			}
1058 			if (qcolor == COLOR_KEEP)
1059 				err = got_object_idset_add(keep, id,
1060 				    (void *)&obj_types[GOT_OBJ_TYPE_COMMIT]);
1061 			else
1062 				err = got_object_idset_add(drop, id,
1063 				    (void *)&obj_types[GOT_OBJ_TYPE_COMMIT]);
1064 			if (err) {
1065 				free(id);
1066 				goto done;
1067 			}
1068 
1069 			err = got_object_open_as_commit(&commit, repo, id);
1070 			if (err) {
1071 				free(id);
1072 				goto done;
1073 			}
1074 			parents = got_object_commit_get_parent_ids(commit);
1075 			if (parents) {
1076 				STAILQ_FOREACH(pid, parents, entry) {
1077 					err = queue_commit_id(&ids, pid->id,
1078 					    qcolor, repo);
1079 					if (err) {
1080 						free(id);
1081 						goto done;
1082 					}
1083 				}
1084 			}
1085 			got_object_commit_close(commit);
1086 			commit = NULL;
1087 		} else {
1088 			/* should not happen */
1089 			err = got_error_fmt(GOT_ERR_NOT_IMPL,
1090 			    "%s ncolor=%d qcolor=%d", __func__, ncolor, qcolor);
1091 			goto done;
1092 		}
1093 
1094 		STAILQ_REMOVE_HEAD(&ids, entry);
1095 		got_object_qid_free(qid);
1096 	}
1097 
1098 	nkeep = got_object_idset_num_elements(keep);
1099 	if (nkeep > 0) {
1100 		struct append_id_arg arg;
1101 		arg.array = calloc(nkeep, sizeof(struct got_object_id *));
1102 		if (arg.array == NULL) {
1103 			err = got_error_from_errno("calloc");
1104 			goto done;
1105 		}
1106 		arg.idx = 0;
1107 		err = got_object_idset_for_each(keep, append_id, &arg);
1108 		if (err) {
1109 			free(arg.array);
1110 			goto done;
1111 		}
1112 		*res = arg.array;
1113 		*nres = nkeep;
1114 	}
1115 done:
1116 	got_object_idset_free(keep);
1117 	got_object_idset_free(drop);
1118 	got_object_id_queue_free(&ids);
1119 	return err;
1120 }
1121 
1122 static const struct got_error *
1123 read_meta(struct got_pack_meta ***meta, int *nmeta,
1124     struct got_object_id **theirs, int ntheirs,
1125     struct got_object_id **ours, int nours, struct got_repository *repo,
1126     int loose_obj_only, got_pack_progress_cb progress_cb, void *progress_arg,
1127     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1128 {
1129 	const struct got_error *err = NULL;
1130 	struct got_object_id **ids = NULL;
1131 	struct got_object_idset *idset;
1132 	int i, nobj = 0, obj_type;
1133 	struct got_pack_metavec v;
1134 
1135 	*meta = NULL;
1136 	*nmeta = 0;
1137 
1138 	idset = got_object_idset_alloc();
1139 	if (idset == NULL)
1140 		return got_error_from_errno("got_object_idset_alloc");
1141 
1142 	v.nmeta = 0;
1143 	v.metasz = 64;
1144 	v.meta = calloc(v.metasz, sizeof(struct got_pack_meta *));
1145 	if (v.meta == NULL) {
1146 		err = got_error_from_errno("calloc");
1147 		goto done;
1148 	}
1149 
1150 	err = findtwixt(&ids, &nobj, ours, nours, theirs, ntheirs, repo,
1151 	    cancel_cb, cancel_arg);
1152 	if (err || nobj == 0)
1153 		goto done;
1154 
1155 	for (i = 0; i < ntheirs; i++) {
1156 		struct got_object_id *id = theirs[i];
1157 		if (id == NULL)
1158 			continue;
1159 		err = got_object_get_type(&obj_type, repo, id);
1160 		if (err)
1161 			return err;
1162 		if (obj_type != GOT_OBJ_TYPE_COMMIT)
1163 			continue;
1164 		err = load_commit(NULL, idset, id, repo,
1165 		    loose_obj_only, cancel_cb, cancel_arg);
1166 		if (err)
1167 			goto done;
1168 		err = report_progress(progress_cb, progress_arg, rl,
1169 		    0L, nours, v.nmeta, 0, 0);
1170 		if (err)
1171 			goto done;
1172 	}
1173 
1174 	for (i = 0; i < ntheirs; i++) {
1175 		struct got_object_id *id = theirs[i];
1176 		int *cached_type;
1177 		if (id == NULL)
1178 			continue;
1179 		cached_type = got_object_idset_get(idset, id);
1180 		if (cached_type == NULL) {
1181 			err = got_object_get_type(&obj_type, repo, id);
1182 			if (err)
1183 				goto done;
1184 		} else
1185 			obj_type = *cached_type;
1186 		if (obj_type != GOT_OBJ_TYPE_TAG)
1187 			continue;
1188 		err = load_tag(NULL, idset, id, repo,
1189 		    loose_obj_only, cancel_cb, cancel_arg);
1190 		if (err)
1191 			goto done;
1192 		err = report_progress(progress_cb, progress_arg, rl,
1193 		    0L, nours, v.nmeta, 0, 0);
1194 		if (err)
1195 			goto done;
1196 	}
1197 
1198 	for (i = 0; i < nobj; i++) {
1199 		err = load_commit(&v, idset, ids[i], repo,
1200 		    loose_obj_only, cancel_cb, cancel_arg);
1201 		if (err)
1202 			goto done;
1203 		if (err)
1204 			goto done;
1205 		err = report_progress(progress_cb, progress_arg, rl,
1206 		    0L, nours, v.nmeta, 0, 0);
1207 		if (err)
1208 			goto done;
1209 	}
1210 
1211 	for (i = 0; i < nours; i++) {
1212 		struct got_object_id *id = ours[i];
1213 		int *cached_type;
1214 		if (id == NULL)
1215 			continue;
1216 		cached_type = got_object_idset_get(idset, id);
1217 		if (cached_type == NULL) {
1218 			err = got_object_get_type(&obj_type, repo, id);
1219 			if (err)
1220 				goto done;
1221 		} else
1222 			obj_type = *cached_type;
1223 		if (obj_type != GOT_OBJ_TYPE_TAG)
1224 			continue;
1225 		err = load_tag(&v, idset, id, repo,
1226 		    loose_obj_only, cancel_cb, cancel_arg);
1227 		if (err)
1228 			goto done;
1229 		err = report_progress(progress_cb, progress_arg, rl,
1230 		    0L, nours, v.nmeta, 0, 0);
1231 		if (err)
1232 			goto done;
1233 	}
1234 
1235 	if (progress_cb) {
1236 		err = progress_cb(progress_arg, 0L, nours, v.nmeta, 0, 0);
1237 		if (err)
1238 			goto done;
1239 	}
1240 done:
1241 	for (i = 0; i < nobj; i++) {
1242 		free(ids[i]);
1243 	}
1244 	free(ids);
1245 	got_object_idset_free(idset);
1246 	if (err == NULL) {
1247 		*meta = v.meta;
1248 		*nmeta = v.nmeta;
1249 	} else
1250 		free(v.meta);
1251 
1252 	return err;
1253 }
1254 
1255 const struct got_error *
1256 hwrite(FILE *f, void *buf, int len, SHA1_CTX *ctx)
1257 {
1258 	size_t n;
1259 
1260 	SHA1Update(ctx, buf, len);
1261 	n = fwrite(buf, 1, len, f);
1262 	if (n != len)
1263 		return got_ferror(f, GOT_ERR_IO);
1264 	return NULL;
1265 }
1266 
1267 static void
1268 putbe32(char *b, uint32_t n)
1269 {
1270 	b[0] = n >> 24;
1271 	b[1] = n >> 16;
1272 	b[2] = n >> 8;
1273 	b[3] = n >> 0;
1274 }
1275 
1276 static int
1277 write_order_cmp(const void *pa, const void *pb)
1278 {
1279 	struct got_pack_meta *a, *b, *ahd, *bhd;
1280 
1281 	a = *(struct got_pack_meta **)pa;
1282 	b = *(struct got_pack_meta **)pb;
1283 	ahd = (a->head == NULL) ? a : a->head;
1284 	bhd = (b->head == NULL) ? b : b->head;
1285 	if (ahd->mtime != bhd->mtime)
1286 		return bhd->mtime - ahd->mtime;
1287 	if (ahd != bhd)
1288 		return (uintptr_t)bhd - (uintptr_t)ahd;
1289 	if (a->nchain != b->nchain)
1290 		return a->nchain - b->nchain;
1291 	return a->mtime - b->mtime;
1292 }
1293 
1294 static const struct got_error *
1295 packhdr(int *hdrlen, char *hdr, size_t bufsize, int obj_type, size_t len)
1296 {
1297 	size_t i;
1298 
1299 	*hdrlen = 0;
1300 
1301 	hdr[0] = obj_type << 4;
1302 	hdr[0] |= len & 0xf;
1303 	len >>= 4;
1304 	for (i = 1; len != 0; i++){
1305 		if (i >= bufsize)
1306 			return got_error(GOT_ERR_NO_SPACE);
1307 		hdr[i - 1] |= GOT_DELTA_SIZE_MORE;
1308 		hdr[i] = len & GOT_DELTA_SIZE_VAL_MASK;
1309 		len >>= GOT_DELTA_SIZE_SHIFT;
1310 	}
1311 
1312 	*hdrlen = i;
1313 	return NULL;
1314 }
1315 
1316 static int
1317 packoff(char *hdr, off_t off)
1318 {
1319 	int i, j;
1320 	char rbuf[8];
1321 
1322 	rbuf[0] = off & GOT_DELTA_SIZE_VAL_MASK;
1323 	for (i = 1; (off >>= GOT_DELTA_SIZE_SHIFT) != 0; i++) {
1324 		rbuf[i] = (--off & GOT_DELTA_SIZE_VAL_MASK) |
1325 		    GOT_DELTA_SIZE_MORE;
1326 	}
1327 
1328 	j = 0;
1329 	while (i > 0)
1330 		hdr[j++] = rbuf[--i];
1331 	return j;
1332 }
1333 
1334 static const struct got_error *
1335 deltahdr(off_t *packfile_size, SHA1_CTX *ctx, FILE *packfile,
1336     struct got_pack_meta *m, int use_offset_deltas)
1337 {
1338 	const struct got_error *err;
1339 	char buf[32];
1340 	int nh;
1341 
1342 	if (use_offset_deltas && m->prev->off != 0) {
1343 		err = packhdr(&nh, buf, sizeof(buf),
1344 		    GOT_OBJ_TYPE_OFFSET_DELTA, m->delta_len);
1345 		if (err)
1346 			return err;
1347 		nh += packoff(buf + nh, m->off - m->prev->off);
1348 		err = hwrite(packfile, buf, nh, ctx);
1349 		if (err)
1350 			return err;
1351 		*packfile_size += nh;
1352 	} else {
1353 		err = packhdr(&nh, buf, sizeof(buf),
1354 		    GOT_OBJ_TYPE_REF_DELTA, m->delta_len);
1355 		if (err)
1356 			return err;
1357 		err = hwrite(packfile, buf, nh, ctx);
1358 		if (err)
1359 			return err;
1360 		*packfile_size += nh;
1361 		err = hwrite(packfile, m->prev->id.sha1,
1362 		    sizeof(m->prev->id.sha1), ctx);
1363 		if (err)
1364 			return err;
1365 		*packfile_size += sizeof(m->prev->id.sha1);
1366 	}
1367 
1368 	return NULL;
1369 }
1370 
1371 static const struct got_error *
1372 genpack(uint8_t *pack_sha1, FILE *packfile, FILE *delta_cache,
1373     struct got_pack_meta **meta, int nmeta, int nours,
1374     int use_offset_deltas, struct got_repository *repo,
1375     got_pack_progress_cb progress_cb, void *progress_arg,
1376     struct got_ratelimit *rl,
1377     got_cancel_cb cancel_cb, void *cancel_arg)
1378 {
1379 	const struct got_error *err = NULL;
1380 	int i, nh;
1381 	SHA1_CTX ctx;
1382 	struct got_pack_meta *m;
1383 	struct got_raw_object *raw = NULL;
1384 	FILE *delta_file = NULL;
1385 	char buf[32];
1386 	size_t outlen, n;
1387 	struct got_deflate_checksum csum;
1388 	off_t packfile_size = 0;
1389 	int outfd = -1;
1390 
1391 	SHA1Init(&ctx);
1392 	csum.output_sha1 = &ctx;
1393 	csum.output_crc = NULL;
1394 
1395 	err = hwrite(packfile, "PACK", 4, &ctx);
1396 	if (err)
1397 		return err;
1398 	putbe32(buf, GOT_PACKFILE_VERSION);
1399 	err = hwrite(packfile, buf, 4, &ctx);
1400 	if (err)
1401 		goto done;
1402 	putbe32(buf, nmeta);
1403 	err = hwrite(packfile, buf, 4, &ctx);
1404 	if (err)
1405 		goto done;
1406 	qsort(meta, nmeta, sizeof(struct got_pack_meta *), write_order_cmp);
1407 	for (i = 0; i < nmeta; i++) {
1408 		err = report_progress(progress_cb, progress_arg, rl,
1409 		    packfile_size, nours, nmeta, nmeta, i);
1410 		if (err)
1411 			goto done;
1412 		m = meta[i];
1413 		m->off = ftello(packfile);
1414 		if (m->delta_len == 0) {
1415 			err = got_object_raw_open(&raw, &outfd, repo, &m->id);
1416 			if (err)
1417 				goto done;
1418 			err = packhdr(&nh, buf, sizeof(buf),
1419 			    m->obj_type, raw->size);
1420 			if (err)
1421 				goto done;
1422 			err = hwrite(packfile, buf, nh, &ctx);
1423 			if (err)
1424 				goto done;
1425 			packfile_size += nh;
1426 			if (raw->f == NULL) {
1427 				err = got_deflate_to_file_mmap(&outlen,
1428 				    raw->data + raw->hdrlen, 0, raw->size,
1429 				    packfile, &csum);
1430 				if (err)
1431 					goto done;
1432 			} else {
1433 				if (fseeko(raw->f, raw->hdrlen, SEEK_SET)
1434 				    == -1) {
1435 					err = got_error_from_errno("fseeko");
1436 					goto done;
1437 				}
1438 				err = got_deflate_to_file(&outlen, raw->f,
1439 				    packfile, &csum);
1440 				if (err)
1441 					goto done;
1442 			}
1443 			packfile_size += outlen;
1444 			got_object_raw_close(raw);
1445 			raw = NULL;
1446 		} else if (m->delta_buf) {
1447 			err = deltahdr(&packfile_size, &ctx, packfile,
1448 			    m, use_offset_deltas);
1449 			if (err)
1450 				goto done;
1451  			err = got_deflate_to_file_mmap(&outlen,
1452 			    m->delta_buf, 0, m->delta_len, packfile, &csum);
1453  			if (err)
1454  				goto done;
1455  			packfile_size += outlen;
1456 			free(m->delta_buf);
1457 			m->delta_buf = NULL;
1458 		} else {
1459 			off_t remain;
1460 			if (delta_file == NULL) {
1461 				delta_file = got_opentemp();
1462 				if (delta_file == NULL) {
1463 					err = got_error_from_errno(
1464 					    "got_opentemp");
1465 					goto done;
1466 				}
1467 			}
1468 			if (ftruncate(fileno(delta_file), 0L) == -1) {
1469 				err = got_error_from_errno("ftruncate");
1470 				goto done;
1471 			}
1472 			if (fseeko(delta_file, 0L, SEEK_SET) == -1) {
1473 				err = got_error_from_errno("fseeko");
1474 				goto done;
1475 			}
1476 			if (fseeko(delta_cache, m->delta_offset, SEEK_SET)
1477 			    == -1) {
1478 				err = got_error_from_errno("fseeko");
1479 				goto done;
1480 			}
1481 			remain = m->delta_len;
1482 			while (remain > 0) {
1483 				char delta_buf[8192];
1484 				size_t r, w, n;
1485 				n = MIN(remain, sizeof(delta_buf));
1486 				r = fread(delta_buf, 1, n, delta_cache);
1487 				if (r != n) {
1488 					err = got_ferror(delta_cache,
1489 					    GOT_ERR_IO);
1490 					goto done;
1491 				}
1492 				w = fwrite(delta_buf, 1, n, delta_file);
1493 				if (w != n) {
1494 					err = got_ferror(delta_file,
1495 					    GOT_ERR_IO);
1496 					goto done;
1497 				}
1498 				remain -= n;
1499 			}
1500 			err = deltahdr(&packfile_size, &ctx, packfile,
1501 			    m, use_offset_deltas);
1502 			if (err)
1503 				goto done;
1504 			if (fseeko(delta_file, 0L, SEEK_SET) == -1) {
1505 				err = got_error_from_errno("fseeko");
1506 				goto done;
1507 			}
1508 			err = got_deflate_to_file(&outlen, delta_file,
1509 			    packfile, &csum);
1510 			if (err)
1511 				goto done;
1512 			packfile_size += outlen;
1513 		}
1514 	}
1515 	SHA1Final(pack_sha1, &ctx);
1516 	n = fwrite(pack_sha1, 1, SHA1_DIGEST_LENGTH, packfile);
1517 	if (n != SHA1_DIGEST_LENGTH)
1518 		err = got_ferror(packfile, GOT_ERR_IO);
1519 	packfile_size += SHA1_DIGEST_LENGTH;
1520 	packfile_size += sizeof(struct got_packfile_hdr);
1521 	if (progress_cb) {
1522 		err = progress_cb(progress_arg, packfile_size, nours,
1523 		    nmeta, nmeta, nmeta);
1524 		if (err)
1525 			goto done;
1526 	}
1527 done:
1528 	if (delta_file && fclose(delta_file) == EOF && err == NULL)
1529 		err = got_error_from_errno("fclose");
1530 	if (raw)
1531 		got_object_raw_close(raw);
1532 	if (outfd != -1 && close(outfd) == -1 && err == NULL)
1533 		err = got_error_from_errno("close");
1534 	return err;
1535 }
1536 
1537 const struct got_error *
1538 got_pack_create(uint8_t *packsha1, FILE *packfile,
1539     struct got_object_id **theirs, int ntheirs,
1540     struct got_object_id **ours, int nours,
1541     struct got_repository *repo, int loose_obj_only, int allow_empty,
1542     got_pack_progress_cb progress_cb, void *progress_arg,
1543     got_cancel_cb cancel_cb, void *cancel_arg)
1544 {
1545 	const struct got_error *err;
1546 	struct got_pack_meta **meta;
1547 	int nmeta;
1548 	FILE *delta_cache = NULL;
1549 	struct got_ratelimit rl;
1550 
1551 	got_ratelimit_init(&rl, 0, 500);
1552 
1553 	err = read_meta(&meta, &nmeta, theirs, ntheirs, ours, nours, repo,
1554 	    loose_obj_only, progress_cb, progress_arg, &rl,
1555 	    cancel_cb, cancel_arg);
1556 	if (err)
1557 		return err;
1558 
1559 	if (nmeta == 0 && !allow_empty) {
1560 		err = got_error(GOT_ERR_CANNOT_PACK);
1561 		goto done;
1562 	}
1563 
1564 	delta_cache = got_opentemp();
1565 	if (delta_cache == NULL) {
1566 		err = got_error_from_errno("got_opentemp");
1567 		goto done;
1568 	}
1569 
1570 	if (nmeta > 0) {
1571 		err = pick_deltas(meta, nmeta, nours, delta_cache, repo,
1572 		    progress_cb, progress_arg, &rl, cancel_cb, cancel_arg);
1573 		if (err)
1574 			goto done;
1575 		if (fseeko(delta_cache, 0L, SEEK_SET) == -1) {
1576 			err = got_error_from_errno("fseeko");
1577 			goto done;
1578 		}
1579 	}
1580 
1581 	err = genpack(packsha1, packfile, delta_cache, meta, nmeta, nours, 1,
1582 	    repo, progress_cb, progress_arg, &rl, cancel_cb, cancel_arg);
1583 	if (err)
1584 		goto done;
1585 done:
1586 	free_nmeta(meta, nmeta);
1587 	if (delta_cache && fclose(delta_cache) == EOF && err == NULL)
1588 		err = got_error_from_errno("fclose");
1589 	return err;
1590 }