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Date:: Wed Jan 19 12:04:58 2022 UTC
Message:: compress delta data from delta_cache directly into pack file
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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 	size_t delta_memsize = 0;
435 	const size_t max_delta_memsize = 25 * GOT_DELTA_RESULT_SIZE_CACHED_MAX;
436 	int outfd = -1;
437 
438 	qsort(meta, nmeta, sizeof(struct got_pack_meta *), delta_order_cmp);
439 	for (i = 0; i < nmeta; i++) {
440 		if (cancel_cb) {
441 			err = (*cancel_cb)(cancel_arg);
442 			if (err)
443 				break;
444 		}
445 		err = report_progress(progress_cb, progress_arg, rl,
446 		    0L, nours, nmeta, i, 0);
447 		if (err)
448 			goto done;
449 		m = meta[i];
450 
451 		if (m->obj_type == GOT_OBJ_TYPE_COMMIT ||
452 		    m->obj_type == GOT_OBJ_TYPE_TAG)
453 			continue;
454 
455 		err = got_object_raw_open(&raw, &outfd, repo, &m->id);
456 		if (err)
457 			goto done;
458 		m->size = raw->size;
459 
460 		if (raw->f == NULL) {
461 			err = got_deltify_init_mem(&m->dtab, raw->data,
462 			    raw->hdrlen, raw->size + raw->hdrlen);
463 		} else {
464 			err = got_deltify_init(&m->dtab, raw->f, raw->hdrlen,
465 			    raw->size + raw->hdrlen);
466 		}
467 		if (err)
468 			goto done;
469 
470 		if (i > max_base_candidates) {
471 			struct got_pack_meta *n = NULL;
472 			n = meta[i - (max_base_candidates + 1)];
473 			got_deltify_free(n->dtab);
474 			n->dtab = NULL;
475 		}
476 
477 		best_size = raw->size;
478 		best_ndeltas = 0;
479 		for (j = MAX(0, i - max_base_candidates); j < i; j++) {
480 			if (cancel_cb) {
481 				err = (*cancel_cb)(cancel_arg);
482 				if (err)
483 					goto done;
484 			}
485 			base = meta[j];
486 			/* long chains make unpacking slow, avoid such bases */
487 			if (base->nchain >= 128 ||
488 			    base->obj_type != m->obj_type)
489 				continue;
490 
491 			err = got_object_raw_open(&base_raw, &outfd, repo,
492 			    &base->id);
493 			if (err)
494 				goto done;
495 			if (raw->f == NULL && base_raw->f == NULL) {
496 				err = got_deltify_mem_mem(&deltas, &ndeltas,
497 				    raw->data, raw->hdrlen,
498 				    raw->size + raw->hdrlen,
499 				    base->dtab, base_raw->data,
500 				    base_raw->hdrlen,
501 				    base_raw->size + base_raw->hdrlen);
502 			} else if (raw->f == NULL) {
503 				err = got_deltify_mem_file(&deltas, &ndeltas,
504 				    raw->data, raw->hdrlen,
505 				    raw->size + raw->hdrlen,
506 				    base->dtab, base_raw->f,
507 				    base_raw->hdrlen,
508 				    base_raw->size + base_raw->hdrlen);
509 			} else if (base_raw->f == NULL) {
510 				err = got_deltify_file_mem(&deltas, &ndeltas,
511 				    raw->f, raw->hdrlen,
512 				    raw->size + raw->hdrlen,
513 				    base->dtab, base_raw->data,
514 				    base_raw->hdrlen,
515 				    base_raw->size + base_raw->hdrlen);
516 			} else {
517 				err = got_deltify(&deltas, &ndeltas,
518 				    raw->f, raw->hdrlen,
519 				    raw->size + raw->hdrlen,
520 				    base->dtab, base_raw->f, base_raw->hdrlen,
521 				    base_raw->size + base_raw->hdrlen);
522 			}
523 			got_object_raw_close(base_raw);
524 			base_raw = NULL;
525 			if (err)
526 				goto done;
527 
528 			size = delta_size(deltas, ndeltas);
529 			if (size + 32 < best_size){
530 				/*
531 				 * if we already picked a best delta,
532 				 * replace it.
533 				 */
534 				best_size = size;
535 				free(best_deltas);
536 				best_deltas = deltas;
537 				best_ndeltas = ndeltas;
538 				deltas = NULL;
539 				m->nchain = base->nchain + 1;
540 				m->prev = base;
541 				m->head = base->head;
542 				if (m->head == NULL)
543 					m->head = base;
544 			} else {
545 				free(deltas);
546 				deltas = NULL;
547 				ndeltas = 0;
548 			}
549 		}
550 
551 		if (best_ndeltas > 0) {
552 			if (best_size <= GOT_DELTA_RESULT_SIZE_CACHED_MAX &&
553 			    delta_memsize + best_size <= max_delta_memsize) {
554 				delta_memsize += best_size;
555 				err = encode_delta_in_mem(m, raw, best_deltas,
556 				    best_ndeltas, best_size, m->prev->size);
557 			} else {
558 				m->delta_offset = ftello(delta_cache);
559 				err = encode_delta(m, raw, best_deltas,
560 				    best_ndeltas, m->prev->size, delta_cache);
561 			}
562 			free(best_deltas);
563 			best_deltas = NULL;
564 			best_ndeltas = 0;
565 			if (err)
566 				goto done;
567 		}
568 
569 		got_object_raw_close(raw);
570 		raw = NULL;
571 	}
572 done:
573 	for (i = MAX(0, nmeta - max_base_candidates); i < nmeta; i++) {
574 		got_deltify_free(meta[i]->dtab);
575 		meta[i]->dtab = NULL;
576 	}
577 	if (raw)
578 		got_object_raw_close(raw);
579 	if (base_raw)
580 		got_object_raw_close(base_raw);
581 	if (outfd != -1 && close(outfd) == -1 && err == NULL)
582 		err = got_error_from_errno("close");
583 	free(deltas);
584 	free(best_deltas);
585 	return err;
586 }
587 
588 static const struct got_error *
589 search_packidx(int *found, struct got_object_id *id,
590     struct got_repository *repo)
591 {
592 	const struct got_error *err = NULL;
593 	struct got_packidx *packidx = NULL;
594 	int idx;
595 
596 	*found = 0;
597 
598 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
599 	if (err == NULL)
600 		*found = 1; /* object is already packed */
601 	else if (err->code == GOT_ERR_NO_OBJ)
602 		err = NULL;
603 	return err;
604 }
605 
606 static const int obj_types[] = {
607 	GOT_OBJ_TYPE_ANY,
608 	GOT_OBJ_TYPE_COMMIT,
609 	GOT_OBJ_TYPE_TREE,
610 	GOT_OBJ_TYPE_BLOB,
611 	GOT_OBJ_TYPE_TAG,
612 	GOT_OBJ_TYPE_OFFSET_DELTA,
613 	GOT_OBJ_TYPE_REF_DELTA
614 };
615 
616 static const struct got_error *
617 add_meta(struct got_pack_metavec *v, struct got_object_idset *idset,
618     struct got_object_id *id, const char *path, int obj_type,
619     time_t mtime, int loose_obj_only, struct got_repository *repo)
620 {
621 	const struct got_error *err;
622 	struct got_pack_meta *m;
623 
624 	if (loose_obj_only) {
625 		int is_packed;
626 		err = search_packidx(&is_packed, id, repo);
627 		if (err)
628 			return err;
629 		if (is_packed)
630 			return NULL;
631 	}
632 
633 	err = got_object_idset_add(idset, id, (void *)&obj_types[obj_type]);
634 	if (err)
635 		return err;
636 
637 	if (v == NULL)
638 		return NULL;
639 
640 	err = alloc_meta(&m, id, path, obj_type, mtime);
641 	if (err)
642 		goto done;
643 
644 	if (v->nmeta == v->metasz){
645 		size_t newsize = 2 * v->metasz;
646 		struct got_pack_meta **new;
647 		new = reallocarray(v->meta, newsize, sizeof(*new));
648 		if (new == NULL) {
649 			err = got_error_from_errno("reallocarray");
650 			goto done;
651 		}
652 		v->meta = new;
653 		v->metasz = newsize; 
654 	}
655 done:
656 	if (err) {
657 		clear_meta(m);
658 		free(m);
659 	} else
660 		v->meta[v->nmeta++] = m;
661 
662 	return err;
663 }
664 
665 static const struct got_error *
666 load_tree_entries(struct got_object_id_queue *ids, struct got_pack_metavec *v,
667     struct got_object_idset *idset, struct got_object_id *tree_id,
668     const char *dpath, time_t mtime, struct got_repository *repo,
669     int loose_obj_only, got_cancel_cb cancel_cb, void *cancel_arg)
670 {
671 	const struct got_error *err;
672 	struct got_tree_object *tree;
673 	char *p = NULL;
674 	int i;
675 
676 	err = got_object_open_as_tree(&tree, repo, tree_id);
677 	if (err)
678 		return err;
679 
680 	for (i = 0; i < got_object_tree_get_nentries(tree); i++) {
681 		struct got_tree_entry *e = got_object_tree_get_entry(tree, i);
682 		struct got_object_id *id = got_tree_entry_get_id(e);
683 		mode_t mode = got_tree_entry_get_mode(e);
684 
685 		if (cancel_cb) {
686 			err = (*cancel_cb)(cancel_arg);
687 			if (err)
688 				break;
689 		}
690 
691 		if (got_object_tree_entry_is_submodule(e) ||
692 		    got_object_idset_contains(idset, id))
693 			continue;
694 		
695 		if (asprintf(&p, "%s%s%s", dpath, dpath[0] != '\0' ? "/" : "",
696 		    got_tree_entry_get_name(e)) == -1) {
697 			err = got_error_from_errno("asprintf");
698 			break;
699 		}
700 
701 		if (S_ISDIR(mode)) {
702 			struct got_object_qid *qid;
703 			err = got_object_qid_alloc(&qid, id);
704 			if (err)
705 				break;
706 			STAILQ_INSERT_TAIL(ids, qid, entry);
707 		} else if (S_ISREG(mode) || S_ISLNK(mode)) {
708 			err = add_meta(v, idset, id, p, GOT_OBJ_TYPE_BLOB,
709 			    mtime, loose_obj_only, repo);
710 			if (err)
711 				break;
712 		}
713 		free(p);
714 		p = NULL;
715 	}
716 
717 	got_object_tree_close(tree);
718 	free(p);
719 	return err;
720 }
721 
722 static const struct got_error *
723 load_tree(struct got_pack_metavec *v, struct got_object_idset *idset,
724     struct got_object_id *tree_id, const char *dpath, time_t mtime,
725     int loose_obj_only, struct got_repository *repo,
726     got_cancel_cb cancel_cb, void *cancel_arg)
727 {
728 	const struct got_error *err = NULL;
729 	struct got_object_id_queue tree_ids;
730 	struct got_object_qid *qid;
731 
732 	if (got_object_idset_contains(idset, tree_id))
733 		return NULL;
734 
735 	err = got_object_qid_alloc(&qid, tree_id);
736 	if (err)
737 		return err;
738 
739 	STAILQ_INIT(&tree_ids);
740 	STAILQ_INSERT_TAIL(&tree_ids, qid, entry);
741 
742 	while (!STAILQ_EMPTY(&tree_ids)) {
743 		if (cancel_cb) {
744 			err = (*cancel_cb)(cancel_arg);
745 			if (err)
746 				break;
747 		}
748 
749 		qid = STAILQ_FIRST(&tree_ids);
750 		STAILQ_REMOVE_HEAD(&tree_ids, entry);
751 
752 		if (got_object_idset_contains(idset, qid->id)) {
753 			got_object_qid_free(qid);
754 			continue;
755 		}
756 
757 		err = add_meta(v, idset, qid->id, dpath, GOT_OBJ_TYPE_TREE,
758 		    mtime, loose_obj_only, repo);
759 		if (err) {
760 			got_object_qid_free(qid);
761 			break;
762 		}
763 
764 		err = load_tree_entries(&tree_ids, v, idset, qid->id, dpath,
765 		    mtime, repo, loose_obj_only, cancel_cb, cancel_arg);
766 		got_object_qid_free(qid);
767 		if (err)
768 			break;
769 	}
770 
771 	got_object_id_queue_free(&tree_ids);
772 	return err;
773 }
774 
775 static const struct got_error *
776 load_commit(struct got_pack_metavec *v, struct got_object_idset *idset,
777     struct got_object_id *id, struct got_repository *repo, int loose_obj_only,
778     got_cancel_cb cancel_cb, void *cancel_arg)
779 {
780 	const struct got_error *err;
781 	struct got_commit_object *commit;
782 
783 	if (got_object_idset_contains(idset, id))
784 		return NULL;
785 
786 	if (loose_obj_only) {
787 		int is_packed;
788 		err = search_packidx(&is_packed, id, repo);
789 		if (err)
790 			return err;
791 		if (is_packed)
792 			return NULL;
793 	}
794 
795 	err = got_object_open_as_commit(&commit, repo, id);
796 	if (err)
797 		return err;
798 
799 	err = add_meta(v, idset, id, "", GOT_OBJ_TYPE_COMMIT,
800 	    got_object_commit_get_committer_time(commit),
801 	    loose_obj_only, repo);
802 	if (err)
803 		goto done;
804 
805 	err = load_tree(v, idset, got_object_commit_get_tree_id(commit),
806 	    "", got_object_commit_get_committer_time(commit),
807 	    loose_obj_only, repo, cancel_cb, cancel_arg);
808 done:
809 	got_object_commit_close(commit);
810 	return err;
811 }
812 
813 static const struct got_error *
814 load_tag(struct got_pack_metavec *v, struct got_object_idset *idset,
815     struct got_object_id *id, struct got_repository *repo, int loose_obj_only,
816     got_cancel_cb cancel_cb, void *cancel_arg)
817 {
818 	const struct got_error *err;
819 	struct got_tag_object *tag = NULL;
820 
821 	if (got_object_idset_contains(idset, id))
822 		return NULL;
823 
824 	if (loose_obj_only) {
825 		int is_packed;
826 		err = search_packidx(&is_packed, id, repo);
827 		if (err)
828 			return err;
829 		if (is_packed)
830 			return NULL;
831 	}
832 
833 	err = got_object_open_as_tag(&tag, repo, id);
834 	if (err)
835 		return err;
836 
837 	err = add_meta(v, idset, id, "", GOT_OBJ_TYPE_TAG,
838 	    got_object_tag_get_tagger_time(tag),
839 	    loose_obj_only, repo);
840 	if (err)
841 		goto done;
842 
843 	switch (got_object_tag_get_object_type(tag)) {
844 	case GOT_OBJ_TYPE_COMMIT:
845 		err = load_commit(v, idset,
846 		    got_object_tag_get_object_id(tag), repo,
847 		    loose_obj_only, cancel_cb, cancel_arg);
848 		break;
849 	case GOT_OBJ_TYPE_TREE:
850 		err = load_tree(v, idset, got_object_tag_get_object_id(tag),
851 		    "", got_object_tag_get_tagger_time(tag),
852 		    loose_obj_only, repo, cancel_cb, cancel_arg);
853 		break;
854 	default:
855 		break;
856 	}
857 
858 done:
859 	got_object_tag_close(tag);
860 	return err;
861 }
862 
863 enum findtwixt_color {
864 	COLOR_KEEP = 0,
865 	COLOR_DROP,
866 	COLOR_BLANK,
867 };
868 static const int findtwixt_colors[] = {
869 	COLOR_KEEP,
870 	COLOR_DROP,
871 	COLOR_BLANK
872 };
873 
874 static const struct got_error *
875 queue_commit_id(struct got_object_id_queue *ids, struct got_object_id *id,
876     int color, struct got_repository *repo)
877 {
878 	const struct got_error *err;
879 	struct got_object_qid *qid;
880 
881 	err = got_object_qid_alloc(&qid, id);
882 	if (err)
883 		return err;
884 
885 	STAILQ_INSERT_TAIL(ids, qid, entry);
886 	qid->data = (void *)&findtwixt_colors[color];
887 	return NULL;
888 }
889 
890 static const struct got_error *
891 drop_commit(struct got_object_idset *keep, struct got_object_idset *drop,
892     struct got_object_id *id, struct got_repository *repo,
893     got_cancel_cb cancel_cb, void *cancel_arg)
894 {
895 	const struct got_error *err = NULL;
896 	struct got_commit_object *commit;
897 	const struct got_object_id_queue *parents;
898 	struct got_object_id_queue ids;
899 	struct got_object_qid *qid;
900 
901 	STAILQ_INIT(&ids);
902 
903 	err = got_object_qid_alloc(&qid, id);
904 	if (err)
905 		return err;
906 	STAILQ_INSERT_HEAD(&ids, qid, entry);
907 
908 	while (!STAILQ_EMPTY(&ids)) {
909 		if (cancel_cb) {
910 			err = (*cancel_cb)(cancel_arg);
911 			if (err)
912 				break;
913 		}
914 
915 		qid = STAILQ_FIRST(&ids);
916 		STAILQ_REMOVE_HEAD(&ids, entry);
917 
918 		if (got_object_idset_contains(drop, qid->id)) {
919 			got_object_qid_free(qid);
920 			continue;
921 		}
922 
923 		err = got_object_idset_add(drop, qid->id,
924 		    (void *)&obj_types[GOT_OBJ_TYPE_COMMIT]);
925 		if (err) {
926 			got_object_qid_free(qid);
927 			break;
928 		}
929 
930 		if (!got_object_idset_contains(keep, qid->id)) {
931 			got_object_qid_free(qid);
932 			continue;
933 		}
934 
935 		err = got_object_open_as_commit(&commit, repo, qid->id);
936 		got_object_qid_free(qid);
937 		if (err)
938 			break;
939 
940 		parents = got_object_commit_get_parent_ids(commit);
941 		if (parents) {
942 			err = got_object_id_queue_copy(parents, &ids);
943 			if (err) {
944 				got_object_commit_close(commit);
945 				break;
946 			}
947 		}
948 		got_object_commit_close(commit);
949 	}
950 
951 	got_object_id_queue_free(&ids);
952 	return err;
953 }
954 
955 struct append_id_arg {
956 	struct got_object_id **array;
957 	int idx;
958 };
959 
960 static const struct got_error *
961 append_id(struct got_object_id *id, void *data, void *arg)
962 {
963 	struct append_id_arg *a = arg;
964 
965 	a->array[a->idx] = got_object_id_dup(id);
966 	if (a->array[a->idx] == NULL)
967 		return got_error_from_errno("got_object_id_dup");
968 
969 	a->idx++;
970 	return NULL;
971 }
972 
973 static const struct got_error *
974 findtwixt(struct got_object_id ***res, int *nres,
975     struct got_object_id **head, int nhead,
976     struct got_object_id **tail, int ntail,
977     struct got_repository *repo,
978     got_cancel_cb cancel_cb, void *cancel_arg)
979 {
980 	const struct got_error *err = NULL;
981 	struct got_object_id_queue ids;
982 	struct got_object_idset *keep, *drop;
983 	struct got_object_qid *qid;
984 	int i, ncolor, nkeep, obj_type;
985 
986 	STAILQ_INIT(&ids);
987 	*res = NULL;
988 	*nres = 0;
989 
990 	keep = got_object_idset_alloc();
991 	if (keep == NULL)
992 		return got_error_from_errno("got_object_idset_alloc");
993 
994 	drop = got_object_idset_alloc();
995 	if (drop == NULL) {
996 		err = got_error_from_errno("got_object_idset_alloc");
997 		goto done;
998 	}
999 
1000 	for (i = 0; i < nhead; i++) {
1001 		struct got_object_id *id = head[i];
1002 		if (id == NULL)
1003 			continue;
1004 		err = got_object_get_type(&obj_type, repo, id);
1005 		if (err)
1006 			return err;
1007 		if (obj_type != GOT_OBJ_TYPE_COMMIT)
1008 			continue;
1009 		err = queue_commit_id(&ids, id, COLOR_KEEP, repo);
1010 		if (err)
1011 			goto done;
1012 	}		
1013 	for (i = 0; i < ntail; i++) {
1014 		struct got_object_id *id = tail[i];
1015 		if (id == NULL)
1016 			continue;
1017 		err = got_object_get_type(&obj_type, repo, id);
1018 		if (err)
1019 			return err;
1020 		if (obj_type != GOT_OBJ_TYPE_COMMIT)
1021 			continue;
1022 		err = queue_commit_id(&ids, id, COLOR_DROP, repo);
1023 		if (err)
1024 			goto done;
1025 	}
1026 
1027 	while (!STAILQ_EMPTY(&ids)) {
1028 		int qcolor;
1029 		qid = STAILQ_FIRST(&ids);
1030 		qcolor = *((int *)qid->data);
1031 
1032 		if (got_object_idset_contains(drop, qid->id))
1033 			ncolor = COLOR_DROP;
1034 		else if (got_object_idset_contains(keep, qid->id))
1035 			ncolor = COLOR_KEEP;
1036 		else
1037 			ncolor = COLOR_BLANK;
1038 
1039 		if (ncolor == COLOR_DROP || (ncolor == COLOR_KEEP &&
1040 		    qcolor == COLOR_KEEP)) {
1041 			STAILQ_REMOVE_HEAD(&ids, entry);
1042 			got_object_qid_free(qid);
1043 			continue;
1044 		}
1045 
1046 		if (ncolor == COLOR_KEEP && qcolor == COLOR_DROP) {
1047 			err = drop_commit(keep, drop, qid->id, repo,
1048 			    cancel_cb, cancel_arg);
1049 			if (err)
1050 				goto done;
1051 		} else if (ncolor == COLOR_BLANK) {
1052 			struct got_commit_object *commit;
1053 			struct got_object_id *id;
1054 			const struct got_object_id_queue *parents;
1055 			struct got_object_qid *pid;
1056 
1057 			id = got_object_id_dup(qid->id);
1058 			if (id == NULL) {
1059 				err = got_error_from_errno("got_object_id_dup");
1060 				goto done;
1061 			}
1062 			if (qcolor == COLOR_KEEP)
1063 				err = got_object_idset_add(keep, id,
1064 				    (void *)&obj_types[GOT_OBJ_TYPE_COMMIT]);
1065 			else
1066 				err = got_object_idset_add(drop, id,
1067 				    (void *)&obj_types[GOT_OBJ_TYPE_COMMIT]);
1068 			if (err) {
1069 				free(id);
1070 				goto done;
1071 			}
1072 
1073 			err = got_object_open_as_commit(&commit, repo, id);
1074 			if (err) {
1075 				free(id);
1076 				goto done;
1077 			}
1078 			parents = got_object_commit_get_parent_ids(commit);
1079 			if (parents) {
1080 				STAILQ_FOREACH(pid, parents, entry) {
1081 					err = queue_commit_id(&ids, pid->id,
1082 					    qcolor, repo);
1083 					if (err) {
1084 						free(id);
1085 						goto done;
1086 					}
1087 				}
1088 			}
1089 			got_object_commit_close(commit);
1090 			commit = NULL;
1091 		} else {
1092 			/* should not happen */
1093 			err = got_error_fmt(GOT_ERR_NOT_IMPL,
1094 			    "%s ncolor=%d qcolor=%d", __func__, ncolor, qcolor);
1095 			goto done;
1096 		}
1097 
1098 		STAILQ_REMOVE_HEAD(&ids, entry);
1099 		got_object_qid_free(qid);
1100 	}
1101 
1102 	nkeep = got_object_idset_num_elements(keep);
1103 	if (nkeep > 0) {
1104 		struct append_id_arg arg;
1105 		arg.array = calloc(nkeep, sizeof(struct got_object_id *));
1106 		if (arg.array == NULL) {
1107 			err = got_error_from_errno("calloc");
1108 			goto done;
1109 		}
1110 		arg.idx = 0;
1111 		err = got_object_idset_for_each(keep, append_id, &arg);
1112 		if (err) {
1113 			free(arg.array);
1114 			goto done;
1115 		}
1116 		*res = arg.array;
1117 		*nres = nkeep;
1118 	}
1119 done:
1120 	got_object_idset_free(keep);
1121 	got_object_idset_free(drop);
1122 	got_object_id_queue_free(&ids);
1123 	return err;
1124 }
1125 
1126 static const struct got_error *
1127 read_meta(struct got_pack_meta ***meta, int *nmeta,
1128     struct got_object_id **theirs, int ntheirs,
1129     struct got_object_id **ours, int nours, struct got_repository *repo,
1130     int loose_obj_only, got_pack_progress_cb progress_cb, void *progress_arg,
1131     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1132 {
1133 	const struct got_error *err = NULL;
1134 	struct got_object_id **ids = NULL;
1135 	struct got_object_idset *idset;
1136 	int i, nobj = 0, obj_type;
1137 	struct got_pack_metavec v;
1138 
1139 	*meta = NULL;
1140 	*nmeta = 0;
1141 
1142 	idset = got_object_idset_alloc();
1143 	if (idset == NULL)
1144 		return got_error_from_errno("got_object_idset_alloc");
1145 
1146 	v.nmeta = 0;
1147 	v.metasz = 64;
1148 	v.meta = calloc(v.metasz, sizeof(struct got_pack_meta *));
1149 	if (v.meta == NULL) {
1150 		err = got_error_from_errno("calloc");
1151 		goto done;
1152 	}
1153 
1154 	err = findtwixt(&ids, &nobj, ours, nours, theirs, ntheirs, repo,
1155 	    cancel_cb, cancel_arg);
1156 	if (err || nobj == 0)
1157 		goto done;
1158 
1159 	for (i = 0; i < ntheirs; i++) {
1160 		struct got_object_id *id = theirs[i];
1161 		if (id == NULL)
1162 			continue;
1163 		err = got_object_get_type(&obj_type, repo, id);
1164 		if (err)
1165 			return err;
1166 		if (obj_type != GOT_OBJ_TYPE_COMMIT)
1167 			continue;
1168 		err = load_commit(NULL, idset, id, repo,
1169 		    loose_obj_only, cancel_cb, cancel_arg);
1170 		if (err)
1171 			goto done;
1172 		err = report_progress(progress_cb, progress_arg, rl,
1173 		    0L, nours, v.nmeta, 0, 0);
1174 		if (err)
1175 			goto done;
1176 	}
1177 
1178 	for (i = 0; i < ntheirs; i++) {
1179 		struct got_object_id *id = theirs[i];
1180 		int *cached_type;
1181 		if (id == NULL)
1182 			continue;
1183 		cached_type = got_object_idset_get(idset, id);
1184 		if (cached_type == NULL) {
1185 			err = got_object_get_type(&obj_type, repo, id);
1186 			if (err)
1187 				goto done;
1188 		} else
1189 			obj_type = *cached_type;
1190 		if (obj_type != GOT_OBJ_TYPE_TAG)
1191 			continue;
1192 		err = load_tag(NULL, idset, id, repo,
1193 		    loose_obj_only, cancel_cb, cancel_arg);
1194 		if (err)
1195 			goto done;
1196 		err = report_progress(progress_cb, progress_arg, rl,
1197 		    0L, nours, v.nmeta, 0, 0);
1198 		if (err)
1199 			goto done;
1200 	}
1201 
1202 	for (i = 0; i < nobj; i++) {
1203 		err = load_commit(&v, idset, ids[i], repo,
1204 		    loose_obj_only, cancel_cb, cancel_arg);
1205 		if (err)
1206 			goto done;
1207 		if (err)
1208 			goto done;
1209 		err = report_progress(progress_cb, progress_arg, rl,
1210 		    0L, nours, v.nmeta, 0, 0);
1211 		if (err)
1212 			goto done;
1213 	}
1214 
1215 	for (i = 0; i < nours; i++) {
1216 		struct got_object_id *id = ours[i];
1217 		int *cached_type;
1218 		if (id == NULL)
1219 			continue;
1220 		cached_type = got_object_idset_get(idset, id);
1221 		if (cached_type == NULL) {
1222 			err = got_object_get_type(&obj_type, repo, id);
1223 			if (err)
1224 				goto done;
1225 		} else
1226 			obj_type = *cached_type;
1227 		if (obj_type != GOT_OBJ_TYPE_TAG)
1228 			continue;
1229 		err = load_tag(&v, idset, id, repo,
1230 		    loose_obj_only, cancel_cb, cancel_arg);
1231 		if (err)
1232 			goto done;
1233 		err = report_progress(progress_cb, progress_arg, rl,
1234 		    0L, nours, v.nmeta, 0, 0);
1235 		if (err)
1236 			goto done;
1237 	}
1238 
1239 	if (progress_cb) {
1240 		err = progress_cb(progress_arg, 0L, nours, v.nmeta, 0, 0);
1241 		if (err)
1242 			goto done;
1243 	}
1244 done:
1245 	for (i = 0; i < nobj; i++) {
1246 		free(ids[i]);
1247 	}
1248 	free(ids);
1249 	got_object_idset_free(idset);
1250 	if (err == NULL) {
1251 		*meta = v.meta;
1252 		*nmeta = v.nmeta;
1253 	} else
1254 		free(v.meta);
1255 
1256 	return err;
1257 }
1258 
1259 const struct got_error *
1260 hwrite(FILE *f, void *buf, int len, SHA1_CTX *ctx)
1261 {
1262 	size_t n;
1263 
1264 	SHA1Update(ctx, buf, len);
1265 	n = fwrite(buf, 1, len, f);
1266 	if (n != len)
1267 		return got_ferror(f, GOT_ERR_IO);
1268 	return NULL;
1269 }
1270 
1271 static void
1272 putbe32(char *b, uint32_t n)
1273 {
1274 	b[0] = n >> 24;
1275 	b[1] = n >> 16;
1276 	b[2] = n >> 8;
1277 	b[3] = n >> 0;
1278 }
1279 
1280 static int
1281 write_order_cmp(const void *pa, const void *pb)
1282 {
1283 	struct got_pack_meta *a, *b, *ahd, *bhd;
1284 
1285 	a = *(struct got_pack_meta **)pa;
1286 	b = *(struct got_pack_meta **)pb;
1287 	ahd = (a->head == NULL) ? a : a->head;
1288 	bhd = (b->head == NULL) ? b : b->head;
1289 	if (ahd->mtime != bhd->mtime)
1290 		return bhd->mtime - ahd->mtime;
1291 	if (ahd != bhd)
1292 		return (uintptr_t)bhd - (uintptr_t)ahd;
1293 	if (a->nchain != b->nchain)
1294 		return a->nchain - b->nchain;
1295 	return a->mtime - b->mtime;
1296 }
1297 
1298 static const struct got_error *
1299 packhdr(int *hdrlen, char *hdr, size_t bufsize, int obj_type, size_t len)
1300 {
1301 	size_t i;
1302 
1303 	*hdrlen = 0;
1304 
1305 	hdr[0] = obj_type << 4;
1306 	hdr[0] |= len & 0xf;
1307 	len >>= 4;
1308 	for (i = 1; len != 0; i++){
1309 		if (i >= bufsize)
1310 			return got_error(GOT_ERR_NO_SPACE);
1311 		hdr[i - 1] |= GOT_DELTA_SIZE_MORE;
1312 		hdr[i] = len & GOT_DELTA_SIZE_VAL_MASK;
1313 		len >>= GOT_DELTA_SIZE_SHIFT;
1314 	}
1315 
1316 	*hdrlen = i;
1317 	return NULL;
1318 }
1319 
1320 static int
1321 packoff(char *hdr, off_t off)
1322 {
1323 	int i, j;
1324 	char rbuf[8];
1325 
1326 	rbuf[0] = off & GOT_DELTA_SIZE_VAL_MASK;
1327 	for (i = 1; (off >>= GOT_DELTA_SIZE_SHIFT) != 0; i++) {
1328 		rbuf[i] = (--off & GOT_DELTA_SIZE_VAL_MASK) |
1329 		    GOT_DELTA_SIZE_MORE;
1330 	}
1331 
1332 	j = 0;
1333 	while (i > 0)
1334 		hdr[j++] = rbuf[--i];
1335 	return j;
1336 }
1337 
1338 static const struct got_error *
1339 deltahdr(off_t *packfile_size, SHA1_CTX *ctx, FILE *packfile,
1340     struct got_pack_meta *m, int use_offset_deltas)
1341 {
1342 	const struct got_error *err;
1343 	char buf[32];
1344 	int nh;
1345 
1346 	if (use_offset_deltas && m->prev->off != 0) {
1347 		err = packhdr(&nh, buf, sizeof(buf),
1348 		    GOT_OBJ_TYPE_OFFSET_DELTA, m->delta_len);
1349 		if (err)
1350 			return err;
1351 		nh += packoff(buf + nh, m->off - m->prev->off);
1352 		err = hwrite(packfile, buf, nh, ctx);
1353 		if (err)
1354 			return err;
1355 		*packfile_size += nh;
1356 	} else {
1357 		err = packhdr(&nh, buf, sizeof(buf),
1358 		    GOT_OBJ_TYPE_REF_DELTA, m->delta_len);
1359 		if (err)
1360 			return err;
1361 		err = hwrite(packfile, buf, nh, ctx);
1362 		if (err)
1363 			return err;
1364 		*packfile_size += nh;
1365 		err = hwrite(packfile, m->prev->id.sha1,
1366 		    sizeof(m->prev->id.sha1), ctx);
1367 		if (err)
1368 			return err;
1369 		*packfile_size += sizeof(m->prev->id.sha1);
1370 	}
1371 
1372 	return NULL;
1373 }
1374 
1375 static const struct got_error *
1376 genpack(uint8_t *pack_sha1, FILE *packfile, FILE *delta_cache,
1377     struct got_pack_meta **meta, int nmeta, int nours,
1378     int use_offset_deltas, struct got_repository *repo,
1379     got_pack_progress_cb progress_cb, void *progress_arg,
1380     struct got_ratelimit *rl,
1381     got_cancel_cb cancel_cb, void *cancel_arg)
1382 {
1383 	const struct got_error *err = NULL;
1384 	int i, nh;
1385 	SHA1_CTX ctx;
1386 	struct got_pack_meta *m;
1387 	struct got_raw_object *raw = NULL;
1388 	char buf[32];
1389 	size_t n;
1390 	struct got_deflate_checksum csum;
1391 	off_t outlen, packfile_size = 0;
1392 	int outfd = -1;
1393 
1394 	SHA1Init(&ctx);
1395 	csum.output_sha1 = &ctx;
1396 	csum.output_crc = NULL;
1397 
1398 	err = hwrite(packfile, "PACK", 4, &ctx);
1399 	if (err)
1400 		return err;
1401 	putbe32(buf, GOT_PACKFILE_VERSION);
1402 	err = hwrite(packfile, buf, 4, &ctx);
1403 	if (err)
1404 		goto done;
1405 	putbe32(buf, nmeta);
1406 	err = hwrite(packfile, buf, 4, &ctx);
1407 	if (err)
1408 		goto done;
1409 	qsort(meta, nmeta, sizeof(struct got_pack_meta *), write_order_cmp);
1410 	for (i = 0; i < nmeta; i++) {
1411 		err = report_progress(progress_cb, progress_arg, rl,
1412 		    packfile_size, nours, nmeta, nmeta, i);
1413 		if (err)
1414 			goto done;
1415 		m = meta[i];
1416 		m->off = ftello(packfile);
1417 		if (m->delta_len == 0) {
1418 			err = got_object_raw_open(&raw, &outfd, repo, &m->id);
1419 			if (err)
1420 				goto done;
1421 			err = packhdr(&nh, buf, sizeof(buf),
1422 			    m->obj_type, raw->size);
1423 			if (err)
1424 				goto done;
1425 			err = hwrite(packfile, buf, nh, &ctx);
1426 			if (err)
1427 				goto done;
1428 			packfile_size += nh;
1429 			if (raw->f == NULL) {
1430 				err = got_deflate_to_file_mmap(&outlen,
1431 				    raw->data + raw->hdrlen, 0, raw->size,
1432 				    packfile, &csum);
1433 				if (err)
1434 					goto done;
1435 			} else {
1436 				if (fseeko(raw->f, raw->hdrlen, SEEK_SET)
1437 				    == -1) {
1438 					err = got_error_from_errno("fseeko");
1439 					goto done;
1440 				}
1441 				err = got_deflate_to_file(&outlen, raw->f,
1442 				    raw->size, packfile, &csum);
1443 				if (err)
1444 					goto done;
1445 			}
1446 			packfile_size += outlen;
1447 			got_object_raw_close(raw);
1448 			raw = NULL;
1449 		} else if (m->delta_buf) {
1450 			err = deltahdr(&packfile_size, &ctx, packfile,
1451 			    m, use_offset_deltas);
1452 			if (err)
1453 				goto done;
1454  			err = got_deflate_to_file_mmap(&outlen,
1455 			    m->delta_buf, 0, m->delta_len, packfile, &csum);
1456  			if (err)
1457  				goto done;
1458  			packfile_size += outlen;
1459 			free(m->delta_buf);
1460 			m->delta_buf = NULL;
1461 		} else {
1462 			if (fseeko(delta_cache, m->delta_offset, SEEK_SET)
1463 			    == -1) {
1464 				err = got_error_from_errno("fseeko");
1465 				goto done;
1466 			}
1467 			err = deltahdr(&packfile_size, &ctx, packfile,
1468 			    m, use_offset_deltas);
1469 			if (err)
1470 				goto done;
1471 			err = got_deflate_to_file(&outlen, delta_cache,
1472 			    m->delta_len, packfile, &csum);
1473 			if (err)
1474 				goto done;
1475 			packfile_size += outlen;
1476 		}
1477 	}
1478 	SHA1Final(pack_sha1, &ctx);
1479 	n = fwrite(pack_sha1, 1, SHA1_DIGEST_LENGTH, packfile);
1480 	if (n != SHA1_DIGEST_LENGTH)
1481 		err = got_ferror(packfile, GOT_ERR_IO);
1482 	packfile_size += SHA1_DIGEST_LENGTH;
1483 	packfile_size += sizeof(struct got_packfile_hdr);
1484 	if (progress_cb) {
1485 		err = progress_cb(progress_arg, packfile_size, nours,
1486 		    nmeta, nmeta, nmeta);
1487 		if (err)
1488 			goto done;
1489 	}
1490 done:
1491 	if (raw)
1492 		got_object_raw_close(raw);
1493 	if (outfd != -1 && close(outfd) == -1 && err == NULL)
1494 		err = got_error_from_errno("close");
1495 	return err;
1496 }
1497 
1498 const struct got_error *
1499 got_pack_create(uint8_t *packsha1, FILE *packfile,
1500     struct got_object_id **theirs, int ntheirs,
1501     struct got_object_id **ours, int nours,
1502     struct got_repository *repo, int loose_obj_only, int allow_empty,
1503     got_pack_progress_cb progress_cb, void *progress_arg,
1504     got_cancel_cb cancel_cb, void *cancel_arg)
1505 {
1506 	const struct got_error *err;
1507 	struct got_pack_meta **meta;
1508 	int nmeta;
1509 	FILE *delta_cache = NULL;
1510 	struct got_ratelimit rl;
1511 
1512 	got_ratelimit_init(&rl, 0, 500);
1513 
1514 	err = read_meta(&meta, &nmeta, theirs, ntheirs, ours, nours, repo,
1515 	    loose_obj_only, progress_cb, progress_arg, &rl,
1516 	    cancel_cb, cancel_arg);
1517 	if (err)
1518 		return err;
1519 
1520 	if (nmeta == 0 && !allow_empty) {
1521 		err = got_error(GOT_ERR_CANNOT_PACK);
1522 		goto done;
1523 	}
1524 
1525 	delta_cache = got_opentemp();
1526 	if (delta_cache == NULL) {
1527 		err = got_error_from_errno("got_opentemp");
1528 		goto done;
1529 	}
1530 
1531 	if (nmeta > 0) {
1532 		err = pick_deltas(meta, nmeta, nours, delta_cache, repo,
1533 		    progress_cb, progress_arg, &rl, cancel_cb, cancel_arg);
1534 		if (err)
1535 			goto done;
1536 		if (fseeko(delta_cache, 0L, SEEK_SET) == -1) {
1537 			err = got_error_from_errno("fseeko");
1538 			goto done;
1539 		}
1540 	}
1541 
1542 	err = genpack(packsha1, packfile, delta_cache, meta, nmeta, nours, 1,
1543 	    repo, progress_cb, progress_arg, &rl, cancel_cb, cancel_arg);
1544 	if (err)
1545 		goto done;
1546 done:
1547 	free_nmeta(meta, nmeta);
1548 	if (delta_cache && fclose(delta_cache) == EOF && err == NULL)
1549 		err = got_error_from_errno("fclose");
1550 	return err;
1551 }