1 /*
2  * Copyright (c) 2020 Ori Bernstein
3  * Copyright (c) 2021 Stefan Sperling <stsp@openbsd.org>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 #include <sys/types.h>
19 #include <sys/queue.h>
20 #include <sys/tree.h>
21 #include <sys/uio.h>
22 #include <sys/stat.h>
23 #include <sys/time.h>
24 #include <sys/mman.h>
25 
26 #include <endian.h>
27 #include <errno.h>
28 #include <stdint.h>
29 #include <imsg.h>
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <sha1.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 #include "got_opentemp.h"
46 
47 #include "got_lib_deltify.h"
48 #include "got_lib_delta.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_pack.h"
54 #include "got_lib_privsep.h"
55 #include "got_lib_repository.h"
56 #include "got_lib_ratelimit.h"
57 #include "got_lib_inflate.h"
58 
59 #ifndef MIN
60 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
61 #endif
62 
63 #ifndef MAX
64 #define	MAX(_a,_b) ((_a) > (_b) ? (_a) : (_b))
65 #endif
66 
67 #ifndef nitems
68 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
69 #endif
70 
71 struct got_pack_meta {
72 	struct got_object_id id;
73 	char	*path;
74 	int	obj_type;
75 	off_t	size;
76 	time_t	mtime;
77 
78 	/* The best delta we picked */
79 	struct got_pack_meta *head;
80 	struct got_pack_meta *prev;
81 	unsigned char *delta_buf; /* if encoded in memory (compressed) */
82 	off_t	delta_offset;	/* offset in delta cache file (compressed) */
83 	off_t	delta_len;	/* encoded delta length */
84 	off_t	delta_compressed_len; /* encoded+compressed delta length */
85 	int	nchain;
86 
87 	int	have_reused_delta;
88 	off_t   reused_delta_offset; /* offset of delta in reused pack file */
89 	struct got_object_id *base_obj_id;
90 
91 	/* Only used for delta window */
92 	struct got_delta_table *dtab;
93 
94 	/* Only used for writing offset deltas */
95 	off_t	off;
96 };
97 
98 struct got_pack_metavec {
99 	struct got_pack_meta **meta;
100 	int nmeta;
101 	int metasz;
102 };
103 
104 static const struct got_error *
105 alloc_meta(struct got_pack_meta **new, struct got_object_id *id,
106     const char *path, int obj_type, time_t mtime)
107 {
108 	const struct got_error *err = NULL;
109 	struct got_pack_meta *m;
110 
111 	*new = NULL;
112 
113 	m = calloc(1, sizeof(*m));
114 	if (m == NULL)
115 		return got_error_from_errno("calloc");
116 
117 	memcpy(&m->id, id, sizeof(m->id));
118 
119 	m->path = strdup(path);
120 	if (m->path == NULL) {
121 		err = got_error_from_errno("strdup");
122 		free(m);
123 		return err;
124 	}
125 
126 	m->obj_type = obj_type;
127 	m->mtime = mtime;
128 	*new = m;
129 	return NULL;
130 }
131 
132 static void
133 clear_meta(struct got_pack_meta *meta)
134 {
135 	if (meta == NULL)
136 		return;
137 	free(meta->path);
138 	meta->path = NULL;
139 	free(meta->delta_buf);
140 	meta->delta_buf = NULL;
141 	free(meta->base_obj_id);
142 	meta->base_obj_id = NULL;
143 }
144 
145 static void
146 free_nmeta(struct got_pack_meta **meta, int nmeta)
147 {
148 	int i;
149 
150 	for (i = 0; i < nmeta; i++)
151 		clear_meta(meta[i]);
152 	free(meta);
153 }
154 
155 static int
156 delta_order_cmp(const void *pa, const void *pb)
157 {
158 	struct got_pack_meta *a, *b;
159 	int cmp;
160 
161 	a = *(struct got_pack_meta **)pa;
162 	b = *(struct got_pack_meta **)pb;
163 
164 	if (a->obj_type != b->obj_type)
165 		return a->obj_type - b->obj_type;
166 	cmp = strcmp(a->path, b->path);
167 	if (cmp != 0)
168 		return cmp;
169 	if (a->mtime < b->mtime)
170 		return -1;
171 	if (a->mtime > b->mtime)
172 		return 1;
173 	return got_object_id_cmp(&a->id, &b->id);
174 }
175 
176 static off_t
177 delta_size(struct got_delta_instruction *deltas, int ndeltas)
178 {
179 	int i;
180 	off_t size = 32;
181 	for (i = 0; i < ndeltas; i++) {
182 		if (deltas[i].copy)
183 			size += GOT_DELTA_SIZE_SHIFT;
184 		else
185 			size += deltas[i].len + 1;
186 	}
187 	return size;
188 }
189 
190 static const struct got_error *
191 append(unsigned char **p, size_t *len, off_t *sz, void *seg, int nseg)
192 {
193 	char *n;
194 
195 	if (*len + nseg >= *sz) {
196 		while (*len + nseg >= *sz)
197 			*sz += *sz / 2;
198 		n = realloc(*p, *sz);
199 		if (n == NULL)
200 			return got_error_from_errno("realloc");
201 		*p = n;
202 	}
203 	memcpy(*p + *len, seg, nseg);
204 	*len += nseg;
205 	return NULL;
206 }
207 
208 static const struct got_error *
209 encode_delta_in_mem(struct got_pack_meta *m, struct got_raw_object *o,
210     struct got_delta_instruction *deltas, int ndeltas,
211     off_t delta_size, off_t base_size)
212 {
213 	const struct got_error *err;
214 	unsigned char buf[16], *bp;
215 	int i, j;
216 	size_t len = 0, compressed_len;
217 	off_t bufsize = delta_size;
218 	off_t n;
219 	struct got_delta_instruction *d;
220 	uint8_t *delta_buf;
221 
222 	delta_buf = malloc(bufsize);
223 	if (delta_buf == NULL)
224 		return got_error_from_errno("malloc");
225 
226 	/* base object size */
227 	buf[0] = base_size & GOT_DELTA_SIZE_VAL_MASK;
228 	n = base_size >> GOT_DELTA_SIZE_SHIFT;
229 	for (i = 1; n > 0; i++) {
230 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
231 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
232 		n >>= GOT_DELTA_SIZE_SHIFT;
233 	}
234 	err = append(&delta_buf, &len, &bufsize, buf, i);
235 	if (err)
236 		goto done;
237 
238 	/* target object size */
239 	buf[0] = o->size & GOT_DELTA_SIZE_VAL_MASK;
240 	n = o->size >> GOT_DELTA_SIZE_SHIFT;
241 	for (i = 1; n > 0; i++) {
242 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
243 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
244 		n >>= GOT_DELTA_SIZE_SHIFT;
245 	}
246 	err = append(&delta_buf, &len, &bufsize, buf, i);
247 	if (err)
248 		goto done;
249 
250 	for (j = 0; j < ndeltas; j++) {
251 		d = &deltas[j];
252 		if (d->copy) {
253 			n = d->offset;
254 			bp = &buf[1];
255 			buf[0] = GOT_DELTA_BASE_COPY;
256 			for (i = 0; i < 4; i++) {
257 				/* DELTA_COPY_OFF1 ... DELTA_COPY_OFF4 */
258 				buf[0] |= 1 << i;
259 				*bp++ = n & 0xff;
260 				n >>= 8;
261 				if (n == 0)
262 					break;
263 			}
264 
265 			n = d->len;
266 			if (n != GOT_DELTA_COPY_DEFAULT_LEN) {
267 				/* DELTA_COPY_LEN1 ... DELTA_COPY_LEN3 */
268 				for (i = 0; i < 3 && n > 0; i++) {
269 					buf[0] |= 1 << (i + 4);
270 					*bp++ = n & 0xff;
271 					n >>= 8;
272 				}
273 			}
274 			err = append(&delta_buf, &len, &bufsize,
275 			    buf, bp - buf);
276 			if (err)
277 				goto done;
278 		} else if (o->f == NULL) {
279 			n = 0;
280 			while (n != d->len) {
281 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
282 				err = append(&delta_buf, &len, &bufsize,
283 				    buf, 1);
284 				if (err)
285 					goto done;
286 				err = append(&delta_buf, &len, &bufsize,
287 				    o->data + o->hdrlen + d->offset + n,
288 				    buf[0]);
289 				if (err)
290 					goto done;
291 				n += buf[0];
292 			}
293 		} else {
294 			char content[128];
295 			size_t r;
296 			if (fseeko(o->f, o->hdrlen + d->offset, SEEK_SET) == -1) {
297 				err = got_error_from_errno("fseeko");
298 				goto done;
299 			}
300 			n = 0;
301 			while (n != d->len) {
302 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
303 				err = append(&delta_buf, &len, &bufsize,
304 				    buf, 1);
305 				if (err)
306 					goto done;
307 				r = fread(content, 1, buf[0], o->f);
308 				if (r != buf[0]) {
309 					err = got_ferror(o->f, GOT_ERR_IO);
310 					goto done;
311 				}
312 				err = append(&delta_buf, &len, &bufsize,
313 				    content, buf[0]);
314 				if (err)
315 					goto done;
316 				n += buf[0];
317 			}
318 		}
319 	}
320 
321 	err = got_deflate_to_mem_mmap(&m->delta_buf, &compressed_len,
322 	    NULL, NULL, delta_buf, 0, len);
323 	if (err)
324 		goto done;
325 
326 	m->delta_len = len;
327 	m->delta_compressed_len = compressed_len;
328 done:
329 	free(delta_buf);
330 	return err;
331 }
332 
333 static const struct got_error *
334 encode_delta(struct got_pack_meta *m, struct got_raw_object *o,
335     struct got_delta_instruction *deltas, int ndeltas,
336     off_t base_size, FILE *f)
337 {
338 	const struct got_error *err;
339 	unsigned char buf[16], *bp;
340 	int i, j;
341 	off_t n;
342 	struct got_deflate_buf zb;
343 	struct got_delta_instruction *d;
344 	off_t delta_len = 0, compressed_len = 0;
345 
346 	err = got_deflate_init(&zb, NULL, GOT_DEFLATE_BUFSIZE);
347 	if (err)
348 		return err;
349 
350 	/* base object size */
351 	buf[0] = base_size & GOT_DELTA_SIZE_VAL_MASK;
352 	n = base_size >> GOT_DELTA_SIZE_SHIFT;
353 	for (i = 1; n > 0; i++) {
354 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
355 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
356 		n >>= GOT_DELTA_SIZE_SHIFT;
357 	}
358 
359 	err = got_deflate_append_to_file_mmap(&zb, &compressed_len,
360 	    buf, 0, i, f, NULL);
361 	if (err)
362 		goto done;
363 	delta_len += i;
364 
365 	/* target object size */
366 	buf[0] = o->size & GOT_DELTA_SIZE_VAL_MASK;
367 	n = o->size >> GOT_DELTA_SIZE_SHIFT;
368 	for (i = 1; n > 0; i++) {
369 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
370 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
371 		n >>= GOT_DELTA_SIZE_SHIFT;
372 	}
373 
374 	err = got_deflate_append_to_file_mmap(&zb, &compressed_len,
375 	    buf, 0, i, f, NULL);
376 	if (err)
377 		goto done;
378 	delta_len += i;
379 
380 	for (j = 0; j < ndeltas; j++) {
381 		d = &deltas[j];
382 		if (d->copy) {
383 			n = d->offset;
384 			bp = &buf[1];
385 			buf[0] = GOT_DELTA_BASE_COPY;
386 			for (i = 0; i < 4; i++) {
387 				/* DELTA_COPY_OFF1 ... DELTA_COPY_OFF4 */
388 				buf[0] |= 1 << i;
389 				*bp++ = n & 0xff;
390 				n >>= 8;
391 				if (n == 0)
392 					break;
393 			}
394 			n = d->len;
395 			if (n != GOT_DELTA_COPY_DEFAULT_LEN) {
396 				/* DELTA_COPY_LEN1 ... DELTA_COPY_LEN3 */
397 				for (i = 0; i < 3 && n > 0; i++) {
398 					buf[0] |= 1 << (i + 4);
399 					*bp++ = n & 0xff;
400 					n >>= 8;
401 				}
402 			}
403 			err = got_deflate_append_to_file_mmap(&zb,
404 			    &compressed_len, buf, 0, bp - buf, f, NULL);
405 			if (err)
406 				goto done;
407 			delta_len += (bp - buf);
408 		} else if (o->f == NULL) {
409 			n = 0;
410 			while (n != d->len) {
411 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
412 				err = got_deflate_append_to_file_mmap(&zb,
413 				    &compressed_len, buf, 0, 1, f, NULL);
414 				if (err)
415 					goto done;
416 				delta_len++;
417 				err = got_deflate_append_to_file_mmap(&zb,
418 				    &compressed_len,
419 				    o->data + o->hdrlen + d->offset + n, 0,
420 				    buf[0], f, NULL);
421 				if (err)
422 					goto done;
423 				delta_len += buf[0];
424 				n += buf[0];
425 			}
426 		} else {
427 			char content[128];
428 			size_t r;
429 			if (fseeko(o->f, o->hdrlen + d->offset, SEEK_SET) == -1) {
430 				err = got_error_from_errno("fseeko");
431 				goto done;
432 			}
433 			n = 0;
434 			while (n != d->len) {
435 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
436 				err = got_deflate_append_to_file_mmap(&zb,
437 				    &compressed_len, buf, 0, 1, f, NULL);
438 				if (err)
439 					goto done;
440 				delta_len++;
441 				r = fread(content, 1, buf[0], o->f);
442 				if (r != buf[0]) {
443 					err = got_ferror(o->f, GOT_ERR_IO);
444 					goto done;
445 				}
446 				err = got_deflate_append_to_file_mmap(&zb,
447 				    &compressed_len, content, 0, buf[0], f,
448 				    NULL);
449 				if (err)
450 					goto done;
451 				delta_len += buf[0];
452 				n += buf[0];
453 			}
454 		}
455 	}
456 
457 	err = got_deflate_flush(&zb, f, NULL, &compressed_len);
458 	if (err)
459 		goto done;
460 
461 	/* sanity check */
462 	if (compressed_len != ftello(f) - m->delta_offset) {
463 		err = got_error(GOT_ERR_COMPRESSION);
464 		goto done;
465 	}
466 
467 	m->delta_len = delta_len;
468 	m->delta_compressed_len = compressed_len;
469 done:
470 	got_deflate_end(&zb);
471 	return err;
472 }
473 
474 static const struct got_error *
475 report_progress(got_pack_progress_cb progress_cb, void *progress_arg,
476     struct got_ratelimit *rl, int ncolored, int nfound, int ntrees,
477     off_t packfile_size, int ncommits, int nobj_total, int obj_deltify,
478     int nobj_written)
479 {
480 	const struct got_error *err;
481 	int elapsed;
482 
483 	if (progress_cb == NULL)
484 		return NULL;
485 
486 	err = got_ratelimit_check(&elapsed, rl);
487 	if (err || !elapsed)
488 		return err;
489 
490 	return progress_cb(progress_arg, ncolored, nfound, ntrees,
491 	    packfile_size, ncommits, nobj_total, obj_deltify, nobj_written);
492 }
493 
494 static const struct got_error *
495 add_meta(struct got_pack_meta *m, struct got_pack_metavec *v)
496 {
497 	if (v->nmeta == v->metasz){
498 		size_t newsize = 2 * v->metasz;
499 		struct got_pack_meta **new;
500 		new = reallocarray(v->meta, newsize, sizeof(*new));
501 		if (new == NULL)
502 			return got_error_from_errno("reallocarray");
503 		v->meta = new;
504 		v->metasz = newsize; 
505 	}
506 
507 	v->meta[v->nmeta++] = m;
508 	return NULL;
509 }
510 
511 static const struct got_error *
512 find_pack_for_reuse(struct got_packidx **best_packidx,
513     struct got_repository *repo)
514 {
515 	const struct got_error *err = NULL;
516 	struct got_pathlist_entry *pe;
517 	const char *best_packidx_path = NULL;
518 	int nobj_max = 0;
519 
520 	*best_packidx = NULL;
521 
522 	TAILQ_FOREACH(pe, &repo->packidx_paths, entry) {
523 		const char *path_packidx = pe->path;
524 		struct got_packidx *packidx;
525 		int nobj;
526 
527 		err = got_repo_get_packidx(&packidx, path_packidx, repo);
528 		if (err)
529 			break;
530 
531 		nobj = be32toh(packidx->hdr.fanout_table[0xff]);
532 		if (nobj > nobj_max) {
533 			best_packidx_path = path_packidx;
534 			nobj_max = nobj;
535 		}
536 	}
537 
538 	if (best_packidx_path) {
539 		err = got_repo_get_packidx(best_packidx, best_packidx_path,
540 		    repo);
541 	}
542 
543 	return err;
544 }
545 
546 struct send_id_arg {
547 	struct imsgbuf *ibuf;
548 	struct got_object_id *ids[GOT_IMSG_OBJ_ID_LIST_MAX_NIDS];
549 	size_t nids;
550 };
551 
552 static const struct got_error *
553 send_id(struct got_object_id *id, void *data, void *arg)
554 {
555 	const struct got_error *err = NULL;
556 	struct send_id_arg *a = arg;
557 
558 	a->ids[a->nids++] = id;
559 
560 	if (a->nids >= GOT_IMSG_OBJ_ID_LIST_MAX_NIDS) {
561 		err = got_privsep_send_object_idlist(a->ibuf, a->ids, a->nids);
562 		if (err)
563 			return err;
564 		a->nids = 0;
565 	}
566 
567 	return NULL;
568 }
569 
570 static const struct got_error *
571 recv_reused_delta(struct got_imsg_reused_delta *delta,
572     struct got_object_idset *idset, struct got_pack_metavec *v)
573 {
574 	struct got_pack_meta *m, *base;
575 
576 	if (delta->delta_offset + delta->delta_size < delta->delta_offset ||
577 	    delta->delta_offset +
578 	    delta->delta_compressed_size < delta->delta_offset)
579 		return got_error(GOT_ERR_BAD_PACKFILE);
580 
581 	m = got_object_idset_get(idset, &delta->id);
582 	if (m == NULL)
583 		return got_error(GOT_ERR_NO_OBJ);
584 
585 	base = got_object_idset_get(idset, &delta->base_id);
586 	if (base == NULL)
587 		return got_error(GOT_ERR_NO_OBJ);
588 
589 	m->delta_len = delta->delta_size;
590 	m->delta_compressed_len = delta->delta_compressed_size;
591 	m->delta_offset = delta->delta_out_offset;
592 	m->prev = base;
593 	m->size = delta->result_size;
594 	m->have_reused_delta = 1;
595 	m->reused_delta_offset = delta->delta_offset;
596 	m->base_obj_id = got_object_id_dup(&delta->base_id);
597 	if (m->base_obj_id == NULL)
598 		return got_error_from_errno("got_object_id_dup");
599 
600 	return add_meta(m, v);
601 }
602 
603 static const struct got_error *
604 search_deltas(struct got_pack_metavec *v, struct got_object_idset *idset,
605     int delta_cache_fd, int ncolored, int nfound, int ntrees, int ncommits,
606     struct got_repository *repo,
607     got_pack_progress_cb progress_cb, void *progress_arg,
608     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
609 {
610 	const struct got_error *err = NULL;
611 	struct got_packidx *packidx;
612 	struct got_pack *pack;
613 	struct send_id_arg sia;
614 	struct got_imsg_reused_delta deltas[GOT_IMSG_REUSED_DELTAS_MAX_NDELTAS];
615 	size_t ndeltas, i;
616 
617 	err = find_pack_for_reuse(&packidx, repo);
618 	if (err)
619 		return err;
620 
621 	if (packidx == NULL)
622 		return NULL;
623 
624 	err = got_object_prepare_delta_reuse(&pack, packidx,
625 	    delta_cache_fd, repo);
626 	if (err)
627 		return err;
628 
629 	memset(&sia, 0, sizeof(sia));
630 	sia.ibuf = pack->privsep_child->ibuf;
631 	err = got_object_idset_for_each(idset, send_id, &sia);
632 	if (err)
633 		return err;
634 	if (sia.nids > 0) {
635 		err = got_privsep_send_object_idlist(pack->privsep_child->ibuf,
636 		    sia.ids, sia.nids);
637 		if (err)
638 			return err;
639 	}
640 	err = got_privsep_send_object_idlist_done(pack->privsep_child->ibuf);
641 	if (err)
642 		return err;
643 
644 	for (;;) {
645 		int done = 0;
646 
647 		if (cancel_cb) {
648 			err = (*cancel_cb)(cancel_arg);
649 			if (err)
650 				break;
651 		}
652 
653 		err = got_privsep_recv_reused_deltas(&done, deltas, &ndeltas,
654 		    pack->privsep_child->ibuf);
655 		if (err || done)
656 			break;
657 
658 		for (i = 0; i < ndeltas; i++) {
659 			struct got_imsg_reused_delta *delta = &deltas[i];
660 			err = recv_reused_delta(delta, idset, v);
661 			if (err)
662 				goto done;
663 		}
664 
665 		err = report_progress(progress_cb, progress_arg, rl,
666 		    ncolored, nfound, ntrees, 0L, ncommits,
667 		    got_object_idset_num_elements(idset), v->nmeta, 0);
668 		if (err)
669 			break;
670 	}
671 done:
672 	return err;
673 }
674 
675 static const struct got_error *
676 pick_deltas(struct got_pack_meta **meta, int nmeta, int ncolored,
677     int nfound, int ntrees, int ncommits, int nreused, FILE *delta_cache,
678     struct got_repository *repo,
679     got_pack_progress_cb progress_cb, void *progress_arg,
680     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
681 {
682 	const struct got_error *err = NULL;
683 	struct got_pack_meta *m = NULL, *base = NULL;
684 	struct got_raw_object *raw = NULL, *base_raw = NULL;
685 	struct got_delta_instruction *deltas = NULL, *best_deltas = NULL;
686 	int i, j, ndeltas, best_ndeltas;
687 	off_t size, best_size;
688 	const int max_base_candidates = 3;
689 	size_t delta_memsize = 0;
690 	const size_t max_delta_memsize = 25 * GOT_DELTA_RESULT_SIZE_CACHED_MAX;
691 	int outfd = -1;
692 
693 	qsort(meta, nmeta, sizeof(struct got_pack_meta *), delta_order_cmp);
694 	for (i = 0; i < nmeta; i++) {
695 		if (cancel_cb) {
696 			err = (*cancel_cb)(cancel_arg);
697 			if (err)
698 				break;
699 		}
700 		err = report_progress(progress_cb, progress_arg, rl,
701 		    ncolored, nfound, ntrees, 0L, ncommits, nreused + nmeta,
702 		    nreused + i, 0);
703 		if (err)
704 			goto done;
705 		m = meta[i];
706 
707 		if (m->obj_type == GOT_OBJ_TYPE_COMMIT ||
708 		    m->obj_type == GOT_OBJ_TYPE_TAG)
709 			continue;
710 
711 		err = got_object_raw_open(&raw, &outfd, repo, &m->id);
712 		if (err)
713 			goto done;
714 		m->size = raw->size;
715 
716 		if (raw->f == NULL) {
717 			err = got_deltify_init_mem(&m->dtab, raw->data,
718 			    raw->hdrlen, raw->size + raw->hdrlen);
719 		} else {
720 			err = got_deltify_init(&m->dtab, raw->f, raw->hdrlen,
721 			    raw->size + raw->hdrlen);
722 		}
723 		if (err)
724 			goto done;
725 
726 		if (i > max_base_candidates) {
727 			struct got_pack_meta *n = NULL;
728 			n = meta[i - (max_base_candidates + 1)];
729 			got_deltify_free(n->dtab);
730 			n->dtab = NULL;
731 		}
732 
733 		best_size = raw->size;
734 		best_ndeltas = 0;
735 		for (j = MAX(0, i - max_base_candidates); j < i; j++) {
736 			if (cancel_cb) {
737 				err = (*cancel_cb)(cancel_arg);
738 				if (err)
739 					goto done;
740 			}
741 			base = meta[j];
742 			/* long chains make unpacking slow, avoid such bases */
743 			if (base->nchain >= 128 ||
744 			    base->obj_type != m->obj_type)
745 				continue;
746 
747 			err = got_object_raw_open(&base_raw, &outfd, repo,
748 			    &base->id);
749 			if (err)
750 				goto done;
751 
752 			if (raw->f == NULL && base_raw->f == NULL) {
753 				err = got_deltify_mem_mem(&deltas, &ndeltas,
754 				    raw->data, raw->hdrlen,
755 				    raw->size + raw->hdrlen,
756 				    base->dtab, base_raw->data,
757 				    base_raw->hdrlen,
758 				    base_raw->size + base_raw->hdrlen);
759 			} else if (raw->f == NULL) {
760 				err = got_deltify_mem_file(&deltas, &ndeltas,
761 				    raw->data, raw->hdrlen,
762 				    raw->size + raw->hdrlen,
763 				    base->dtab, base_raw->f,
764 				    base_raw->hdrlen,
765 				    base_raw->size + base_raw->hdrlen);
766 			} else if (base_raw->f == NULL) {
767 				err = got_deltify_file_mem(&deltas, &ndeltas,
768 				    raw->f, raw->hdrlen,
769 				    raw->size + raw->hdrlen,
770 				    base->dtab, base_raw->data,
771 				    base_raw->hdrlen,
772 				    base_raw->size + base_raw->hdrlen);
773 			} else {
774 				err = got_deltify(&deltas, &ndeltas,
775 				    raw->f, raw->hdrlen,
776 				    raw->size + raw->hdrlen,
777 				    base->dtab, base_raw->f, base_raw->hdrlen,
778 				    base_raw->size + base_raw->hdrlen);
779 			}
780 			got_object_raw_close(base_raw);
781 			base_raw = NULL;
782 			if (err)
783 				goto done;
784 
785 			size = delta_size(deltas, ndeltas);
786 			if (size + 32 < best_size){
787 				/*
788 				 * if we already picked a best delta,
789 				 * replace it.
790 				 */
791 				best_size = size;
792 				free(best_deltas);
793 				best_deltas = deltas;
794 				best_ndeltas = ndeltas;
795 				deltas = NULL;
796 				m->nchain = base->nchain + 1;
797 				m->prev = base;
798 				m->head = base->head;
799 				if (m->head == NULL)
800 					m->head = base;
801 			} else {
802 				free(deltas);
803 				deltas = NULL;
804 				ndeltas = 0;
805 			}
806 		}
807 
808 		if (best_ndeltas > 0) {
809 			if (best_size <= GOT_DELTA_RESULT_SIZE_CACHED_MAX &&
810 			    delta_memsize + best_size <= max_delta_memsize) {
811 				delta_memsize += best_size;
812 				err = encode_delta_in_mem(m, raw, best_deltas,
813 				    best_ndeltas, best_size, m->prev->size);
814 			} else {
815 				m->delta_offset = ftello(delta_cache);
816 				err = encode_delta(m, raw, best_deltas,
817 				    best_ndeltas, m->prev->size, delta_cache);
818 			}
819 			free(best_deltas);
820 			best_deltas = NULL;
821 			best_ndeltas = 0;
822 			if (err)
823 				goto done;
824 		}
825 
826 		got_object_raw_close(raw);
827 		raw = NULL;
828 	}
829 done:
830 	for (i = MAX(0, nmeta - max_base_candidates); i < nmeta; i++) {
831 		got_deltify_free(meta[i]->dtab);
832 		meta[i]->dtab = NULL;
833 	}
834 	if (raw)
835 		got_object_raw_close(raw);
836 	if (base_raw)
837 		got_object_raw_close(base_raw);
838 	if (outfd != -1 && close(outfd) == -1 && err == NULL)
839 		err = got_error_from_errno("close");
840 	free(deltas);
841 	free(best_deltas);
842 	return err;
843 }
844 
845 static const struct got_error *
846 search_packidx(int *found, struct got_object_id *id,
847     struct got_repository *repo)
848 {
849 	const struct got_error *err = NULL;
850 	struct got_packidx *packidx = NULL;
851 	int idx;
852 
853 	*found = 0;
854 
855 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
856 	if (err == NULL)
857 		*found = 1; /* object is already packed */
858 	else if (err->code == GOT_ERR_NO_OBJ)
859 		err = NULL;
860 	return err;
861 }
862 
863 static const struct got_error *
864 add_object(int want_meta, struct got_object_idset *idset,
865     struct got_object_id *id, const char *path, int obj_type,
866     time_t mtime, int loose_obj_only, struct got_repository *repo,
867     int *ncolored, int *nfound, int *ntrees,
868     got_pack_progress_cb progress_cb, void *progress_arg,
869     struct got_ratelimit *rl)
870 {
871 	const struct got_error *err;
872 	struct got_pack_meta *m = NULL;
873 
874 	if (loose_obj_only) {
875 		int is_packed;
876 		err = search_packidx(&is_packed, id, repo);
877 		if (err)
878 			return err;
879 		if (is_packed && want_meta)
880 			return NULL;
881 	}
882 
883 	if (want_meta) {
884 		err = alloc_meta(&m, id, path, obj_type, mtime);
885 		if (err)
886 			return err;
887 
888 		(*nfound)++;
889 		err = report_progress(progress_cb, progress_arg, rl,
890 		    *ncolored, *nfound, *ntrees, 0L, 0, 0, 0, 0);
891 		if (err) {
892 			clear_meta(m);
893 			free(m);
894 			return err;
895 		}
896 	}
897 
898 	err = got_object_idset_add(idset, id, m);
899 	if (err) {
900 		clear_meta(m);
901 		free(m);
902 	}
903 	return err;
904 }
905 
906 static const struct got_error *
907 load_tree_entries(struct got_object_id_queue *ids, int want_meta,
908     struct got_object_idset *idset, struct got_object_idset *idset_exclude,
909     struct got_object_id *tree_id,
910     const char *dpath, time_t mtime, struct got_repository *repo,
911     int loose_obj_only, int *ncolored, int *nfound, int *ntrees,
912     got_pack_progress_cb progress_cb, void *progress_arg,
913     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
914 {
915 	const struct got_error *err;
916 	struct got_tree_object *tree;
917 	char *p = NULL;
918 	int i;
919 
920 	err = got_object_open_as_tree(&tree, repo, tree_id);
921 	if (err)
922 		return err;
923 
924 	(*ntrees)++;
925 	err = report_progress(progress_cb, progress_arg, rl,
926 	    *ncolored, *nfound, *ntrees, 0L, 0, 0, 0, 0);
927 	if (err)
928 		return err;
929 
930 	for (i = 0; i < got_object_tree_get_nentries(tree); i++) {
931 		struct got_tree_entry *e = got_object_tree_get_entry(tree, i);
932 		struct got_object_id *id = got_tree_entry_get_id(e);
933 		mode_t mode = got_tree_entry_get_mode(e);
934 
935 		if (cancel_cb) {
936 			err = (*cancel_cb)(cancel_arg);
937 			if (err)
938 				break;
939 		}
940 
941 		if (got_object_tree_entry_is_submodule(e) ||
942 		    got_object_idset_contains(idset, id) ||
943 		    got_object_idset_contains(idset_exclude, id))
944 			continue;
945 		
946 		if (asprintf(&p, "%s%s%s", dpath, dpath[0] != '\0' ? "/" : "",
947 		    got_tree_entry_get_name(e)) == -1) {
948 			err = got_error_from_errno("asprintf");
949 			break;
950 		}
951 
952 		if (S_ISDIR(mode)) {
953 			struct got_object_qid *qid;
954 			err = got_object_qid_alloc(&qid, id);
955 			if (err)
956 				break;
957 			qid->data = p;
958 			p = NULL;
959 			STAILQ_INSERT_TAIL(ids, qid, entry);
960 		} else if (S_ISREG(mode) || S_ISLNK(mode)) {
961 			err = add_object(want_meta,
962 			    want_meta ? idset : idset_exclude, id, p,
963 			    GOT_OBJ_TYPE_BLOB, mtime, loose_obj_only, repo,
964 			    ncolored, nfound, ntrees,
965 			    progress_cb, progress_arg, rl);
966 			if (err)
967 				break;
968 			free(p);
969 			p = NULL;
970 		} else {
971 			free(p);
972 			p = NULL;
973 		}
974 	}
975 
976 	got_object_tree_close(tree);
977 	free(p);
978 	return err;
979 }
980 
981 static const struct got_error *
982 load_tree(int want_meta, struct got_object_idset *idset,
983     struct got_object_idset *idset_exclude,
984     struct got_object_id *tree_id, const char *dpath, time_t mtime,
985     struct got_repository *repo, int loose_obj_only,
986     int *ncolored, int *nfound, int *ntrees,
987     got_pack_progress_cb progress_cb, void *progress_arg,
988     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
989 {
990 	const struct got_error *err = NULL;
991 	struct got_object_id_queue tree_ids;
992 	struct got_object_qid *qid;
993 
994 	if (got_object_idset_contains(idset, tree_id) ||
995 	    got_object_idset_contains(idset_exclude, tree_id))
996 		return NULL;
997 
998 	err = got_object_qid_alloc(&qid, tree_id);
999 	if (err)
1000 		return err;
1001 	qid->data = strdup(dpath);
1002 	if (qid->data == NULL) {
1003 		err = got_error_from_errno("strdup");
1004 		got_object_qid_free(qid);
1005 		return err;
1006 	}
1007 
1008 	STAILQ_INIT(&tree_ids);
1009 	STAILQ_INSERT_TAIL(&tree_ids, qid, entry);
1010 
1011 	while (!STAILQ_EMPTY(&tree_ids)) {
1012 		const char *path;
1013 		if (cancel_cb) {
1014 			err = (*cancel_cb)(cancel_arg);
1015 			if (err)
1016 				break;
1017 		}
1018 
1019 		qid = STAILQ_FIRST(&tree_ids);
1020 		STAILQ_REMOVE_HEAD(&tree_ids, entry);
1021 		path = qid->data;
1022 
1023 		if (got_object_idset_contains(idset, &qid->id) ||
1024 		    got_object_idset_contains(idset_exclude, &qid->id)) {
1025 			free(qid->data);
1026 			got_object_qid_free(qid);
1027 			continue;
1028 		}
1029 
1030 		err = add_object(want_meta, want_meta ? idset : idset_exclude,
1031 		    &qid->id, path, GOT_OBJ_TYPE_TREE,
1032 		    mtime, loose_obj_only, repo,
1033 		    ncolored, nfound, ntrees, progress_cb, progress_arg, rl);
1034 		if (err) {
1035 			free(qid->data);
1036 			got_object_qid_free(qid);
1037 			break;
1038 		}
1039 
1040 		err = load_tree_entries(&tree_ids, want_meta, idset,
1041 		    idset_exclude, &qid->id,
1042 		    path, mtime, repo, loose_obj_only, ncolored, nfound,
1043 		    ntrees, progress_cb, progress_arg, rl,
1044 		    cancel_cb, cancel_arg);
1045 		free(qid->data);
1046 		got_object_qid_free(qid);
1047 		if (err)
1048 			break;
1049 	}
1050 
1051 	STAILQ_FOREACH(qid, &tree_ids, entry)
1052 		free(qid->data);
1053 	got_object_id_queue_free(&tree_ids);
1054 	return err;
1055 }
1056 
1057 static const struct got_error *
1058 load_commit(int want_meta, struct got_object_idset *idset,
1059     struct got_object_idset *idset_exclude,
1060     struct got_object_id *id, struct got_repository *repo, int loose_obj_only,
1061     int *ncolored, int *nfound, int *ntrees,
1062     got_pack_progress_cb progress_cb, void *progress_arg,
1063     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1064 {
1065 	const struct got_error *err;
1066 	struct got_commit_object *commit;
1067 
1068 	if (got_object_idset_contains(idset, id) ||
1069 	    got_object_idset_contains(idset_exclude, id))
1070 		return NULL;
1071 
1072 	if (loose_obj_only) {
1073 		int is_packed;
1074 		err = search_packidx(&is_packed, id, repo);
1075 		if (err)
1076 			return err;
1077 		if (is_packed && want_meta)
1078 			return NULL;
1079 	}
1080 
1081 	err = got_object_open_as_commit(&commit, repo, id);
1082 	if (err)
1083 		return err;
1084 
1085 	err = add_object(want_meta, want_meta ? idset : idset_exclude,
1086 	    id, "", GOT_OBJ_TYPE_COMMIT,
1087 	    got_object_commit_get_committer_time(commit),
1088 	    loose_obj_only, repo,
1089 	    ncolored, nfound, ntrees, progress_cb, progress_arg, rl);
1090 	if (err)
1091 		goto done;
1092 
1093 	err = load_tree(want_meta, idset, idset_exclude,
1094 	    got_object_commit_get_tree_id(commit),
1095 	    "", got_object_commit_get_committer_time(commit),
1096 	    repo, loose_obj_only, ncolored, nfound, ntrees,
1097 	    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1098 done:
1099 	got_object_commit_close(commit);
1100 	return err;
1101 }
1102 
1103 static const struct got_error *
1104 load_tag(int want_meta, struct got_object_idset *idset,
1105     struct got_object_idset *idset_exclude,
1106     struct got_object_id *id, struct got_repository *repo, int loose_obj_only,
1107     int *ncolored, int *nfound, int *ntrees,
1108     got_pack_progress_cb progress_cb, void *progress_arg,
1109     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1110 {
1111 	const struct got_error *err;
1112 	struct got_tag_object *tag = NULL;
1113 
1114 	if (got_object_idset_contains(idset, id) ||
1115 	    got_object_idset_contains(idset_exclude, id))
1116 		return NULL;
1117 
1118 	if (loose_obj_only) {
1119 		int is_packed;
1120 		err = search_packidx(&is_packed, id, repo);
1121 		if (err)
1122 			return err;
1123 		if (is_packed && want_meta)
1124 			return NULL;
1125 	}
1126 
1127 	err = got_object_open_as_tag(&tag, repo, id);
1128 	if (err)
1129 		return err;
1130 
1131 	err = add_object(want_meta, want_meta ? idset : idset_exclude,
1132 	    id, "", GOT_OBJ_TYPE_TAG,
1133 	    got_object_tag_get_tagger_time(tag), loose_obj_only, repo,
1134 	    ncolored, nfound, ntrees, progress_cb, progress_arg, rl);
1135 	if (err)
1136 		goto done;
1137 
1138 	switch (got_object_tag_get_object_type(tag)) {
1139 	case GOT_OBJ_TYPE_COMMIT:
1140 		err = load_commit(want_meta, idset, idset_exclude,
1141 		    got_object_tag_get_object_id(tag), repo, loose_obj_only,
1142 		    ncolored, nfound, ntrees, progress_cb, progress_arg, rl,
1143 		    cancel_cb, cancel_arg);
1144 		break;
1145 	case GOT_OBJ_TYPE_TREE:
1146 		err = load_tree(want_meta, idset, idset_exclude,
1147 		    got_object_tag_get_object_id(tag), "",
1148 		    got_object_tag_get_tagger_time(tag), repo, loose_obj_only,
1149 		    ncolored, nfound, ntrees, progress_cb, progress_arg, rl,
1150 		    cancel_cb, cancel_arg);
1151 		break;
1152 	default:
1153 		break;
1154 	}
1155 
1156 done:
1157 	got_object_tag_close(tag);
1158 	return err;
1159 }
1160 
1161 enum findtwixt_color {
1162 	COLOR_KEEP = 0,
1163 	COLOR_DROP,
1164 	COLOR_BLANK,
1165 	COLOR_SKIP,
1166 };
1167 
1168 static const int findtwixt_colors[] = {
1169 	COLOR_KEEP,
1170 	COLOR_DROP,
1171 	COLOR_BLANK,
1172 	COLOR_SKIP,
1173 };
1174 
1175 static const struct got_error *
1176 paint_commit(struct got_object_qid *qid, int color)
1177 {
1178 	if (color < 0 || color >= nitems(findtwixt_colors))
1179 		return got_error(GOT_ERR_RANGE);
1180 
1181 	qid->data = (void *)&findtwixt_colors[color];
1182 	return NULL;
1183 }
1184 
1185 static const struct got_error *
1186 queue_commit_id(struct got_object_id_queue *ids, struct got_object_id *id,
1187     int color, struct got_repository *repo)
1188 {
1189 	const struct got_error *err;
1190 	struct got_object_qid *qid;
1191 
1192 	err = got_object_qid_alloc(&qid, id);
1193 	if (err)
1194 		return err;
1195 
1196 	STAILQ_INSERT_TAIL(ids, qid, entry);
1197 	return paint_commit(qid, color);
1198 }
1199 
1200 struct append_id_arg {
1201 	struct got_object_id **array;
1202 	int idx;
1203 	struct got_object_idset *drop;
1204 	struct got_object_idset *skip;
1205 };
1206 
1207 static const struct got_error *
1208 append_id(struct got_object_id *id, void *data, void *arg)
1209 {
1210 	struct append_id_arg *a = arg;
1211 
1212 	if (got_object_idset_contains(a->skip, id) ||
1213 	    got_object_idset_contains(a->drop, id))
1214 		return NULL;
1215 
1216 	a->array[++a->idx] = got_object_id_dup(id);
1217 	if (a->array[a->idx] == NULL)
1218 		return got_error_from_errno("got_object_id_dup");
1219 
1220 	return NULL;
1221 }
1222 
1223 static const struct got_error *
1224 queue_commit_or_tag_id(struct got_object_id *id, int color,
1225     struct got_object_id_queue *ids, struct got_repository *repo)
1226 {
1227 	const struct got_error *err;
1228 	struct got_tag_object *tag = NULL;
1229 	int obj_type;
1230 
1231 	err = got_object_get_type(&obj_type, repo, id);
1232 	if (err)
1233 		return err;
1234 
1235 	if (obj_type == GOT_OBJ_TYPE_TAG) {
1236 		err = got_object_open_as_tag(&tag, repo, id);
1237 		if (err)
1238 			return err;
1239 		obj_type = got_object_tag_get_object_type(tag);
1240 		id = got_object_tag_get_object_id(tag);
1241 	}
1242 
1243 	if (obj_type == GOT_OBJ_TYPE_COMMIT) {
1244 		err = queue_commit_id(ids, id, color, repo);
1245 		if (err)
1246 			goto done;
1247 	}
1248 done:
1249 	if (tag)
1250 		got_object_tag_close(tag);
1251 	return err;
1252 }
1253 
1254 static const struct got_error *
1255 paint_commits(int *ncolored, struct got_object_id_queue *ids, int nids,
1256     struct got_object_idset *keep, struct got_object_idset *drop,
1257     struct got_object_idset *skip, struct got_repository *repo,
1258     got_pack_progress_cb progress_cb, void *progress_arg,
1259     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1260 {
1261 	const struct got_error *err = NULL;
1262 	struct got_commit_object *commit = NULL;
1263 	const struct got_object_id_queue *parents;
1264 	struct got_object_qid *qid;
1265 	int nqueued = nids, nskip = 0;
1266 
1267 	while (!STAILQ_EMPTY(ids) && nskip != nqueued) {
1268 		int color;
1269 
1270 		if (cancel_cb) {
1271 			err = cancel_cb(cancel_arg);
1272 			if (err)
1273 				break;
1274 		}
1275 
1276 		qid = STAILQ_FIRST(ids);
1277 		STAILQ_REMOVE_HEAD(ids, entry);
1278 		nqueued--;
1279 		color = *((int *)qid->data);
1280 		if (color == COLOR_SKIP)
1281 			nskip--;
1282 
1283 		if (got_object_idset_contains(skip, &qid->id)) {
1284 			got_object_qid_free(qid);
1285 			continue;
1286 		}
1287 
1288 		switch (color) {
1289 		case COLOR_KEEP:
1290 			if (got_object_idset_contains(keep, &qid->id)) {
1291 				got_object_qid_free(qid);
1292 				continue;
1293 			}
1294 			if (got_object_idset_contains(drop, &qid->id)) {
1295 				err = paint_commit(qid, COLOR_SKIP);
1296 				if (err)
1297 					goto done;
1298 				nskip++;
1299 			} else
1300 				(*ncolored)++;
1301 			err = got_object_idset_add(keep, &qid->id, NULL);
1302 			if (err)
1303 				goto done;
1304 			break;
1305 		case COLOR_DROP:
1306 			if (got_object_idset_contains(drop, &qid->id)) {
1307 				got_object_qid_free(qid);
1308 				continue;
1309 			}
1310 			if (got_object_idset_contains(keep, &qid->id)) {
1311 				err = paint_commit(qid, COLOR_SKIP);
1312 				if (err)
1313 					goto done;
1314 				nskip++;
1315 			} else
1316 				(*ncolored)++;
1317 			err = got_object_idset_add(drop, &qid->id, NULL);
1318 			if (err)
1319 				goto done;
1320 			break;
1321 		case COLOR_SKIP:
1322 			if (!got_object_idset_contains(skip, &qid->id)) {
1323 				err = got_object_idset_add(skip, &qid->id,
1324 				    NULL);
1325 				if (err)
1326 					goto done;
1327 			}
1328 			break;
1329 		default:
1330 			/* should not happen */
1331 			err = got_error_fmt(GOT_ERR_NOT_IMPL,
1332 			    "%s invalid commit color %d", __func__, color);
1333 			goto done;
1334 		}
1335 
1336 		err = report_progress(progress_cb, progress_arg, rl,
1337 		    *ncolored, 0, 0, 0L, 0, 0, 0, 0);
1338 		if (err)
1339 			break;
1340 
1341 
1342 		err = got_object_open_as_commit(&commit, repo, &qid->id);
1343 		if (err)
1344 			break;
1345 
1346 		parents = got_object_commit_get_parent_ids(commit);
1347 		if (parents) {
1348 			struct got_object_qid *pid;
1349 			color = *((int *)qid->data);
1350 			STAILQ_FOREACH(pid, parents, entry) {
1351 				err = queue_commit_id(ids, &pid->id, color,
1352 				    repo);
1353 				if (err)
1354 					break;
1355 				nqueued++;
1356 				if (color == COLOR_SKIP)
1357 					nskip++;
1358 			}
1359 		}
1360 
1361 		got_object_commit_close(commit);
1362 		commit = NULL;
1363 		got_object_qid_free(qid);
1364 	}
1365 done:
1366 	if (commit)
1367 		got_object_commit_close(commit);
1368 	return err;
1369 }
1370 
1371 static const struct got_error *
1372 findtwixt(struct got_object_id ***res, int *nres, int *ncolored,
1373     struct got_object_id **head, int nhead,
1374     struct got_object_id **tail, int ntail,
1375     struct got_repository *repo,
1376     got_pack_progress_cb progress_cb, void *progress_arg,
1377     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1378 {
1379 	const struct got_error *err = NULL;
1380 	struct got_object_id_queue ids;
1381 	struct got_object_idset *keep, *drop, *skip = NULL;
1382 	int i, nkeep;
1383 
1384 	STAILQ_INIT(&ids);
1385 	*res = NULL;
1386 	*nres = 0;
1387 	*ncolored = 0;
1388 
1389 	keep = got_object_idset_alloc();
1390 	if (keep == NULL)
1391 		return got_error_from_errno("got_object_idset_alloc");
1392 
1393 	drop = got_object_idset_alloc();
1394 	if (drop == NULL) {
1395 		err = got_error_from_errno("got_object_idset_alloc");
1396 		goto done;
1397 	}
1398 
1399 	skip = got_object_idset_alloc();
1400 	if (skip == NULL) {
1401 		err = got_error_from_errno("got_object_idset_alloc");
1402 		goto done;
1403 	}
1404 
1405 	for (i = 0; i < nhead; i++) {
1406 		struct got_object_id *id = head[i];
1407 		if (id == NULL)
1408 			continue;
1409 		err = queue_commit_or_tag_id(id, COLOR_KEEP, &ids, repo);
1410 		if (err)
1411 			goto done;
1412 	}		
1413 
1414 	for (i = 0; i < ntail; i++) {
1415 		struct got_object_id *id = tail[i];
1416 		if (id == NULL)
1417 			continue;
1418 		err = queue_commit_or_tag_id(id, COLOR_DROP, &ids, repo);
1419 		if (err)
1420 			goto done;
1421 	}
1422 
1423 	err = paint_commits(ncolored, &ids, nhead + ntail,
1424 	    keep, drop, skip, repo, progress_cb, progress_arg, rl,
1425 	    cancel_cb, cancel_arg);
1426 	if (err)
1427 		goto done;
1428 
1429 	nkeep = got_object_idset_num_elements(keep);
1430 	if (nkeep > 0) {
1431 		struct append_id_arg arg;
1432 		arg.array = calloc(nkeep, sizeof(struct got_object_id *));
1433 		if (arg.array == NULL) {
1434 			err = got_error_from_errno("calloc");
1435 			goto done;
1436 		}
1437 		arg.idx = -1;
1438 		arg.skip = skip;
1439 		arg.drop = drop;
1440 		err = got_object_idset_for_each(keep, append_id, &arg);
1441 		if (err) {
1442 			free(arg.array);
1443 			goto done;
1444 		}
1445 		*res = arg.array;
1446 		*nres = arg.idx + 1;
1447 	}
1448 done:
1449 	got_object_idset_free(keep);
1450 	got_object_idset_free(drop);
1451 	if (skip)
1452 		got_object_idset_free(skip);
1453 	got_object_id_queue_free(&ids);
1454 	return err;
1455 }
1456 
1457 static const struct got_error *
1458 load_object_ids(int *ncolored, int *nfound, int *ntrees,
1459     struct got_object_idset *idset, struct got_object_id **theirs, int ntheirs,
1460     struct got_object_id **ours, int nours, struct got_repository *repo,
1461     int loose_obj_only, got_pack_progress_cb progress_cb, void *progress_arg,
1462     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1463 {
1464 	const struct got_error *err = NULL;
1465 	struct got_object_id **ids = NULL;
1466 	int i, nobj = 0, obj_type;
1467 	struct got_object_idset *idset_exclude;
1468 
1469 	idset_exclude = got_object_idset_alloc();
1470 	if (idset_exclude == NULL)
1471 		return got_error_from_errno("got_object_idset_alloc");
1472 
1473 	*ncolored = 0;
1474 	*nfound = 0;
1475 	*ntrees = 0;
1476 
1477 	err = findtwixt(&ids, &nobj, ncolored, ours, nours, theirs, ntheirs,
1478 	    repo, progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1479 	if (err)
1480 		goto done;
1481 
1482 	for (i = 0; i < ntheirs; i++) {
1483 		struct got_object_id *id = theirs[i];
1484 		if (id == NULL)
1485 			continue;
1486 		err = got_object_get_type(&obj_type, repo, id);
1487 		if (err)
1488 			return err;
1489 		if (obj_type == GOT_OBJ_TYPE_COMMIT) {
1490 			err = load_commit(0, idset, idset_exclude, id, repo,
1491 			    loose_obj_only, ncolored, nfound, ntrees,
1492 			    progress_cb, progress_arg, rl,
1493 			    cancel_cb, cancel_arg);
1494 			if (err)
1495 				goto done;
1496 		} else if (obj_type == GOT_OBJ_TYPE_TAG) {
1497 			err = load_tag(0, idset, idset_exclude, id, repo,
1498 			    loose_obj_only, ncolored, nfound, ntrees,
1499 			    progress_cb, progress_arg, rl,
1500 			    cancel_cb, cancel_arg);
1501 			if (err)
1502 				goto done;
1503 		}
1504 	}
1505 
1506 	for (i = 0; i < nobj; i++) {
1507 		err = load_commit(1, idset, idset_exclude,
1508 		    ids[i], repo, loose_obj_only, ncolored, nfound, ntrees,
1509 		    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1510 		if (err)
1511 			goto done;
1512 	}
1513 
1514 	for (i = 0; i < nours; i++) {
1515 		struct got_object_id *id = ours[i];
1516 		struct got_pack_meta *m;
1517 		if (id == NULL)
1518 			continue;
1519 		m = got_object_idset_get(idset, id);
1520 		if (m == NULL) {
1521 			err = got_object_get_type(&obj_type, repo, id);
1522 			if (err)
1523 				goto done;
1524 		} else
1525 			obj_type = m->obj_type;
1526 		if (obj_type != GOT_OBJ_TYPE_TAG)
1527 			continue;
1528 		err = load_tag(1, idset, idset_exclude, id, repo,
1529 		    loose_obj_only, ncolored, nfound, ntrees,
1530 		    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1531 		if (err)
1532 			goto done;
1533 	}
1534 done:
1535 	for (i = 0; i < nobj; i++) {
1536 		free(ids[i]);
1537 	}
1538 	free(ids);
1539 	got_object_idset_free(idset_exclude);
1540 	return err;
1541 }
1542 
1543 const struct got_error *
1544 hwrite(FILE *f, void *buf, off_t len, SHA1_CTX *ctx)
1545 {
1546 	size_t n;
1547 
1548 	SHA1Update(ctx, buf, len);
1549 	n = fwrite(buf, 1, len, f);
1550 	if (n != len)
1551 		return got_ferror(f, GOT_ERR_IO);
1552 	return NULL;
1553 }
1554 
1555 const struct got_error *
1556 hcopy(FILE *fsrc, FILE *fdst, off_t len, SHA1_CTX *ctx)
1557 {
1558 	unsigned char buf[65536];
1559 	off_t remain = len;
1560 	size_t n;
1561 
1562 	while (remain > 0) {
1563 		size_t copylen = MIN(sizeof(buf), remain);
1564 		n = fread(buf, 1, copylen, fsrc);
1565 		if (n != copylen)
1566 			return got_ferror(fsrc, GOT_ERR_IO);
1567 		SHA1Update(ctx, buf, copylen);
1568 		n = fwrite(buf, 1, copylen, fdst);
1569 		if (n != copylen)
1570 			return got_ferror(fdst, GOT_ERR_IO);
1571 		remain -= copylen;
1572 	}
1573 
1574 	return NULL;
1575 }
1576 
1577 const struct got_error *
1578 hcopy_mmap(uint8_t *src, off_t src_offset, size_t src_size,
1579     FILE *fdst, off_t len, SHA1_CTX *ctx)
1580 {
1581 	size_t n;
1582 
1583 	if (src_offset + len > src_size)
1584 		return got_error(GOT_ERR_RANGE);
1585 
1586 	SHA1Update(ctx, src + src_offset, len);
1587 	n = fwrite(src + src_offset, 1, len, fdst);
1588 	if (n != len)
1589 		return got_ferror(fdst, GOT_ERR_IO);
1590 
1591 	return NULL;
1592 }
1593 
1594 static void
1595 putbe32(char *b, uint32_t n)
1596 {
1597 	b[0] = n >> 24;
1598 	b[1] = n >> 16;
1599 	b[2] = n >> 8;
1600 	b[3] = n >> 0;
1601 }
1602 
1603 static int
1604 write_order_cmp(const void *pa, const void *pb)
1605 {
1606 	struct got_pack_meta *a, *b, *ahd, *bhd;
1607 
1608 	a = *(struct got_pack_meta **)pa;
1609 	b = *(struct got_pack_meta **)pb;
1610 	ahd = (a->head == NULL) ? a : a->head;
1611 	bhd = (b->head == NULL) ? b : b->head;
1612 	if (bhd->mtime < ahd->mtime)
1613 		return -1;
1614 	if (bhd->mtime > ahd->mtime)
1615 		return 1;
1616 	if (bhd < ahd)
1617 		return -1;
1618 	if (bhd > ahd)
1619 		return 1;
1620 	if (a->nchain != b->nchain)
1621 		return a->nchain - b->nchain;
1622 	if (a->mtime < b->mtime)
1623 		return -1;
1624 	if (a->mtime > b->mtime)
1625 		return 1;
1626 	return got_object_id_cmp(&a->id, &b->id);
1627 }
1628 
1629 static int
1630 reuse_write_order_cmp(const void *pa, const void *pb)
1631 {
1632 	struct got_pack_meta *a, *b;
1633 
1634 	a = *(struct got_pack_meta **)pa;
1635 	b = *(struct got_pack_meta **)pb;
1636 
1637 	if (a->reused_delta_offset < b->reused_delta_offset)
1638 		return -1;
1639 	if (a->reused_delta_offset > b->reused_delta_offset)
1640 		return 1;
1641 	return 0;
1642 }
1643 
1644 static const struct got_error *
1645 packhdr(int *hdrlen, char *hdr, size_t bufsize, int obj_type, size_t len)
1646 {
1647 	size_t i;
1648 
1649 	*hdrlen = 0;
1650 
1651 	hdr[0] = obj_type << 4;
1652 	hdr[0] |= len & 0xf;
1653 	len >>= 4;
1654 	for (i = 1; len != 0; i++){
1655 		if (i >= bufsize)
1656 			return got_error(GOT_ERR_NO_SPACE);
1657 		hdr[i - 1] |= GOT_DELTA_SIZE_MORE;
1658 		hdr[i] = len & GOT_DELTA_SIZE_VAL_MASK;
1659 		len >>= GOT_DELTA_SIZE_SHIFT;
1660 	}
1661 
1662 	*hdrlen = i;
1663 	return NULL;
1664 }
1665 
1666 static int
1667 packoff(char *hdr, off_t off)
1668 {
1669 	int i, j;
1670 	char rbuf[8];
1671 
1672 	rbuf[0] = off & GOT_DELTA_SIZE_VAL_MASK;
1673 	for (i = 1; (off >>= GOT_DELTA_SIZE_SHIFT) != 0; i++) {
1674 		rbuf[i] = (--off & GOT_DELTA_SIZE_VAL_MASK) |
1675 		    GOT_DELTA_SIZE_MORE;
1676 	}
1677 
1678 	j = 0;
1679 	while (i > 0)
1680 		hdr[j++] = rbuf[--i];
1681 	return j;
1682 }
1683 
1684 static const struct got_error *
1685 deltahdr(off_t *packfile_size, SHA1_CTX *ctx, FILE *packfile,
1686     struct got_pack_meta *m)
1687 {
1688 	const struct got_error *err;
1689 	char buf[32];
1690 	int nh;
1691 
1692 	if (m->prev->off != 0) {
1693 		err = packhdr(&nh, buf, sizeof(buf),
1694 		    GOT_OBJ_TYPE_OFFSET_DELTA, m->delta_len);
1695 		if (err)
1696 			return err;
1697 		nh += packoff(buf + nh, m->off - m->prev->off);
1698 		err = hwrite(packfile, buf, nh, ctx);
1699 		if (err)
1700 			return err;
1701 		*packfile_size += nh;
1702 	} else {
1703 		err = packhdr(&nh, buf, sizeof(buf),
1704 		    GOT_OBJ_TYPE_REF_DELTA, m->delta_len);
1705 		if (err)
1706 			return err;
1707 		err = hwrite(packfile, buf, nh, ctx);
1708 		if (err)
1709 			return err;
1710 		*packfile_size += nh;
1711 		err = hwrite(packfile, m->prev->id.sha1,
1712 		    sizeof(m->prev->id.sha1), ctx);
1713 		if (err)
1714 			return err;
1715 		*packfile_size += sizeof(m->prev->id.sha1);
1716 	}
1717 
1718 	return NULL;
1719 }
1720 
1721 static const struct got_error *
1722 write_packed_object(off_t *packfile_size, FILE *packfile,
1723     FILE *delta_cache, uint8_t *delta_cache_map, size_t delta_cache_size,
1724     struct got_pack_meta *m, int *outfd, SHA1_CTX *ctx,
1725     struct got_repository *repo)
1726 {
1727 	const struct got_error *err = NULL;
1728 	struct got_deflate_checksum csum;
1729 	char buf[32];
1730 	int nh;
1731 	struct got_raw_object *raw = NULL;
1732 	off_t outlen;
1733 
1734 	csum.output_sha1 = ctx;
1735 	csum.output_crc = NULL;
1736 
1737 	m->off = ftello(packfile);
1738 	if (m->delta_len == 0) {
1739 		err = got_object_raw_open(&raw, outfd, repo, &m->id);
1740 		if (err)
1741 			goto done;
1742 		err = packhdr(&nh, buf, sizeof(buf),
1743 		    m->obj_type, raw->size);
1744 		if (err)
1745 			goto done;
1746 		err = hwrite(packfile, buf, nh, ctx);
1747 		if (err)
1748 			goto done;
1749 		*packfile_size += nh;
1750 		if (raw->f == NULL) {
1751 			err = got_deflate_to_file_mmap(&outlen,
1752 			    raw->data + raw->hdrlen, 0, raw->size,
1753 			    packfile, &csum);
1754 			if (err)
1755 				goto done;
1756 		} else {
1757 			if (fseeko(raw->f, raw->hdrlen, SEEK_SET)
1758 			    == -1) {
1759 				err = got_error_from_errno("fseeko");
1760 				goto done;
1761 			}
1762 			err = got_deflate_to_file(&outlen, raw->f,
1763 			    raw->size, packfile, &csum);
1764 			if (err)
1765 				goto done;
1766 		}
1767 		*packfile_size += outlen;
1768 		got_object_raw_close(raw);
1769 		raw = NULL;
1770 	} else if (m->delta_buf) {
1771 		err = deltahdr(packfile_size, ctx, packfile, m);
1772 		if (err)
1773 			goto done;
1774 		err = hwrite(packfile, m->delta_buf,
1775 		    m->delta_compressed_len, ctx);
1776 		if (err)
1777 			goto done;
1778 		*packfile_size += m->delta_compressed_len;
1779 		free(m->delta_buf);
1780 		m->delta_buf = NULL;
1781 	} else if (delta_cache_map) {
1782 		err = deltahdr(packfile_size, ctx, packfile, m);
1783 		if (err)
1784 			goto done;
1785 		err = hcopy_mmap(delta_cache_map, m->delta_offset,
1786 		    delta_cache_size, packfile, m->delta_compressed_len,
1787 		    ctx);
1788 		if (err)
1789 			goto done;
1790 		*packfile_size += m->delta_compressed_len;
1791 	} else {
1792 		if (fseeko(delta_cache, m->delta_offset, SEEK_SET)
1793 		    == -1) {
1794 			err = got_error_from_errno("fseeko");
1795 			goto done;
1796 		}
1797 		err = deltahdr(packfile_size, ctx, packfile, m);
1798 		if (err)
1799 			goto done;
1800 		err = hcopy(delta_cache, packfile,
1801 		    m->delta_compressed_len, ctx);
1802 		if (err)
1803 			goto done;
1804 		*packfile_size += m->delta_compressed_len;
1805 	}
1806 done:
1807 	if (raw)
1808 		got_object_raw_close(raw);
1809 	return err;
1810 }
1811 
1812 static const struct got_error *
1813 genpack(uint8_t *pack_sha1, FILE *packfile, FILE *delta_cache,
1814     struct got_pack_meta **deltify, int ndeltify,
1815     struct got_pack_meta **reuse, int nreuse,
1816     int ncolored, int nfound, int ntrees, int nours,
1817     struct got_repository *repo,
1818     got_pack_progress_cb progress_cb, void *progress_arg,
1819     struct got_ratelimit *rl,
1820     got_cancel_cb cancel_cb, void *cancel_arg)
1821 {
1822 	const struct got_error *err = NULL;
1823 	int i;
1824 	SHA1_CTX ctx;
1825 	struct got_pack_meta *m;
1826 	char buf[32];
1827 	size_t n;
1828 	off_t packfile_size = 0;
1829 	int outfd = -1;
1830 	int delta_cache_fd = -1;
1831 	uint8_t *delta_cache_map = NULL;
1832 	size_t delta_cache_size = 0;
1833 
1834 	SHA1Init(&ctx);
1835 
1836 #ifndef GOT_PACK_NO_MMAP
1837 	delta_cache_fd = dup(fileno(delta_cache));
1838 	if (delta_cache_fd != -1) {
1839 		struct stat sb;
1840 		if (fstat(delta_cache_fd, &sb) == -1) {
1841 			err = got_error_from_errno("fstat");
1842 			goto done;
1843 		}
1844 		if (sb.st_size > 0 && sb.st_size <= SIZE_MAX) {
1845 			delta_cache_map = mmap(NULL, sb.st_size,
1846 			    PROT_READ, MAP_PRIVATE, delta_cache_fd, 0);
1847 			if (delta_cache_map == MAP_FAILED) {
1848 				if (errno != ENOMEM) {
1849 					err = got_error_from_errno("mmap");
1850 					goto done;
1851 				}
1852 				delta_cache_map = NULL; /* fallback on stdio */
1853 			} else
1854 				delta_cache_size = (size_t)sb.st_size;
1855 		}
1856 	}
1857 #endif
1858 	err = hwrite(packfile, "PACK", 4, &ctx);
1859 	if (err)
1860 		goto done;
1861 	putbe32(buf, GOT_PACKFILE_VERSION);
1862 	err = hwrite(packfile, buf, 4, &ctx);
1863 	if (err)
1864 		goto done;
1865 	putbe32(buf, ndeltify + nreuse);
1866 	err = hwrite(packfile, buf, 4, &ctx);
1867 	if (err)
1868 		goto done;
1869 
1870 	qsort(deltify, ndeltify, sizeof(struct got_pack_meta *),
1871 	    write_order_cmp);
1872 	for (i = 0; i < ndeltify; i++) {
1873 		err = report_progress(progress_cb, progress_arg, rl,
1874 		    ncolored, nfound, ntrees, packfile_size, nours,
1875 		    ndeltify + nreuse, ndeltify + nreuse, i);
1876 		if (err)
1877 			goto done;
1878 		m = deltify[i];
1879 		err = write_packed_object(&packfile_size, packfile,
1880 		    delta_cache, delta_cache_map, delta_cache_size,
1881 		    m, &outfd, &ctx, repo);
1882 		if (err)
1883 			goto done;
1884 	}
1885 
1886 	qsort(reuse, nreuse, sizeof(struct got_pack_meta *),
1887 	    reuse_write_order_cmp);
1888 	for (i = 0; i < nreuse; i++) {
1889 		err = report_progress(progress_cb, progress_arg, rl,
1890 		    ncolored, nfound, ntrees, packfile_size, nours,
1891 		    ndeltify + nreuse, ndeltify + nreuse, ndeltify + i);
1892 		if (err)
1893 			goto done;
1894 		m = reuse[i];
1895 		err = write_packed_object(&packfile_size, packfile,
1896 		    delta_cache, delta_cache_map, delta_cache_size,
1897 		    m, &outfd, &ctx, repo);
1898 		if (err)
1899 			goto done;
1900 	}
1901 
1902 	SHA1Final(pack_sha1, &ctx);
1903 	n = fwrite(pack_sha1, 1, SHA1_DIGEST_LENGTH, packfile);
1904 	if (n != SHA1_DIGEST_LENGTH)
1905 		err = got_ferror(packfile, GOT_ERR_IO);
1906 	packfile_size += SHA1_DIGEST_LENGTH;
1907 	packfile_size += sizeof(struct got_packfile_hdr);
1908 	if (progress_cb) {
1909 		err = progress_cb(progress_arg, ncolored, nfound, ntrees,
1910 		    packfile_size, nours, ndeltify + nreuse,
1911 		    ndeltify + nreuse, ndeltify + nreuse);
1912 		if (err)
1913 			goto done;
1914 	}
1915 done:
1916 	if (outfd != -1 && close(outfd) == -1 && err == NULL)
1917 		err = got_error_from_errno("close");
1918 	if (delta_cache_map && munmap(delta_cache_map, delta_cache_size) == -1)
1919 		err = got_error_from_errno("munmap");
1920 	if (delta_cache_fd != -1 && close(delta_cache_fd) == -1 && err == NULL)
1921 		err = got_error_from_errno("close");
1922 	return err;
1923 }
1924 
1925 static const struct got_error *
1926 add_meta_idset_cb(struct got_object_id *id, void *data, void *arg)
1927 {
1928 	struct got_pack_meta *m = data;
1929 	struct got_pack_metavec *v = arg;
1930 
1931 	if (m->have_reused_delta)
1932 		return NULL;
1933 
1934 	return add_meta(m, v);
1935 }
1936 
1937 const struct got_error *
1938 got_pack_create(uint8_t *packsha1, FILE *packfile,
1939     struct got_object_id **theirs, int ntheirs,
1940     struct got_object_id **ours, int nours,
1941     struct got_repository *repo, int loose_obj_only, int allow_empty,
1942     got_pack_progress_cb progress_cb, void *progress_arg,
1943     got_cancel_cb cancel_cb, void *cancel_arg)
1944 {
1945 	const struct got_error *err;
1946 	int delta_cache_fd = -1;
1947 	FILE *delta_cache = NULL;
1948 	struct got_object_idset *idset;
1949 	struct got_ratelimit rl;
1950 	struct got_pack_metavec deltify, reuse;
1951 	int ncolored = 0, nfound = 0, ntrees = 0;
1952 	size_t ndeltify;
1953 
1954 	memset(&deltify, 0, sizeof(deltify));
1955 	memset(&reuse, 0, sizeof(reuse));
1956 
1957 	got_ratelimit_init(&rl, 0, 500);
1958 
1959 	idset = got_object_idset_alloc();
1960 	if (idset == NULL)
1961 		return got_error_from_errno("got_object_idset_alloc");
1962 
1963 	err = load_object_ids(&ncolored, &nfound, &ntrees, idset, theirs,
1964 	    ntheirs, ours, nours, repo, loose_obj_only,
1965 	    progress_cb, progress_arg, &rl, cancel_cb, cancel_arg);
1966 	if (err)
1967 		goto done;
1968 
1969 	if (progress_cb) {
1970 		err = progress_cb(progress_arg, ncolored, nfound, ntrees,
1971 		    0L, nours, got_object_idset_num_elements(idset), 0, 0);
1972 		if (err)
1973 			goto done;
1974 	}
1975 
1976 	if (got_object_idset_num_elements(idset) == 0 && !allow_empty) {
1977 		err = got_error(GOT_ERR_CANNOT_PACK);
1978 		goto done;
1979 	}
1980 
1981 	delta_cache_fd = got_opentempfd();
1982 	if (delta_cache_fd == -1) {
1983 		err = got_error_from_errno("got_opentemp");
1984 		goto done;
1985 	}
1986 
1987 	reuse.metasz = 64;
1988 	reuse.meta = calloc(reuse.metasz,
1989 	    sizeof(struct got_pack_meta *));
1990 	if (reuse.meta == NULL) {
1991 		err = got_error_from_errno("calloc");
1992 		goto done;
1993 	}
1994 
1995 	err = search_deltas(&reuse, idset, delta_cache_fd, ncolored, nfound,
1996 	    ntrees, nours, repo, progress_cb, progress_arg, &rl,
1997 	    cancel_cb, cancel_arg);
1998 	if (err)
1999 		goto done;
2000 
2001 	delta_cache = fdopen(delta_cache_fd, "a+");
2002 	if (delta_cache == NULL) {
2003 		err = got_error_from_errno("fdopen");
2004 		goto done;
2005 	}
2006 	delta_cache_fd = -1;
2007 
2008 	if (fseeko(delta_cache, 0L, SEEK_END) == -1) {
2009 		err = got_error_from_errno("fseeko");
2010 		goto done;
2011 	}
2012 
2013 	ndeltify = got_object_idset_num_elements(idset) - reuse.nmeta;
2014 	if (ndeltify > 0) {
2015 		deltify.meta = calloc(ndeltify, sizeof(struct got_pack_meta *));
2016 		if (deltify.meta == NULL) {
2017 			err = got_error_from_errno("calloc");
2018 			goto done;
2019 		}
2020 		deltify.metasz = ndeltify;
2021 
2022 		err = got_object_idset_for_each(idset, add_meta_idset_cb,
2023 		    &deltify);
2024 		if (err)
2025 			goto done;
2026 		if (deltify.nmeta > 0) {
2027 			err = pick_deltas(deltify.meta, deltify.nmeta,
2028 			    ncolored, nfound, ntrees, nours, reuse.nmeta,
2029 			    delta_cache, repo, progress_cb, progress_arg, &rl,
2030 			    cancel_cb, cancel_arg);
2031 			if (err)
2032 				goto done;
2033 		}
2034 	}
2035 
2036 	if (fflush(delta_cache) == EOF) {
2037 		err = got_error_from_errno("fflush");
2038 		goto done;
2039 	}
2040 	err = genpack(packsha1, packfile, delta_cache, deltify.meta,
2041 	    deltify.nmeta, reuse.meta, reuse.nmeta, ncolored, nfound, ntrees,
2042 	    nours, repo, progress_cb, progress_arg, &rl,
2043 	    cancel_cb, cancel_arg);
2044 	if (err)
2045 		goto done;
2046 done:
2047 	free_nmeta(deltify.meta, deltify.nmeta);
2048 	free_nmeta(reuse.meta, reuse.nmeta);
2049 	got_object_idset_free(idset);
2050 	if (delta_cache_fd != -1 && close(delta_cache_fd) == -1 && err == NULL)
2051 		err = got_error_from_errno("close");
2052 	if (delta_cache && fclose(delta_cache) == EOF && err == NULL)
2053 		err = got_error_from_errno("fclose");
2054 	return err;
2055 }