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 			STAILQ_INSERT_TAIL(ids, qid, entry);
958 		} else if (S_ISREG(mode) || S_ISLNK(mode)) {
959 			err = add_object(want_meta,
960 			    want_meta ? idset : idset_exclude, id, p,
961 			    GOT_OBJ_TYPE_BLOB, mtime, loose_obj_only, repo,
962 			    ncolored, nfound, ntrees,
963 			    progress_cb, progress_arg, rl);
964 			if (err)
965 				break;
966 		}
967 		free(p);
968 		p = NULL;
969 	}
970 
971 	got_object_tree_close(tree);
972 	free(p);
973 	return err;
974 }
975 
976 static const struct got_error *
977 load_tree(int want_meta, struct got_object_idset *idset,
978     struct got_object_idset *idset_exclude,
979     struct got_object_id *tree_id, const char *dpath, time_t mtime,
980     struct got_repository *repo, int loose_obj_only,
981     int *ncolored, int *nfound, int *ntrees,
982     got_pack_progress_cb progress_cb, void *progress_arg,
983     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
984 {
985 	const struct got_error *err = NULL;
986 	struct got_object_id_queue tree_ids;
987 	struct got_object_qid *qid;
988 
989 	if (got_object_idset_contains(idset, tree_id) ||
990 	    got_object_idset_contains(idset_exclude, tree_id))
991 		return NULL;
992 
993 	err = got_object_qid_alloc(&qid, tree_id);
994 	if (err)
995 		return err;
996 
997 	STAILQ_INIT(&tree_ids);
998 	STAILQ_INSERT_TAIL(&tree_ids, qid, entry);
999 
1000 	while (!STAILQ_EMPTY(&tree_ids)) {
1001 		if (cancel_cb) {
1002 			err = (*cancel_cb)(cancel_arg);
1003 			if (err)
1004 				break;
1005 		}
1006 
1007 		qid = STAILQ_FIRST(&tree_ids);
1008 		STAILQ_REMOVE_HEAD(&tree_ids, entry);
1009 
1010 		if (got_object_idset_contains(idset, &qid->id) ||
1011 		    got_object_idset_contains(idset_exclude, &qid->id)) {
1012 			got_object_qid_free(qid);
1013 			continue;
1014 		}
1015 
1016 		err = add_object(want_meta, want_meta ? idset : idset_exclude,
1017 		    &qid->id, dpath, GOT_OBJ_TYPE_TREE,
1018 		    mtime, loose_obj_only, repo,
1019 		    ncolored, nfound, ntrees, progress_cb, progress_arg, rl);
1020 		if (err) {
1021 			got_object_qid_free(qid);
1022 			break;
1023 		}
1024 
1025 		err = load_tree_entries(&tree_ids, want_meta, idset,
1026 		    idset_exclude, &qid->id,
1027 		    dpath, mtime, repo, loose_obj_only, ncolored, nfound,
1028 		    ntrees, progress_cb, progress_arg, rl,
1029 		    cancel_cb, cancel_arg);
1030 		got_object_qid_free(qid);
1031 		if (err)
1032 			break;
1033 	}
1034 
1035 	got_object_id_queue_free(&tree_ids);
1036 	return err;
1037 }
1038 
1039 static const struct got_error *
1040 load_commit(int want_meta, struct got_object_idset *idset,
1041     struct got_object_idset *idset_exclude,
1042     struct got_object_id *id, struct got_repository *repo, int loose_obj_only,
1043     int *ncolored, int *nfound, int *ntrees,
1044     got_pack_progress_cb progress_cb, void *progress_arg,
1045     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1046 {
1047 	const struct got_error *err;
1048 	struct got_commit_object *commit;
1049 
1050 	if (got_object_idset_contains(idset, id) ||
1051 	    got_object_idset_contains(idset_exclude, id))
1052 		return NULL;
1053 
1054 	if (loose_obj_only) {
1055 		int is_packed;
1056 		err = search_packidx(&is_packed, id, repo);
1057 		if (err)
1058 			return err;
1059 		if (is_packed && want_meta)
1060 			return NULL;
1061 	}
1062 
1063 	err = got_object_open_as_commit(&commit, repo, id);
1064 	if (err)
1065 		return err;
1066 
1067 	err = add_object(want_meta, want_meta ? idset : idset_exclude,
1068 	    id, "", GOT_OBJ_TYPE_COMMIT,
1069 	    got_object_commit_get_committer_time(commit),
1070 	    loose_obj_only, repo,
1071 	    ncolored, nfound, ntrees, progress_cb, progress_arg, rl);
1072 	if (err)
1073 		goto done;
1074 
1075 	err = load_tree(want_meta, idset, idset_exclude,
1076 	    got_object_commit_get_tree_id(commit),
1077 	    "", got_object_commit_get_committer_time(commit),
1078 	    repo, loose_obj_only, ncolored, nfound, ntrees,
1079 	    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1080 done:
1081 	got_object_commit_close(commit);
1082 	return err;
1083 }
1084 
1085 static const struct got_error *
1086 load_tag(int want_meta, struct got_object_idset *idset,
1087     struct got_object_idset *idset_exclude,
1088     struct got_object_id *id, struct got_repository *repo, int loose_obj_only,
1089     int *ncolored, int *nfound, int *ntrees,
1090     got_pack_progress_cb progress_cb, void *progress_arg,
1091     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1092 {
1093 	const struct got_error *err;
1094 	struct got_tag_object *tag = NULL;
1095 
1096 	if (got_object_idset_contains(idset, id) ||
1097 	    got_object_idset_contains(idset_exclude, id))
1098 		return NULL;
1099 
1100 	if (loose_obj_only) {
1101 		int is_packed;
1102 		err = search_packidx(&is_packed, id, repo);
1103 		if (err)
1104 			return err;
1105 		if (is_packed && want_meta)
1106 			return NULL;
1107 	}
1108 
1109 	err = got_object_open_as_tag(&tag, repo, id);
1110 	if (err)
1111 		return err;
1112 
1113 	err = add_object(want_meta, want_meta ? idset : idset_exclude,
1114 	    id, "", GOT_OBJ_TYPE_TAG,
1115 	    got_object_tag_get_tagger_time(tag), loose_obj_only, repo,
1116 	    ncolored, nfound, ntrees, progress_cb, progress_arg, rl);
1117 	if (err)
1118 		goto done;
1119 
1120 	switch (got_object_tag_get_object_type(tag)) {
1121 	case GOT_OBJ_TYPE_COMMIT:
1122 		err = load_commit(want_meta, idset, idset_exclude,
1123 		    got_object_tag_get_object_id(tag), repo, loose_obj_only,
1124 		    ncolored, nfound, ntrees, progress_cb, progress_arg, rl,
1125 		    cancel_cb, cancel_arg);
1126 		break;
1127 	case GOT_OBJ_TYPE_TREE:
1128 		err = load_tree(want_meta, idset, idset_exclude,
1129 		    got_object_tag_get_object_id(tag), "",
1130 		    got_object_tag_get_tagger_time(tag), repo, loose_obj_only,
1131 		    ncolored, nfound, ntrees, progress_cb, progress_arg, rl,
1132 		    cancel_cb, cancel_arg);
1133 		break;
1134 	default:
1135 		break;
1136 	}
1137 
1138 done:
1139 	got_object_tag_close(tag);
1140 	return err;
1141 }
1142 
1143 enum findtwixt_color {
1144 	COLOR_KEEP = 0,
1145 	COLOR_DROP,
1146 	COLOR_BLANK,
1147 	COLOR_SKIP,
1148 };
1149 
1150 static const int findtwixt_colors[] = {
1151 	COLOR_KEEP,
1152 	COLOR_DROP,
1153 	COLOR_BLANK,
1154 	COLOR_SKIP,
1155 };
1156 
1157 static const struct got_error *
1158 paint_commit(struct got_object_qid *qid, int color)
1159 {
1160 	if (color < 0 || color >= nitems(findtwixt_colors))
1161 		return got_error(GOT_ERR_RANGE);
1162 
1163 	qid->data = (void *)&findtwixt_colors[color];
1164 	return NULL;
1165 }
1166 
1167 static const struct got_error *
1168 queue_commit_id(struct got_object_id_queue *ids, struct got_object_id *id,
1169     int color, struct got_repository *repo)
1170 {
1171 	const struct got_error *err;
1172 	struct got_object_qid *qid;
1173 
1174 	err = got_object_qid_alloc(&qid, id);
1175 	if (err)
1176 		return err;
1177 
1178 	STAILQ_INSERT_TAIL(ids, qid, entry);
1179 	return paint_commit(qid, color);
1180 }
1181 
1182 struct append_id_arg {
1183 	struct got_object_id **array;
1184 	int idx;
1185 	struct got_object_idset *drop;
1186 	struct got_object_idset *skip;
1187 };
1188 
1189 static const struct got_error *
1190 append_id(struct got_object_id *id, void *data, void *arg)
1191 {
1192 	struct append_id_arg *a = arg;
1193 
1194 	if (got_object_idset_contains(a->skip, id) ||
1195 	    got_object_idset_contains(a->drop, id))
1196 		return NULL;
1197 
1198 	a->array[++a->idx] = got_object_id_dup(id);
1199 	if (a->array[a->idx] == NULL)
1200 		return got_error_from_errno("got_object_id_dup");
1201 
1202 	return NULL;
1203 }
1204 
1205 static const struct got_error *
1206 queue_commit_or_tag_id(struct got_object_id *id, int color,
1207     struct got_object_id_queue *ids, struct got_repository *repo)
1208 {
1209 	const struct got_error *err;
1210 	struct got_tag_object *tag = NULL;
1211 	int obj_type;
1212 
1213 	err = got_object_get_type(&obj_type, repo, id);
1214 	if (err)
1215 		return err;
1216 
1217 	if (obj_type == GOT_OBJ_TYPE_TAG) {
1218 		err = got_object_open_as_tag(&tag, repo, id);
1219 		if (err)
1220 			return err;
1221 		obj_type = got_object_tag_get_object_type(tag);
1222 		id = got_object_tag_get_object_id(tag);
1223 	}
1224 
1225 	if (obj_type == GOT_OBJ_TYPE_COMMIT) {
1226 		err = queue_commit_id(ids, id, color, repo);
1227 		if (err)
1228 			goto done;
1229 	}
1230 done:
1231 	if (tag)
1232 		got_object_tag_close(tag);
1233 	return err;
1234 }
1235 
1236 static const struct got_error *
1237 paint_commits(int *ncolored, struct got_object_id_queue *ids, int nids,
1238     struct got_object_idset *keep, struct got_object_idset *drop,
1239     struct got_object_idset *skip, struct got_repository *repo,
1240     got_pack_progress_cb progress_cb, void *progress_arg,
1241     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1242 {
1243 	const struct got_error *err = NULL;
1244 	struct got_commit_object *commit = NULL;
1245 	const struct got_object_id_queue *parents;
1246 	struct got_object_qid *qid;
1247 	int nqueued = nids, nskip = 0;
1248 
1249 	while (!STAILQ_EMPTY(ids) && nskip != nqueued) {
1250 		int color;
1251 
1252 		if (cancel_cb) {
1253 			err = cancel_cb(cancel_arg);
1254 			if (err)
1255 				break;
1256 		}
1257 
1258 		qid = STAILQ_FIRST(ids);
1259 		STAILQ_REMOVE_HEAD(ids, entry);
1260 		nqueued--;
1261 		color = *((int *)qid->data);
1262 		if (color == COLOR_SKIP)
1263 			nskip--;
1264 
1265 		if (got_object_idset_contains(skip, &qid->id)) {
1266 			got_object_qid_free(qid);
1267 			continue;
1268 		}
1269 
1270 		switch (color) {
1271 		case COLOR_KEEP:
1272 			if (got_object_idset_contains(keep, &qid->id)) {
1273 				got_object_qid_free(qid);
1274 				continue;
1275 			}
1276 			if (got_object_idset_contains(drop, &qid->id)) {
1277 				err = paint_commit(qid, COLOR_SKIP);
1278 				if (err)
1279 					goto done;
1280 				nskip++;
1281 			} else
1282 				(*ncolored)++;
1283 			err = got_object_idset_add(keep, &qid->id, NULL);
1284 			if (err)
1285 				goto done;
1286 			break;
1287 		case COLOR_DROP:
1288 			if (got_object_idset_contains(drop, &qid->id)) {
1289 				got_object_qid_free(qid);
1290 				continue;
1291 			}
1292 			if (got_object_idset_contains(keep, &qid->id)) {
1293 				err = paint_commit(qid, COLOR_SKIP);
1294 				if (err)
1295 					goto done;
1296 				nskip++;
1297 			} else
1298 				(*ncolored)++;
1299 			err = got_object_idset_add(drop, &qid->id, NULL);
1300 			if (err)
1301 				goto done;
1302 			break;
1303 		case COLOR_SKIP:
1304 			if (!got_object_idset_contains(skip, &qid->id)) {
1305 				err = got_object_idset_add(skip, &qid->id,
1306 				    NULL);
1307 				if (err)
1308 					goto done;
1309 			}
1310 			break;
1311 		default:
1312 			/* should not happen */
1313 			err = got_error_fmt(GOT_ERR_NOT_IMPL,
1314 			    "%s invalid commit color %d", __func__, color);
1315 			goto done;
1316 		}
1317 
1318 		err = report_progress(progress_cb, progress_arg, rl,
1319 		    *ncolored, 0, 0, 0L, 0, 0, 0, 0);
1320 		if (err)
1321 			break;
1322 
1323 
1324 		err = got_object_open_as_commit(&commit, repo, &qid->id);
1325 		if (err)
1326 			break;
1327 
1328 		parents = got_object_commit_get_parent_ids(commit);
1329 		if (parents) {
1330 			struct got_object_qid *pid;
1331 			color = *((int *)qid->data);
1332 			STAILQ_FOREACH(pid, parents, entry) {
1333 				err = queue_commit_id(ids, &pid->id, color,
1334 				    repo);
1335 				if (err)
1336 					break;
1337 				nqueued++;
1338 				if (color == COLOR_SKIP)
1339 					nskip++;
1340 			}
1341 		}
1342 
1343 		got_object_commit_close(commit);
1344 		commit = NULL;
1345 		got_object_qid_free(qid);
1346 	}
1347 done:
1348 	if (commit)
1349 		got_object_commit_close(commit);
1350 	return err;
1351 }
1352 
1353 static const struct got_error *
1354 findtwixt(struct got_object_id ***res, int *nres, int *ncolored,
1355     struct got_object_id **head, int nhead,
1356     struct got_object_id **tail, int ntail,
1357     struct got_repository *repo,
1358     got_pack_progress_cb progress_cb, void *progress_arg,
1359     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1360 {
1361 	const struct got_error *err = NULL;
1362 	struct got_object_id_queue ids;
1363 	struct got_object_idset *keep, *drop, *skip = NULL;
1364 	int i, nkeep;
1365 
1366 	STAILQ_INIT(&ids);
1367 	*res = NULL;
1368 	*nres = 0;
1369 	*ncolored = 0;
1370 
1371 	keep = got_object_idset_alloc();
1372 	if (keep == NULL)
1373 		return got_error_from_errno("got_object_idset_alloc");
1374 
1375 	drop = got_object_idset_alloc();
1376 	if (drop == NULL) {
1377 		err = got_error_from_errno("got_object_idset_alloc");
1378 		goto done;
1379 	}
1380 
1381 	skip = got_object_idset_alloc();
1382 	if (skip == NULL) {
1383 		err = got_error_from_errno("got_object_idset_alloc");
1384 		goto done;
1385 	}
1386 
1387 	for (i = 0; i < nhead; i++) {
1388 		struct got_object_id *id = head[i];
1389 		if (id == NULL)
1390 			continue;
1391 		err = queue_commit_or_tag_id(id, COLOR_KEEP, &ids, repo);
1392 		if (err)
1393 			goto done;
1394 	}		
1395 
1396 	for (i = 0; i < ntail; i++) {
1397 		struct got_object_id *id = tail[i];
1398 		if (id == NULL)
1399 			continue;
1400 		err = queue_commit_or_tag_id(id, COLOR_DROP, &ids, repo);
1401 		if (err)
1402 			goto done;
1403 	}
1404 
1405 	err = paint_commits(ncolored, &ids, nhead + ntail,
1406 	    keep, drop, skip, repo, progress_cb, progress_arg, rl,
1407 	    cancel_cb, cancel_arg);
1408 	if (err)
1409 		goto done;
1410 
1411 	nkeep = got_object_idset_num_elements(keep);
1412 	if (nkeep > 0) {
1413 		struct append_id_arg arg;
1414 		arg.array = calloc(nkeep, sizeof(struct got_object_id *));
1415 		if (arg.array == NULL) {
1416 			err = got_error_from_errno("calloc");
1417 			goto done;
1418 		}
1419 		arg.idx = -1;
1420 		arg.skip = skip;
1421 		arg.drop = drop;
1422 		err = got_object_idset_for_each(keep, append_id, &arg);
1423 		if (err) {
1424 			free(arg.array);
1425 			goto done;
1426 		}
1427 		*res = arg.array;
1428 		*nres = arg.idx + 1;
1429 	}
1430 done:
1431 	got_object_idset_free(keep);
1432 	got_object_idset_free(drop);
1433 	if (skip)
1434 		got_object_idset_free(skip);
1435 	got_object_id_queue_free(&ids);
1436 	return err;
1437 }
1438 
1439 static const struct got_error *
1440 load_object_ids(int *ncolored, int *nfound, int *ntrees,
1441     struct got_object_idset *idset, struct got_object_id **theirs, int ntheirs,
1442     struct got_object_id **ours, int nours, struct got_repository *repo,
1443     int loose_obj_only, got_pack_progress_cb progress_cb, void *progress_arg,
1444     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1445 {
1446 	const struct got_error *err = NULL;
1447 	struct got_object_id **ids = NULL;
1448 	int i, nobj = 0, obj_type;
1449 	struct got_object_idset *idset_exclude;
1450 
1451 	idset_exclude = got_object_idset_alloc();
1452 	if (idset_exclude == NULL)
1453 		return got_error_from_errno("got_object_idset_alloc");
1454 
1455 	*ncolored = 0;
1456 	*nfound = 0;
1457 	*ntrees = 0;
1458 
1459 	err = findtwixt(&ids, &nobj, ncolored, ours, nours, theirs, ntheirs,
1460 	    repo, progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1461 	if (err)
1462 		goto done;
1463 
1464 	for (i = 0; i < ntheirs; i++) {
1465 		struct got_object_id *id = theirs[i];
1466 		if (id == NULL)
1467 			continue;
1468 		err = got_object_get_type(&obj_type, repo, id);
1469 		if (err)
1470 			return err;
1471 		if (obj_type == GOT_OBJ_TYPE_COMMIT) {
1472 			err = load_commit(0, idset, idset_exclude, id, repo,
1473 			    loose_obj_only, ncolored, nfound, ntrees,
1474 			    progress_cb, progress_arg, rl,
1475 			    cancel_cb, cancel_arg);
1476 			if (err)
1477 				goto done;
1478 		} else if (obj_type == GOT_OBJ_TYPE_TAG) {
1479 			err = load_tag(0, idset, idset_exclude, id, repo,
1480 			    loose_obj_only, ncolored, nfound, ntrees,
1481 			    progress_cb, progress_arg, rl,
1482 			    cancel_cb, cancel_arg);
1483 			if (err)
1484 				goto done;
1485 		}
1486 	}
1487 
1488 	for (i = 0; i < nobj; i++) {
1489 		err = load_commit(1, idset, idset_exclude,
1490 		    ids[i], repo, loose_obj_only, ncolored, nfound, ntrees,
1491 		    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1492 		if (err)
1493 			goto done;
1494 	}
1495 
1496 	for (i = 0; i < nours; i++) {
1497 		struct got_object_id *id = ours[i];
1498 		struct got_pack_meta *m;
1499 		if (id == NULL)
1500 			continue;
1501 		m = got_object_idset_get(idset, id);
1502 		if (m == NULL) {
1503 			err = got_object_get_type(&obj_type, repo, id);
1504 			if (err)
1505 				goto done;
1506 		} else
1507 			obj_type = m->obj_type;
1508 		if (obj_type != GOT_OBJ_TYPE_TAG)
1509 			continue;
1510 		err = load_tag(1, idset, idset_exclude, id, repo,
1511 		    loose_obj_only, ncolored, nfound, ntrees,
1512 		    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1513 		if (err)
1514 			goto done;
1515 	}
1516 done:
1517 	for (i = 0; i < nobj; i++) {
1518 		free(ids[i]);
1519 	}
1520 	free(ids);
1521 	got_object_idset_free(idset_exclude);
1522 	return err;
1523 }
1524 
1525 const struct got_error *
1526 hwrite(FILE *f, void *buf, off_t len, SHA1_CTX *ctx)
1527 {
1528 	size_t n;
1529 
1530 	SHA1Update(ctx, buf, len);
1531 	n = fwrite(buf, 1, len, f);
1532 	if (n != len)
1533 		return got_ferror(f, GOT_ERR_IO);
1534 	return NULL;
1535 }
1536 
1537 const struct got_error *
1538 hcopy(FILE *fsrc, FILE *fdst, off_t len, SHA1_CTX *ctx)
1539 {
1540 	unsigned char buf[65536];
1541 	off_t remain = len;
1542 	size_t n;
1543 
1544 	while (remain > 0) {
1545 		size_t copylen = MIN(sizeof(buf), remain);
1546 		n = fread(buf, 1, copylen, fsrc);
1547 		if (n != copylen)
1548 			return got_ferror(fsrc, GOT_ERR_IO);
1549 		SHA1Update(ctx, buf, copylen);
1550 		n = fwrite(buf, 1, copylen, fdst);
1551 		if (n != copylen)
1552 			return got_ferror(fdst, GOT_ERR_IO);
1553 		remain -= copylen;
1554 	}
1555 
1556 	return NULL;
1557 }
1558 
1559 const struct got_error *
1560 hcopy_mmap(uint8_t *src, off_t src_offset, size_t src_size,
1561     FILE *fdst, off_t len, SHA1_CTX *ctx)
1562 {
1563 	size_t n;
1564 
1565 	if (src_offset + len > src_size)
1566 		return got_error(GOT_ERR_RANGE);
1567 
1568 	SHA1Update(ctx, src + src_offset, len);
1569 	n = fwrite(src + src_offset, 1, len, fdst);
1570 	if (n != len)
1571 		return got_ferror(fdst, GOT_ERR_IO);
1572 
1573 	return NULL;
1574 }
1575 
1576 static void
1577 putbe32(char *b, uint32_t n)
1578 {
1579 	b[0] = n >> 24;
1580 	b[1] = n >> 16;
1581 	b[2] = n >> 8;
1582 	b[3] = n >> 0;
1583 }
1584 
1585 static int
1586 write_order_cmp(const void *pa, const void *pb)
1587 {
1588 	struct got_pack_meta *a, *b, *ahd, *bhd;
1589 
1590 	a = *(struct got_pack_meta **)pa;
1591 	b = *(struct got_pack_meta **)pb;
1592 	ahd = (a->head == NULL) ? a : a->head;
1593 	bhd = (b->head == NULL) ? b : b->head;
1594 	if (bhd->mtime < ahd->mtime)
1595 		return -1;
1596 	if (bhd->mtime > ahd->mtime)
1597 		return 1;
1598 	if (bhd < ahd)
1599 		return -1;
1600 	if (bhd > ahd)
1601 		return 1;
1602 	if (a->nchain != b->nchain)
1603 		return a->nchain - b->nchain;
1604 	if (a->mtime < b->mtime)
1605 		return -1;
1606 	if (a->mtime > b->mtime)
1607 		return 1;
1608 	return got_object_id_cmp(&a->id, &b->id);
1609 }
1610 
1611 static int
1612 reuse_write_order_cmp(const void *pa, const void *pb)
1613 {
1614 	struct got_pack_meta *a, *b;
1615 
1616 	a = *(struct got_pack_meta **)pa;
1617 	b = *(struct got_pack_meta **)pb;
1618 
1619 	if (a->reused_delta_offset < b->reused_delta_offset)
1620 		return -1;
1621 	if (a->reused_delta_offset > b->reused_delta_offset)
1622 		return 1;
1623 	return 0;
1624 }
1625 
1626 static const struct got_error *
1627 packhdr(int *hdrlen, char *hdr, size_t bufsize, int obj_type, size_t len)
1628 {
1629 	size_t i;
1630 
1631 	*hdrlen = 0;
1632 
1633 	hdr[0] = obj_type << 4;
1634 	hdr[0] |= len & 0xf;
1635 	len >>= 4;
1636 	for (i = 1; len != 0; i++){
1637 		if (i >= bufsize)
1638 			return got_error(GOT_ERR_NO_SPACE);
1639 		hdr[i - 1] |= GOT_DELTA_SIZE_MORE;
1640 		hdr[i] = len & GOT_DELTA_SIZE_VAL_MASK;
1641 		len >>= GOT_DELTA_SIZE_SHIFT;
1642 	}
1643 
1644 	*hdrlen = i;
1645 	return NULL;
1646 }
1647 
1648 static int
1649 packoff(char *hdr, off_t off)
1650 {
1651 	int i, j;
1652 	char rbuf[8];
1653 
1654 	rbuf[0] = off & GOT_DELTA_SIZE_VAL_MASK;
1655 	for (i = 1; (off >>= GOT_DELTA_SIZE_SHIFT) != 0; i++) {
1656 		rbuf[i] = (--off & GOT_DELTA_SIZE_VAL_MASK) |
1657 		    GOT_DELTA_SIZE_MORE;
1658 	}
1659 
1660 	j = 0;
1661 	while (i > 0)
1662 		hdr[j++] = rbuf[--i];
1663 	return j;
1664 }
1665 
1666 static const struct got_error *
1667 deltahdr(off_t *packfile_size, SHA1_CTX *ctx, FILE *packfile,
1668     struct got_pack_meta *m)
1669 {
1670 	const struct got_error *err;
1671 	char buf[32];
1672 	int nh;
1673 
1674 	if (m->prev->off != 0) {
1675 		err = packhdr(&nh, buf, sizeof(buf),
1676 		    GOT_OBJ_TYPE_OFFSET_DELTA, m->delta_len);
1677 		if (err)
1678 			return err;
1679 		nh += packoff(buf + nh, m->off - m->prev->off);
1680 		err = hwrite(packfile, buf, nh, ctx);
1681 		if (err)
1682 			return err;
1683 		*packfile_size += nh;
1684 	} else {
1685 		err = packhdr(&nh, buf, sizeof(buf),
1686 		    GOT_OBJ_TYPE_REF_DELTA, m->delta_len);
1687 		if (err)
1688 			return err;
1689 		err = hwrite(packfile, buf, nh, ctx);
1690 		if (err)
1691 			return err;
1692 		*packfile_size += nh;
1693 		err = hwrite(packfile, m->prev->id.sha1,
1694 		    sizeof(m->prev->id.sha1), ctx);
1695 		if (err)
1696 			return err;
1697 		*packfile_size += sizeof(m->prev->id.sha1);
1698 	}
1699 
1700 	return NULL;
1701 }
1702 
1703 static const struct got_error *
1704 write_packed_object(off_t *packfile_size, FILE *packfile,
1705     FILE *delta_cache, uint8_t *delta_cache_map, size_t delta_cache_size,
1706     struct got_pack_meta *m, int *outfd, SHA1_CTX *ctx,
1707     struct got_repository *repo)
1708 {
1709 	const struct got_error *err = NULL;
1710 	struct got_deflate_checksum csum;
1711 	char buf[32];
1712 	int nh;
1713 	struct got_raw_object *raw = NULL;
1714 	off_t outlen;
1715 
1716 	csum.output_sha1 = ctx;
1717 	csum.output_crc = NULL;
1718 
1719 	m->off = ftello(packfile);
1720 	if (m->delta_len == 0) {
1721 		err = got_object_raw_open(&raw, outfd, repo, &m->id);
1722 		if (err)
1723 			goto done;
1724 		err = packhdr(&nh, buf, sizeof(buf),
1725 		    m->obj_type, raw->size);
1726 		if (err)
1727 			goto done;
1728 		err = hwrite(packfile, buf, nh, ctx);
1729 		if (err)
1730 			goto done;
1731 		*packfile_size += nh;
1732 		if (raw->f == NULL) {
1733 			err = got_deflate_to_file_mmap(&outlen,
1734 			    raw->data + raw->hdrlen, 0, raw->size,
1735 			    packfile, &csum);
1736 			if (err)
1737 				goto done;
1738 		} else {
1739 			if (fseeko(raw->f, raw->hdrlen, SEEK_SET)
1740 			    == -1) {
1741 				err = got_error_from_errno("fseeko");
1742 				goto done;
1743 			}
1744 			err = got_deflate_to_file(&outlen, raw->f,
1745 			    raw->size, packfile, &csum);
1746 			if (err)
1747 				goto done;
1748 		}
1749 		*packfile_size += outlen;
1750 		got_object_raw_close(raw);
1751 		raw = NULL;
1752 	} else if (m->delta_buf) {
1753 		err = deltahdr(packfile_size, ctx, packfile, m);
1754 		if (err)
1755 			goto done;
1756 		err = hwrite(packfile, m->delta_buf,
1757 		    m->delta_compressed_len, ctx);
1758 		if (err)
1759 			goto done;
1760 		*packfile_size += m->delta_compressed_len;
1761 		free(m->delta_buf);
1762 		m->delta_buf = NULL;
1763 	} else if (delta_cache_map) {
1764 		err = deltahdr(packfile_size, ctx, packfile, m);
1765 		if (err)
1766 			goto done;
1767 		err = hcopy_mmap(delta_cache_map, m->delta_offset,
1768 		    delta_cache_size, packfile, m->delta_compressed_len,
1769 		    ctx);
1770 		if (err)
1771 			goto done;
1772 		*packfile_size += m->delta_compressed_len;
1773 	} else {
1774 		if (fseeko(delta_cache, m->delta_offset, SEEK_SET)
1775 		    == -1) {
1776 			err = got_error_from_errno("fseeko");
1777 			goto done;
1778 		}
1779 		err = deltahdr(packfile_size, ctx, packfile, m);
1780 		if (err)
1781 			goto done;
1782 		err = hcopy(delta_cache, packfile,
1783 		    m->delta_compressed_len, ctx);
1784 		if (err)
1785 			goto done;
1786 		*packfile_size += m->delta_compressed_len;
1787 	}
1788 done:
1789 	if (raw)
1790 		got_object_raw_close(raw);
1791 	return err;
1792 }
1793 
1794 static const struct got_error *
1795 genpack(uint8_t *pack_sha1, FILE *packfile, FILE *delta_cache,
1796     struct got_pack_meta **deltify, int ndeltify,
1797     struct got_pack_meta **reuse, int nreuse,
1798     int ncolored, int nfound, int ntrees, int nours,
1799     struct got_repository *repo,
1800     got_pack_progress_cb progress_cb, void *progress_arg,
1801     struct got_ratelimit *rl,
1802     got_cancel_cb cancel_cb, void *cancel_arg)
1803 {
1804 	const struct got_error *err = NULL;
1805 	int i;
1806 	SHA1_CTX ctx;
1807 	struct got_pack_meta *m;
1808 	char buf[32];
1809 	size_t n;
1810 	off_t packfile_size = 0;
1811 	int outfd = -1;
1812 	int delta_cache_fd = -1;
1813 	uint8_t *delta_cache_map = NULL;
1814 	size_t delta_cache_size = 0;
1815 
1816 	SHA1Init(&ctx);
1817 
1818 #ifndef GOT_PACK_NO_MMAP
1819 	delta_cache_fd = dup(fileno(delta_cache));
1820 	if (delta_cache_fd != -1) {
1821 		struct stat sb;
1822 		if (fstat(delta_cache_fd, &sb) == -1) {
1823 			err = got_error_from_errno("fstat");
1824 			goto done;
1825 		}
1826 		if (sb.st_size > 0 && sb.st_size <= SIZE_MAX) {
1827 			delta_cache_map = mmap(NULL, sb.st_size,
1828 			    PROT_READ, MAP_PRIVATE, delta_cache_fd, 0);
1829 			if (delta_cache_map == MAP_FAILED) {
1830 				if (errno != ENOMEM) {
1831 					err = got_error_from_errno("mmap");
1832 					goto done;
1833 				}
1834 				delta_cache_map = NULL; /* fallback on stdio */
1835 			} else
1836 				delta_cache_size = (size_t)sb.st_size;
1837 		}
1838 	}
1839 #endif
1840 	err = hwrite(packfile, "PACK", 4, &ctx);
1841 	if (err)
1842 		goto done;
1843 	putbe32(buf, GOT_PACKFILE_VERSION);
1844 	err = hwrite(packfile, buf, 4, &ctx);
1845 	if (err)
1846 		goto done;
1847 	putbe32(buf, ndeltify + nreuse);
1848 	err = hwrite(packfile, buf, 4, &ctx);
1849 	if (err)
1850 		goto done;
1851 
1852 	qsort(deltify, ndeltify, sizeof(struct got_pack_meta *),
1853 	    write_order_cmp);
1854 	for (i = 0; i < ndeltify; i++) {
1855 		err = report_progress(progress_cb, progress_arg, rl,
1856 		    ncolored, nfound, ntrees, packfile_size, nours,
1857 		    ndeltify + nreuse, ndeltify + nreuse, i);
1858 		if (err)
1859 			goto done;
1860 		m = deltify[i];
1861 		err = write_packed_object(&packfile_size, packfile,
1862 		    delta_cache, delta_cache_map, delta_cache_size,
1863 		    m, &outfd, &ctx, repo);
1864 		if (err)
1865 			goto done;
1866 	}
1867 
1868 	qsort(reuse, nreuse, sizeof(struct got_pack_meta *),
1869 	    reuse_write_order_cmp);
1870 	for (i = 0; i < nreuse; i++) {
1871 		err = report_progress(progress_cb, progress_arg, rl,
1872 		    ncolored, nfound, ntrees, packfile_size, nours,
1873 		    ndeltify + nreuse, ndeltify + nreuse, ndeltify + i);
1874 		if (err)
1875 			goto done;
1876 		m = reuse[i];
1877 		err = write_packed_object(&packfile_size, packfile,
1878 		    delta_cache, delta_cache_map, delta_cache_size,
1879 		    m, &outfd, &ctx, repo);
1880 		if (err)
1881 			goto done;
1882 	}
1883 
1884 	SHA1Final(pack_sha1, &ctx);
1885 	n = fwrite(pack_sha1, 1, SHA1_DIGEST_LENGTH, packfile);
1886 	if (n != SHA1_DIGEST_LENGTH)
1887 		err = got_ferror(packfile, GOT_ERR_IO);
1888 	packfile_size += SHA1_DIGEST_LENGTH;
1889 	packfile_size += sizeof(struct got_packfile_hdr);
1890 	if (progress_cb) {
1891 		err = progress_cb(progress_arg, ncolored, nfound, ntrees,
1892 		    packfile_size, nours, ndeltify + nreuse,
1893 		    ndeltify + nreuse, ndeltify + nreuse);
1894 		if (err)
1895 			goto done;
1896 	}
1897 done:
1898 	if (outfd != -1 && close(outfd) == -1 && err == NULL)
1899 		err = got_error_from_errno("close");
1900 	if (delta_cache_map && munmap(delta_cache_map, delta_cache_size) == -1)
1901 		err = got_error_from_errno("munmap");
1902 	if (delta_cache_fd != -1 && close(delta_cache_fd) == -1 && err == NULL)
1903 		err = got_error_from_errno("close");
1904 	return err;
1905 }
1906 
1907 static const struct got_error *
1908 add_meta_idset_cb(struct got_object_id *id, void *data, void *arg)
1909 {
1910 	struct got_pack_meta *m = data;
1911 	struct got_pack_metavec *v = arg;
1912 
1913 	if (m->have_reused_delta)
1914 		return NULL;
1915 
1916 	return add_meta(m, v);
1917 }
1918 
1919 const struct got_error *
1920 got_pack_create(uint8_t *packsha1, FILE *packfile,
1921     struct got_object_id **theirs, int ntheirs,
1922     struct got_object_id **ours, int nours,
1923     struct got_repository *repo, int loose_obj_only, int allow_empty,
1924     got_pack_progress_cb progress_cb, void *progress_arg,
1925     got_cancel_cb cancel_cb, void *cancel_arg)
1926 {
1927 	const struct got_error *err;
1928 	int delta_cache_fd = -1;
1929 	FILE *delta_cache = NULL;
1930 	struct got_object_idset *idset;
1931 	struct got_ratelimit rl;
1932 	struct got_pack_metavec deltify, reuse;
1933 	int ncolored = 0, nfound = 0, ntrees = 0;
1934 	size_t ndeltify;
1935 
1936 	memset(&deltify, 0, sizeof(deltify));
1937 	memset(&reuse, 0, sizeof(reuse));
1938 
1939 	got_ratelimit_init(&rl, 0, 500);
1940 
1941 	idset = got_object_idset_alloc();
1942 	if (idset == NULL)
1943 		return got_error_from_errno("got_object_idset_alloc");
1944 
1945 	err = load_object_ids(&ncolored, &nfound, &ntrees, idset, theirs,
1946 	    ntheirs, ours, nours, repo, loose_obj_only,
1947 	    progress_cb, progress_arg, &rl, cancel_cb, cancel_arg);
1948 	if (err)
1949 		return err;
1950 
1951 	if (progress_cb) {
1952 		err = progress_cb(progress_arg, ncolored, nfound, ntrees,
1953 		    0L, nours, got_object_idset_num_elements(idset), 0, 0);
1954 		if (err)
1955 			goto done;
1956 	}
1957 
1958 	if (got_object_idset_num_elements(idset) == 0 && !allow_empty) {
1959 		err = got_error(GOT_ERR_CANNOT_PACK);
1960 		goto done;
1961 	}
1962 
1963 	delta_cache_fd = got_opentempfd();
1964 	if (delta_cache_fd == -1) {
1965 		err = got_error_from_errno("got_opentemp");
1966 		goto done;
1967 	}
1968 
1969 	reuse.metasz = 64;
1970 	reuse.meta = calloc(reuse.metasz,
1971 	    sizeof(struct got_pack_meta *));
1972 	if (reuse.meta == NULL) {
1973 		err = got_error_from_errno("calloc");
1974 		goto done;
1975 	}
1976 
1977 	err = search_deltas(&reuse, idset, delta_cache_fd, ncolored, nfound,
1978 	    ntrees, nours, repo, progress_cb, progress_arg, &rl,
1979 	    cancel_cb, cancel_arg);
1980 	if (err)
1981 		goto done;
1982 
1983 	delta_cache = fdopen(delta_cache_fd, "a+");
1984 	if (delta_cache == NULL) {
1985 		err = got_error_from_errno("fdopen");
1986 		goto done;
1987 	}
1988 	delta_cache_fd = -1;
1989 
1990 	if (fseeko(delta_cache, 0L, SEEK_END) == -1) {
1991 		err = got_error_from_errno("fseeko");
1992 		goto done;
1993 	}
1994 
1995 	ndeltify = got_object_idset_num_elements(idset) - reuse.nmeta;
1996 	if (ndeltify > 0) {
1997 		deltify.meta = calloc(ndeltify, sizeof(struct got_pack_meta *));
1998 		if (deltify.meta == NULL) {
1999 			err = got_error_from_errno("calloc");
2000 			goto done;
2001 		}
2002 		deltify.metasz = ndeltify;
2003 
2004 		err = got_object_idset_for_each(idset, add_meta_idset_cb,
2005 		    &deltify);
2006 		if (err)
2007 			goto done;
2008 		if (deltify.nmeta > 0) {
2009 			err = pick_deltas(deltify.meta, deltify.nmeta,
2010 			    ncolored, nfound, ntrees, nours, reuse.nmeta,
2011 			    delta_cache, repo, progress_cb, progress_arg, &rl,
2012 			    cancel_cb, cancel_arg);
2013 			if (err)
2014 				goto done;
2015 		}
2016 	}
2017 
2018 	if (fflush(delta_cache) == EOF) {
2019 		err = got_error_from_errno("fflush");
2020 		goto done;
2021 	}
2022 	err = genpack(packsha1, packfile, delta_cache, deltify.meta,
2023 	    deltify.nmeta, reuse.meta, reuse.nmeta, ncolored, nfound, ntrees,
2024 	    nours, repo, progress_cb, progress_arg, &rl,
2025 	    cancel_cb, cancel_arg);
2026 	if (err)
2027 		goto done;
2028 done:
2029 	free_nmeta(deltify.meta, deltify.nmeta);
2030 	free_nmeta(reuse.meta, reuse.nmeta);
2031 	got_object_idset_free(idset);
2032 	if (delta_cache_fd != -1 && close(delta_cache_fd) == -1 && err == NULL)
2033 		err = got_error_from_errno("close");
2034 	if (delta_cache && fclose(delta_cache) == EOF && err == NULL)
2035 		err = got_error_from_errno("fclose");
2036 	return err;
2037 }