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_pack_create.h"
55 #include "got_lib_privsep.h"
56 #include "got_lib_repository.h"
57 #include "got_lib_ratelimit.h"
58 #include "got_lib_inflate.h"
59 
60 #include "murmurhash2.h"
61 
62 #ifndef MIN
63 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
64 #endif
65 
66 #ifndef MAX
67 #define	MAX(_a,_b) ((_a) > (_b) ? (_a) : (_b))
68 #endif
69 
70 #ifndef nitems
71 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
72 #endif
73 
74 struct got_pack_meta {
75 	struct got_object_id id;
76 	uint32_t path_hash;
77 	int	obj_type;
78 	off_t	size;
79 	time_t	mtime;
80 
81 	/* The best delta we picked */
82 	struct got_pack_meta *head;
83 	struct got_pack_meta *prev;
84 	unsigned char *delta_buf; /* if encoded in memory (compressed) */
85 	off_t	delta_offset;	/* offset in delta cache file (compressed) */
86 	off_t	delta_len;	/* encoded delta length */
87 	off_t	delta_compressed_len; /* encoded+compressed delta length */
88 	int	nchain;
89 
90 	off_t   reused_delta_offset; /* offset of delta in reused pack file */
91 	struct got_object_id *base_obj_id;
92 
93 	/* Only used for delta window */
94 	struct got_delta_table *dtab;
95 
96 	/* Only used for writing offset deltas */
97 	off_t	off;
98 };
99 
100 struct got_pack_metavec {
101 	struct got_pack_meta **meta;
102 	int nmeta;
103 	int metasz;
104 };
105 
106 static const struct got_error *
107 alloc_meta(struct got_pack_meta **new, struct got_object_id *id,
108     const char *path, int obj_type, time_t mtime, uint32_t seed)
109 {
110 	struct got_pack_meta *m;
111 
112 	*new = NULL;
113 
114 	m = calloc(1, sizeof(*m));
115 	if (m == NULL)
116 		return got_error_from_errno("calloc");
117 
118 	memcpy(&m->id, id, sizeof(m->id));
119 
120 	m->path_hash = murmurhash2(path, strlen(path), seed);
121 	m->obj_type = obj_type;
122 	m->mtime = mtime;
123 	*new = m;
124 	return NULL;
125 }
126 
127 static void
128 clear_meta(struct got_pack_meta *meta)
129 {
130 	if (meta == NULL)
131 		return;
132 	meta->path_hash = 0;
133 	free(meta->delta_buf);
134 	meta->delta_buf = NULL;
135 	free(meta->base_obj_id);
136 	meta->base_obj_id = NULL;
137 	meta->reused_delta_offset = 0;
138 }
139 
140 static void
141 free_nmeta(struct got_pack_meta **meta, int nmeta)
142 {
143 	int i;
144 
145 	for (i = 0; i < nmeta; i++)
146 		clear_meta(meta[i]);
147 	free(meta);
148 }
149 
150 static int
151 delta_order_cmp(const void *pa, const void *pb)
152 {
153 	struct got_pack_meta *a, *b;
154 
155 	a = *(struct got_pack_meta **)pa;
156 	b = *(struct got_pack_meta **)pb;
157 
158 	if (a->obj_type != b->obj_type)
159 		return a->obj_type - b->obj_type;
160 	if (a->path_hash < b->path_hash)
161 		return -1;
162 	if (a->path_hash > b->path_hash)
163 		return 1;
164 	if (a->mtime < b->mtime)
165 		return -1;
166 	if (a->mtime > b->mtime)
167 		return 1;
168 	return got_object_id_cmp(&a->id, &b->id);
169 }
170 
171 static off_t
172 delta_size(struct got_delta_instruction *deltas, int ndeltas)
173 {
174 	int i;
175 	off_t size = 32;
176 	for (i = 0; i < ndeltas; i++) {
177 		if (deltas[i].copy)
178 			size += GOT_DELTA_SIZE_SHIFT;
179 		else
180 			size += deltas[i].len + 1;
181 	}
182 	return size;
183 }
184 
185 static const struct got_error *
186 append(unsigned char **p, size_t *len, off_t *sz, void *seg, int nseg)
187 {
188 	char *n;
189 
190 	if (*len + nseg >= *sz) {
191 		while (*len + nseg >= *sz)
192 			*sz += *sz / 2;
193 		n = realloc(*p, *sz);
194 		if (n == NULL)
195 			return got_error_from_errno("realloc");
196 		*p = n;
197 	}
198 	memcpy(*p + *len, seg, nseg);
199 	*len += nseg;
200 	return NULL;
201 }
202 
203 static const struct got_error *
204 encode_delta_in_mem(struct got_pack_meta *m, struct got_raw_object *o,
205     struct got_delta_instruction *deltas, int ndeltas,
206     off_t delta_size, off_t base_size)
207 {
208 	const struct got_error *err;
209 	unsigned char buf[16], *bp;
210 	int i, j;
211 	size_t len = 0, compressed_len;
212 	off_t bufsize = delta_size;
213 	off_t n;
214 	struct got_delta_instruction *d;
215 	uint8_t *delta_buf;
216 
217 	delta_buf = malloc(bufsize);
218 	if (delta_buf == NULL)
219 		return got_error_from_errno("malloc");
220 
221 	/* base object size */
222 	buf[0] = base_size & GOT_DELTA_SIZE_VAL_MASK;
223 	n = base_size >> GOT_DELTA_SIZE_SHIFT;
224 	for (i = 1; n > 0; i++) {
225 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
226 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
227 		n >>= GOT_DELTA_SIZE_SHIFT;
228 	}
229 	err = append(&delta_buf, &len, &bufsize, buf, i);
230 	if (err)
231 		goto done;
232 
233 	/* target object size */
234 	buf[0] = o->size & GOT_DELTA_SIZE_VAL_MASK;
235 	n = o->size >> GOT_DELTA_SIZE_SHIFT;
236 	for (i = 1; n > 0; i++) {
237 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
238 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
239 		n >>= GOT_DELTA_SIZE_SHIFT;
240 	}
241 	err = append(&delta_buf, &len, &bufsize, buf, i);
242 	if (err)
243 		goto done;
244 
245 	for (j = 0; j < ndeltas; j++) {
246 		d = &deltas[j];
247 		if (d->copy) {
248 			n = d->offset;
249 			bp = &buf[1];
250 			buf[0] = GOT_DELTA_BASE_COPY;
251 			for (i = 0; i < 4; i++) {
252 				/* DELTA_COPY_OFF1 ... DELTA_COPY_OFF4 */
253 				buf[0] |= 1 << i;
254 				*bp++ = n & 0xff;
255 				n >>= 8;
256 				if (n == 0)
257 					break;
258 			}
259 
260 			n = d->len;
261 			if (n != GOT_DELTA_COPY_DEFAULT_LEN) {
262 				/* DELTA_COPY_LEN1 ... DELTA_COPY_LEN3 */
263 				for (i = 0; i < 3 && n > 0; i++) {
264 					buf[0] |= 1 << (i + 4);
265 					*bp++ = n & 0xff;
266 					n >>= 8;
267 				}
268 			}
269 			err = append(&delta_buf, &len, &bufsize,
270 			    buf, bp - buf);
271 			if (err)
272 				goto done;
273 		} else if (o->f == NULL) {
274 			n = 0;
275 			while (n != d->len) {
276 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
277 				err = append(&delta_buf, &len, &bufsize,
278 				    buf, 1);
279 				if (err)
280 					goto done;
281 				err = append(&delta_buf, &len, &bufsize,
282 				    o->data + o->hdrlen + d->offset + n,
283 				    buf[0]);
284 				if (err)
285 					goto done;
286 				n += buf[0];
287 			}
288 		} else {
289 			char content[128];
290 			size_t r;
291 			if (fseeko(o->f, o->hdrlen + d->offset, SEEK_SET) == -1) {
292 				err = got_error_from_errno("fseeko");
293 				goto done;
294 			}
295 			n = 0;
296 			while (n != d->len) {
297 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
298 				err = append(&delta_buf, &len, &bufsize,
299 				    buf, 1);
300 				if (err)
301 					goto done;
302 				r = fread(content, 1, buf[0], o->f);
303 				if (r != buf[0]) {
304 					err = got_ferror(o->f, GOT_ERR_IO);
305 					goto done;
306 				}
307 				err = append(&delta_buf, &len, &bufsize,
308 				    content, buf[0]);
309 				if (err)
310 					goto done;
311 				n += buf[0];
312 			}
313 		}
314 	}
315 
316 	err = got_deflate_to_mem_mmap(&m->delta_buf, &compressed_len,
317 	    NULL, NULL, delta_buf, 0, len);
318 	if (err)
319 		goto done;
320 
321 	m->delta_len = len;
322 	m->delta_compressed_len = compressed_len;
323 done:
324 	free(delta_buf);
325 	return err;
326 }
327 
328 static const struct got_error *
329 encode_delta(struct got_pack_meta *m, struct got_raw_object *o,
330     struct got_delta_instruction *deltas, int ndeltas,
331     off_t base_size, FILE *f)
332 {
333 	const struct got_error *err;
334 	unsigned char buf[16], *bp;
335 	int i, j;
336 	off_t n;
337 	struct got_deflate_buf zb;
338 	struct got_delta_instruction *d;
339 	off_t delta_len = 0, compressed_len = 0;
340 
341 	err = got_deflate_init(&zb, NULL, GOT_DEFLATE_BUFSIZE);
342 	if (err)
343 		return err;
344 
345 	/* base object size */
346 	buf[0] = base_size & GOT_DELTA_SIZE_VAL_MASK;
347 	n = base_size >> GOT_DELTA_SIZE_SHIFT;
348 	for (i = 1; n > 0; i++) {
349 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
350 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
351 		n >>= GOT_DELTA_SIZE_SHIFT;
352 	}
353 
354 	err = got_deflate_append_to_file_mmap(&zb, &compressed_len,
355 	    buf, 0, i, f, NULL);
356 	if (err)
357 		goto done;
358 	delta_len += i;
359 
360 	/* target object size */
361 	buf[0] = o->size & GOT_DELTA_SIZE_VAL_MASK;
362 	n = o->size >> GOT_DELTA_SIZE_SHIFT;
363 	for (i = 1; n > 0; i++) {
364 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
365 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
366 		n >>= GOT_DELTA_SIZE_SHIFT;
367 	}
368 
369 	err = got_deflate_append_to_file_mmap(&zb, &compressed_len,
370 	    buf, 0, i, f, NULL);
371 	if (err)
372 		goto done;
373 	delta_len += i;
374 
375 	for (j = 0; j < ndeltas; j++) {
376 		d = &deltas[j];
377 		if (d->copy) {
378 			n = d->offset;
379 			bp = &buf[1];
380 			buf[0] = GOT_DELTA_BASE_COPY;
381 			for (i = 0; i < 4; i++) {
382 				/* DELTA_COPY_OFF1 ... DELTA_COPY_OFF4 */
383 				buf[0] |= 1 << i;
384 				*bp++ = n & 0xff;
385 				n >>= 8;
386 				if (n == 0)
387 					break;
388 			}
389 			n = d->len;
390 			if (n != GOT_DELTA_COPY_DEFAULT_LEN) {
391 				/* DELTA_COPY_LEN1 ... DELTA_COPY_LEN3 */
392 				for (i = 0; i < 3 && n > 0; i++) {
393 					buf[0] |= 1 << (i + 4);
394 					*bp++ = n & 0xff;
395 					n >>= 8;
396 				}
397 			}
398 			err = got_deflate_append_to_file_mmap(&zb,
399 			    &compressed_len, buf, 0, bp - buf, f, NULL);
400 			if (err)
401 				goto done;
402 			delta_len += (bp - buf);
403 		} else if (o->f == NULL) {
404 			n = 0;
405 			while (n != d->len) {
406 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
407 				err = got_deflate_append_to_file_mmap(&zb,
408 				    &compressed_len, buf, 0, 1, f, NULL);
409 				if (err)
410 					goto done;
411 				delta_len++;
412 				err = got_deflate_append_to_file_mmap(&zb,
413 				    &compressed_len,
414 				    o->data + o->hdrlen + d->offset + n, 0,
415 				    buf[0], f, NULL);
416 				if (err)
417 					goto done;
418 				delta_len += buf[0];
419 				n += buf[0];
420 			}
421 		} else {
422 			char content[128];
423 			size_t r;
424 			if (fseeko(o->f, o->hdrlen + d->offset, SEEK_SET) == -1) {
425 				err = got_error_from_errno("fseeko");
426 				goto done;
427 			}
428 			n = 0;
429 			while (n != d->len) {
430 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
431 				err = got_deflate_append_to_file_mmap(&zb,
432 				    &compressed_len, buf, 0, 1, f, NULL);
433 				if (err)
434 					goto done;
435 				delta_len++;
436 				r = fread(content, 1, buf[0], o->f);
437 				if (r != buf[0]) {
438 					err = got_ferror(o->f, GOT_ERR_IO);
439 					goto done;
440 				}
441 				err = got_deflate_append_to_file_mmap(&zb,
442 				    &compressed_len, content, 0, buf[0], f,
443 				    NULL);
444 				if (err)
445 					goto done;
446 				delta_len += buf[0];
447 				n += buf[0];
448 			}
449 		}
450 	}
451 
452 	err = got_deflate_flush(&zb, f, NULL, &compressed_len);
453 	if (err)
454 		goto done;
455 
456 	/* sanity check */
457 	if (compressed_len != ftello(f) - m->delta_offset) {
458 		err = got_error(GOT_ERR_COMPRESSION);
459 		goto done;
460 	}
461 
462 	m->delta_len = delta_len;
463 	m->delta_compressed_len = compressed_len;
464 done:
465 	got_deflate_end(&zb);
466 	return err;
467 }
468 
469 static const struct got_error *
470 report_progress(got_pack_progress_cb progress_cb, void *progress_arg,
471     struct got_ratelimit *rl, int ncolored, int nfound, int ntrees,
472     off_t packfile_size, int ncommits, int nobj_total, int obj_deltify,
473     int nobj_written)
474 {
475 	const struct got_error *err;
476 	int elapsed;
477 
478 	if (progress_cb == NULL)
479 		return NULL;
480 
481 	err = got_ratelimit_check(&elapsed, rl);
482 	if (err || !elapsed)
483 		return err;
484 
485 	return progress_cb(progress_arg, ncolored, nfound, ntrees,
486 	    packfile_size, ncommits, nobj_total, obj_deltify, nobj_written);
487 }
488 
489 static const struct got_error *
490 add_meta(struct got_pack_meta *m, struct got_pack_metavec *v)
491 {
492 	if (v->nmeta == v->metasz){
493 		size_t newsize = 2 * v->metasz;
494 		struct got_pack_meta **new;
495 		new = reallocarray(v->meta, newsize, sizeof(*new));
496 		if (new == NULL)
497 			return got_error_from_errno("reallocarray");
498 		v->meta = new;
499 		v->metasz = newsize; 
500 	}
501 
502 	v->meta[v->nmeta++] = m;
503 	return NULL;
504 }
505 
506 static const struct got_error *
507 find_pack_for_reuse(struct got_packidx **best_packidx,
508     struct got_repository *repo)
509 {
510 	const struct got_error *err = NULL;
511 	struct got_pathlist_entry *pe;
512 	const char *best_packidx_path = NULL;
513 	int nobj_max = 0;
514 
515 	*best_packidx = NULL;
516 
517 	TAILQ_FOREACH(pe, &repo->packidx_paths, entry) {
518 		const char *path_packidx = pe->path;
519 		struct got_packidx *packidx;
520 		int nobj;
521 
522 		err = got_repo_get_packidx(&packidx, path_packidx, repo);
523 		if (err)
524 			break;
525 
526 		nobj = be32toh(packidx->hdr.fanout_table[0xff]);
527 		if (nobj > nobj_max) {
528 			best_packidx_path = path_packidx;
529 			nobj_max = nobj;
530 		}
531 	}
532 
533 	if (best_packidx_path) {
534 		err = got_repo_get_packidx(best_packidx, best_packidx_path,
535 		    repo);
536 	}
537 
538 	return err;
539 }
540 
541 struct send_id_arg {
542 	struct imsgbuf *ibuf;
543 	struct got_object_id *ids[GOT_IMSG_OBJ_ID_LIST_MAX_NIDS];
544 	size_t nids;
545 };
546 
547 static const struct got_error *
548 send_id(struct got_object_id *id, void *data, void *arg)
549 {
550 	const struct got_error *err = NULL;
551 	struct send_id_arg *a = arg;
552 
553 	a->ids[a->nids++] = id;
554 
555 	if (a->nids >= GOT_IMSG_OBJ_ID_LIST_MAX_NIDS) {
556 		err = got_privsep_send_object_idlist(a->ibuf, a->ids, a->nids);
557 		if (err)
558 			return err;
559 		a->nids = 0;
560 	}
561 
562 	return NULL;
563 }
564 
565 static const struct got_error *
566 recv_reused_delta(struct got_imsg_reused_delta *delta,
567     struct got_object_idset *idset, struct got_pack_metavec *v)
568 {
569 	struct got_pack_meta *m, *base;
570 
571 	if (delta->delta_offset + delta->delta_size < delta->delta_offset ||
572 	    delta->delta_offset +
573 	    delta->delta_compressed_size < delta->delta_offset)
574 		return got_error(GOT_ERR_BAD_PACKFILE);
575 
576 	m = got_object_idset_get(idset, &delta->id);
577 	if (m == NULL)
578 		return got_error(GOT_ERR_NO_OBJ);
579 
580 	base = got_object_idset_get(idset, &delta->base_id);
581 	if (base == NULL)
582 		return got_error(GOT_ERR_NO_OBJ);
583 
584 	m->delta_len = delta->delta_size;
585 	m->delta_compressed_len = delta->delta_compressed_size;
586 	m->delta_offset = delta->delta_out_offset;
587 	m->prev = base;
588 	m->size = delta->result_size;
589 	m->reused_delta_offset = delta->delta_offset;
590 	m->base_obj_id = got_object_id_dup(&delta->base_id);
591 	if (m->base_obj_id == NULL)
592 		return got_error_from_errno("got_object_id_dup");
593 
594 	return add_meta(m, v);
595 }
596 
597 static const struct got_error *
598 search_deltas(struct got_pack_metavec *v, struct got_object_idset *idset,
599     int delta_cache_fd, int ncolored, int nfound, int ntrees, int ncommits,
600     struct got_repository *repo,
601     got_pack_progress_cb progress_cb, void *progress_arg,
602     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
603 {
604 	const struct got_error *err = NULL;
605 	struct got_packidx *packidx;
606 	struct got_pack *pack;
607 	struct send_id_arg sia;
608 	struct got_imsg_reused_delta deltas[GOT_IMSG_REUSED_DELTAS_MAX_NDELTAS];
609 	size_t ndeltas, i;
610 
611 	err = find_pack_for_reuse(&packidx, repo);
612 	if (err)
613 		return err;
614 
615 	if (packidx == NULL)
616 		return NULL;
617 
618 	err = got_object_prepare_delta_reuse(&pack, packidx,
619 	    delta_cache_fd, repo);
620 	if (err)
621 		return err;
622 
623 	memset(&sia, 0, sizeof(sia));
624 	sia.ibuf = pack->privsep_child->ibuf;
625 	err = got_object_idset_for_each(idset, send_id, &sia);
626 	if (err)
627 		return err;
628 	if (sia.nids > 0) {
629 		err = got_privsep_send_object_idlist(pack->privsep_child->ibuf,
630 		    sia.ids, sia.nids);
631 		if (err)
632 			return err;
633 	}
634 	err = got_privsep_send_object_idlist_done(pack->privsep_child->ibuf);
635 	if (err)
636 		return err;
637 
638 	for (;;) {
639 		int done = 0;
640 
641 		if (cancel_cb) {
642 			err = (*cancel_cb)(cancel_arg);
643 			if (err)
644 				break;
645 		}
646 
647 		err = got_privsep_recv_reused_deltas(&done, deltas, &ndeltas,
648 		    pack->privsep_child->ibuf);
649 		if (err || done)
650 			break;
651 
652 		for (i = 0; i < ndeltas; i++) {
653 			struct got_imsg_reused_delta *delta = &deltas[i];
654 			err = recv_reused_delta(delta, idset, v);
655 			if (err)
656 				goto done;
657 		}
658 
659 		err = report_progress(progress_cb, progress_arg, rl,
660 		    ncolored, nfound, ntrees, 0L, ncommits,
661 		    got_object_idset_num_elements(idset), v->nmeta, 0);
662 		if (err)
663 			break;
664 	}
665 done:
666 	return err;
667 }
668 
669 static const struct got_error *
670 pick_deltas(struct got_pack_meta **meta, int nmeta, int ncolored,
671     int nfound, int ntrees, int ncommits, int nreused, FILE *delta_cache,
672     struct got_repository *repo,
673     got_pack_progress_cb progress_cb, void *progress_arg,
674     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
675 {
676 	const struct got_error *err = NULL;
677 	struct got_pack_meta *m = NULL, *base = NULL;
678 	struct got_raw_object *raw = NULL, *base_raw = NULL;
679 	struct got_delta_instruction *deltas = NULL, *best_deltas = NULL;
680 	int i, j, ndeltas, best_ndeltas;
681 	off_t size, best_size;
682 	const int max_base_candidates = 3;
683 	size_t delta_memsize = 0;
684 	const size_t max_delta_memsize = 4 * GOT_DELTA_RESULT_SIZE_CACHED_MAX;
685 	int outfd = -1;
686 	uint32_t delta_seed;
687 
688 	delta_seed = arc4random();
689 
690 	qsort(meta, nmeta, sizeof(struct got_pack_meta *), delta_order_cmp);
691 	for (i = 0; i < nmeta; i++) {
692 		if (cancel_cb) {
693 			err = (*cancel_cb)(cancel_arg);
694 			if (err)
695 				break;
696 		}
697 		err = report_progress(progress_cb, progress_arg, rl,
698 		    ncolored, nfound, ntrees, 0L, ncommits, nreused + nmeta,
699 		    nreused + i, 0);
700 		if (err)
701 			goto done;
702 		m = meta[i];
703 
704 		if (m->obj_type == GOT_OBJ_TYPE_COMMIT ||
705 		    m->obj_type == GOT_OBJ_TYPE_TAG)
706 			continue;
707 
708 		err = got_object_raw_open(&raw, &outfd, repo, &m->id);
709 		if (err)
710 			goto done;
711 		m->size = raw->size;
712 
713 		if (raw->f == NULL) {
714 			err = got_deltify_init_mem(&m->dtab, raw->data,
715 			    raw->hdrlen, raw->size + raw->hdrlen, delta_seed);
716 		} else {
717 			err = got_deltify_init(&m->dtab, raw->f, raw->hdrlen,
718 			    raw->size + raw->hdrlen, delta_seed);
719 		}
720 		if (err)
721 			goto done;
722 
723 		if (i > max_base_candidates) {
724 			struct got_pack_meta *n = NULL;
725 			n = meta[i - (max_base_candidates + 1)];
726 			got_deltify_free(n->dtab);
727 			n->dtab = NULL;
728 		}
729 
730 		best_size = raw->size;
731 		best_ndeltas = 0;
732 		for (j = MAX(0, i - max_base_candidates); j < i; j++) {
733 			if (cancel_cb) {
734 				err = (*cancel_cb)(cancel_arg);
735 				if (err)
736 					goto done;
737 			}
738 			base = meta[j];
739 			/* long chains make unpacking slow, avoid such bases */
740 			if (base->nchain >= 128 ||
741 			    base->obj_type != m->obj_type)
742 				continue;
743 
744 			err = got_object_raw_open(&base_raw, &outfd, repo,
745 			    &base->id);
746 			if (err)
747 				goto done;
748 
749 			if (raw->f == NULL && base_raw->f == NULL) {
750 				err = got_deltify_mem_mem(&deltas, &ndeltas,
751 				    raw->data, raw->hdrlen,
752 				    raw->size + raw->hdrlen, delta_seed,
753 				    base->dtab, base_raw->data,
754 				    base_raw->hdrlen,
755 				    base_raw->size + base_raw->hdrlen);
756 			} else if (raw->f == NULL) {
757 				err = got_deltify_mem_file(&deltas, &ndeltas,
758 				    raw->data, raw->hdrlen,
759 				    raw->size + raw->hdrlen, delta_seed,
760 				    base->dtab, base_raw->f,
761 				    base_raw->hdrlen,
762 				    base_raw->size + base_raw->hdrlen);
763 			} else if (base_raw->f == NULL) {
764 				err = got_deltify_file_mem(&deltas, &ndeltas,
765 				    raw->f, raw->hdrlen,
766 				    raw->size + raw->hdrlen, delta_seed,
767 				    base->dtab, base_raw->data,
768 				    base_raw->hdrlen,
769 				    base_raw->size + base_raw->hdrlen);
770 			} else {
771 				err = got_deltify(&deltas, &ndeltas,
772 				    raw->f, raw->hdrlen,
773 				    raw->size + raw->hdrlen, delta_seed,
774 				    base->dtab, base_raw->f, base_raw->hdrlen,
775 				    base_raw->size + base_raw->hdrlen);
776 			}
777 			got_object_raw_close(base_raw);
778 			base_raw = NULL;
779 			if (err)
780 				goto done;
781 
782 			size = delta_size(deltas, ndeltas);
783 			if (size + 32 < best_size){
784 				/*
785 				 * if we already picked a best delta,
786 				 * replace it.
787 				 */
788 				best_size = size;
789 				free(best_deltas);
790 				best_deltas = deltas;
791 				best_ndeltas = ndeltas;
792 				deltas = NULL;
793 				m->nchain = base->nchain + 1;
794 				m->prev = base;
795 				m->head = base->head;
796 				if (m->head == NULL)
797 					m->head = base;
798 			} else {
799 				free(deltas);
800 				deltas = NULL;
801 				ndeltas = 0;
802 			}
803 		}
804 
805 		if (best_ndeltas > 0) {
806 			if (best_size <= GOT_DELTA_RESULT_SIZE_CACHED_MAX &&
807 			    delta_memsize + best_size <= max_delta_memsize) {
808 				delta_memsize += best_size;
809 				err = encode_delta_in_mem(m, raw, best_deltas,
810 				    best_ndeltas, best_size, m->prev->size);
811 			} else {
812 				m->delta_offset = ftello(delta_cache);
813 				err = encode_delta(m, raw, best_deltas,
814 				    best_ndeltas, m->prev->size, delta_cache);
815 			}
816 			free(best_deltas);
817 			best_deltas = NULL;
818 			best_ndeltas = 0;
819 			if (err)
820 				goto done;
821 		}
822 
823 		got_object_raw_close(raw);
824 		raw = NULL;
825 	}
826 done:
827 	for (i = MAX(0, nmeta - max_base_candidates); i < nmeta; i++) {
828 		got_deltify_free(meta[i]->dtab);
829 		meta[i]->dtab = NULL;
830 	}
831 	if (raw)
832 		got_object_raw_close(raw);
833 	if (base_raw)
834 		got_object_raw_close(base_raw);
835 	if (outfd != -1 && close(outfd) == -1 && err == NULL)
836 		err = got_error_from_errno("close");
837 	free(deltas);
838 	free(best_deltas);
839 	return err;
840 }
841 
842 static const struct got_error *
843 search_packidx(int *found, struct got_object_id *id,
844     struct got_repository *repo)
845 {
846 	const struct got_error *err = NULL;
847 	struct got_packidx *packidx = NULL;
848 	int idx;
849 
850 	*found = 0;
851 
852 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
853 	if (err == NULL)
854 		*found = 1; /* object is already packed */
855 	else if (err->code == GOT_ERR_NO_OBJ)
856 		err = NULL;
857 	return err;
858 }
859 
860 static const struct got_error *
861 add_object(int want_meta, struct got_object_idset *idset,
862     struct got_object_id *id, const char *path, int obj_type,
863     time_t mtime, uint32_t seed, int loose_obj_only,
864     struct got_repository *repo, int *ncolored, int *nfound, int *ntrees,
865     got_pack_progress_cb progress_cb, void *progress_arg,
866     struct got_ratelimit *rl)
867 {
868 	const struct got_error *err;
869 	struct got_pack_meta *m = NULL;
870 
871 	if (loose_obj_only) {
872 		int is_packed;
873 		err = search_packidx(&is_packed, id, repo);
874 		if (err)
875 			return err;
876 		if (is_packed && want_meta)
877 			return NULL;
878 	}
879 
880 	if (want_meta) {
881 		err = alloc_meta(&m, id, path, obj_type, mtime, seed);
882 		if (err)
883 			return err;
884 
885 		(*nfound)++;
886 		err = report_progress(progress_cb, progress_arg, rl,
887 		    *ncolored, *nfound, *ntrees, 0L, 0, 0, 0, 0);
888 		if (err) {
889 			clear_meta(m);
890 			free(m);
891 			return err;
892 		}
893 	}
894 
895 	err = got_object_idset_add(idset, id, m);
896 	if (err) {
897 		clear_meta(m);
898 		free(m);
899 	}
900 	return err;
901 }
902 
903 static const struct got_error *
904 load_tree_entries(struct got_object_id_queue *ids, int want_meta,
905     struct got_object_idset *idset, struct got_object_idset *idset_exclude,
906     struct got_object_id *tree_id,
907     const char *dpath, time_t mtime, uint32_t seed, struct got_repository *repo,
908     int loose_obj_only, int *ncolored, int *nfound, int *ntrees,
909     got_pack_progress_cb progress_cb, void *progress_arg,
910     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
911 {
912 	const struct got_error *err;
913 	struct got_tree_object *tree;
914 	char *p = NULL;
915 	int i;
916 
917 	err = got_object_open_as_tree(&tree, repo, tree_id);
918 	if (err)
919 		return err;
920 
921 	(*ntrees)++;
922 	err = report_progress(progress_cb, progress_arg, rl,
923 	    *ncolored, *nfound, *ntrees, 0L, 0, 0, 0, 0);
924 	if (err)
925 		return err;
926 
927 	for (i = 0; i < got_object_tree_get_nentries(tree); i++) {
928 		struct got_tree_entry *e = got_object_tree_get_entry(tree, i);
929 		struct got_object_id *id = got_tree_entry_get_id(e);
930 		mode_t mode = got_tree_entry_get_mode(e);
931 
932 		if (cancel_cb) {
933 			err = (*cancel_cb)(cancel_arg);
934 			if (err)
935 				break;
936 		}
937 
938 		if (got_object_tree_entry_is_submodule(e) ||
939 		    got_object_idset_contains(idset, id) ||
940 		    got_object_idset_contains(idset_exclude, id))
941 			continue;
942 		
943 		if (asprintf(&p, "%s%s%s", dpath, dpath[0] != '\0' ? "/" : "",
944 		    got_tree_entry_get_name(e)) == -1) {
945 			err = got_error_from_errno("asprintf");
946 			break;
947 		}
948 
949 		if (S_ISDIR(mode)) {
950 			struct got_object_qid *qid;
951 			err = got_object_qid_alloc(&qid, id);
952 			if (err)
953 				break;
954 			qid->data = p;
955 			p = NULL;
956 			STAILQ_INSERT_TAIL(ids, qid, entry);
957 		} else if (S_ISREG(mode) || S_ISLNK(mode)) {
958 			err = add_object(want_meta,
959 			    want_meta ? idset : idset_exclude, id, p,
960 			    GOT_OBJ_TYPE_BLOB, mtime, seed, loose_obj_only,
961 			    repo, ncolored, nfound, ntrees,
962 			    progress_cb, progress_arg, rl);
963 			if (err)
964 				break;
965 			free(p);
966 			p = NULL;
967 		} else {
968 			free(p);
969 			p = NULL;
970 		}
971 	}
972 
973 	got_object_tree_close(tree);
974 	free(p);
975 	return err;
976 }
977 
978 static const struct got_error *
979 load_tree(int want_meta, struct got_object_idset *idset,
980     struct got_object_idset *idset_exclude,
981     struct got_object_id *tree_id, const char *dpath, time_t mtime,
982     uint32_t seed, struct got_repository *repo, int loose_obj_only,
983     int *ncolored, int *nfound, int *ntrees,
984     got_pack_progress_cb progress_cb, void *progress_arg,
985     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
986 {
987 	const struct got_error *err = NULL;
988 	struct got_object_id_queue tree_ids;
989 	struct got_object_qid *qid;
990 
991 	if (got_object_idset_contains(idset, tree_id) ||
992 	    got_object_idset_contains(idset_exclude, tree_id))
993 		return NULL;
994 
995 	err = got_object_qid_alloc(&qid, tree_id);
996 	if (err)
997 		return err;
998 	qid->data = strdup(dpath);
999 	if (qid->data == NULL) {
1000 		err = got_error_from_errno("strdup");
1001 		got_object_qid_free(qid);
1002 		return err;
1003 	}
1004 
1005 	STAILQ_INIT(&tree_ids);
1006 	STAILQ_INSERT_TAIL(&tree_ids, qid, entry);
1007 
1008 	while (!STAILQ_EMPTY(&tree_ids)) {
1009 		const char *path;
1010 		if (cancel_cb) {
1011 			err = (*cancel_cb)(cancel_arg);
1012 			if (err)
1013 				break;
1014 		}
1015 
1016 		qid = STAILQ_FIRST(&tree_ids);
1017 		STAILQ_REMOVE_HEAD(&tree_ids, entry);
1018 		path = qid->data;
1019 
1020 		if (got_object_idset_contains(idset, &qid->id) ||
1021 		    got_object_idset_contains(idset_exclude, &qid->id)) {
1022 			free(qid->data);
1023 			got_object_qid_free(qid);
1024 			continue;
1025 		}
1026 
1027 		err = add_object(want_meta, want_meta ? idset : idset_exclude,
1028 		    &qid->id, path, GOT_OBJ_TYPE_TREE,
1029 		    mtime, seed, loose_obj_only, repo,
1030 		    ncolored, nfound, ntrees, progress_cb, progress_arg, rl);
1031 		if (err) {
1032 			free(qid->data);
1033 			got_object_qid_free(qid);
1034 			break;
1035 		}
1036 
1037 		err = load_tree_entries(&tree_ids, want_meta, idset,
1038 		    idset_exclude, &qid->id,
1039 		    path, mtime, seed, repo, loose_obj_only, ncolored, nfound,
1040 		    ntrees, progress_cb, progress_arg, rl,
1041 		    cancel_cb, cancel_arg);
1042 		free(qid->data);
1043 		got_object_qid_free(qid);
1044 		if (err)
1045 			break;
1046 	}
1047 
1048 	STAILQ_FOREACH(qid, &tree_ids, entry)
1049 		free(qid->data);
1050 	got_object_id_queue_free(&tree_ids);
1051 	return err;
1052 }
1053 
1054 static const struct got_error *
1055 load_commit(int want_meta, struct got_object_idset *idset,
1056     struct got_object_idset *idset_exclude,
1057     struct got_object_id *id, struct got_repository *repo, uint32_t seed,
1058     int loose_obj_only, int *ncolored, int *nfound, int *ntrees,
1059     got_pack_progress_cb progress_cb, void *progress_arg,
1060     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1061 {
1062 	const struct got_error *err;
1063 	struct got_commit_object *commit;
1064 
1065 	if (got_object_idset_contains(idset, id) ||
1066 	    got_object_idset_contains(idset_exclude, id))
1067 		return NULL;
1068 
1069 	if (loose_obj_only) {
1070 		int is_packed;
1071 		err = search_packidx(&is_packed, id, repo);
1072 		if (err)
1073 			return err;
1074 		if (is_packed && want_meta)
1075 			return NULL;
1076 	}
1077 
1078 	err = got_object_open_as_commit(&commit, repo, id);
1079 	if (err)
1080 		return err;
1081 
1082 	err = add_object(want_meta, want_meta ? idset : idset_exclude,
1083 	    id, "", GOT_OBJ_TYPE_COMMIT,
1084 	    got_object_commit_get_committer_time(commit), seed,
1085 	    loose_obj_only, repo,
1086 	    ncolored, nfound, ntrees, progress_cb, progress_arg, rl);
1087 	if (err)
1088 		goto done;
1089 
1090 	err = load_tree(want_meta, idset, idset_exclude,
1091 	    got_object_commit_get_tree_id(commit),
1092 	    "", got_object_commit_get_committer_time(commit), seed,
1093 	    repo, loose_obj_only, ncolored, nfound, ntrees,
1094 	    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1095 done:
1096 	got_object_commit_close(commit);
1097 	return err;
1098 }
1099 
1100 static const struct got_error *
1101 load_tag(int want_meta, struct got_object_idset *idset,
1102     struct got_object_idset *idset_exclude,
1103     struct got_object_id *id, struct got_repository *repo, uint32_t seed,
1104     int loose_obj_only, int *ncolored, int *nfound, int *ntrees,
1105     got_pack_progress_cb progress_cb, void *progress_arg,
1106     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1107 {
1108 	const struct got_error *err;
1109 	struct got_tag_object *tag = NULL;
1110 
1111 	if (got_object_idset_contains(idset, id) ||
1112 	    got_object_idset_contains(idset_exclude, id))
1113 		return NULL;
1114 
1115 	if (loose_obj_only) {
1116 		int is_packed;
1117 		err = search_packidx(&is_packed, id, repo);
1118 		if (err)
1119 			return err;
1120 		if (is_packed && want_meta)
1121 			return NULL;
1122 	}
1123 
1124 	err = got_object_open_as_tag(&tag, repo, id);
1125 	if (err)
1126 		return err;
1127 
1128 	err = add_object(want_meta, want_meta ? idset : idset_exclude,
1129 	    id, "", GOT_OBJ_TYPE_TAG,
1130 	    got_object_tag_get_tagger_time(tag), seed, loose_obj_only, repo,
1131 	    ncolored, nfound, ntrees, progress_cb, progress_arg, rl);
1132 	if (err)
1133 		goto done;
1134 
1135 	switch (got_object_tag_get_object_type(tag)) {
1136 	case GOT_OBJ_TYPE_COMMIT:
1137 		err = load_commit(want_meta, idset, idset_exclude,
1138 		    got_object_tag_get_object_id(tag), repo, seed,
1139 		    loose_obj_only, ncolored, nfound, ntrees,
1140 		    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1141 		break;
1142 	case GOT_OBJ_TYPE_TREE:
1143 		err = load_tree(want_meta, idset, idset_exclude,
1144 		    got_object_tag_get_object_id(tag), "",
1145 		    got_object_tag_get_tagger_time(tag), seed, repo,
1146 		    loose_obj_only, ncolored, nfound, ntrees,
1147 		    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1148 		break;
1149 	default:
1150 		break;
1151 	}
1152 
1153 done:
1154 	got_object_tag_close(tag);
1155 	return err;
1156 }
1157 
1158 enum findtwixt_color {
1159 	COLOR_KEEP = 0,
1160 	COLOR_DROP,
1161 	COLOR_BLANK,
1162 	COLOR_SKIP,
1163 };
1164 
1165 static const int findtwixt_colors[] = {
1166 	COLOR_KEEP,
1167 	COLOR_DROP,
1168 	COLOR_BLANK,
1169 	COLOR_SKIP,
1170 };
1171 
1172 static const struct got_error *
1173 paint_commit(struct got_object_qid *qid, int color)
1174 {
1175 	if (color < 0 || color >= nitems(findtwixt_colors))
1176 		return got_error(GOT_ERR_RANGE);
1177 
1178 	qid->data = (void *)&findtwixt_colors[color];
1179 	return NULL;
1180 }
1181 
1182 static const struct got_error *
1183 queue_commit_id(struct got_object_id_queue *ids, struct got_object_id *id,
1184     int color, struct got_repository *repo)
1185 {
1186 	const struct got_error *err;
1187 	struct got_object_qid *qid;
1188 
1189 	err = got_object_qid_alloc(&qid, id);
1190 	if (err)
1191 		return err;
1192 
1193 	STAILQ_INSERT_TAIL(ids, qid, entry);
1194 	return paint_commit(qid, color);
1195 }
1196 
1197 struct append_id_arg {
1198 	struct got_object_id **array;
1199 	int idx;
1200 	struct got_object_idset *drop;
1201 	struct got_object_idset *skip;
1202 };
1203 
1204 static const struct got_error *
1205 append_id(struct got_object_id *id, void *data, void *arg)
1206 {
1207 	struct append_id_arg *a = arg;
1208 
1209 	if (got_object_idset_contains(a->skip, id) ||
1210 	    got_object_idset_contains(a->drop, id))
1211 		return NULL;
1212 
1213 	a->array[++a->idx] = got_object_id_dup(id);
1214 	if (a->array[a->idx] == NULL)
1215 		return got_error_from_errno("got_object_id_dup");
1216 
1217 	return NULL;
1218 }
1219 
1220 static const struct got_error *
1221 queue_commit_or_tag_id(struct got_object_id *id, int color,
1222     struct got_object_id_queue *ids, struct got_repository *repo)
1223 {
1224 	const struct got_error *err;
1225 	struct got_tag_object *tag = NULL;
1226 	int obj_type;
1227 
1228 	err = got_object_get_type(&obj_type, repo, id);
1229 	if (err)
1230 		return err;
1231 
1232 	if (obj_type == GOT_OBJ_TYPE_TAG) {
1233 		err = got_object_open_as_tag(&tag, repo, id);
1234 		if (err)
1235 			return err;
1236 		obj_type = got_object_tag_get_object_type(tag);
1237 		id = got_object_tag_get_object_id(tag);
1238 	}
1239 
1240 	if (obj_type == GOT_OBJ_TYPE_COMMIT) {
1241 		err = queue_commit_id(ids, id, color, repo);
1242 		if (err)
1243 			goto done;
1244 	}
1245 done:
1246 	if (tag)
1247 		got_object_tag_close(tag);
1248 	return err;
1249 }
1250 
1251 static const struct got_error *
1252 paint_commits(int *ncolored, struct got_object_id_queue *ids, int nids,
1253     struct got_object_idset *keep, struct got_object_idset *drop,
1254     struct got_object_idset *skip, struct got_repository *repo,
1255     got_pack_progress_cb progress_cb, void *progress_arg,
1256     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1257 {
1258 	const struct got_error *err = NULL;
1259 	struct got_commit_object *commit = NULL;
1260 	const struct got_object_id_queue *parents;
1261 	struct got_object_qid *qid;
1262 	int nqueued = nids, nskip = 0;
1263 
1264 	while (!STAILQ_EMPTY(ids) && nskip != nqueued) {
1265 		int color;
1266 
1267 		if (cancel_cb) {
1268 			err = cancel_cb(cancel_arg);
1269 			if (err)
1270 				break;
1271 		}
1272 
1273 		qid = STAILQ_FIRST(ids);
1274 		STAILQ_REMOVE_HEAD(ids, entry);
1275 		nqueued--;
1276 		color = *((int *)qid->data);
1277 		if (color == COLOR_SKIP)
1278 			nskip--;
1279 
1280 		if (got_object_idset_contains(skip, &qid->id)) {
1281 			got_object_qid_free(qid);
1282 			continue;
1283 		}
1284 
1285 		switch (color) {
1286 		case COLOR_KEEP:
1287 			if (got_object_idset_contains(keep, &qid->id)) {
1288 				got_object_qid_free(qid);
1289 				continue;
1290 			}
1291 			if (got_object_idset_contains(drop, &qid->id)) {
1292 				err = paint_commit(qid, COLOR_SKIP);
1293 				if (err)
1294 					goto done;
1295 				nskip++;
1296 			} else
1297 				(*ncolored)++;
1298 			err = got_object_idset_add(keep, &qid->id, NULL);
1299 			if (err)
1300 				goto done;
1301 			break;
1302 		case COLOR_DROP:
1303 			if (got_object_idset_contains(drop, &qid->id)) {
1304 				got_object_qid_free(qid);
1305 				continue;
1306 			}
1307 			if (got_object_idset_contains(keep, &qid->id)) {
1308 				err = paint_commit(qid, COLOR_SKIP);
1309 				if (err)
1310 					goto done;
1311 				nskip++;
1312 			} else
1313 				(*ncolored)++;
1314 			err = got_object_idset_add(drop, &qid->id, NULL);
1315 			if (err)
1316 				goto done;
1317 			break;
1318 		case COLOR_SKIP:
1319 			if (!got_object_idset_contains(skip, &qid->id)) {
1320 				err = got_object_idset_add(skip, &qid->id,
1321 				    NULL);
1322 				if (err)
1323 					goto done;
1324 			}
1325 			break;
1326 		default:
1327 			/* should not happen */
1328 			err = got_error_fmt(GOT_ERR_NOT_IMPL,
1329 			    "%s invalid commit color %d", __func__, color);
1330 			goto done;
1331 		}
1332 
1333 		err = report_progress(progress_cb, progress_arg, rl,
1334 		    *ncolored, 0, 0, 0L, 0, 0, 0, 0);
1335 		if (err)
1336 			break;
1337 
1338 
1339 		err = got_object_open_as_commit(&commit, repo, &qid->id);
1340 		if (err)
1341 			break;
1342 
1343 		parents = got_object_commit_get_parent_ids(commit);
1344 		if (parents) {
1345 			struct got_object_qid *pid;
1346 			color = *((int *)qid->data);
1347 			STAILQ_FOREACH(pid, parents, entry) {
1348 				err = queue_commit_id(ids, &pid->id, color,
1349 				    repo);
1350 				if (err)
1351 					break;
1352 				nqueued++;
1353 				if (color == COLOR_SKIP)
1354 					nskip++;
1355 			}
1356 		}
1357 
1358 		got_object_commit_close(commit);
1359 		commit = NULL;
1360 		got_object_qid_free(qid);
1361 	}
1362 done:
1363 	if (commit)
1364 		got_object_commit_close(commit);
1365 	return err;
1366 }
1367 
1368 static const struct got_error *
1369 findtwixt(struct got_object_id ***res, int *nres, int *ncolored,
1370     struct got_object_id **head, int nhead,
1371     struct got_object_id **tail, int ntail,
1372     struct got_repository *repo,
1373     got_pack_progress_cb progress_cb, void *progress_arg,
1374     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1375 {
1376 	const struct got_error *err = NULL;
1377 	struct got_object_id_queue ids;
1378 	struct got_object_idset *keep, *drop, *skip = NULL;
1379 	int i, nkeep;
1380 
1381 	STAILQ_INIT(&ids);
1382 	*res = NULL;
1383 	*nres = 0;
1384 	*ncolored = 0;
1385 
1386 	keep = got_object_idset_alloc();
1387 	if (keep == NULL)
1388 		return got_error_from_errno("got_object_idset_alloc");
1389 
1390 	drop = got_object_idset_alloc();
1391 	if (drop == NULL) {
1392 		err = got_error_from_errno("got_object_idset_alloc");
1393 		goto done;
1394 	}
1395 
1396 	skip = got_object_idset_alloc();
1397 	if (skip == NULL) {
1398 		err = got_error_from_errno("got_object_idset_alloc");
1399 		goto done;
1400 	}
1401 
1402 	for (i = 0; i < nhead; i++) {
1403 		struct got_object_id *id = head[i];
1404 		if (id == NULL)
1405 			continue;
1406 		err = queue_commit_or_tag_id(id, COLOR_KEEP, &ids, repo);
1407 		if (err)
1408 			goto done;
1409 	}		
1410 
1411 	for (i = 0; i < ntail; i++) {
1412 		struct got_object_id *id = tail[i];
1413 		if (id == NULL)
1414 			continue;
1415 		err = queue_commit_or_tag_id(id, COLOR_DROP, &ids, repo);
1416 		if (err)
1417 			goto done;
1418 	}
1419 
1420 	err = paint_commits(ncolored, &ids, nhead + ntail,
1421 	    keep, drop, skip, repo, progress_cb, progress_arg, rl,
1422 	    cancel_cb, cancel_arg);
1423 	if (err)
1424 		goto done;
1425 
1426 	nkeep = got_object_idset_num_elements(keep);
1427 	if (nkeep > 0) {
1428 		struct append_id_arg arg;
1429 		arg.array = calloc(nkeep, sizeof(struct got_object_id *));
1430 		if (arg.array == NULL) {
1431 			err = got_error_from_errno("calloc");
1432 			goto done;
1433 		}
1434 		arg.idx = -1;
1435 		arg.skip = skip;
1436 		arg.drop = drop;
1437 		err = got_object_idset_for_each(keep, append_id, &arg);
1438 		if (err) {
1439 			free(arg.array);
1440 			goto done;
1441 		}
1442 		*res = arg.array;
1443 		*nres = arg.idx + 1;
1444 	}
1445 done:
1446 	got_object_idset_free(keep);
1447 	got_object_idset_free(drop);
1448 	if (skip)
1449 		got_object_idset_free(skip);
1450 	got_object_id_queue_free(&ids);
1451 	return err;
1452 }
1453 
1454 static const struct got_error *
1455 load_object_ids(int *ncolored, int *nfound, int *ntrees,
1456     struct got_object_idset *idset, struct got_object_id **theirs, int ntheirs,
1457     struct got_object_id **ours, int nours, struct got_repository *repo,
1458     uint32_t seed, int loose_obj_only, got_pack_progress_cb progress_cb,
1459     void *progress_arg, struct got_ratelimit *rl, got_cancel_cb cancel_cb,
1460     void *cancel_arg)
1461 {
1462 	const struct got_error *err = NULL;
1463 	struct got_object_id **ids = NULL;
1464 	int i, nobj = 0, obj_type;
1465 	struct got_object_idset *idset_exclude;
1466 
1467 	idset_exclude = got_object_idset_alloc();
1468 	if (idset_exclude == NULL)
1469 		return got_error_from_errno("got_object_idset_alloc");
1470 
1471 	*ncolored = 0;
1472 	*nfound = 0;
1473 	*ntrees = 0;
1474 
1475 	err = findtwixt(&ids, &nobj, ncolored, ours, nours, theirs, ntheirs,
1476 	    repo, progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1477 	if (err)
1478 		goto done;
1479 
1480 	for (i = 0; i < ntheirs; i++) {
1481 		struct got_object_id *id = theirs[i];
1482 		if (id == NULL)
1483 			continue;
1484 		err = got_object_get_type(&obj_type, repo, id);
1485 		if (err)
1486 			return err;
1487 		if (obj_type == GOT_OBJ_TYPE_COMMIT) {
1488 			err = load_commit(0, idset, idset_exclude, id, repo,
1489 			    seed, loose_obj_only, ncolored, nfound, ntrees,
1490 			    progress_cb, progress_arg, rl,
1491 			    cancel_cb, cancel_arg);
1492 			if (err)
1493 				goto done;
1494 		} else if (obj_type == GOT_OBJ_TYPE_TAG) {
1495 			err = load_tag(0, idset, idset_exclude, id, repo,
1496 			    seed, loose_obj_only, ncolored, nfound, ntrees,
1497 			    progress_cb, progress_arg, rl,
1498 			    cancel_cb, cancel_arg);
1499 			if (err)
1500 				goto done;
1501 		}
1502 	}
1503 
1504 	for (i = 0; i < nobj; i++) {
1505 		err = load_commit(1, idset, idset_exclude, ids[i], repo,
1506 		    seed, loose_obj_only, ncolored, nfound, ntrees,
1507 		    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1508 		if (err)
1509 			goto done;
1510 	}
1511 
1512 	for (i = 0; i < nours; i++) {
1513 		struct got_object_id *id = ours[i];
1514 		struct got_pack_meta *m;
1515 		if (id == NULL)
1516 			continue;
1517 		m = got_object_idset_get(idset, id);
1518 		if (m == NULL) {
1519 			err = got_object_get_type(&obj_type, repo, id);
1520 			if (err)
1521 				goto done;
1522 		} else
1523 			obj_type = m->obj_type;
1524 		if (obj_type != GOT_OBJ_TYPE_TAG)
1525 			continue;
1526 		err = load_tag(1, idset, idset_exclude, id, repo,
1527 		    seed, loose_obj_only, ncolored, nfound, ntrees,
1528 		    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1529 		if (err)
1530 			goto done;
1531 	}
1532 done:
1533 	for (i = 0; i < nobj; i++) {
1534 		free(ids[i]);
1535 	}
1536 	free(ids);
1537 	got_object_idset_free(idset_exclude);
1538 	return err;
1539 }
1540 
1541 const struct got_error *
1542 hwrite(FILE *f, void *buf, off_t len, SHA1_CTX *ctx)
1543 {
1544 	size_t n;
1545 
1546 	SHA1Update(ctx, buf, len);
1547 	n = fwrite(buf, 1, len, f);
1548 	if (n != len)
1549 		return got_ferror(f, GOT_ERR_IO);
1550 	return NULL;
1551 }
1552 
1553 const struct got_error *
1554 hcopy(FILE *fsrc, FILE *fdst, off_t len, SHA1_CTX *ctx)
1555 {
1556 	unsigned char buf[65536];
1557 	off_t remain = len;
1558 	size_t n;
1559 
1560 	while (remain > 0) {
1561 		size_t copylen = MIN(sizeof(buf), remain);
1562 		n = fread(buf, 1, copylen, fsrc);
1563 		if (n != copylen)
1564 			return got_ferror(fsrc, GOT_ERR_IO);
1565 		SHA1Update(ctx, buf, copylen);
1566 		n = fwrite(buf, 1, copylen, fdst);
1567 		if (n != copylen)
1568 			return got_ferror(fdst, GOT_ERR_IO);
1569 		remain -= copylen;
1570 	}
1571 
1572 	return NULL;
1573 }
1574 
1575 const struct got_error *
1576 hcopy_mmap(uint8_t *src, off_t src_offset, size_t src_size,
1577     FILE *fdst, off_t len, SHA1_CTX *ctx)
1578 {
1579 	size_t n;
1580 
1581 	if (src_offset + len > src_size)
1582 		return got_error(GOT_ERR_RANGE);
1583 
1584 	SHA1Update(ctx, src + src_offset, len);
1585 	n = fwrite(src + src_offset, 1, len, fdst);
1586 	if (n != len)
1587 		return got_ferror(fdst, GOT_ERR_IO);
1588 
1589 	return NULL;
1590 }
1591 
1592 static void
1593 putbe32(char *b, uint32_t n)
1594 {
1595 	b[0] = n >> 24;
1596 	b[1] = n >> 16;
1597 	b[2] = n >> 8;
1598 	b[3] = n >> 0;
1599 }
1600 
1601 static int
1602 write_order_cmp(const void *pa, const void *pb)
1603 {
1604 	struct got_pack_meta *a, *b, *ahd, *bhd;
1605 
1606 	a = *(struct got_pack_meta **)pa;
1607 	b = *(struct got_pack_meta **)pb;
1608 	ahd = (a->head == NULL) ? a : a->head;
1609 	bhd = (b->head == NULL) ? b : b->head;
1610 	if (bhd->mtime < ahd->mtime)
1611 		return -1;
1612 	if (bhd->mtime > ahd->mtime)
1613 		return 1;
1614 	if (bhd < ahd)
1615 		return -1;
1616 	if (bhd > ahd)
1617 		return 1;
1618 	if (a->nchain != b->nchain)
1619 		return a->nchain - b->nchain;
1620 	if (a->mtime < b->mtime)
1621 		return -1;
1622 	if (a->mtime > b->mtime)
1623 		return 1;
1624 	return got_object_id_cmp(&a->id, &b->id);
1625 }
1626 
1627 static int
1628 reuse_write_order_cmp(const void *pa, const void *pb)
1629 {
1630 	struct got_pack_meta *a, *b;
1631 
1632 	a = *(struct got_pack_meta **)pa;
1633 	b = *(struct got_pack_meta **)pb;
1634 
1635 	if (a->reused_delta_offset < b->reused_delta_offset)
1636 		return -1;
1637 	if (a->reused_delta_offset > b->reused_delta_offset)
1638 		return 1;
1639 	return 0;
1640 }
1641 
1642 static const struct got_error *
1643 packhdr(int *hdrlen, char *hdr, size_t bufsize, int obj_type, size_t len)
1644 {
1645 	size_t i;
1646 
1647 	*hdrlen = 0;
1648 
1649 	hdr[0] = obj_type << 4;
1650 	hdr[0] |= len & 0xf;
1651 	len >>= 4;
1652 	for (i = 1; len != 0; i++){
1653 		if (i >= bufsize)
1654 			return got_error(GOT_ERR_NO_SPACE);
1655 		hdr[i - 1] |= GOT_DELTA_SIZE_MORE;
1656 		hdr[i] = len & GOT_DELTA_SIZE_VAL_MASK;
1657 		len >>= GOT_DELTA_SIZE_SHIFT;
1658 	}
1659 
1660 	*hdrlen = i;
1661 	return NULL;
1662 }
1663 
1664 static int
1665 packoff(char *hdr, off_t off)
1666 {
1667 	int i, j;
1668 	char rbuf[8];
1669 
1670 	rbuf[0] = off & GOT_DELTA_SIZE_VAL_MASK;
1671 	for (i = 1; (off >>= GOT_DELTA_SIZE_SHIFT) != 0; i++) {
1672 		rbuf[i] = (--off & GOT_DELTA_SIZE_VAL_MASK) |
1673 		    GOT_DELTA_SIZE_MORE;
1674 	}
1675 
1676 	j = 0;
1677 	while (i > 0)
1678 		hdr[j++] = rbuf[--i];
1679 	return j;
1680 }
1681 
1682 static const struct got_error *
1683 deltahdr(off_t *packfile_size, SHA1_CTX *ctx, FILE *packfile,
1684     struct got_pack_meta *m)
1685 {
1686 	const struct got_error *err;
1687 	char buf[32];
1688 	int nh;
1689 
1690 	if (m->prev->off != 0) {
1691 		err = packhdr(&nh, buf, sizeof(buf),
1692 		    GOT_OBJ_TYPE_OFFSET_DELTA, m->delta_len);
1693 		if (err)
1694 			return err;
1695 		nh += packoff(buf + nh, m->off - m->prev->off);
1696 		err = hwrite(packfile, buf, nh, ctx);
1697 		if (err)
1698 			return err;
1699 		*packfile_size += nh;
1700 	} else {
1701 		err = packhdr(&nh, buf, sizeof(buf),
1702 		    GOT_OBJ_TYPE_REF_DELTA, m->delta_len);
1703 		if (err)
1704 			return err;
1705 		err = hwrite(packfile, buf, nh, ctx);
1706 		if (err)
1707 			return err;
1708 		*packfile_size += nh;
1709 		err = hwrite(packfile, m->prev->id.sha1,
1710 		    sizeof(m->prev->id.sha1), ctx);
1711 		if (err)
1712 			return err;
1713 		*packfile_size += sizeof(m->prev->id.sha1);
1714 	}
1715 
1716 	return NULL;
1717 }
1718 
1719 static const struct got_error *
1720 write_packed_object(off_t *packfile_size, FILE *packfile,
1721     FILE *delta_cache, uint8_t *delta_cache_map, size_t delta_cache_size,
1722     struct got_pack_meta *m, int *outfd, SHA1_CTX *ctx,
1723     struct got_repository *repo)
1724 {
1725 	const struct got_error *err = NULL;
1726 	struct got_deflate_checksum csum;
1727 	char buf[32];
1728 	int nh;
1729 	struct got_raw_object *raw = NULL;
1730 	off_t outlen;
1731 
1732 	csum.output_sha1 = ctx;
1733 	csum.output_crc = NULL;
1734 
1735 	m->off = ftello(packfile);
1736 	if (m->delta_len == 0) {
1737 		err = got_object_raw_open(&raw, outfd, repo, &m->id);
1738 		if (err)
1739 			goto done;
1740 		err = packhdr(&nh, buf, sizeof(buf),
1741 		    m->obj_type, raw->size);
1742 		if (err)
1743 			goto done;
1744 		err = hwrite(packfile, buf, nh, ctx);
1745 		if (err)
1746 			goto done;
1747 		*packfile_size += nh;
1748 		if (raw->f == NULL) {
1749 			err = got_deflate_to_file_mmap(&outlen,
1750 			    raw->data + raw->hdrlen, 0, raw->size,
1751 			    packfile, &csum);
1752 			if (err)
1753 				goto done;
1754 		} else {
1755 			if (fseeko(raw->f, raw->hdrlen, SEEK_SET)
1756 			    == -1) {
1757 				err = got_error_from_errno("fseeko");
1758 				goto done;
1759 			}
1760 			err = got_deflate_to_file(&outlen, raw->f,
1761 			    raw->size, packfile, &csum);
1762 			if (err)
1763 				goto done;
1764 		}
1765 		*packfile_size += outlen;
1766 		got_object_raw_close(raw);
1767 		raw = NULL;
1768 	} else if (m->delta_buf) {
1769 		err = deltahdr(packfile_size, ctx, packfile, m);
1770 		if (err)
1771 			goto done;
1772 		err = hwrite(packfile, m->delta_buf,
1773 		    m->delta_compressed_len, ctx);
1774 		if (err)
1775 			goto done;
1776 		*packfile_size += m->delta_compressed_len;
1777 		free(m->delta_buf);
1778 		m->delta_buf = NULL;
1779 	} else if (delta_cache_map) {
1780 		err = deltahdr(packfile_size, ctx, packfile, m);
1781 		if (err)
1782 			goto done;
1783 		err = hcopy_mmap(delta_cache_map, m->delta_offset,
1784 		    delta_cache_size, packfile, m->delta_compressed_len,
1785 		    ctx);
1786 		if (err)
1787 			goto done;
1788 		*packfile_size += m->delta_compressed_len;
1789 	} else {
1790 		if (fseeko(delta_cache, m->delta_offset, SEEK_SET)
1791 		    == -1) {
1792 			err = got_error_from_errno("fseeko");
1793 			goto done;
1794 		}
1795 		err = deltahdr(packfile_size, ctx, packfile, m);
1796 		if (err)
1797 			goto done;
1798 		err = hcopy(delta_cache, packfile,
1799 		    m->delta_compressed_len, ctx);
1800 		if (err)
1801 			goto done;
1802 		*packfile_size += m->delta_compressed_len;
1803 	}
1804 done:
1805 	if (raw)
1806 		got_object_raw_close(raw);
1807 	return err;
1808 }
1809 
1810 static const struct got_error *
1811 genpack(uint8_t *pack_sha1, FILE *packfile, FILE *delta_cache,
1812     struct got_pack_meta **deltify, int ndeltify,
1813     struct got_pack_meta **reuse, int nreuse,
1814     int ncolored, int nfound, int ntrees, int nours,
1815     struct got_repository *repo,
1816     got_pack_progress_cb progress_cb, void *progress_arg,
1817     struct got_ratelimit *rl,
1818     got_cancel_cb cancel_cb, void *cancel_arg)
1819 {
1820 	const struct got_error *err = NULL;
1821 	int i;
1822 	SHA1_CTX ctx;
1823 	struct got_pack_meta *m;
1824 	char buf[32];
1825 	size_t n;
1826 	off_t packfile_size = 0;
1827 	int outfd = -1;
1828 	int delta_cache_fd = -1;
1829 	uint8_t *delta_cache_map = NULL;
1830 	size_t delta_cache_size = 0;
1831 
1832 	SHA1Init(&ctx);
1833 
1834 #ifndef GOT_PACK_NO_MMAP
1835 	delta_cache_fd = dup(fileno(delta_cache));
1836 	if (delta_cache_fd != -1) {
1837 		struct stat sb;
1838 		if (fstat(delta_cache_fd, &sb) == -1) {
1839 			err = got_error_from_errno("fstat");
1840 			goto done;
1841 		}
1842 		if (sb.st_size > 0 && sb.st_size <= SIZE_MAX) {
1843 			delta_cache_map = mmap(NULL, sb.st_size,
1844 			    PROT_READ, MAP_PRIVATE, delta_cache_fd, 0);
1845 			if (delta_cache_map == MAP_FAILED) {
1846 				if (errno != ENOMEM) {
1847 					err = got_error_from_errno("mmap");
1848 					goto done;
1849 				}
1850 				delta_cache_map = NULL; /* fallback on stdio */
1851 			} else
1852 				delta_cache_size = (size_t)sb.st_size;
1853 		}
1854 	}
1855 #endif
1856 	err = hwrite(packfile, "PACK", 4, &ctx);
1857 	if (err)
1858 		goto done;
1859 	putbe32(buf, GOT_PACKFILE_VERSION);
1860 	err = hwrite(packfile, buf, 4, &ctx);
1861 	if (err)
1862 		goto done;
1863 	putbe32(buf, ndeltify + nreuse);
1864 	err = hwrite(packfile, buf, 4, &ctx);
1865 	if (err)
1866 		goto done;
1867 
1868 	qsort(deltify, ndeltify, sizeof(struct got_pack_meta *),
1869 	    write_order_cmp);
1870 	for (i = 0; i < ndeltify; i++) {
1871 		err = report_progress(progress_cb, progress_arg, rl,
1872 		    ncolored, nfound, ntrees, packfile_size, nours,
1873 		    ndeltify + nreuse, ndeltify + nreuse, i);
1874 		if (err)
1875 			goto done;
1876 		m = deltify[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 	qsort(reuse, nreuse, sizeof(struct got_pack_meta *),
1885 	    reuse_write_order_cmp);
1886 	for (i = 0; i < nreuse; i++) {
1887 		err = report_progress(progress_cb, progress_arg, rl,
1888 		    ncolored, nfound, ntrees, packfile_size, nours,
1889 		    ndeltify + nreuse, ndeltify + nreuse, ndeltify + i);
1890 		if (err)
1891 			goto done;
1892 		m = reuse[i];
1893 		err = write_packed_object(&packfile_size, packfile,
1894 		    delta_cache, delta_cache_map, delta_cache_size,
1895 		    m, &outfd, &ctx, repo);
1896 		if (err)
1897 			goto done;
1898 	}
1899 
1900 	SHA1Final(pack_sha1, &ctx);
1901 	n = fwrite(pack_sha1, 1, SHA1_DIGEST_LENGTH, packfile);
1902 	if (n != SHA1_DIGEST_LENGTH)
1903 		err = got_ferror(packfile, GOT_ERR_IO);
1904 	packfile_size += SHA1_DIGEST_LENGTH;
1905 	packfile_size += sizeof(struct got_packfile_hdr);
1906 	if (progress_cb) {
1907 		err = progress_cb(progress_arg, ncolored, nfound, ntrees,
1908 		    packfile_size, nours, ndeltify + nreuse,
1909 		    ndeltify + nreuse, ndeltify + nreuse);
1910 		if (err)
1911 			goto done;
1912 	}
1913 done:
1914 	if (outfd != -1 && close(outfd) == -1 && err == NULL)
1915 		err = got_error_from_errno("close");
1916 	if (delta_cache_map && munmap(delta_cache_map, delta_cache_size) == -1)
1917 		err = got_error_from_errno("munmap");
1918 	if (delta_cache_fd != -1 && close(delta_cache_fd) == -1 && err == NULL)
1919 		err = got_error_from_errno("close");
1920 	return err;
1921 }
1922 
1923 static const struct got_error *
1924 add_meta_idset_cb(struct got_object_id *id, void *data, void *arg)
1925 {
1926 	struct got_pack_meta *m = data;
1927 	struct got_pack_metavec *v = arg;
1928 
1929 	if (m->reused_delta_offset != 0)
1930 		return NULL;
1931 
1932 	return add_meta(m, v);
1933 }
1934 
1935 const struct got_error *
1936 got_pack_create(uint8_t *packsha1, FILE *packfile,
1937     struct got_object_id **theirs, int ntheirs,
1938     struct got_object_id **ours, int nours,
1939     struct got_repository *repo, int loose_obj_only, int allow_empty,
1940     got_pack_progress_cb progress_cb, void *progress_arg,
1941     got_cancel_cb cancel_cb, void *cancel_arg)
1942 {
1943 	const struct got_error *err;
1944 	int delta_cache_fd = -1;
1945 	FILE *delta_cache = NULL;
1946 	struct got_object_idset *idset;
1947 	struct got_ratelimit rl;
1948 	struct got_pack_metavec deltify, reuse;
1949 	int ncolored = 0, nfound = 0, ntrees = 0;
1950 	size_t ndeltify;
1951 	uint32_t seed;
1952 
1953 	seed = arc4random();
1954 
1955 	memset(&deltify, 0, sizeof(deltify));
1956 	memset(&reuse, 0, sizeof(reuse));
1957 
1958 	got_ratelimit_init(&rl, 0, 500);
1959 
1960 	idset = got_object_idset_alloc();
1961 	if (idset == NULL)
1962 		return got_error_from_errno("got_object_idset_alloc");
1963 
1964 	err = load_object_ids(&ncolored, &nfound, &ntrees, idset, theirs,
1965 	    ntheirs, ours, nours, repo, seed, loose_obj_only,
1966 	    progress_cb, progress_arg, &rl, cancel_cb, cancel_arg);
1967 	if (err)
1968 		goto done;
1969 
1970 	if (progress_cb) {
1971 		err = progress_cb(progress_arg, ncolored, nfound, ntrees,
1972 		    0L, nours, got_object_idset_num_elements(idset), 0, 0);
1973 		if (err)
1974 			goto done;
1975 	}
1976 
1977 	if (got_object_idset_num_elements(idset) == 0 && !allow_empty) {
1978 		err = got_error(GOT_ERR_CANNOT_PACK);
1979 		goto done;
1980 	}
1981 
1982 	delta_cache_fd = got_opentempfd();
1983 	if (delta_cache_fd == -1) {
1984 		err = got_error_from_errno("got_opentemp");
1985 		goto done;
1986 	}
1987 
1988 	reuse.metasz = 64;
1989 	reuse.meta = calloc(reuse.metasz,
1990 	    sizeof(struct got_pack_meta *));
1991 	if (reuse.meta == NULL) {
1992 		err = got_error_from_errno("calloc");
1993 		goto done;
1994 	}
1995 
1996 	err = search_deltas(&reuse, idset, delta_cache_fd, ncolored, nfound,
1997 	    ntrees, nours, repo, progress_cb, progress_arg, &rl,
1998 	    cancel_cb, cancel_arg);
1999 	if (err)
2000 		goto done;
2001 
2002 	delta_cache = fdopen(delta_cache_fd, "a+");
2003 	if (delta_cache == NULL) {
2004 		err = got_error_from_errno("fdopen");
2005 		goto done;
2006 	}
2007 	delta_cache_fd = -1;
2008 
2009 	if (fseeko(delta_cache, 0L, SEEK_END) == -1) {
2010 		err = got_error_from_errno("fseeko");
2011 		goto done;
2012 	}
2013 
2014 	ndeltify = got_object_idset_num_elements(idset) - reuse.nmeta;
2015 	if (ndeltify > 0) {
2016 		deltify.meta = calloc(ndeltify, sizeof(struct got_pack_meta *));
2017 		if (deltify.meta == NULL) {
2018 			err = got_error_from_errno("calloc");
2019 			goto done;
2020 		}
2021 		deltify.metasz = ndeltify;
2022 
2023 		err = got_object_idset_for_each(idset, add_meta_idset_cb,
2024 		    &deltify);
2025 		if (err)
2026 			goto done;
2027 		if (deltify.nmeta > 0) {
2028 			err = pick_deltas(deltify.meta, deltify.nmeta,
2029 			    ncolored, nfound, ntrees, nours, reuse.nmeta,
2030 			    delta_cache, repo, progress_cb, progress_arg, &rl,
2031 			    cancel_cb, cancel_arg);
2032 			if (err)
2033 				goto done;
2034 		}
2035 	}
2036 
2037 	if (fflush(delta_cache) == EOF) {
2038 		err = got_error_from_errno("fflush");
2039 		goto done;
2040 	}
2041 	err = genpack(packsha1, packfile, delta_cache, deltify.meta,
2042 	    deltify.nmeta, reuse.meta, reuse.nmeta, ncolored, nfound, ntrees,
2043 	    nours, repo, progress_cb, progress_arg, &rl,
2044 	    cancel_cb, cancel_arg);
2045 	if (err)
2046 		goto done;
2047 done:
2048 	free_nmeta(deltify.meta, deltify.nmeta);
2049 	free_nmeta(reuse.meta, reuse.nmeta);
2050 	got_object_idset_free(idset);
2051 	if (delta_cache_fd != -1 && close(delta_cache_fd) == -1 && err == NULL)
2052 		err = got_error_from_errno("close");
2053 	if (delta_cache && fclose(delta_cache) == EOF && err == NULL)
2054 		err = got_error_from_errno("fclose");
2055 	return err;
2056 }