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 #include "murmurhash2.h"
60 
61 #ifndef MIN
62 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
63 #endif
64 
65 #ifndef MAX
66 #define	MAX(_a,_b) ((_a) > (_b) ? (_a) : (_b))
67 #endif
68 
69 #ifndef nitems
70 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
71 #endif
72 
73 struct got_pack_meta {
74 	struct got_object_id id;
75 	uint32_t path_hash;
76 	int	obj_type;
77 	off_t	size;
78 	time_t	mtime;
79 
80 	/* The best delta we picked */
81 	struct got_pack_meta *head;
82 	struct got_pack_meta *prev;
83 	unsigned char *delta_buf; /* if encoded in memory (compressed) */
84 	off_t	delta_offset;	/* offset in delta cache file (compressed) */
85 	off_t	delta_len;	/* encoded delta length */
86 	off_t	delta_compressed_len; /* encoded+compressed delta length */
87 	int	nchain;
88 
89 	off_t   reused_delta_offset; /* offset of delta in reused pack file */
90 	struct got_object_id *base_obj_id;
91 
92 	/* Only used for delta window */
93 	struct got_delta_table *dtab;
94 
95 	/* Only used for writing offset deltas */
96 	off_t	off;
97 };
98 
99 struct got_pack_metavec {
100 	struct got_pack_meta **meta;
101 	int nmeta;
102 	int metasz;
103 };
104 
105 static const struct got_error *
106 alloc_meta(struct got_pack_meta **new, struct got_object_id *id,
107     const char *path, int obj_type, time_t mtime)
108 {
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_hash = murmurhash2(path, strlen(path), 0xd70af26a);
120 	m->obj_type = obj_type;
121 	m->mtime = mtime;
122 	*new = m;
123 	return NULL;
124 }
125 
126 static void
127 clear_meta(struct got_pack_meta *meta)
128 {
129 	if (meta == NULL)
130 		return;
131 	meta->path_hash = 0;
132 	free(meta->delta_buf);
133 	meta->delta_buf = NULL;
134 	free(meta->base_obj_id);
135 	meta->base_obj_id = NULL;
136 	meta->reused_delta_offset = 0;
137 }
138 
139 static void
140 free_nmeta(struct got_pack_meta **meta, int nmeta)
141 {
142 	int i;
143 
144 	for (i = 0; i < nmeta; i++)
145 		clear_meta(meta[i]);
146 	free(meta);
147 }
148 
149 static int
150 delta_order_cmp(const void *pa, const void *pb)
151 {
152 	struct got_pack_meta *a, *b;
153 
154 	a = *(struct got_pack_meta **)pa;
155 	b = *(struct got_pack_meta **)pb;
156 
157 	if (a->obj_type != b->obj_type)
158 		return a->obj_type - b->obj_type;
159 	if (a->path_hash < b->path_hash)
160 		return -1;
161 	if (a->path_hash > b->path_hash)
162 		return 1;
163 	if (a->mtime < b->mtime)
164 		return -1;
165 	if (a->mtime > b->mtime)
166 		return 1;
167 	return got_object_id_cmp(&a->id, &b->id);
168 }
169 
170 static off_t
171 delta_size(struct got_delta_instruction *deltas, int ndeltas)
172 {
173 	int i;
174 	off_t size = 32;
175 	for (i = 0; i < ndeltas; i++) {
176 		if (deltas[i].copy)
177 			size += GOT_DELTA_SIZE_SHIFT;
178 		else
179 			size += deltas[i].len + 1;
180 	}
181 	return size;
182 }
183 
184 static const struct got_error *
185 append(unsigned char **p, size_t *len, off_t *sz, void *seg, int nseg)
186 {
187 	char *n;
188 
189 	if (*len + nseg >= *sz) {
190 		while (*len + nseg >= *sz)
191 			*sz += *sz / 2;
192 		n = realloc(*p, *sz);
193 		if (n == NULL)
194 			return got_error_from_errno("realloc");
195 		*p = n;
196 	}
197 	memcpy(*p + *len, seg, nseg);
198 	*len += nseg;
199 	return NULL;
200 }
201 
202 static const struct got_error *
203 encode_delta_in_mem(struct got_pack_meta *m, struct got_raw_object *o,
204     struct got_delta_instruction *deltas, int ndeltas,
205     off_t delta_size, off_t base_size)
206 {
207 	const struct got_error *err;
208 	unsigned char buf[16], *bp;
209 	int i, j;
210 	size_t len = 0, compressed_len;
211 	off_t bufsize = delta_size;
212 	off_t n;
213 	struct got_delta_instruction *d;
214 	uint8_t *delta_buf;
215 
216 	delta_buf = malloc(bufsize);
217 	if (delta_buf == NULL)
218 		return got_error_from_errno("malloc");
219 
220 	/* base object size */
221 	buf[0] = base_size & GOT_DELTA_SIZE_VAL_MASK;
222 	n = base_size >> GOT_DELTA_SIZE_SHIFT;
223 	for (i = 1; n > 0; i++) {
224 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
225 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
226 		n >>= GOT_DELTA_SIZE_SHIFT;
227 	}
228 	err = append(&delta_buf, &len, &bufsize, buf, i);
229 	if (err)
230 		goto done;
231 
232 	/* target object size */
233 	buf[0] = o->size & GOT_DELTA_SIZE_VAL_MASK;
234 	n = o->size >> GOT_DELTA_SIZE_SHIFT;
235 	for (i = 1; n > 0; i++) {
236 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
237 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
238 		n >>= GOT_DELTA_SIZE_SHIFT;
239 	}
240 	err = append(&delta_buf, &len, &bufsize, buf, i);
241 	if (err)
242 		goto done;
243 
244 	for (j = 0; j < ndeltas; j++) {
245 		d = &deltas[j];
246 		if (d->copy) {
247 			n = d->offset;
248 			bp = &buf[1];
249 			buf[0] = GOT_DELTA_BASE_COPY;
250 			for (i = 0; i < 4; i++) {
251 				/* DELTA_COPY_OFF1 ... DELTA_COPY_OFF4 */
252 				buf[0] |= 1 << i;
253 				*bp++ = n & 0xff;
254 				n >>= 8;
255 				if (n == 0)
256 					break;
257 			}
258 
259 			n = d->len;
260 			if (n != GOT_DELTA_COPY_DEFAULT_LEN) {
261 				/* DELTA_COPY_LEN1 ... DELTA_COPY_LEN3 */
262 				for (i = 0; i < 3 && n > 0; i++) {
263 					buf[0] |= 1 << (i + 4);
264 					*bp++ = n & 0xff;
265 					n >>= 8;
266 				}
267 			}
268 			err = append(&delta_buf, &len, &bufsize,
269 			    buf, bp - buf);
270 			if (err)
271 				goto done;
272 		} else if (o->f == NULL) {
273 			n = 0;
274 			while (n != d->len) {
275 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
276 				err = append(&delta_buf, &len, &bufsize,
277 				    buf, 1);
278 				if (err)
279 					goto done;
280 				err = append(&delta_buf, &len, &bufsize,
281 				    o->data + o->hdrlen + d->offset + n,
282 				    buf[0]);
283 				if (err)
284 					goto done;
285 				n += buf[0];
286 			}
287 		} else {
288 			char content[128];
289 			size_t r;
290 			if (fseeko(o->f, o->hdrlen + d->offset, SEEK_SET) == -1) {
291 				err = got_error_from_errno("fseeko");
292 				goto done;
293 			}
294 			n = 0;
295 			while (n != d->len) {
296 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
297 				err = append(&delta_buf, &len, &bufsize,
298 				    buf, 1);
299 				if (err)
300 					goto done;
301 				r = fread(content, 1, buf[0], o->f);
302 				if (r != buf[0]) {
303 					err = got_ferror(o->f, GOT_ERR_IO);
304 					goto done;
305 				}
306 				err = append(&delta_buf, &len, &bufsize,
307 				    content, buf[0]);
308 				if (err)
309 					goto done;
310 				n += buf[0];
311 			}
312 		}
313 	}
314 
315 	err = got_deflate_to_mem_mmap(&m->delta_buf, &compressed_len,
316 	    NULL, NULL, delta_buf, 0, len);
317 	if (err)
318 		goto done;
319 
320 	m->delta_len = len;
321 	m->delta_compressed_len = compressed_len;
322 done:
323 	free(delta_buf);
324 	return err;
325 }
326 
327 static const struct got_error *
328 encode_delta(struct got_pack_meta *m, struct got_raw_object *o,
329     struct got_delta_instruction *deltas, int ndeltas,
330     off_t base_size, FILE *f)
331 {
332 	const struct got_error *err;
333 	unsigned char buf[16], *bp;
334 	int i, j;
335 	off_t n;
336 	struct got_deflate_buf zb;
337 	struct got_delta_instruction *d;
338 	off_t delta_len = 0, compressed_len = 0;
339 
340 	err = got_deflate_init(&zb, NULL, GOT_DEFLATE_BUFSIZE);
341 	if (err)
342 		return err;
343 
344 	/* base object size */
345 	buf[0] = base_size & GOT_DELTA_SIZE_VAL_MASK;
346 	n = base_size >> GOT_DELTA_SIZE_SHIFT;
347 	for (i = 1; n > 0; i++) {
348 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
349 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
350 		n >>= GOT_DELTA_SIZE_SHIFT;
351 	}
352 
353 	err = got_deflate_append_to_file_mmap(&zb, &compressed_len,
354 	    buf, 0, i, f, NULL);
355 	if (err)
356 		goto done;
357 	delta_len += i;
358 
359 	/* target object size */
360 	buf[0] = o->size & GOT_DELTA_SIZE_VAL_MASK;
361 	n = o->size >> GOT_DELTA_SIZE_SHIFT;
362 	for (i = 1; n > 0; i++) {
363 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
364 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
365 		n >>= GOT_DELTA_SIZE_SHIFT;
366 	}
367 
368 	err = got_deflate_append_to_file_mmap(&zb, &compressed_len,
369 	    buf, 0, i, f, NULL);
370 	if (err)
371 		goto done;
372 	delta_len += i;
373 
374 	for (j = 0; j < ndeltas; j++) {
375 		d = &deltas[j];
376 		if (d->copy) {
377 			n = d->offset;
378 			bp = &buf[1];
379 			buf[0] = GOT_DELTA_BASE_COPY;
380 			for (i = 0; i < 4; i++) {
381 				/* DELTA_COPY_OFF1 ... DELTA_COPY_OFF4 */
382 				buf[0] |= 1 << i;
383 				*bp++ = n & 0xff;
384 				n >>= 8;
385 				if (n == 0)
386 					break;
387 			}
388 			n = d->len;
389 			if (n != GOT_DELTA_COPY_DEFAULT_LEN) {
390 				/* DELTA_COPY_LEN1 ... DELTA_COPY_LEN3 */
391 				for (i = 0; i < 3 && n > 0; i++) {
392 					buf[0] |= 1 << (i + 4);
393 					*bp++ = n & 0xff;
394 					n >>= 8;
395 				}
396 			}
397 			err = got_deflate_append_to_file_mmap(&zb,
398 			    &compressed_len, buf, 0, bp - buf, f, NULL);
399 			if (err)
400 				goto done;
401 			delta_len += (bp - buf);
402 		} else if (o->f == NULL) {
403 			n = 0;
404 			while (n != d->len) {
405 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
406 				err = got_deflate_append_to_file_mmap(&zb,
407 				    &compressed_len, buf, 0, 1, f, NULL);
408 				if (err)
409 					goto done;
410 				delta_len++;
411 				err = got_deflate_append_to_file_mmap(&zb,
412 				    &compressed_len,
413 				    o->data + o->hdrlen + d->offset + n, 0,
414 				    buf[0], f, NULL);
415 				if (err)
416 					goto done;
417 				delta_len += buf[0];
418 				n += buf[0];
419 			}
420 		} else {
421 			char content[128];
422 			size_t r;
423 			if (fseeko(o->f, o->hdrlen + d->offset, SEEK_SET) == -1) {
424 				err = got_error_from_errno("fseeko");
425 				goto done;
426 			}
427 			n = 0;
428 			while (n != d->len) {
429 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
430 				err = got_deflate_append_to_file_mmap(&zb,
431 				    &compressed_len, buf, 0, 1, f, NULL);
432 				if (err)
433 					goto done;
434 				delta_len++;
435 				r = fread(content, 1, buf[0], o->f);
436 				if (r != buf[0]) {
437 					err = got_ferror(o->f, GOT_ERR_IO);
438 					goto done;
439 				}
440 				err = got_deflate_append_to_file_mmap(&zb,
441 				    &compressed_len, content, 0, buf[0], f,
442 				    NULL);
443 				if (err)
444 					goto done;
445 				delta_len += buf[0];
446 				n += buf[0];
447 			}
448 		}
449 	}
450 
451 	err = got_deflate_flush(&zb, f, NULL, &compressed_len);
452 	if (err)
453 		goto done;
454 
455 	/* sanity check */
456 	if (compressed_len != ftello(f) - m->delta_offset) {
457 		err = got_error(GOT_ERR_COMPRESSION);
458 		goto done;
459 	}
460 
461 	m->delta_len = delta_len;
462 	m->delta_compressed_len = compressed_len;
463 done:
464 	got_deflate_end(&zb);
465 	return err;
466 }
467 
468 static const struct got_error *
469 report_progress(got_pack_progress_cb progress_cb, void *progress_arg,
470     struct got_ratelimit *rl, int ncolored, int nfound, int ntrees,
471     off_t packfile_size, int ncommits, int nobj_total, int obj_deltify,
472     int nobj_written)
473 {
474 	const struct got_error *err;
475 	int elapsed;
476 
477 	if (progress_cb == NULL)
478 		return NULL;
479 
480 	err = got_ratelimit_check(&elapsed, rl);
481 	if (err || !elapsed)
482 		return err;
483 
484 	return progress_cb(progress_arg, ncolored, nfound, ntrees,
485 	    packfile_size, ncommits, nobj_total, obj_deltify, nobj_written);
486 }
487 
488 static const struct got_error *
489 add_meta(struct got_pack_meta *m, struct got_pack_metavec *v)
490 {
491 	if (v->nmeta == v->metasz){
492 		size_t newsize = 2 * v->metasz;
493 		struct got_pack_meta **new;
494 		new = reallocarray(v->meta, newsize, sizeof(*new));
495 		if (new == NULL)
496 			return got_error_from_errno("reallocarray");
497 		v->meta = new;
498 		v->metasz = newsize; 
499 	}
500 
501 	v->meta[v->nmeta++] = m;
502 	return NULL;
503 }
504 
505 static const struct got_error *
506 find_pack_for_reuse(struct got_packidx **best_packidx,
507     struct got_repository *repo)
508 {
509 	const struct got_error *err = NULL;
510 	struct got_pathlist_entry *pe;
511 	const char *best_packidx_path = NULL;
512 	int nobj_max = 0;
513 
514 	*best_packidx = NULL;
515 
516 	TAILQ_FOREACH(pe, &repo->packidx_paths, entry) {
517 		const char *path_packidx = pe->path;
518 		struct got_packidx *packidx;
519 		int nobj;
520 
521 		err = got_repo_get_packidx(&packidx, path_packidx, repo);
522 		if (err)
523 			break;
524 
525 		nobj = be32toh(packidx->hdr.fanout_table[0xff]);
526 		if (nobj > nobj_max) {
527 			best_packidx_path = path_packidx;
528 			nobj_max = nobj;
529 		}
530 	}
531 
532 	if (best_packidx_path) {
533 		err = got_repo_get_packidx(best_packidx, best_packidx_path,
534 		    repo);
535 	}
536 
537 	return err;
538 }
539 
540 struct send_id_arg {
541 	struct imsgbuf *ibuf;
542 	struct got_object_id *ids[GOT_IMSG_OBJ_ID_LIST_MAX_NIDS];
543 	size_t nids;
544 };
545 
546 static const struct got_error *
547 send_id(struct got_object_id *id, void *data, void *arg)
548 {
549 	const struct got_error *err = NULL;
550 	struct send_id_arg *a = arg;
551 
552 	a->ids[a->nids++] = id;
553 
554 	if (a->nids >= GOT_IMSG_OBJ_ID_LIST_MAX_NIDS) {
555 		err = got_privsep_send_object_idlist(a->ibuf, a->ids, a->nids);
556 		if (err)
557 			return err;
558 		a->nids = 0;
559 	}
560 
561 	return NULL;
562 }
563 
564 static const struct got_error *
565 recv_reused_delta(struct got_imsg_reused_delta *delta,
566     struct got_object_idset *idset, struct got_pack_metavec *v)
567 {
568 	struct got_pack_meta *m, *base;
569 
570 	if (delta->delta_offset + delta->delta_size < delta->delta_offset ||
571 	    delta->delta_offset +
572 	    delta->delta_compressed_size < delta->delta_offset)
573 		return got_error(GOT_ERR_BAD_PACKFILE);
574 
575 	m = got_object_idset_get(idset, &delta->id);
576 	if (m == NULL)
577 		return got_error(GOT_ERR_NO_OBJ);
578 
579 	base = got_object_idset_get(idset, &delta->base_id);
580 	if (base == NULL)
581 		return got_error(GOT_ERR_NO_OBJ);
582 
583 	m->delta_len = delta->delta_size;
584 	m->delta_compressed_len = delta->delta_compressed_size;
585 	m->delta_offset = delta->delta_out_offset;
586 	m->prev = base;
587 	m->size = delta->result_size;
588 	m->reused_delta_offset = delta->delta_offset;
589 	m->base_obj_id = got_object_id_dup(&delta->base_id);
590 	if (m->base_obj_id == NULL)
591 		return got_error_from_errno("got_object_id_dup");
592 
593 	return add_meta(m, v);
594 }
595 
596 static const struct got_error *
597 search_deltas(struct got_pack_metavec *v, struct got_object_idset *idset,
598     int delta_cache_fd, int ncolored, int nfound, int ntrees, int ncommits,
599     struct got_repository *repo,
600     got_pack_progress_cb progress_cb, void *progress_arg,
601     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
602 {
603 	const struct got_error *err = NULL;
604 	struct got_packidx *packidx;
605 	struct got_pack *pack;
606 	struct send_id_arg sia;
607 	struct got_imsg_reused_delta deltas[GOT_IMSG_REUSED_DELTAS_MAX_NDELTAS];
608 	size_t ndeltas, i;
609 
610 	err = find_pack_for_reuse(&packidx, repo);
611 	if (err)
612 		return err;
613 
614 	if (packidx == NULL)
615 		return NULL;
616 
617 	err = got_object_prepare_delta_reuse(&pack, packidx,
618 	    delta_cache_fd, repo);
619 	if (err)
620 		return err;
621 
622 	memset(&sia, 0, sizeof(sia));
623 	sia.ibuf = pack->privsep_child->ibuf;
624 	err = got_object_idset_for_each(idset, send_id, &sia);
625 	if (err)
626 		return err;
627 	if (sia.nids > 0) {
628 		err = got_privsep_send_object_idlist(pack->privsep_child->ibuf,
629 		    sia.ids, sia.nids);
630 		if (err)
631 			return err;
632 	}
633 	err = got_privsep_send_object_idlist_done(pack->privsep_child->ibuf);
634 	if (err)
635 		return err;
636 
637 	for (;;) {
638 		int done = 0;
639 
640 		if (cancel_cb) {
641 			err = (*cancel_cb)(cancel_arg);
642 			if (err)
643 				break;
644 		}
645 
646 		err = got_privsep_recv_reused_deltas(&done, deltas, &ndeltas,
647 		    pack->privsep_child->ibuf);
648 		if (err || done)
649 			break;
650 
651 		for (i = 0; i < ndeltas; i++) {
652 			struct got_imsg_reused_delta *delta = &deltas[i];
653 			err = recv_reused_delta(delta, idset, v);
654 			if (err)
655 				goto done;
656 		}
657 
658 		err = report_progress(progress_cb, progress_arg, rl,
659 		    ncolored, nfound, ntrees, 0L, ncommits,
660 		    got_object_idset_num_elements(idset), v->nmeta, 0);
661 		if (err)
662 			break;
663 	}
664 done:
665 	return err;
666 }
667 
668 static const struct got_error *
669 pick_deltas(struct got_pack_meta **meta, int nmeta, int ncolored,
670     int nfound, int ntrees, int ncommits, int nreused, FILE *delta_cache,
671     struct got_repository *repo,
672     got_pack_progress_cb progress_cb, void *progress_arg,
673     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
674 {
675 	const struct got_error *err = NULL;
676 	struct got_pack_meta *m = NULL, *base = NULL;
677 	struct got_raw_object *raw = NULL, *base_raw = NULL;
678 	struct got_delta_instruction *deltas = NULL, *best_deltas = NULL;
679 	int i, j, ndeltas, best_ndeltas;
680 	off_t size, best_size;
681 	const int max_base_candidates = 3;
682 	size_t delta_memsize = 0;
683 	const size_t max_delta_memsize = 4 * GOT_DELTA_RESULT_SIZE_CACHED_MAX;
684 	int outfd = -1;
685 
686 	qsort(meta, nmeta, sizeof(struct got_pack_meta *), delta_order_cmp);
687 	for (i = 0; i < nmeta; i++) {
688 		if (cancel_cb) {
689 			err = (*cancel_cb)(cancel_arg);
690 			if (err)
691 				break;
692 		}
693 		err = report_progress(progress_cb, progress_arg, rl,
694 		    ncolored, nfound, ntrees, 0L, ncommits, nreused + nmeta,
695 		    nreused + i, 0);
696 		if (err)
697 			goto done;
698 		m = meta[i];
699 
700 		if (m->obj_type == GOT_OBJ_TYPE_COMMIT ||
701 		    m->obj_type == GOT_OBJ_TYPE_TAG)
702 			continue;
703 
704 		err = got_object_raw_open(&raw, &outfd, repo, &m->id);
705 		if (err)
706 			goto done;
707 		m->size = raw->size;
708 
709 		if (raw->f == NULL) {
710 			err = got_deltify_init_mem(&m->dtab, raw->data,
711 			    raw->hdrlen, raw->size + raw->hdrlen);
712 		} else {
713 			err = got_deltify_init(&m->dtab, raw->f, raw->hdrlen,
714 			    raw->size + raw->hdrlen);
715 		}
716 		if (err)
717 			goto done;
718 
719 		if (i > max_base_candidates) {
720 			struct got_pack_meta *n = NULL;
721 			n = meta[i - (max_base_candidates + 1)];
722 			got_deltify_free(n->dtab);
723 			n->dtab = NULL;
724 		}
725 
726 		best_size = raw->size;
727 		best_ndeltas = 0;
728 		for (j = MAX(0, i - max_base_candidates); j < i; j++) {
729 			if (cancel_cb) {
730 				err = (*cancel_cb)(cancel_arg);
731 				if (err)
732 					goto done;
733 			}
734 			base = meta[j];
735 			/* long chains make unpacking slow, avoid such bases */
736 			if (base->nchain >= 128 ||
737 			    base->obj_type != m->obj_type)
738 				continue;
739 
740 			err = got_object_raw_open(&base_raw, &outfd, repo,
741 			    &base->id);
742 			if (err)
743 				goto done;
744 
745 			if (raw->f == NULL && base_raw->f == NULL) {
746 				err = got_deltify_mem_mem(&deltas, &ndeltas,
747 				    raw->data, raw->hdrlen,
748 				    raw->size + raw->hdrlen,
749 				    base->dtab, base_raw->data,
750 				    base_raw->hdrlen,
751 				    base_raw->size + base_raw->hdrlen);
752 			} else if (raw->f == NULL) {
753 				err = got_deltify_mem_file(&deltas, &ndeltas,
754 				    raw->data, raw->hdrlen,
755 				    raw->size + raw->hdrlen,
756 				    base->dtab, base_raw->f,
757 				    base_raw->hdrlen,
758 				    base_raw->size + base_raw->hdrlen);
759 			} else if (base_raw->f == NULL) {
760 				err = got_deltify_file_mem(&deltas, &ndeltas,
761 				    raw->f, raw->hdrlen,
762 				    raw->size + raw->hdrlen,
763 				    base->dtab, base_raw->data,
764 				    base_raw->hdrlen,
765 				    base_raw->size + base_raw->hdrlen);
766 			} else {
767 				err = got_deltify(&deltas, &ndeltas,
768 				    raw->f, raw->hdrlen,
769 				    raw->size + raw->hdrlen,
770 				    base->dtab, base_raw->f, base_raw->hdrlen,
771 				    base_raw->size + base_raw->hdrlen);
772 			}
773 			got_object_raw_close(base_raw);
774 			base_raw = NULL;
775 			if (err)
776 				goto done;
777 
778 			size = delta_size(deltas, ndeltas);
779 			if (size + 32 < best_size){
780 				/*
781 				 * if we already picked a best delta,
782 				 * replace it.
783 				 */
784 				best_size = size;
785 				free(best_deltas);
786 				best_deltas = deltas;
787 				best_ndeltas = ndeltas;
788 				deltas = NULL;
789 				m->nchain = base->nchain + 1;
790 				m->prev = base;
791 				m->head = base->head;
792 				if (m->head == NULL)
793 					m->head = base;
794 			} else {
795 				free(deltas);
796 				deltas = NULL;
797 				ndeltas = 0;
798 			}
799 		}
800 
801 		if (best_ndeltas > 0) {
802 			if (best_size <= GOT_DELTA_RESULT_SIZE_CACHED_MAX &&
803 			    delta_memsize + best_size <= max_delta_memsize) {
804 				delta_memsize += best_size;
805 				err = encode_delta_in_mem(m, raw, best_deltas,
806 				    best_ndeltas, best_size, m->prev->size);
807 			} else {
808 				m->delta_offset = ftello(delta_cache);
809 				err = encode_delta(m, raw, best_deltas,
810 				    best_ndeltas, m->prev->size, delta_cache);
811 			}
812 			free(best_deltas);
813 			best_deltas = NULL;
814 			best_ndeltas = 0;
815 			if (err)
816 				goto done;
817 		}
818 
819 		got_object_raw_close(raw);
820 		raw = NULL;
821 	}
822 done:
823 	for (i = MAX(0, nmeta - max_base_candidates); i < nmeta; i++) {
824 		got_deltify_free(meta[i]->dtab);
825 		meta[i]->dtab = NULL;
826 	}
827 	if (raw)
828 		got_object_raw_close(raw);
829 	if (base_raw)
830 		got_object_raw_close(base_raw);
831 	if (outfd != -1 && close(outfd) == -1 && err == NULL)
832 		err = got_error_from_errno("close");
833 	free(deltas);
834 	free(best_deltas);
835 	return err;
836 }
837 
838 static const struct got_error *
839 search_packidx(int *found, struct got_object_id *id,
840     struct got_repository *repo)
841 {
842 	const struct got_error *err = NULL;
843 	struct got_packidx *packidx = NULL;
844 	int idx;
845 
846 	*found = 0;
847 
848 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
849 	if (err == NULL)
850 		*found = 1; /* object is already packed */
851 	else if (err->code == GOT_ERR_NO_OBJ)
852 		err = NULL;
853 	return err;
854 }
855 
856 static const struct got_error *
857 add_object(int want_meta, struct got_object_idset *idset,
858     struct got_object_id *id, const char *path, int obj_type,
859     time_t mtime, int loose_obj_only, struct got_repository *repo,
860     int *ncolored, int *nfound, int *ntrees,
861     got_pack_progress_cb progress_cb, void *progress_arg,
862     struct got_ratelimit *rl)
863 {
864 	const struct got_error *err;
865 	struct got_pack_meta *m = NULL;
866 
867 	if (loose_obj_only) {
868 		int is_packed;
869 		err = search_packidx(&is_packed, id, repo);
870 		if (err)
871 			return err;
872 		if (is_packed && want_meta)
873 			return NULL;
874 	}
875 
876 	if (want_meta) {
877 		err = alloc_meta(&m, id, path, obj_type, mtime);
878 		if (err)
879 			return err;
880 
881 		(*nfound)++;
882 		err = report_progress(progress_cb, progress_arg, rl,
883 		    *ncolored, *nfound, *ntrees, 0L, 0, 0, 0, 0);
884 		if (err) {
885 			clear_meta(m);
886 			free(m);
887 			return err;
888 		}
889 	}
890 
891 	err = got_object_idset_add(idset, id, m);
892 	if (err) {
893 		clear_meta(m);
894 		free(m);
895 	}
896 	return err;
897 }
898 
899 static const struct got_error *
900 load_tree_entries(struct got_object_id_queue *ids, int want_meta,
901     struct got_object_idset *idset, struct got_object_idset *idset_exclude,
902     struct got_object_id *tree_id,
903     const char *dpath, time_t mtime, struct got_repository *repo,
904     int loose_obj_only, int *ncolored, int *nfound, int *ntrees,
905     got_pack_progress_cb progress_cb, void *progress_arg,
906     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
907 {
908 	const struct got_error *err;
909 	struct got_tree_object *tree;
910 	char *p = NULL;
911 	int i;
912 
913 	err = got_object_open_as_tree(&tree, repo, tree_id);
914 	if (err)
915 		return err;
916 
917 	(*ntrees)++;
918 	err = report_progress(progress_cb, progress_arg, rl,
919 	    *ncolored, *nfound, *ntrees, 0L, 0, 0, 0, 0);
920 	if (err)
921 		return err;
922 
923 	for (i = 0; i < got_object_tree_get_nentries(tree); i++) {
924 		struct got_tree_entry *e = got_object_tree_get_entry(tree, i);
925 		struct got_object_id *id = got_tree_entry_get_id(e);
926 		mode_t mode = got_tree_entry_get_mode(e);
927 
928 		if (cancel_cb) {
929 			err = (*cancel_cb)(cancel_arg);
930 			if (err)
931 				break;
932 		}
933 
934 		if (got_object_tree_entry_is_submodule(e) ||
935 		    got_object_idset_contains(idset, id) ||
936 		    got_object_idset_contains(idset_exclude, id))
937 			continue;
938 		
939 		if (asprintf(&p, "%s%s%s", dpath, dpath[0] != '\0' ? "/" : "",
940 		    got_tree_entry_get_name(e)) == -1) {
941 			err = got_error_from_errno("asprintf");
942 			break;
943 		}
944 
945 		if (S_ISDIR(mode)) {
946 			struct got_object_qid *qid;
947 			err = got_object_qid_alloc(&qid, id);
948 			if (err)
949 				break;
950 			qid->data = p;
951 			p = NULL;
952 			STAILQ_INSERT_TAIL(ids, qid, entry);
953 		} else if (S_ISREG(mode) || S_ISLNK(mode)) {
954 			err = add_object(want_meta,
955 			    want_meta ? idset : idset_exclude, id, p,
956 			    GOT_OBJ_TYPE_BLOB, mtime, loose_obj_only, repo,
957 			    ncolored, nfound, ntrees,
958 			    progress_cb, progress_arg, rl);
959 			if (err)
960 				break;
961 			free(p);
962 			p = NULL;
963 		} else {
964 			free(p);
965 			p = NULL;
966 		}
967 	}
968 
969 	got_object_tree_close(tree);
970 	free(p);
971 	return err;
972 }
973 
974 static const struct got_error *
975 load_tree(int want_meta, struct got_object_idset *idset,
976     struct got_object_idset *idset_exclude,
977     struct got_object_id *tree_id, const char *dpath, time_t mtime,
978     struct got_repository *repo, int loose_obj_only,
979     int *ncolored, int *nfound, int *ntrees,
980     got_pack_progress_cb progress_cb, void *progress_arg,
981     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
982 {
983 	const struct got_error *err = NULL;
984 	struct got_object_id_queue tree_ids;
985 	struct got_object_qid *qid;
986 
987 	if (got_object_idset_contains(idset, tree_id) ||
988 	    got_object_idset_contains(idset_exclude, tree_id))
989 		return NULL;
990 
991 	err = got_object_qid_alloc(&qid, tree_id);
992 	if (err)
993 		return err;
994 	qid->data = strdup(dpath);
995 	if (qid->data == NULL) {
996 		err = got_error_from_errno("strdup");
997 		got_object_qid_free(qid);
998 		return err;
999 	}
1000 
1001 	STAILQ_INIT(&tree_ids);
1002 	STAILQ_INSERT_TAIL(&tree_ids, qid, entry);
1003 
1004 	while (!STAILQ_EMPTY(&tree_ids)) {
1005 		const char *path;
1006 		if (cancel_cb) {
1007 			err = (*cancel_cb)(cancel_arg);
1008 			if (err)
1009 				break;
1010 		}
1011 
1012 		qid = STAILQ_FIRST(&tree_ids);
1013 		STAILQ_REMOVE_HEAD(&tree_ids, entry);
1014 		path = qid->data;
1015 
1016 		if (got_object_idset_contains(idset, &qid->id) ||
1017 		    got_object_idset_contains(idset_exclude, &qid->id)) {
1018 			free(qid->data);
1019 			got_object_qid_free(qid);
1020 			continue;
1021 		}
1022 
1023 		err = add_object(want_meta, want_meta ? idset : idset_exclude,
1024 		    &qid->id, path, GOT_OBJ_TYPE_TREE,
1025 		    mtime, loose_obj_only, repo,
1026 		    ncolored, nfound, ntrees, progress_cb, progress_arg, rl);
1027 		if (err) {
1028 			free(qid->data);
1029 			got_object_qid_free(qid);
1030 			break;
1031 		}
1032 
1033 		err = load_tree_entries(&tree_ids, want_meta, idset,
1034 		    idset_exclude, &qid->id,
1035 		    path, mtime, repo, loose_obj_only, ncolored, nfound,
1036 		    ntrees, progress_cb, progress_arg, rl,
1037 		    cancel_cb, cancel_arg);
1038 		free(qid->data);
1039 		got_object_qid_free(qid);
1040 		if (err)
1041 			break;
1042 	}
1043 
1044 	STAILQ_FOREACH(qid, &tree_ids, entry)
1045 		free(qid->data);
1046 	got_object_id_queue_free(&tree_ids);
1047 	return err;
1048 }
1049 
1050 static const struct got_error *
1051 load_commit(int want_meta, struct got_object_idset *idset,
1052     struct got_object_idset *idset_exclude,
1053     struct got_object_id *id, struct got_repository *repo, int loose_obj_only,
1054     int *ncolored, int *nfound, int *ntrees,
1055     got_pack_progress_cb progress_cb, void *progress_arg,
1056     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1057 {
1058 	const struct got_error *err;
1059 	struct got_commit_object *commit;
1060 
1061 	if (got_object_idset_contains(idset, id) ||
1062 	    got_object_idset_contains(idset_exclude, id))
1063 		return NULL;
1064 
1065 	if (loose_obj_only) {
1066 		int is_packed;
1067 		err = search_packidx(&is_packed, id, repo);
1068 		if (err)
1069 			return err;
1070 		if (is_packed && want_meta)
1071 			return NULL;
1072 	}
1073 
1074 	err = got_object_open_as_commit(&commit, repo, id);
1075 	if (err)
1076 		return err;
1077 
1078 	err = add_object(want_meta, want_meta ? idset : idset_exclude,
1079 	    id, "", GOT_OBJ_TYPE_COMMIT,
1080 	    got_object_commit_get_committer_time(commit),
1081 	    loose_obj_only, repo,
1082 	    ncolored, nfound, ntrees, progress_cb, progress_arg, rl);
1083 	if (err)
1084 		goto done;
1085 
1086 	err = load_tree(want_meta, idset, idset_exclude,
1087 	    got_object_commit_get_tree_id(commit),
1088 	    "", got_object_commit_get_committer_time(commit),
1089 	    repo, loose_obj_only, ncolored, nfound, ntrees,
1090 	    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1091 done:
1092 	got_object_commit_close(commit);
1093 	return err;
1094 }
1095 
1096 static const struct got_error *
1097 load_tag(int want_meta, struct got_object_idset *idset,
1098     struct got_object_idset *idset_exclude,
1099     struct got_object_id *id, struct got_repository *repo, int loose_obj_only,
1100     int *ncolored, int *nfound, int *ntrees,
1101     got_pack_progress_cb progress_cb, void *progress_arg,
1102     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1103 {
1104 	const struct got_error *err;
1105 	struct got_tag_object *tag = NULL;
1106 
1107 	if (got_object_idset_contains(idset, id) ||
1108 	    got_object_idset_contains(idset_exclude, id))
1109 		return NULL;
1110 
1111 	if (loose_obj_only) {
1112 		int is_packed;
1113 		err = search_packidx(&is_packed, id, repo);
1114 		if (err)
1115 			return err;
1116 		if (is_packed && want_meta)
1117 			return NULL;
1118 	}
1119 
1120 	err = got_object_open_as_tag(&tag, repo, id);
1121 	if (err)
1122 		return err;
1123 
1124 	err = add_object(want_meta, want_meta ? idset : idset_exclude,
1125 	    id, "", GOT_OBJ_TYPE_TAG,
1126 	    got_object_tag_get_tagger_time(tag), loose_obj_only, repo,
1127 	    ncolored, nfound, ntrees, progress_cb, progress_arg, rl);
1128 	if (err)
1129 		goto done;
1130 
1131 	switch (got_object_tag_get_object_type(tag)) {
1132 	case GOT_OBJ_TYPE_COMMIT:
1133 		err = load_commit(want_meta, idset, idset_exclude,
1134 		    got_object_tag_get_object_id(tag), repo, loose_obj_only,
1135 		    ncolored, nfound, ntrees, progress_cb, progress_arg, rl,
1136 		    cancel_cb, cancel_arg);
1137 		break;
1138 	case GOT_OBJ_TYPE_TREE:
1139 		err = load_tree(want_meta, idset, idset_exclude,
1140 		    got_object_tag_get_object_id(tag), "",
1141 		    got_object_tag_get_tagger_time(tag), repo, loose_obj_only,
1142 		    ncolored, nfound, ntrees, progress_cb, progress_arg, rl,
1143 		    cancel_cb, cancel_arg);
1144 		break;
1145 	default:
1146 		break;
1147 	}
1148 
1149 done:
1150 	got_object_tag_close(tag);
1151 	return err;
1152 }
1153 
1154 enum findtwixt_color {
1155 	COLOR_KEEP = 0,
1156 	COLOR_DROP,
1157 	COLOR_BLANK,
1158 	COLOR_SKIP,
1159 };
1160 
1161 static const int findtwixt_colors[] = {
1162 	COLOR_KEEP,
1163 	COLOR_DROP,
1164 	COLOR_BLANK,
1165 	COLOR_SKIP,
1166 };
1167 
1168 static const struct got_error *
1169 paint_commit(struct got_object_qid *qid, int color)
1170 {
1171 	if (color < 0 || color >= nitems(findtwixt_colors))
1172 		return got_error(GOT_ERR_RANGE);
1173 
1174 	qid->data = (void *)&findtwixt_colors[color];
1175 	return NULL;
1176 }
1177 
1178 static const struct got_error *
1179 queue_commit_id(struct got_object_id_queue *ids, struct got_object_id *id,
1180     int color, struct got_repository *repo)
1181 {
1182 	const struct got_error *err;
1183 	struct got_object_qid *qid;
1184 
1185 	err = got_object_qid_alloc(&qid, id);
1186 	if (err)
1187 		return err;
1188 
1189 	STAILQ_INSERT_TAIL(ids, qid, entry);
1190 	return paint_commit(qid, color);
1191 }
1192 
1193 struct append_id_arg {
1194 	struct got_object_id **array;
1195 	int idx;
1196 	struct got_object_idset *drop;
1197 	struct got_object_idset *skip;
1198 };
1199 
1200 static const struct got_error *
1201 append_id(struct got_object_id *id, void *data, void *arg)
1202 {
1203 	struct append_id_arg *a = arg;
1204 
1205 	if (got_object_idset_contains(a->skip, id) ||
1206 	    got_object_idset_contains(a->drop, id))
1207 		return NULL;
1208 
1209 	a->array[++a->idx] = got_object_id_dup(id);
1210 	if (a->array[a->idx] == NULL)
1211 		return got_error_from_errno("got_object_id_dup");
1212 
1213 	return NULL;
1214 }
1215 
1216 static const struct got_error *
1217 queue_commit_or_tag_id(struct got_object_id *id, int color,
1218     struct got_object_id_queue *ids, struct got_repository *repo)
1219 {
1220 	const struct got_error *err;
1221 	struct got_tag_object *tag = NULL;
1222 	int obj_type;
1223 
1224 	err = got_object_get_type(&obj_type, repo, id);
1225 	if (err)
1226 		return err;
1227 
1228 	if (obj_type == GOT_OBJ_TYPE_TAG) {
1229 		err = got_object_open_as_tag(&tag, repo, id);
1230 		if (err)
1231 			return err;
1232 		obj_type = got_object_tag_get_object_type(tag);
1233 		id = got_object_tag_get_object_id(tag);
1234 	}
1235 
1236 	if (obj_type == GOT_OBJ_TYPE_COMMIT) {
1237 		err = queue_commit_id(ids, id, color, repo);
1238 		if (err)
1239 			goto done;
1240 	}
1241 done:
1242 	if (tag)
1243 		got_object_tag_close(tag);
1244 	return err;
1245 }
1246 
1247 static const struct got_error *
1248 paint_commits(int *ncolored, struct got_object_id_queue *ids, int nids,
1249     struct got_object_idset *keep, struct got_object_idset *drop,
1250     struct got_object_idset *skip, struct got_repository *repo,
1251     got_pack_progress_cb progress_cb, void *progress_arg,
1252     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1253 {
1254 	const struct got_error *err = NULL;
1255 	struct got_commit_object *commit = NULL;
1256 	const struct got_object_id_queue *parents;
1257 	struct got_object_qid *qid;
1258 	int nqueued = nids, nskip = 0;
1259 
1260 	while (!STAILQ_EMPTY(ids) && nskip != nqueued) {
1261 		int color;
1262 
1263 		if (cancel_cb) {
1264 			err = cancel_cb(cancel_arg);
1265 			if (err)
1266 				break;
1267 		}
1268 
1269 		qid = STAILQ_FIRST(ids);
1270 		STAILQ_REMOVE_HEAD(ids, entry);
1271 		nqueued--;
1272 		color = *((int *)qid->data);
1273 		if (color == COLOR_SKIP)
1274 			nskip--;
1275 
1276 		if (got_object_idset_contains(skip, &qid->id)) {
1277 			got_object_qid_free(qid);
1278 			continue;
1279 		}
1280 
1281 		switch (color) {
1282 		case COLOR_KEEP:
1283 			if (got_object_idset_contains(keep, &qid->id)) {
1284 				got_object_qid_free(qid);
1285 				continue;
1286 			}
1287 			if (got_object_idset_contains(drop, &qid->id)) {
1288 				err = paint_commit(qid, COLOR_SKIP);
1289 				if (err)
1290 					goto done;
1291 				nskip++;
1292 			} else
1293 				(*ncolored)++;
1294 			err = got_object_idset_add(keep, &qid->id, NULL);
1295 			if (err)
1296 				goto done;
1297 			break;
1298 		case COLOR_DROP:
1299 			if (got_object_idset_contains(drop, &qid->id)) {
1300 				got_object_qid_free(qid);
1301 				continue;
1302 			}
1303 			if (got_object_idset_contains(keep, &qid->id)) {
1304 				err = paint_commit(qid, COLOR_SKIP);
1305 				if (err)
1306 					goto done;
1307 				nskip++;
1308 			} else
1309 				(*ncolored)++;
1310 			err = got_object_idset_add(drop, &qid->id, NULL);
1311 			if (err)
1312 				goto done;
1313 			break;
1314 		case COLOR_SKIP:
1315 			if (!got_object_idset_contains(skip, &qid->id)) {
1316 				err = got_object_idset_add(skip, &qid->id,
1317 				    NULL);
1318 				if (err)
1319 					goto done;
1320 			}
1321 			break;
1322 		default:
1323 			/* should not happen */
1324 			err = got_error_fmt(GOT_ERR_NOT_IMPL,
1325 			    "%s invalid commit color %d", __func__, color);
1326 			goto done;
1327 		}
1328 
1329 		err = report_progress(progress_cb, progress_arg, rl,
1330 		    *ncolored, 0, 0, 0L, 0, 0, 0, 0);
1331 		if (err)
1332 			break;
1333 
1334 
1335 		err = got_object_open_as_commit(&commit, repo, &qid->id);
1336 		if (err)
1337 			break;
1338 
1339 		parents = got_object_commit_get_parent_ids(commit);
1340 		if (parents) {
1341 			struct got_object_qid *pid;
1342 			color = *((int *)qid->data);
1343 			STAILQ_FOREACH(pid, parents, entry) {
1344 				err = queue_commit_id(ids, &pid->id, color,
1345 				    repo);
1346 				if (err)
1347 					break;
1348 				nqueued++;
1349 				if (color == COLOR_SKIP)
1350 					nskip++;
1351 			}
1352 		}
1353 
1354 		got_object_commit_close(commit);
1355 		commit = NULL;
1356 		got_object_qid_free(qid);
1357 	}
1358 done:
1359 	if (commit)
1360 		got_object_commit_close(commit);
1361 	return err;
1362 }
1363 
1364 static const struct got_error *
1365 findtwixt(struct got_object_id ***res, int *nres, int *ncolored,
1366     struct got_object_id **head, int nhead,
1367     struct got_object_id **tail, int ntail,
1368     struct got_repository *repo,
1369     got_pack_progress_cb progress_cb, void *progress_arg,
1370     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1371 {
1372 	const struct got_error *err = NULL;
1373 	struct got_object_id_queue ids;
1374 	struct got_object_idset *keep, *drop, *skip = NULL;
1375 	int i, nkeep;
1376 
1377 	STAILQ_INIT(&ids);
1378 	*res = NULL;
1379 	*nres = 0;
1380 	*ncolored = 0;
1381 
1382 	keep = got_object_idset_alloc();
1383 	if (keep == NULL)
1384 		return got_error_from_errno("got_object_idset_alloc");
1385 
1386 	drop = got_object_idset_alloc();
1387 	if (drop == NULL) {
1388 		err = got_error_from_errno("got_object_idset_alloc");
1389 		goto done;
1390 	}
1391 
1392 	skip = got_object_idset_alloc();
1393 	if (skip == NULL) {
1394 		err = got_error_from_errno("got_object_idset_alloc");
1395 		goto done;
1396 	}
1397 
1398 	for (i = 0; i < nhead; i++) {
1399 		struct got_object_id *id = head[i];
1400 		if (id == NULL)
1401 			continue;
1402 		err = queue_commit_or_tag_id(id, COLOR_KEEP, &ids, repo);
1403 		if (err)
1404 			goto done;
1405 	}		
1406 
1407 	for (i = 0; i < ntail; i++) {
1408 		struct got_object_id *id = tail[i];
1409 		if (id == NULL)
1410 			continue;
1411 		err = queue_commit_or_tag_id(id, COLOR_DROP, &ids, repo);
1412 		if (err)
1413 			goto done;
1414 	}
1415 
1416 	err = paint_commits(ncolored, &ids, nhead + ntail,
1417 	    keep, drop, skip, repo, progress_cb, progress_arg, rl,
1418 	    cancel_cb, cancel_arg);
1419 	if (err)
1420 		goto done;
1421 
1422 	nkeep = got_object_idset_num_elements(keep);
1423 	if (nkeep > 0) {
1424 		struct append_id_arg arg;
1425 		arg.array = calloc(nkeep, sizeof(struct got_object_id *));
1426 		if (arg.array == NULL) {
1427 			err = got_error_from_errno("calloc");
1428 			goto done;
1429 		}
1430 		arg.idx = -1;
1431 		arg.skip = skip;
1432 		arg.drop = drop;
1433 		err = got_object_idset_for_each(keep, append_id, &arg);
1434 		if (err) {
1435 			free(arg.array);
1436 			goto done;
1437 		}
1438 		*res = arg.array;
1439 		*nres = arg.idx + 1;
1440 	}
1441 done:
1442 	got_object_idset_free(keep);
1443 	got_object_idset_free(drop);
1444 	if (skip)
1445 		got_object_idset_free(skip);
1446 	got_object_id_queue_free(&ids);
1447 	return err;
1448 }
1449 
1450 static const struct got_error *
1451 load_object_ids(int *ncolored, int *nfound, int *ntrees,
1452     struct got_object_idset *idset, struct got_object_id **theirs, int ntheirs,
1453     struct got_object_id **ours, int nours, struct got_repository *repo,
1454     int loose_obj_only, got_pack_progress_cb progress_cb, void *progress_arg,
1455     struct got_ratelimit *rl, got_cancel_cb cancel_cb, void *cancel_arg)
1456 {
1457 	const struct got_error *err = NULL;
1458 	struct got_object_id **ids = NULL;
1459 	int i, nobj = 0, obj_type;
1460 	struct got_object_idset *idset_exclude;
1461 
1462 	idset_exclude = got_object_idset_alloc();
1463 	if (idset_exclude == NULL)
1464 		return got_error_from_errno("got_object_idset_alloc");
1465 
1466 	*ncolored = 0;
1467 	*nfound = 0;
1468 	*ntrees = 0;
1469 
1470 	err = findtwixt(&ids, &nobj, ncolored, ours, nours, theirs, ntheirs,
1471 	    repo, progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1472 	if (err)
1473 		goto done;
1474 
1475 	for (i = 0; i < ntheirs; i++) {
1476 		struct got_object_id *id = theirs[i];
1477 		if (id == NULL)
1478 			continue;
1479 		err = got_object_get_type(&obj_type, repo, id);
1480 		if (err)
1481 			return err;
1482 		if (obj_type == GOT_OBJ_TYPE_COMMIT) {
1483 			err = load_commit(0, idset, idset_exclude, id, repo,
1484 			    loose_obj_only, ncolored, nfound, ntrees,
1485 			    progress_cb, progress_arg, rl,
1486 			    cancel_cb, cancel_arg);
1487 			if (err)
1488 				goto done;
1489 		} else if (obj_type == GOT_OBJ_TYPE_TAG) {
1490 			err = load_tag(0, idset, idset_exclude, id, repo,
1491 			    loose_obj_only, ncolored, nfound, ntrees,
1492 			    progress_cb, progress_arg, rl,
1493 			    cancel_cb, cancel_arg);
1494 			if (err)
1495 				goto done;
1496 		}
1497 	}
1498 
1499 	for (i = 0; i < nobj; i++) {
1500 		err = load_commit(1, idset, idset_exclude,
1501 		    ids[i], repo, loose_obj_only, ncolored, nfound, ntrees,
1502 		    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1503 		if (err)
1504 			goto done;
1505 	}
1506 
1507 	for (i = 0; i < nours; i++) {
1508 		struct got_object_id *id = ours[i];
1509 		struct got_pack_meta *m;
1510 		if (id == NULL)
1511 			continue;
1512 		m = got_object_idset_get(idset, id);
1513 		if (m == NULL) {
1514 			err = got_object_get_type(&obj_type, repo, id);
1515 			if (err)
1516 				goto done;
1517 		} else
1518 			obj_type = m->obj_type;
1519 		if (obj_type != GOT_OBJ_TYPE_TAG)
1520 			continue;
1521 		err = load_tag(1, idset, idset_exclude, id, repo,
1522 		    loose_obj_only, ncolored, nfound, ntrees,
1523 		    progress_cb, progress_arg, rl, cancel_cb, cancel_arg);
1524 		if (err)
1525 			goto done;
1526 	}
1527 done:
1528 	for (i = 0; i < nobj; i++) {
1529 		free(ids[i]);
1530 	}
1531 	free(ids);
1532 	got_object_idset_free(idset_exclude);
1533 	return err;
1534 }
1535 
1536 const struct got_error *
1537 hwrite(FILE *f, void *buf, off_t len, SHA1_CTX *ctx)
1538 {
1539 	size_t n;
1540 
1541 	SHA1Update(ctx, buf, len);
1542 	n = fwrite(buf, 1, len, f);
1543 	if (n != len)
1544 		return got_ferror(f, GOT_ERR_IO);
1545 	return NULL;
1546 }
1547 
1548 const struct got_error *
1549 hcopy(FILE *fsrc, FILE *fdst, off_t len, SHA1_CTX *ctx)
1550 {
1551 	unsigned char buf[65536];
1552 	off_t remain = len;
1553 	size_t n;
1554 
1555 	while (remain > 0) {
1556 		size_t copylen = MIN(sizeof(buf), remain);
1557 		n = fread(buf, 1, copylen, fsrc);
1558 		if (n != copylen)
1559 			return got_ferror(fsrc, GOT_ERR_IO);
1560 		SHA1Update(ctx, buf, copylen);
1561 		n = fwrite(buf, 1, copylen, fdst);
1562 		if (n != copylen)
1563 			return got_ferror(fdst, GOT_ERR_IO);
1564 		remain -= copylen;
1565 	}
1566 
1567 	return NULL;
1568 }
1569 
1570 const struct got_error *
1571 hcopy_mmap(uint8_t *src, off_t src_offset, size_t src_size,
1572     FILE *fdst, off_t len, SHA1_CTX *ctx)
1573 {
1574 	size_t n;
1575 
1576 	if (src_offset + len > src_size)
1577 		return got_error(GOT_ERR_RANGE);
1578 
1579 	SHA1Update(ctx, src + src_offset, len);
1580 	n = fwrite(src + src_offset, 1, len, fdst);
1581 	if (n != len)
1582 		return got_ferror(fdst, GOT_ERR_IO);
1583 
1584 	return NULL;
1585 }
1586 
1587 static void
1588 putbe32(char *b, uint32_t n)
1589 {
1590 	b[0] = n >> 24;
1591 	b[1] = n >> 16;
1592 	b[2] = n >> 8;
1593 	b[3] = n >> 0;
1594 }
1595 
1596 static int
1597 write_order_cmp(const void *pa, const void *pb)
1598 {
1599 	struct got_pack_meta *a, *b, *ahd, *bhd;
1600 
1601 	a = *(struct got_pack_meta **)pa;
1602 	b = *(struct got_pack_meta **)pb;
1603 	ahd = (a->head == NULL) ? a : a->head;
1604 	bhd = (b->head == NULL) ? b : b->head;
1605 	if (bhd->mtime < ahd->mtime)
1606 		return -1;
1607 	if (bhd->mtime > ahd->mtime)
1608 		return 1;
1609 	if (bhd < ahd)
1610 		return -1;
1611 	if (bhd > ahd)
1612 		return 1;
1613 	if (a->nchain != b->nchain)
1614 		return a->nchain - b->nchain;
1615 	if (a->mtime < b->mtime)
1616 		return -1;
1617 	if (a->mtime > b->mtime)
1618 		return 1;
1619 	return got_object_id_cmp(&a->id, &b->id);
1620 }
1621 
1622 static int
1623 reuse_write_order_cmp(const void *pa, const void *pb)
1624 {
1625 	struct got_pack_meta *a, *b;
1626 
1627 	a = *(struct got_pack_meta **)pa;
1628 	b = *(struct got_pack_meta **)pb;
1629 
1630 	if (a->reused_delta_offset < b->reused_delta_offset)
1631 		return -1;
1632 	if (a->reused_delta_offset > b->reused_delta_offset)
1633 		return 1;
1634 	return 0;
1635 }
1636 
1637 static const struct got_error *
1638 packhdr(int *hdrlen, char *hdr, size_t bufsize, int obj_type, size_t len)
1639 {
1640 	size_t i;
1641 
1642 	*hdrlen = 0;
1643 
1644 	hdr[0] = obj_type << 4;
1645 	hdr[0] |= len & 0xf;
1646 	len >>= 4;
1647 	for (i = 1; len != 0; i++){
1648 		if (i >= bufsize)
1649 			return got_error(GOT_ERR_NO_SPACE);
1650 		hdr[i - 1] |= GOT_DELTA_SIZE_MORE;
1651 		hdr[i] = len & GOT_DELTA_SIZE_VAL_MASK;
1652 		len >>= GOT_DELTA_SIZE_SHIFT;
1653 	}
1654 
1655 	*hdrlen = i;
1656 	return NULL;
1657 }
1658 
1659 static int
1660 packoff(char *hdr, off_t off)
1661 {
1662 	int i, j;
1663 	char rbuf[8];
1664 
1665 	rbuf[0] = off & GOT_DELTA_SIZE_VAL_MASK;
1666 	for (i = 1; (off >>= GOT_DELTA_SIZE_SHIFT) != 0; i++) {
1667 		rbuf[i] = (--off & GOT_DELTA_SIZE_VAL_MASK) |
1668 		    GOT_DELTA_SIZE_MORE;
1669 	}
1670 
1671 	j = 0;
1672 	while (i > 0)
1673 		hdr[j++] = rbuf[--i];
1674 	return j;
1675 }
1676 
1677 static const struct got_error *
1678 deltahdr(off_t *packfile_size, SHA1_CTX *ctx, FILE *packfile,
1679     struct got_pack_meta *m)
1680 {
1681 	const struct got_error *err;
1682 	char buf[32];
1683 	int nh;
1684 
1685 	if (m->prev->off != 0) {
1686 		err = packhdr(&nh, buf, sizeof(buf),
1687 		    GOT_OBJ_TYPE_OFFSET_DELTA, m->delta_len);
1688 		if (err)
1689 			return err;
1690 		nh += packoff(buf + nh, m->off - m->prev->off);
1691 		err = hwrite(packfile, buf, nh, ctx);
1692 		if (err)
1693 			return err;
1694 		*packfile_size += nh;
1695 	} else {
1696 		err = packhdr(&nh, buf, sizeof(buf),
1697 		    GOT_OBJ_TYPE_REF_DELTA, m->delta_len);
1698 		if (err)
1699 			return err;
1700 		err = hwrite(packfile, buf, nh, ctx);
1701 		if (err)
1702 			return err;
1703 		*packfile_size += nh;
1704 		err = hwrite(packfile, m->prev->id.sha1,
1705 		    sizeof(m->prev->id.sha1), ctx);
1706 		if (err)
1707 			return err;
1708 		*packfile_size += sizeof(m->prev->id.sha1);
1709 	}
1710 
1711 	return NULL;
1712 }
1713 
1714 static const struct got_error *
1715 write_packed_object(off_t *packfile_size, FILE *packfile,
1716     FILE *delta_cache, uint8_t *delta_cache_map, size_t delta_cache_size,
1717     struct got_pack_meta *m, int *outfd, SHA1_CTX *ctx,
1718     struct got_repository *repo)
1719 {
1720 	const struct got_error *err = NULL;
1721 	struct got_deflate_checksum csum;
1722 	char buf[32];
1723 	int nh;
1724 	struct got_raw_object *raw = NULL;
1725 	off_t outlen;
1726 
1727 	csum.output_sha1 = ctx;
1728 	csum.output_crc = NULL;
1729 
1730 	m->off = ftello(packfile);
1731 	if (m->delta_len == 0) {
1732 		err = got_object_raw_open(&raw, outfd, repo, &m->id);
1733 		if (err)
1734 			goto done;
1735 		err = packhdr(&nh, buf, sizeof(buf),
1736 		    m->obj_type, raw->size);
1737 		if (err)
1738 			goto done;
1739 		err = hwrite(packfile, buf, nh, ctx);
1740 		if (err)
1741 			goto done;
1742 		*packfile_size += nh;
1743 		if (raw->f == NULL) {
1744 			err = got_deflate_to_file_mmap(&outlen,
1745 			    raw->data + raw->hdrlen, 0, raw->size,
1746 			    packfile, &csum);
1747 			if (err)
1748 				goto done;
1749 		} else {
1750 			if (fseeko(raw->f, raw->hdrlen, SEEK_SET)
1751 			    == -1) {
1752 				err = got_error_from_errno("fseeko");
1753 				goto done;
1754 			}
1755 			err = got_deflate_to_file(&outlen, raw->f,
1756 			    raw->size, packfile, &csum);
1757 			if (err)
1758 				goto done;
1759 		}
1760 		*packfile_size += outlen;
1761 		got_object_raw_close(raw);
1762 		raw = NULL;
1763 	} else if (m->delta_buf) {
1764 		err = deltahdr(packfile_size, ctx, packfile, m);
1765 		if (err)
1766 			goto done;
1767 		err = hwrite(packfile, m->delta_buf,
1768 		    m->delta_compressed_len, ctx);
1769 		if (err)
1770 			goto done;
1771 		*packfile_size += m->delta_compressed_len;
1772 		free(m->delta_buf);
1773 		m->delta_buf = NULL;
1774 	} else if (delta_cache_map) {
1775 		err = deltahdr(packfile_size, ctx, packfile, m);
1776 		if (err)
1777 			goto done;
1778 		err = hcopy_mmap(delta_cache_map, m->delta_offset,
1779 		    delta_cache_size, packfile, m->delta_compressed_len,
1780 		    ctx);
1781 		if (err)
1782 			goto done;
1783 		*packfile_size += m->delta_compressed_len;
1784 	} else {
1785 		if (fseeko(delta_cache, m->delta_offset, SEEK_SET)
1786 		    == -1) {
1787 			err = got_error_from_errno("fseeko");
1788 			goto done;
1789 		}
1790 		err = deltahdr(packfile_size, ctx, packfile, m);
1791 		if (err)
1792 			goto done;
1793 		err = hcopy(delta_cache, packfile,
1794 		    m->delta_compressed_len, ctx);
1795 		if (err)
1796 			goto done;
1797 		*packfile_size += m->delta_compressed_len;
1798 	}
1799 done:
1800 	if (raw)
1801 		got_object_raw_close(raw);
1802 	return err;
1803 }
1804 
1805 static const struct got_error *
1806 genpack(uint8_t *pack_sha1, FILE *packfile, FILE *delta_cache,
1807     struct got_pack_meta **deltify, int ndeltify,
1808     struct got_pack_meta **reuse, int nreuse,
1809     int ncolored, int nfound, int ntrees, int nours,
1810     struct got_repository *repo,
1811     got_pack_progress_cb progress_cb, void *progress_arg,
1812     struct got_ratelimit *rl,
1813     got_cancel_cb cancel_cb, void *cancel_arg)
1814 {
1815 	const struct got_error *err = NULL;
1816 	int i;
1817 	SHA1_CTX ctx;
1818 	struct got_pack_meta *m;
1819 	char buf[32];
1820 	size_t n;
1821 	off_t packfile_size = 0;
1822 	int outfd = -1;
1823 	int delta_cache_fd = -1;
1824 	uint8_t *delta_cache_map = NULL;
1825 	size_t delta_cache_size = 0;
1826 
1827 	SHA1Init(&ctx);
1828 
1829 #ifndef GOT_PACK_NO_MMAP
1830 	delta_cache_fd = dup(fileno(delta_cache));
1831 	if (delta_cache_fd != -1) {
1832 		struct stat sb;
1833 		if (fstat(delta_cache_fd, &sb) == -1) {
1834 			err = got_error_from_errno("fstat");
1835 			goto done;
1836 		}
1837 		if (sb.st_size > 0 && sb.st_size <= SIZE_MAX) {
1838 			delta_cache_map = mmap(NULL, sb.st_size,
1839 			    PROT_READ, MAP_PRIVATE, delta_cache_fd, 0);
1840 			if (delta_cache_map == MAP_FAILED) {
1841 				if (errno != ENOMEM) {
1842 					err = got_error_from_errno("mmap");
1843 					goto done;
1844 				}
1845 				delta_cache_map = NULL; /* fallback on stdio */
1846 			} else
1847 				delta_cache_size = (size_t)sb.st_size;
1848 		}
1849 	}
1850 #endif
1851 	err = hwrite(packfile, "PACK", 4, &ctx);
1852 	if (err)
1853 		goto done;
1854 	putbe32(buf, GOT_PACKFILE_VERSION);
1855 	err = hwrite(packfile, buf, 4, &ctx);
1856 	if (err)
1857 		goto done;
1858 	putbe32(buf, ndeltify + nreuse);
1859 	err = hwrite(packfile, buf, 4, &ctx);
1860 	if (err)
1861 		goto done;
1862 
1863 	qsort(deltify, ndeltify, sizeof(struct got_pack_meta *),
1864 	    write_order_cmp);
1865 	for (i = 0; i < ndeltify; i++) {
1866 		err = report_progress(progress_cb, progress_arg, rl,
1867 		    ncolored, nfound, ntrees, packfile_size, nours,
1868 		    ndeltify + nreuse, ndeltify + nreuse, i);
1869 		if (err)
1870 			goto done;
1871 		m = deltify[i];
1872 		err = write_packed_object(&packfile_size, packfile,
1873 		    delta_cache, delta_cache_map, delta_cache_size,
1874 		    m, &outfd, &ctx, repo);
1875 		if (err)
1876 			goto done;
1877 	}
1878 
1879 	qsort(reuse, nreuse, sizeof(struct got_pack_meta *),
1880 	    reuse_write_order_cmp);
1881 	for (i = 0; i < nreuse; i++) {
1882 		err = report_progress(progress_cb, progress_arg, rl,
1883 		    ncolored, nfound, ntrees, packfile_size, nours,
1884 		    ndeltify + nreuse, ndeltify + nreuse, ndeltify + i);
1885 		if (err)
1886 			goto done;
1887 		m = reuse[i];
1888 		err = write_packed_object(&packfile_size, packfile,
1889 		    delta_cache, delta_cache_map, delta_cache_size,
1890 		    m, &outfd, &ctx, repo);
1891 		if (err)
1892 			goto done;
1893 	}
1894 
1895 	SHA1Final(pack_sha1, &ctx);
1896 	n = fwrite(pack_sha1, 1, SHA1_DIGEST_LENGTH, packfile);
1897 	if (n != SHA1_DIGEST_LENGTH)
1898 		err = got_ferror(packfile, GOT_ERR_IO);
1899 	packfile_size += SHA1_DIGEST_LENGTH;
1900 	packfile_size += sizeof(struct got_packfile_hdr);
1901 	if (progress_cb) {
1902 		err = progress_cb(progress_arg, ncolored, nfound, ntrees,
1903 		    packfile_size, nours, ndeltify + nreuse,
1904 		    ndeltify + nreuse, ndeltify + nreuse);
1905 		if (err)
1906 			goto done;
1907 	}
1908 done:
1909 	if (outfd != -1 && close(outfd) == -1 && err == NULL)
1910 		err = got_error_from_errno("close");
1911 	if (delta_cache_map && munmap(delta_cache_map, delta_cache_size) == -1)
1912 		err = got_error_from_errno("munmap");
1913 	if (delta_cache_fd != -1 && close(delta_cache_fd) == -1 && err == NULL)
1914 		err = got_error_from_errno("close");
1915 	return err;
1916 }
1917 
1918 static const struct got_error *
1919 add_meta_idset_cb(struct got_object_id *id, void *data, void *arg)
1920 {
1921 	struct got_pack_meta *m = data;
1922 	struct got_pack_metavec *v = arg;
1923 
1924 	if (m->reused_delta_offset != 0)
1925 		return NULL;
1926 
1927 	return add_meta(m, v);
1928 }
1929 
1930 const struct got_error *
1931 got_pack_create(uint8_t *packsha1, FILE *packfile,
1932     struct got_object_id **theirs, int ntheirs,
1933     struct got_object_id **ours, int nours,
1934     struct got_repository *repo, int loose_obj_only, int allow_empty,
1935     got_pack_progress_cb progress_cb, void *progress_arg,
1936     got_cancel_cb cancel_cb, void *cancel_arg)
1937 {
1938 	const struct got_error *err;
1939 	int delta_cache_fd = -1;
1940 	FILE *delta_cache = NULL;
1941 	struct got_object_idset *idset;
1942 	struct got_ratelimit rl;
1943 	struct got_pack_metavec deltify, reuse;
1944 	int ncolored = 0, nfound = 0, ntrees = 0;
1945 	size_t ndeltify;
1946 
1947 	memset(&deltify, 0, sizeof(deltify));
1948 	memset(&reuse, 0, sizeof(reuse));
1949 
1950 	got_ratelimit_init(&rl, 0, 500);
1951 
1952 	idset = got_object_idset_alloc();
1953 	if (idset == NULL)
1954 		return got_error_from_errno("got_object_idset_alloc");
1955 
1956 	err = load_object_ids(&ncolored, &nfound, &ntrees, idset, theirs,
1957 	    ntheirs, ours, nours, repo, loose_obj_only,
1958 	    progress_cb, progress_arg, &rl, cancel_cb, cancel_arg);
1959 	if (err)
1960 		goto done;
1961 
1962 	if (progress_cb) {
1963 		err = progress_cb(progress_arg, ncolored, nfound, ntrees,
1964 		    0L, nours, got_object_idset_num_elements(idset), 0, 0);
1965 		if (err)
1966 			goto done;
1967 	}
1968 
1969 	if (got_object_idset_num_elements(idset) == 0 && !allow_empty) {
1970 		err = got_error(GOT_ERR_CANNOT_PACK);
1971 		goto done;
1972 	}
1973 
1974 	delta_cache_fd = got_opentempfd();
1975 	if (delta_cache_fd == -1) {
1976 		err = got_error_from_errno("got_opentemp");
1977 		goto done;
1978 	}
1979 
1980 	reuse.metasz = 64;
1981 	reuse.meta = calloc(reuse.metasz,
1982 	    sizeof(struct got_pack_meta *));
1983 	if (reuse.meta == NULL) {
1984 		err = got_error_from_errno("calloc");
1985 		goto done;
1986 	}
1987 
1988 	err = search_deltas(&reuse, idset, delta_cache_fd, ncolored, nfound,
1989 	    ntrees, nours, repo, progress_cb, progress_arg, &rl,
1990 	    cancel_cb, cancel_arg);
1991 	if (err)
1992 		goto done;
1993 
1994 	delta_cache = fdopen(delta_cache_fd, "a+");
1995 	if (delta_cache == NULL) {
1996 		err = got_error_from_errno("fdopen");
1997 		goto done;
1998 	}
1999 	delta_cache_fd = -1;
2000 
2001 	if (fseeko(delta_cache, 0L, SEEK_END) == -1) {
2002 		err = got_error_from_errno("fseeko");
2003 		goto done;
2004 	}
2005 
2006 	ndeltify = got_object_idset_num_elements(idset) - reuse.nmeta;
2007 	if (ndeltify > 0) {
2008 		deltify.meta = calloc(ndeltify, sizeof(struct got_pack_meta *));
2009 		if (deltify.meta == NULL) {
2010 			err = got_error_from_errno("calloc");
2011 			goto done;
2012 		}
2013 		deltify.metasz = ndeltify;
2014 
2015 		err = got_object_idset_for_each(idset, add_meta_idset_cb,
2016 		    &deltify);
2017 		if (err)
2018 			goto done;
2019 		if (deltify.nmeta > 0) {
2020 			err = pick_deltas(deltify.meta, deltify.nmeta,
2021 			    ncolored, nfound, ntrees, nours, reuse.nmeta,
2022 			    delta_cache, repo, progress_cb, progress_arg, &rl,
2023 			    cancel_cb, cancel_arg);
2024 			if (err)
2025 				goto done;
2026 		}
2027 	}
2028 
2029 	if (fflush(delta_cache) == EOF) {
2030 		err = got_error_from_errno("fflush");
2031 		goto done;
2032 	}
2033 	err = genpack(packsha1, packfile, delta_cache, deltify.meta,
2034 	    deltify.nmeta, reuse.meta, reuse.nmeta, ncolored, nfound, ntrees,
2035 	    nours, repo, progress_cb, progress_arg, &rl,
2036 	    cancel_cb, cancel_arg);
2037 	if (err)
2038 		goto done;
2039 done:
2040 	free_nmeta(deltify.meta, deltify.nmeta);
2041 	free_nmeta(reuse.meta, reuse.nmeta);
2042 	got_object_idset_free(idset);
2043 	if (delta_cache_fd != -1 && close(delta_cache_fd) == -1 && err == NULL)
2044 		err = got_error_from_errno("close");
2045 	if (delta_cache && fclose(delta_cache) == EOF && err == NULL)
2046 		err = got_error_from_errno("fclose");
2047 	return err;
2048 }