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Blob

Date:: Wed Aug 21 21:49:33 2019 UTC
Message:: fix and simplify blame algorithm Always diff against latest version of file. This is much easier since there is no need to keep track of lines shifting around.
Actions:: History | Blame | Raw File
1 /*
2  * Copyright (c) 2017 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/queue.h>
18 #include <sys/stat.h>
19 
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <limits.h>
24 #include <sha1.h>
25 #include <zlib.h>
26 
27 #include "got_object.h"
28 #include "got_repository.h"
29 #include "got_error.h"
30 #include "got_diff.h"
31 #include "got_opentemp.h"
32 #include "got_path.h"
33 
34 #include "got_lib_diff.h"
35 #include "got_lib_delta.h"
36 #include "got_lib_inflate.h"
37 #include "got_lib_object.h"
38 
39 static const struct got_error *
40 diff_blobs(struct got_blob_object *blob1, struct got_blob_object *blob2,
41     const char *label1, const char *label2, int diff_context, FILE *outfile,
42     struct got_diff_changes *changes)
43 {
44 	struct got_diff_state ds;
45 	struct got_diff_args args;
46 	const struct got_error *err = NULL;
47 	FILE *f1 = NULL, *f2 = NULL;
48 	char hex1[SHA1_DIGEST_STRING_LENGTH];
49 	char hex2[SHA1_DIGEST_STRING_LENGTH];
50 	char *idstr1 = NULL, *idstr2 = NULL;
51 	size_t size1, size2;
52 	int res, flags = 0;
53 
54 	if (blob1) {
55 		f1 = got_opentemp();
56 		if (f1 == NULL)
57 			return got_error_from_errno("got_opentemp");
58 	} else
59 		flags |= D_EMPTY1;
60 
61 	if (blob2) {
62 		f2 = got_opentemp();
63 		if (f2 == NULL) {
64 			err = got_error_from_errno("got_opentemp");
65 			fclose(f1);
66 			return err;
67 		}
68 	} else
69 		flags |= D_EMPTY2;
70 
71 	size1 = 0;
72 	if (blob1) {
73 		idstr1 = got_object_blob_id_str(blob1, hex1, sizeof(hex1));
74 		err = got_object_blob_dump_to_file(&size1, NULL, NULL, f1,
75 		    blob1);
76 		if (err)
77 			goto done;
78 	} else
79 		idstr1 = "/dev/null";
80 
81 	size2 = 0;
82 	if (blob2) {
83 		idstr2 = got_object_blob_id_str(blob2, hex2, sizeof(hex2));
84 		err = got_object_blob_dump_to_file(&size2, NULL, NULL, f2,
85 		    blob2);
86 		if (err)
87 			goto done;
88 	} else
89 		idstr2 = "/dev/null";
90 
91 	memset(&ds, 0, sizeof(ds));
92 	/* XXX should stat buffers be passed in args instead of ds? */
93 	ds.stb1.st_mode = S_IFREG;
94 	if (blob1)
95 		ds.stb1.st_size = size1;
96 	ds.stb1.st_mtime = 0; /* XXX */
97 
98 	ds.stb2.st_mode = S_IFREG;
99 	if (blob2)
100 		ds.stb2.st_size = size2;
101 	ds.stb2.st_mtime = 0; /* XXX */
102 
103 	memset(&args, 0, sizeof(args));
104 	args.diff_format = D_UNIFIED;
105 	args.label[0] = label1 ? label1 : idstr1;
106 	args.label[1] = label2 ? label2 : idstr2;
107 	args.diff_context = diff_context;
108 	flags |= D_PROTOTYPE;
109 
110 	if (outfile) {
111 		fprintf(outfile, "blob - %s\n", idstr1);
112 		fprintf(outfile, "blob + %s\n", idstr2);
113 	}
114 	err = got_diffreg(&res, f1, f2, flags, &args, &ds, outfile, changes);
115 	got_diff_state_free(&ds);
116 done:
117 	if (f1 && fclose(f1) != 0 && err == NULL)
118 		err = got_error_from_errno("fclose");
119 	if (f2 && fclose(f2) != 0 && err == NULL)
120 		err = got_error_from_errno("fclose");
121 	return err;
122 }
123 
124 const struct got_error *
125 got_diff_blob_output_unidiff(void *arg, struct got_blob_object *blob1,
126     struct got_blob_object *blob2, struct got_object_id *id1,
127     struct got_object_id *id2, const char *label1, const char *label2,
128     struct got_repository *repo)
129 {
130 	struct got_diff_blob_output_unidiff_arg *a = arg;
131 
132 	return diff_blobs(blob1, blob2, label1, label2, a->diff_context,
133 	    a->outfile, NULL);
134 }
135 
136 const struct got_error *
137 got_diff_blob(struct got_blob_object *blob1, struct got_blob_object *blob2,
138     const char *label1, const char *label2, int diff_context, FILE *outfile)
139 {
140 	return diff_blobs(blob1, blob2, label1, label2, diff_context, outfile,
141 	    NULL);
142 }
143 
144 static const struct got_error *
145 alloc_changes(struct got_diff_changes **changes)
146 {
147 	*changes = calloc(1, sizeof(**changes));
148 	if (*changes == NULL)
149 		return got_error_from_errno("calloc");
150 	SIMPLEQ_INIT(&(*changes)->entries);
151 	return NULL;
152 }
153 
154 static const struct got_error *
155 diff_blob_file(struct got_diff_changes **changes,
156     struct got_blob_object *blob1, const char *label1, FILE *f2, size_t size2,
157     const char *label2, int diff_context, FILE *outfile)
158 {
159 	struct got_diff_state ds;
160 	struct got_diff_args args;
161 	const struct got_error *err = NULL;
162 	FILE *f1 = NULL;
163 	char hex1[SHA1_DIGEST_STRING_LENGTH];
164 	char *idstr1 = NULL;
165 	size_t size1;
166 	int res, flags = 0;
167 
168 	if (changes)
169 		*changes = NULL;
170 
171 	size1 = 0;
172 	if (blob1) {
173 		f1 = got_opentemp();
174 		if (f1 == NULL)
175 			return got_error_from_errno("got_opentemp");
176 		idstr1 = got_object_blob_id_str(blob1, hex1, sizeof(hex1));
177 		err = got_object_blob_dump_to_file(&size1, NULL, NULL, f1,
178 		    blob1);
179 		if (err)
180 			goto done;
181 	} else {
182 		flags |= D_EMPTY1;
183 		idstr1 = "/dev/null";
184 	}
185 
186 	if (f2 == NULL)
187 		flags |= D_EMPTY2;
188 
189 	memset(&ds, 0, sizeof(ds));
190 	/* XXX should stat buffers be passed in args instead of ds? */
191 	ds.stb1.st_mode = S_IFREG;
192 	if (blob1)
193 		ds.stb1.st_size = size1;
194 	ds.stb1.st_mtime = 0; /* XXX */
195 
196 	ds.stb2.st_mode = S_IFREG;
197 	ds.stb2.st_size = size2;
198 	ds.stb2.st_mtime = 0; /* XXX */
199 
200 	memset(&args, 0, sizeof(args));
201 	args.diff_format = D_UNIFIED;
202 	args.label[0] = label2;
203 	args.label[1] = label2;
204 	args.diff_context = diff_context;
205 	flags |= D_PROTOTYPE;
206 
207 	if (outfile) {
208 		fprintf(outfile, "blob - %s\n", label1 ? label1 : idstr1);
209 		fprintf(outfile, "file + %s\n",
210 		    f2 == NULL ? "/dev/null" : label2);
211 	}
212 	if (changes) {
213 		err = alloc_changes(changes);
214 		if (err)
215 			return err;
216 	}
217 	err = got_diffreg(&res, f1, f2, flags, &args, &ds, outfile,
218 	    changes ? *changes : NULL);
219 	got_diff_state_free(&ds);
220 done:
221 	if (f1 && fclose(f1) != 0 && err == NULL)
222 		err = got_error_from_errno("fclose");
223 	return err;
224 }
225 
226 const struct got_error *
227 got_diff_blob_file(struct got_blob_object *blob1, const char *label1,
228     FILE *f2, size_t size2, const char *label2, int diff_context,
229     FILE *outfile)
230 {
231 	return diff_blob_file(NULL, blob1, label1, f2, size2, label2,
232 	    diff_context, outfile);
233 }
234 
235 const struct got_error *
236 got_diff_blob_file_lines_changed(struct got_diff_changes **changes,
237     struct got_blob_object *blob1, FILE *f2, size_t size2)
238 {
239 	return diff_blob_file(changes, blob1, NULL, f2, size2, NULL,
240 	    0, NULL);
241 }
242 
243 const struct got_error *
244 got_diff_blob_lines_changed(struct got_diff_changes **changes,
245     struct got_blob_object *blob1, struct got_blob_object *blob2)
246 {
247 	const struct got_error *err = NULL;
248 
249 	err = alloc_changes(changes);
250 	if (err)
251 		return err;
252 
253 	err = diff_blobs(blob1, blob2, NULL, NULL, 3, NULL, *changes);
254 	if (err) {
255 		got_diff_free_changes(*changes);
256 		*changes = NULL;
257 	}
258 	return err;
259 }
260 
261 void
262 got_diff_free_changes(struct got_diff_changes *changes)
263 {
264 	struct got_diff_change *change;
265 	while (!SIMPLEQ_EMPTY(&changes->entries)) {
266 		change = SIMPLEQ_FIRST(&changes->entries);
267 		SIMPLEQ_REMOVE_HEAD(&changes->entries, entry);
268 		free(change);
269 	}
270 	free(changes);
271 }
272 
273 static const struct got_error *
274 diff_added_blob(struct got_object_id *id, const char *label,
275     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg)
276 {
277 	const struct got_error *err;
278 	struct got_blob_object  *blob = NULL;
279 	struct got_object *obj = NULL;
280 
281 	err = got_object_open(&obj, repo, id);
282 	if (err)
283 		return err;
284 
285 	err = got_object_blob_open(&blob, repo, obj, 8192);
286 	if (err)
287 		goto done;
288 	err = cb(cb_arg, NULL, blob, NULL, id, NULL, label, repo);
289 done:
290 	got_object_close(obj);
291 	if (blob)
292 		got_object_blob_close(blob);
293 	return err;
294 }
295 
296 static const struct got_error *
297 diff_modified_blob(struct got_object_id *id1, struct got_object_id *id2,
298     const char *label1, const char *label2, struct got_repository *repo,
299     got_diff_blob_cb cb, void *cb_arg)
300 {
301 	const struct got_error *err;
302 	struct got_object *obj1 = NULL;
303 	struct got_object *obj2 = NULL;
304 	struct got_blob_object *blob1 = NULL;
305 	struct got_blob_object *blob2 = NULL;
306 
307 	err = got_object_open(&obj1, repo, id1);
308 	if (err)
309 		return err;
310 	if (obj1->type != GOT_OBJ_TYPE_BLOB) {
311 		err = got_error(GOT_ERR_OBJ_TYPE);
312 		goto done;
313 	}
314 
315 	err = got_object_open(&obj2, repo, id2);
316 	if (err)
317 		goto done;
318 	if (obj2->type != GOT_OBJ_TYPE_BLOB) {
319 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
320 		goto done;
321 	}
322 
323 	err = got_object_blob_open(&blob1, repo, obj1, 8192);
324 	if (err)
325 		goto done;
326 
327 	err = got_object_blob_open(&blob2, repo, obj2, 8192);
328 	if (err)
329 		goto done;
330 
331 	err = cb(cb_arg, blob1, blob2, id1, id2, label1, label2, repo);
332 done:
333 	if (obj1)
334 		got_object_close(obj1);
335 	if (obj2)
336 		got_object_close(obj2);
337 	if (blob1)
338 		got_object_blob_close(blob1);
339 	if (blob2)
340 		got_object_blob_close(blob2);
341 	return err;
342 }
343 
344 static const struct got_error *
345 diff_deleted_blob(struct got_object_id *id, const char *label,
346     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg)
347 {
348 	const struct got_error *err;
349 	struct got_blob_object  *blob = NULL;
350 	struct got_object *obj = NULL;
351 
352 	err = got_object_open(&obj, repo, id);
353 	if (err)
354 		return err;
355 
356 	err = got_object_blob_open(&blob, repo, obj, 8192);
357 	if (err)
358 		goto done;
359 	err = cb(cb_arg, blob, NULL, id, NULL, label, NULL, repo);
360 done:
361 	got_object_close(obj);
362 	if (blob)
363 		got_object_blob_close(blob);
364 	return err;
365 }
366 
367 static const struct got_error *
368 diff_added_tree(struct got_object_id *id, const char *label,
369     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg,
370     int diff_content)
371 {
372 	const struct got_error *err = NULL;
373 	struct got_object *treeobj = NULL;
374 	struct got_tree_object *tree = NULL;
375 
376 	err = got_object_open(&treeobj, repo, id);
377 	if (err)
378 		goto done;
379 
380 	if (treeobj->type != GOT_OBJ_TYPE_TREE) {
381 		err = got_error(GOT_ERR_OBJ_TYPE);
382 		goto done;
383 	}
384 
385 	err = got_object_tree_open(&tree, repo, treeobj);
386 	if (err)
387 		goto done;
388 
389 	err = got_diff_tree(NULL, tree, NULL, label, repo, cb, cb_arg,
390 	    diff_content);
391 done:
392 	if (tree)
393 		got_object_tree_close(tree);
394 	if (treeobj)
395 		got_object_close(treeobj);
396 	return err;
397 }
398 
399 static const struct got_error *
400 diff_modified_tree(struct got_object_id *id1, struct got_object_id *id2,
401     const char *label1, const char *label2, struct got_repository *repo,
402     got_diff_blob_cb cb, void *cb_arg, int diff_content)
403 {
404 	const struct got_error *err;
405 	struct got_object *treeobj1 = NULL;
406 	struct got_object *treeobj2 = NULL;
407 	struct got_tree_object *tree1 = NULL;
408 	struct got_tree_object *tree2 = NULL;
409 
410 	err = got_object_open(&treeobj1, repo, id1);
411 	if (err)
412 		goto done;
413 
414 	if (treeobj1->type != GOT_OBJ_TYPE_TREE) {
415 		err = got_error(GOT_ERR_OBJ_TYPE);
416 		goto done;
417 	}
418 
419 	err = got_object_open(&treeobj2, repo, id2);
420 	if (err)
421 		goto done;
422 
423 	if (treeobj2->type != GOT_OBJ_TYPE_TREE) {
424 		err = got_error(GOT_ERR_OBJ_TYPE);
425 		goto done;
426 	}
427 
428 	err = got_object_tree_open(&tree1, repo, treeobj1);
429 	if (err)
430 		goto done;
431 
432 	err = got_object_tree_open(&tree2, repo, treeobj2);
433 	if (err)
434 		goto done;
435 
436 	err = got_diff_tree(tree1, tree2, label1, label2, repo, cb, cb_arg,
437 	    diff_content);
438 
439 done:
440 	if (tree1)
441 		got_object_tree_close(tree1);
442 	if (tree2)
443 		got_object_tree_close(tree2);
444 	if (treeobj1)
445 		got_object_close(treeobj1);
446 	if (treeobj2)
447 		got_object_close(treeobj2);
448 	return err;
449 }
450 
451 static const struct got_error *
452 diff_deleted_tree(struct got_object_id *id, const char *label,
453     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg,
454     int diff_content)
455 {
456 	const struct got_error *err;
457 	struct got_object *treeobj = NULL;
458 	struct got_tree_object *tree = NULL;
459 
460 	err = got_object_open(&treeobj, repo, id);
461 	if (err)
462 		goto done;
463 
464 	if (treeobj->type != GOT_OBJ_TYPE_TREE) {
465 		err = got_error(GOT_ERR_OBJ_TYPE);
466 		goto done;
467 	}
468 
469 	err = got_object_tree_open(&tree, repo, treeobj);
470 	if (err)
471 		goto done;
472 
473 	err = got_diff_tree(tree, NULL, label, NULL, repo, cb, cb_arg,
474 	    diff_content);
475 done:
476 	if (tree)
477 		got_object_tree_close(tree);
478 	if (treeobj)
479 		got_object_close(treeobj);
480 	return err;
481 }
482 
483 static const struct got_error *
484 diff_kind_mismatch(struct got_object_id *id1, struct got_object_id *id2,
485     const char *label1, const char *label2, struct got_repository *repo,
486     got_diff_blob_cb cb, void *cb_arg)
487 {
488 	/* XXX TODO */
489 	return NULL;
490 }
491 
492 static const struct got_error *
493 diff_entry_old_new(const struct got_tree_entry *te1,
494     const struct got_tree_entry *te2, const char *label1, const char *label2,
495     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg,
496     int diff_content)
497 {
498 	const struct got_error *err = NULL;
499 	int id_match;
500 
501 	if (te2 == NULL) {
502 		if (S_ISDIR(te1->mode))
503 			err = diff_deleted_tree(te1->id, label1, repo,
504 			    cb, cb_arg, diff_content);
505 		else {
506 			if (diff_content)
507 				err = diff_deleted_blob(te1->id, label1, repo,
508 				    cb, cb_arg);
509 			else
510 				err = cb(cb_arg, NULL, NULL, te1->id, NULL,
511 				    label1, NULL, repo);
512 		}
513 		return err;
514 	}
515 
516 	id_match = (got_object_id_cmp(te1->id, te2->id) == 0);
517 	if (S_ISDIR(te1->mode) && S_ISDIR(te2->mode)) {
518 		if (!id_match)
519 			return diff_modified_tree(te1->id, te2->id,
520 			    label1, label2, repo, cb, cb_arg, diff_content);
521 	} else if (S_ISREG(te1->mode) && S_ISREG(te2->mode)) {
522 		if (!id_match) {
523 			if (diff_content)
524 				return diff_modified_blob(te1->id, te2->id,
525 				    label1, label2, repo, cb, cb_arg);
526 			else
527 				return cb(cb_arg, NULL, NULL, te1->id,
528 				    te2->id, label1, label2, repo);
529 		}
530 	}
531 
532 	if (id_match)
533 		return NULL;
534 
535 	return diff_kind_mismatch(te1->id, te2->id, label1, label2, repo,
536 	    cb, cb_arg);
537 }
538 
539 static const struct got_error *
540 diff_entry_new_old(const struct got_tree_entry *te2,
541     const struct got_tree_entry *te1, const char *label2,
542     struct got_repository *repo, got_diff_blob_cb cb, void *cb_arg,
543     int diff_content)
544 {
545 	if (te1 != NULL) /* handled by diff_entry_old_new() */
546 		return NULL;
547 
548 	if (S_ISDIR(te2->mode))
549 		return diff_added_tree(te2->id, label2, repo, cb, cb_arg,
550 		    diff_content);
551 
552 	if (diff_content)
553 		return diff_added_blob(te2->id, label2, repo, cb, cb_arg);
554 
555 	return cb(cb_arg, NULL, NULL, NULL, te2->id, NULL, label2, repo);
556 }
557 
558 const struct got_error *
559 got_diff_tree(struct got_tree_object *tree1, struct got_tree_object *tree2,
560     const char *label1, const char *label2, struct got_repository *repo,
561     got_diff_blob_cb cb, void *cb_arg, int diff_content)
562 {
563 	const struct got_error *err = NULL;
564 	struct got_tree_entry *te1 = NULL;
565 	struct got_tree_entry *te2 = NULL;
566 	char *l1 = NULL, *l2 = NULL;
567 
568 	if (tree1) {
569 		const struct got_tree_entries *entries;
570 		entries = got_object_tree_get_entries(tree1);
571 		te1 = SIMPLEQ_FIRST(&entries->head);
572 		if (te1 && asprintf(&l1, "%s%s%s", label1, label1[0] ? "/" : "",
573 		    te1->name) == -1)
574 			return got_error_from_errno("asprintf");
575 	}
576 	if (tree2) {
577 		const struct got_tree_entries *entries;
578 		entries = got_object_tree_get_entries(tree2);
579 		te2 = SIMPLEQ_FIRST(&entries->head);
580 		if (te2 && asprintf(&l2, "%s%s%s", label2, label2[0] ? "/" : "",
581 		    te2->name) == -1)
582 			return got_error_from_errno("asprintf");
583 	}
584 
585 	do {
586 		if (te1) {
587 			const struct got_tree_entry *te = NULL;
588 			if (tree2)
589 				te = got_object_tree_find_entry(tree2,
590 				    te1->name);
591 			if (te) {
592 				free(l2);
593 				l2 = NULL;
594 				if (te && asprintf(&l2, "%s%s%s", label2,
595 				    label2[0] ? "/" : "", te->name) == -1)
596 					return
597 					    got_error_from_errno("asprintf");
598 			}
599 			err = diff_entry_old_new(te1, te, l1, l2, repo, cb,
600 			    cb_arg, diff_content);
601 			if (err)
602 				break;
603 		}
604 
605 		if (te2) {
606 			const struct got_tree_entry *te = NULL;
607 			if (tree1)
608 				te = got_object_tree_find_entry(tree1,
609 				    te2->name);
610 			free(l2);
611 			if (te) {
612 				if (asprintf(&l2, "%s%s%s", label2,
613 				    label2[0] ? "/" : "", te->name) == -1)
614 					return
615 					    got_error_from_errno("asprintf");
616 			} else {
617 				if (asprintf(&l2, "%s%s%s", label2,
618 				    label2[0] ? "/" : "", te2->name) == -1)
619 					return
620 					    got_error_from_errno("asprintf");
621 			}
622 			err = diff_entry_new_old(te2, te, l2, repo,
623 			    cb, cb_arg, diff_content);
624 			if (err)
625 				break;
626 		}
627 
628 		free(l1);
629 		l1 = NULL;
630 		if (te1) {
631 			te1 = SIMPLEQ_NEXT(te1, entry);
632 			if (te1 &&
633 			    asprintf(&l1, "%s%s%s", label1,
634 			    label1[0] ? "/" : "", te1->name) == -1)
635 				return got_error_from_errno("asprintf");
636 		}
637 		free(l2);
638 		l2 = NULL;
639 		if (te2) {
640 			te2 = SIMPLEQ_NEXT(te2, entry);
641 			if (te2 &&
642 			    asprintf(&l2, "%s%s%s", label2,
643 			        label2[0] ? "/" : "", te2->name) == -1)
644 				return got_error_from_errno("asprintf");
645 		}
646 	} while (te1 || te2);
647 
648 	return err;
649 }
650 
651 const struct got_error *
652 got_diff_objects_as_blobs(struct got_object_id *id1, struct got_object_id *id2,
653     const char *label1, const char *label2, int diff_context,
654     struct got_repository *repo, FILE *outfile)
655 {
656 	const struct got_error *err;
657 	struct got_blob_object *blob1 = NULL, *blob2 = NULL;
658 
659 	if (id1 == NULL && id2 == NULL)
660 		return got_error(GOT_ERR_NO_OBJ);
661 
662 	if (id1) {
663 		err = got_object_open_as_blob(&blob1, repo, id1, 8192);
664 		if (err)
665 			goto done;
666 	}
667 	if (id2) {
668 		err = got_object_open_as_blob(&blob2, repo, id2, 8192);
669 		if (err)
670 			goto done;
671 	}
672 	err = got_diff_blob(blob1, blob2, label1, label2, diff_context,
673 	    outfile);
674 done:
675 	if (blob1)
676 		got_object_blob_close(blob1);
677 	if (blob2)
678 		got_object_blob_close(blob2);
679 	return err;
680 }
681 
682 const struct got_error *
683 got_diff_objects_as_trees(struct got_object_id *id1, struct got_object_id *id2,
684     char *label1, char *label2, int diff_context, struct got_repository *repo,
685     FILE *outfile)
686 {
687 	const struct got_error *err;
688 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
689 	struct got_diff_blob_output_unidiff_arg arg;
690 
691 	if (id1 == NULL && id2 == NULL)
692 		return got_error(GOT_ERR_NO_OBJ);
693 
694 	if (id1) {
695 		err = got_object_open_as_tree(&tree1, repo, id1);
696 		if (err)
697 			goto done;
698 	}
699 	if (id2) {
700 		err = got_object_open_as_tree(&tree2, repo, id2);
701 		if (err)
702 			goto done;
703 	}
704 	arg.diff_context = diff_context;
705 	arg.outfile = outfile;
706 	err = got_diff_tree(tree1, tree2, label1, label2, repo,
707 	    got_diff_blob_output_unidiff, &arg, 1);
708 done:
709 	if (tree1)
710 		got_object_tree_close(tree1);
711 	if (tree2)
712 		got_object_tree_close(tree2);
713 	return err;
714 }
715 
716 const struct got_error *
717 got_diff_objects_as_commits(struct got_object_id *id1,
718     struct got_object_id *id2, int diff_context,
719     struct got_repository *repo, FILE *outfile)
720 {
721 	const struct got_error *err;
722 	struct got_commit_object *commit1 = NULL, *commit2 = NULL;
723 
724 	if (id2 == NULL)
725 		return got_error(GOT_ERR_NO_OBJ);
726 
727 	if (id1) {
728 		err = got_object_open_as_commit(&commit1, repo, id1);
729 		if (err)
730 			goto done;
731 	}
732 
733 	err = got_object_open_as_commit(&commit2, repo, id2);
734 	if (err)
735 		goto done;
736 
737 	err = got_diff_objects_as_trees(
738 	    commit1 ? got_object_commit_get_tree_id(commit1) : NULL,
739 	    got_object_commit_get_tree_id(commit2), "", "", diff_context, repo,
740 	    outfile);
741 done:
742 	if (commit1)
743 		got_object_commit_close(commit1);
744 	if (commit2)
745 		got_object_commit_close(commit2);
746 	return err;
747 }
748 
749 const struct got_error *
750 got_diff_files(struct got_diff_changes **changes,
751     struct got_diff_state **ds,
752     struct got_diff_args **args,
753     int *flags,
754     FILE *f1, size_t size1, const char *label1,
755     FILE *f2, size_t size2, const char *label2,
756     int diff_context, FILE *outfile)
757 {
758 	const struct got_error *err = NULL;
759 	int res;
760 
761 	*flags = 0;
762 	*ds = calloc(1, sizeof(**ds));
763 	if (*ds == NULL)
764 		return got_error_from_errno("calloc");
765 	*args = calloc(1, sizeof(**args));
766 	if (*args == NULL) {
767 		err = got_error_from_errno("calloc");
768 		goto done;
769 	}
770 
771 	if (changes)
772 		*changes = NULL;
773 
774 	if (f1 == NULL)
775 		*flags |= D_EMPTY1;
776 
777 	if (f2 == NULL)
778 		*flags |= D_EMPTY2;
779 
780 	/* XXX should stat buffers be passed in args instead of ds? */
781 	(*ds)->stb1.st_mode = S_IFREG;
782 	(*ds)->stb1.st_size = size1;
783 	(*ds)->stb1.st_mtime = 0; /* XXX */
784 
785 	(*ds)->stb2.st_mode = S_IFREG;
786 	(*ds)->stb2.st_size = size2;
787 	(*ds)->stb2.st_mtime = 0; /* XXX */
788 
789 	(*args)->diff_format = D_UNIFIED;
790 	(*args)->label[0] = label1;
791 	(*args)->label[1] = label2;
792 	(*args)->diff_context = diff_context;
793 	*flags |= D_PROTOTYPE;
794 
795 	if (outfile) {
796 		fprintf(outfile, "file - %s\n",
797 		    f1 == NULL ? "/dev/null" : label1);
798 		fprintf(outfile, "file + %s\n",
799 		    f2 == NULL ? "/dev/null" : label2);
800 	}
801 	if (changes) {
802 		err = alloc_changes(changes);
803 		if (err)
804 			goto done;
805 	}
806 	err = got_diffreg(&res, f1, f2, *flags, *args, *ds, outfile,
807 	    changes ? *changes : NULL);
808 done:
809 	if (err) {
810 		if (*ds) {
811 			got_diff_state_free(*ds);
812 			free(*ds);
813 			*ds = NULL;
814 		}
815 		if (*args) {
816 			free(*args);
817 			*args = NULL;
818 		}
819 		if (changes) {
820 			if (*changes)
821 				got_diff_free_changes(*changes);
822 			*changes = NULL;
823 		}
824 	}
825 	return err;
826 }