aboutsummaryrefslogtreecommitdiff
path: root/builtin-bundle.c
blob: 616335819162be2163c655490724fb40f58f127f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
#include "cache.h"
#include "object.h"
#include "commit.h"
#include "diff.h"
#include "revision.h"
#include "list-objects.h"
#include "exec_cmd.h"

/*
 * Basic handler for bundle files to connect repositories via sneakernet.
 * Invocation must include action.
 * This function can create a bundle or provide information on an existing
 * bundle supporting git-fetch, git-pull, and git-ls-remote
 */

static const char *bundle_usage="git-bundle (create <bundle> <git-rev-list args> | verify <bundle> | list-heads <bundle> [refname]... | unbundle <bundle> [refname]... )";

static const char bundle_signature[] = "# v2 git bundle\n";

struct ref_list {
	unsigned int nr, alloc;
	struct ref_list_entry {
		unsigned char sha1[20];
		char *name;
	} *list;
};

static void add_to_ref_list(const unsigned char *sha1, const char *name,
		struct ref_list *list)
{
	if (list->nr + 1 >= list->alloc) {
		list->alloc = alloc_nr(list->nr + 1);
		list->list = xrealloc(list->list,
				list->alloc * sizeof(list->list[0]));
	}
	memcpy(list->list[list->nr].sha1, sha1, 20);
	list->list[list->nr].name = xstrdup(name);
	list->nr++;
}

struct bundle_header {
	struct ref_list prerequisites;
	struct ref_list references;
};

/* this function returns the length of the string */
static int read_string(int fd, char *buffer, int size)
{
	int i;
	for (i = 0; i < size - 1; i++) {
		int count = xread(fd, buffer + i, 1);
		if (count < 0)
			return error("Read error: %s", strerror(errno));
		if (count == 0) {
			i--;
			break;
		}
		if (buffer[i] == '\n')
			break;
	}
	buffer[i + 1] = '\0';
	return i + 1;
}

/* returns an fd */
static int read_header(const char *path, struct bundle_header *header) {
	char buffer[1024];
	int fd = open(path, O_RDONLY);

	if (fd < 0)
		return error("could not open '%s'", path);
	if (read_string(fd, buffer, sizeof(buffer)) < 0 ||
			strcmp(buffer, bundle_signature)) {
		close(fd);
		return error("'%s' does not look like a v2 bundle file", path);
	}
	while (read_string(fd, buffer, sizeof(buffer)) > 0
			&& buffer[0] != '\n') {
		int is_prereq = buffer[0] == '-';
		int offset = is_prereq ? 1 : 0;
		int len = strlen(buffer);
		unsigned char sha1[20];
		struct ref_list *list = is_prereq ? &header->prerequisites
			: &header->references;
		char delim;

		if (buffer[len - 1] == '\n')
			buffer[len - 1] = '\0';
		if (get_sha1_hex(buffer + offset, sha1)) {
			warn("unrecognized header: %s", buffer);
			continue;
		}
		delim = buffer[40 + offset];
		if (!isspace(delim) && (delim != '\0' || !is_prereq))
			die ("invalid header: %s", buffer);
		add_to_ref_list(sha1, isspace(delim) ?
				buffer + 41 + offset : "", list);
	}
	return fd;
}

/* if in && *in >= 0, take that as input file descriptor instead */
static int fork_with_pipe(const char **argv, int *in, int *out)
{
	int needs_in, needs_out;
	int fdin[2], fdout[2], pid;

	needs_in = in && *in < 0;
	if (needs_in) {
		if (pipe(fdin) < 0)
			return error("could not setup pipe");
		*in = fdin[1];
	}

	needs_out = out && *out < 0;
	if (needs_out) {
		if (pipe(fdout) < 0)
			return error("could not setup pipe");
		*out = fdout[0];
	}

	if ((pid = fork()) < 0) {
		if (needs_in) {
			close(fdin[0]);
			close(fdin[1]);
		}
		if (needs_out) {
			close(fdout[0]);
			close(fdout[1]);
		}
		return error("could not fork");
	}
	if (!pid) {
		if (needs_in) {
			dup2(fdin[0], 0);
			close(fdin[0]);
			close(fdin[1]);
		} else if (in) {
			dup2(*in, 0);
			close(*in);
		}
		if (needs_out) {
			dup2(fdout[1], 1);
			close(fdout[0]);
			close(fdout[1]);
		} else if (out) {
			dup2(*out, 1);
			close(*out);
		}
		exit(execv_git_cmd(argv));
	}
	if (needs_in)
		close(fdin[0]);
	else if (in)
		close(*in);
	if (needs_out)
		close(fdout[1]);
	else if (out)
		close(*out);
	return pid;
}

static int list_refs(struct ref_list *r, int argc, const char **argv)
{
	int i;

	for (i = 0; i < r->nr; i++) {
		if (argc > 1) {
			int j;
			for (j = 1; j < argc; j++)
				if (!strcmp(r->list[i].name, argv[j]))
					break;
			if (j == argc)
				continue;
		}
		printf("%s %s\n", sha1_to_hex(r->list[i].sha1),
				r->list[i].name);
	}
	return 0;
}

#define PREREQ_MARK (1u<<16)

static int verify_bundle(struct bundle_header *header, int verbose)
{
	/*
	 * Do fast check, then if any prereqs are missing then go line by line
	 * to be verbose about the errors
	 */
	struct ref_list *p = &header->prerequisites;
	struct rev_info revs;
	const char *argv[] = {NULL, "--all"};
	struct object_array refs;
	struct commit *commit;
	int i, ret = 0, req_nr;
	const char *message = "Repository lacks these prerequisite commits:";

	init_revisions(&revs, NULL);
	for (i = 0; i < p->nr; i++) {
		struct ref_list_entry *e = p->list + i;
		struct object *o = parse_object(e->sha1);
		if (o) {
			o->flags |= PREREQ_MARK;
			add_pending_object(&revs, o, e->name);
			continue;
		}
		if (++ret == 1)
			error(message);
		error("%s %s", sha1_to_hex(e->sha1), e->name);
	}
	if (revs.pending.nr != p->nr)
		return ret;
	req_nr = revs.pending.nr;
	setup_revisions(2, argv, &revs, NULL);

	memset(&refs, 0, sizeof(struct object_array));
	for (i = 0; i < revs.pending.nr; i++) {
		struct object_array_entry *e = revs.pending.objects + i;
		add_object_array(e->item, e->name, &refs);
	}

	prepare_revision_walk(&revs);

	i = req_nr;
	while (i && (commit = get_revision(&revs)))
		if (commit->object.flags & PREREQ_MARK)
			i--;

	for (i = 0; i < req_nr; i++)
		if (!(refs.objects[i].item->flags & SHOWN)) {
			if (++ret == 1)
				error(message);
			error("%s %s", sha1_to_hex(refs.objects[i].item->sha1),
				refs.objects[i].name);
		}

	for (i = 0; i < refs.nr; i++)
		clear_commit_marks((struct commit *)refs.objects[i].item, -1);

	if (verbose) {
		struct ref_list *r;

		r = &header->references;
		printf("The bundle contains %d ref%s\n",
		       r->nr, (1 < r->nr) ? "s" : "");
		list_refs(r, 0, NULL);
		r = &header->prerequisites;
		printf("The bundle requires these %d ref%s\n",
		       r->nr, (1 < r->nr) ? "s" : "");
		list_refs(r, 0, NULL);
	}
	return ret;
}

static int list_heads(struct bundle_header *header, int argc, const char **argv)
{
	return list_refs(&header->references, argc, argv);
}

static int create_bundle(struct bundle_header *header, const char *path,
		int argc, const char **argv)
{
	int bundle_fd = -1;
	const char **argv_boundary = xmalloc((argc + 4) * sizeof(const char *));
	const char **argv_pack = xmalloc(5 * sizeof(const char *));
	int pid, in, out, i, status;
	char buffer[1024];
	struct rev_info revs;

	bundle_fd = (!strcmp(path, "-") ? 1 :
			open(path, O_CREAT | O_WRONLY, 0666));
	if (bundle_fd < 0)
		return error("Could not write to '%s'", path);

	/* write signature */
	write_or_die(bundle_fd, bundle_signature, strlen(bundle_signature));

	/* init revs to list objects for pack-objects later */
	save_commit_buffer = 0;
	init_revisions(&revs, NULL);

	/* write prerequisites */
	memcpy(argv_boundary + 3, argv + 1, argc * sizeof(const char *));
	argv_boundary[0] = "rev-list";
	argv_boundary[1] = "--boundary";
	argv_boundary[2] = "--pretty=oneline";
	argv_boundary[argc + 2] = NULL;
	out = -1;
	pid = fork_with_pipe(argv_boundary, NULL, &out);
	if (pid < 0)
		return -1;
	while ((i = read_string(out, buffer, sizeof(buffer))) > 0) {
		unsigned char sha1[20];
		if (buffer[0] == '-') {
			write_or_die(bundle_fd, buffer, i);
			if (!get_sha1_hex(buffer + 1, sha1)) {
				struct object *object = parse_object(sha1);
				object->flags |= UNINTERESTING;
				add_pending_object(&revs, object, buffer);
			}
		} else if (!get_sha1_hex(buffer, sha1)) {
			struct object *object = parse_object(sha1);
			object->flags |= SHOWN;
		}
	}
	while ((i = waitpid(pid, &status, 0)) < 0)
		if (errno != EINTR)
			return error("rev-list died");
	if (!WIFEXITED(status) || WEXITSTATUS(status))
		return error("rev-list died %d", WEXITSTATUS(status));

	/* write references */
	argc = setup_revisions(argc, argv, &revs, NULL);
	if (argc > 1)
		return error("unrecognized argument: %s'", argv[1]);

	for (i = 0; i < revs.pending.nr; i++) {
		struct object_array_entry *e = revs.pending.objects + i;
		unsigned char sha1[20];
		char *ref;

		if (e->item->flags & UNINTERESTING)
			continue;
		if (dwim_ref(e->name, strlen(e->name), sha1, &ref) != 1)
			continue;
		/*
		 * Make sure the refs we wrote out is correct; --max-count and
		 * other limiting options could have prevented all the tips
		 * from getting output.
		 */
		if (!(e->item->flags & SHOWN)) {
			warn("ref '%s' is excluded by the rev-list options",
				e->name);
			continue;
		}
		write_or_die(bundle_fd, sha1_to_hex(e->item->sha1), 40);
		write_or_die(bundle_fd, " ", 1);
		write_or_die(bundle_fd, ref, strlen(ref));
		write_or_die(bundle_fd, "\n", 1);
		free(ref);
	}

	/* end header */
	write_or_die(bundle_fd, "\n", 1);

	/* write pack */
	argv_pack[0] = "pack-objects";
	argv_pack[1] = "--all-progress";
	argv_pack[2] = "--stdout";
	argv_pack[3] = "--thin";
	argv_pack[4] = NULL;
	in = -1;
	out = bundle_fd;
	pid = fork_with_pipe(argv_pack, &in, &out);
	if (pid < 0)
		return error("Could not spawn pack-objects");
	for (i = 0; i < revs.pending.nr; i++) {
		struct object *object = revs.pending.objects[i].item;
		if (object->flags & UNINTERESTING)
			write(in, "^", 1);
		write(in, sha1_to_hex(object->sha1), 40);
		write(in, "\n", 1);
	}
	close(in);
	while (waitpid(pid, &status, 0) < 0)
		if (errno != EINTR)
			return -1;
	if (!WIFEXITED(status) || WEXITSTATUS(status))
		return error ("pack-objects died");

	return status;
}

static int unbundle(struct bundle_header *header, int bundle_fd,
		int argc, const char **argv)
{
	const char *argv_index_pack[] = {"index-pack", "--stdin", NULL};
	int pid, status, dev_null;

	if (verify_bundle(header, 0))
		return -1;
	dev_null = open("/dev/null", O_WRONLY);
	if (dev_null < 0)
		return error("Could not open /dev/null");
	pid = fork_with_pipe(argv_index_pack, &bundle_fd, &dev_null);
	if (pid < 0)
		return error("Could not spawn index-pack");
	while (waitpid(pid, &status, 0) < 0)
		if (errno != EINTR)
			return error("index-pack died");
	if (!WIFEXITED(status) || WEXITSTATUS(status))
		return error("index-pack exited with status %d",
				WEXITSTATUS(status));
	return list_heads(header, argc, argv);
}

int cmd_bundle(int argc, const char **argv, const char *prefix)
{
	struct bundle_header header;
	int nongit = 0;
	const char *cmd, *bundle_file;
	int bundle_fd = -1;
	char buffer[PATH_MAX];

	if (argc < 3)
		usage(bundle_usage);

	cmd = argv[1];
	bundle_file = argv[2];
	argc -= 2;
	argv += 2;

	prefix = setup_git_directory_gently(&nongit);
	if (prefix && bundle_file[0] != '/') {
		snprintf(buffer, sizeof(buffer), "%s/%s", prefix, bundle_file);
		bundle_file = buffer;
	}

	memset(&header, 0, sizeof(header));
	if (strcmp(cmd, "create") &&
			(bundle_fd = read_header(bundle_file, &header)) < 0)
		return 1;

	if (!strcmp(cmd, "verify")) {
		close(bundle_fd);
		if (verify_bundle(&header, 1))
			return 1;
		fprintf(stderr, "%s is okay\n", bundle_file);
		return 0;
	}
	if (!strcmp(cmd, "list-heads")) {
		close(bundle_fd);
		return !!list_heads(&header, argc, argv);
	}
	if (!strcmp(cmd, "create")) {
		if (nongit)
			die("Need a repository to create a bundle.");
		return !!create_bundle(&header, bundle_file, argc, argv);
	} else if (!strcmp(cmd, "unbundle")) {
		if (nongit)
			die("Need a repository to unbundle.");
		return !!unbundle(&header, bundle_fd, argc, argv);
	} else
		usage(bundle_usage);
}