Merge branch 'jc/how-to-document-api'
[git] / archive.c
1 #include "cache.h"
2 #include "config.h"
3 #include "refs.h"
4 #include "object-store.h"
5 #include "commit.h"
6 #include "tree-walk.h"
7 #include "attr.h"
8 #include "archive.h"
9 #include "parse-options.h"
10 #include "unpack-trees.h"
11 #include "dir.h"
12
13 static char const * const archive_usage[] = {
14         N_("git archive [<options>] <tree-ish> [<path>...]"),
15         N_("git archive --list"),
16         N_("git archive --remote <repo> [--exec <cmd>] [<options>] <tree-ish> [<path>...]"),
17         N_("git archive --remote <repo> [--exec <cmd>] --list"),
18         NULL
19 };
20
21 static const struct archiver **archivers;
22 static int nr_archivers;
23 static int alloc_archivers;
24 static int remote_allow_unreachable;
25
26 void register_archiver(struct archiver *ar)
27 {
28         ALLOC_GROW(archivers, nr_archivers + 1, alloc_archivers);
29         archivers[nr_archivers++] = ar;
30 }
31
32 static void format_subst(const struct commit *commit,
33                          const char *src, size_t len,
34                          struct strbuf *buf)
35 {
36         char *to_free = NULL;
37         struct strbuf fmt = STRBUF_INIT;
38         struct pretty_print_context ctx = {0};
39         ctx.date_mode.type = DATE_NORMAL;
40         ctx.abbrev = DEFAULT_ABBREV;
41
42         if (src == buf->buf)
43                 to_free = strbuf_detach(buf, NULL);
44         for (;;) {
45                 const char *b, *c;
46
47                 b = memmem(src, len, "$Format:", 8);
48                 if (!b)
49                         break;
50                 c = memchr(b + 8, '$', (src + len) - b - 8);
51                 if (!c)
52                         break;
53
54                 strbuf_reset(&fmt);
55                 strbuf_add(&fmt, b + 8, c - b - 8);
56
57                 strbuf_add(buf, src, b - src);
58                 format_commit_message(commit, fmt.buf, buf, &ctx);
59                 len -= c + 1 - src;
60                 src  = c + 1;
61         }
62         strbuf_add(buf, src, len);
63         strbuf_release(&fmt);
64         free(to_free);
65 }
66
67 void *object_file_to_archive(const struct archiver_args *args,
68                              const char *path, const struct object_id *oid,
69                              unsigned int mode, enum object_type *type,
70                              unsigned long *sizep)
71 {
72         void *buffer;
73         const struct commit *commit = args->convert ? args->commit : NULL;
74
75         path += args->baselen;
76         buffer = read_object_file(oid, type, sizep);
77         if (buffer && S_ISREG(mode)) {
78                 struct strbuf buf = STRBUF_INIT;
79                 size_t size = 0;
80
81                 strbuf_attach(&buf, buffer, *sizep, *sizep + 1);
82                 convert_to_working_tree(args->repo->index, path, buf.buf, buf.len, &buf);
83                 if (commit)
84                         format_subst(commit, buf.buf, buf.len, &buf);
85                 buffer = strbuf_detach(&buf, &size);
86                 *sizep = size;
87         }
88
89         return buffer;
90 }
91
92 struct directory {
93         struct directory *up;
94         struct object_id oid;
95         int baselen, len;
96         unsigned mode;
97         int stage;
98         char path[FLEX_ARRAY];
99 };
100
101 struct archiver_context {
102         struct archiver_args *args;
103         write_archive_entry_fn_t write_entry;
104         struct directory *bottom;
105 };
106
107 static const struct attr_check *get_archive_attrs(struct index_state *istate,
108                                                   const char *path)
109 {
110         static struct attr_check *check;
111         if (!check)
112                 check = attr_check_initl("export-ignore", "export-subst", NULL);
113         git_check_attr(istate, path, check);
114         return check;
115 }
116
117 static int check_attr_export_ignore(const struct attr_check *check)
118 {
119         return check && ATTR_TRUE(check->items[0].value);
120 }
121
122 static int check_attr_export_subst(const struct attr_check *check)
123 {
124         return check && ATTR_TRUE(check->items[1].value);
125 }
126
127 static int write_archive_entry(const struct object_id *oid, const char *base,
128                 int baselen, const char *filename, unsigned mode, int stage,
129                 void *context)
130 {
131         static struct strbuf path = STRBUF_INIT;
132         struct archiver_context *c = context;
133         struct archiver_args *args = c->args;
134         write_archive_entry_fn_t write_entry = c->write_entry;
135         int err;
136         const char *path_without_prefix;
137
138         args->convert = 0;
139         strbuf_reset(&path);
140         strbuf_grow(&path, PATH_MAX);
141         strbuf_add(&path, args->base, args->baselen);
142         strbuf_add(&path, base, baselen);
143         strbuf_addstr(&path, filename);
144         if (S_ISDIR(mode) || S_ISGITLINK(mode))
145                 strbuf_addch(&path, '/');
146         path_without_prefix = path.buf + args->baselen;
147
148         if (!S_ISDIR(mode)) {
149                 const struct attr_check *check;
150                 check = get_archive_attrs(args->repo->index, path_without_prefix);
151                 if (check_attr_export_ignore(check))
152                         return 0;
153                 args->convert = check_attr_export_subst(check);
154         }
155
156         if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
157                 if (args->verbose)
158                         fprintf(stderr, "%.*s\n", (int)path.len, path.buf);
159                 err = write_entry(args, oid, path.buf, path.len, mode);
160                 if (err)
161                         return err;
162                 return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
163         }
164
165         if (args->verbose)
166                 fprintf(stderr, "%.*s\n", (int)path.len, path.buf);
167         return write_entry(args, oid, path.buf, path.len, mode);
168 }
169
170 static void queue_directory(const unsigned char *sha1,
171                 struct strbuf *base, const char *filename,
172                 unsigned mode, int stage, struct archiver_context *c)
173 {
174         struct directory *d;
175         size_t len = st_add4(base->len, 1, strlen(filename), 1);
176         d = xmalloc(st_add(sizeof(*d), len));
177         d->up      = c->bottom;
178         d->baselen = base->len;
179         d->mode    = mode;
180         d->stage   = stage;
181         c->bottom  = d;
182         d->len = xsnprintf(d->path, len, "%.*s%s/", (int)base->len, base->buf, filename);
183         hashcpy(d->oid.hash, sha1);
184 }
185
186 static int write_directory(struct archiver_context *c)
187 {
188         struct directory *d = c->bottom;
189         int ret;
190
191         if (!d)
192                 return 0;
193         c->bottom = d->up;
194         d->path[d->len - 1] = '\0'; /* no trailing slash */
195         ret =
196                 write_directory(c) ||
197                 write_archive_entry(&d->oid, d->path, d->baselen,
198                                     d->path + d->baselen, d->mode,
199                                     d->stage, c) != READ_TREE_RECURSIVE;
200         free(d);
201         return ret ? -1 : 0;
202 }
203
204 static int queue_or_write_archive_entry(const struct object_id *oid,
205                 struct strbuf *base, const char *filename,
206                 unsigned mode, int stage, void *context)
207 {
208         struct archiver_context *c = context;
209
210         while (c->bottom &&
211                !(base->len >= c->bottom->len &&
212                  !strncmp(base->buf, c->bottom->path, c->bottom->len))) {
213                 struct directory *next = c->bottom->up;
214                 free(c->bottom);
215                 c->bottom = next;
216         }
217
218         if (S_ISDIR(mode)) {
219                 size_t baselen = base->len;
220                 const struct attr_check *check;
221
222                 /* Borrow base, but restore its original value when done. */
223                 strbuf_addstr(base, filename);
224                 strbuf_addch(base, '/');
225                 check = get_archive_attrs(c->args->repo->index, base->buf);
226                 strbuf_setlen(base, baselen);
227
228                 if (check_attr_export_ignore(check))
229                         return 0;
230                 queue_directory(oid->hash, base, filename,
231                                 mode, stage, c);
232                 return READ_TREE_RECURSIVE;
233         }
234
235         if (write_directory(c))
236                 return -1;
237         return write_archive_entry(oid, base->buf, base->len, filename, mode,
238                                    stage, context);
239 }
240
241 int write_archive_entries(struct archiver_args *args,
242                 write_archive_entry_fn_t write_entry)
243 {
244         struct archiver_context context;
245         struct unpack_trees_options opts;
246         struct tree_desc t;
247         int err;
248
249         if (args->baselen > 0 && args->base[args->baselen - 1] == '/') {
250                 size_t len = args->baselen;
251
252                 while (len > 1 && args->base[len - 2] == '/')
253                         len--;
254                 if (args->verbose)
255                         fprintf(stderr, "%.*s\n", (int)len, args->base);
256                 err = write_entry(args, &args->tree->object.oid, args->base,
257                                   len, 040777);
258                 if (err)
259                         return err;
260         }
261
262         memset(&context, 0, sizeof(context));
263         context.args = args;
264         context.write_entry = write_entry;
265
266         /*
267          * Setup index and instruct attr to read index only
268          */
269         if (!args->worktree_attributes) {
270                 memset(&opts, 0, sizeof(opts));
271                 opts.index_only = 1;
272                 opts.head_idx = -1;
273                 opts.src_index = args->repo->index;
274                 opts.dst_index = args->repo->index;
275                 opts.fn = oneway_merge;
276                 init_tree_desc(&t, args->tree->buffer, args->tree->size);
277                 if (unpack_trees(1, &t, &opts))
278                         return -1;
279                 git_attr_set_direction(GIT_ATTR_INDEX);
280         }
281
282         err = read_tree_recursive(args->tree, "", 0, 0, &args->pathspec,
283                                   queue_or_write_archive_entry,
284                                   &context);
285         if (err == READ_TREE_RECURSIVE)
286                 err = 0;
287         while (context.bottom) {
288                 struct directory *next = context.bottom->up;
289                 free(context.bottom);
290                 context.bottom = next;
291         }
292         return err;
293 }
294
295 static const struct archiver *lookup_archiver(const char *name)
296 {
297         int i;
298
299         if (!name)
300                 return NULL;
301
302         for (i = 0; i < nr_archivers; i++) {
303                 if (!strcmp(name, archivers[i]->name))
304                         return archivers[i];
305         }
306         return NULL;
307 }
308
309 struct path_exists_context {
310         struct pathspec pathspec;
311         struct archiver_args *args;
312 };
313
314 static int reject_entry(const struct object_id *oid, struct strbuf *base,
315                         const char *filename, unsigned mode,
316                         int stage, void *context)
317 {
318         int ret = -1;
319         struct path_exists_context *ctx = context;
320
321         if (S_ISDIR(mode)) {
322                 struct strbuf sb = STRBUF_INIT;
323                 strbuf_addbuf(&sb, base);
324                 strbuf_addstr(&sb, filename);
325                 if (!match_pathspec(ctx->args->repo->index,
326                                     &ctx->pathspec,
327                                     sb.buf, sb.len, 0, NULL, 1))
328                         ret = READ_TREE_RECURSIVE;
329                 strbuf_release(&sb);
330         }
331         return ret;
332 }
333
334 static int path_exists(struct archiver_args *args, const char *path)
335 {
336         const char *paths[] = { path, NULL };
337         struct path_exists_context ctx;
338         int ret;
339
340         ctx.args = args;
341         parse_pathspec(&ctx.pathspec, 0, 0, "", paths);
342         ctx.pathspec.recursive = 1;
343         ret = read_tree_recursive(args->tree, "", 0, 0, &ctx.pathspec,
344                                   reject_entry, &ctx);
345         clear_pathspec(&ctx.pathspec);
346         return ret != 0;
347 }
348
349 static void parse_pathspec_arg(const char **pathspec,
350                 struct archiver_args *ar_args)
351 {
352         /*
353          * must be consistent with parse_pathspec in path_exists()
354          * Also if pathspec patterns are dependent, we're in big
355          * trouble as we test each one separately
356          */
357         parse_pathspec(&ar_args->pathspec, 0,
358                        PATHSPEC_PREFER_FULL,
359                        "", pathspec);
360         ar_args->pathspec.recursive = 1;
361         if (pathspec) {
362                 while (*pathspec) {
363                         if (**pathspec && !path_exists(ar_args, *pathspec))
364                                 die(_("pathspec '%s' did not match any files"), *pathspec);
365                         pathspec++;
366                 }
367         }
368 }
369
370 static void parse_treeish_arg(const char **argv,
371                 struct archiver_args *ar_args, const char *prefix,
372                 int remote)
373 {
374         const char *name = argv[0];
375         const unsigned char *commit_sha1;
376         time_t archive_time;
377         struct tree *tree;
378         const struct commit *commit;
379         struct object_id oid;
380
381         /* Remotes are only allowed to fetch actual refs */
382         if (remote && !remote_allow_unreachable) {
383                 char *ref = NULL;
384                 const char *colon = strchrnul(name, ':');
385                 int refnamelen = colon - name;
386
387                 if (!dwim_ref(name, refnamelen, &oid, &ref))
388                         die("no such ref: %.*s", refnamelen, name);
389                 free(ref);
390         }
391
392         if (get_oid(name, &oid))
393                 die("Not a valid object name");
394
395         commit = lookup_commit_reference_gently(ar_args->repo, &oid, 1);
396         if (commit) {
397                 commit_sha1 = commit->object.oid.hash;
398                 archive_time = commit->date;
399         } else {
400                 commit_sha1 = NULL;
401                 archive_time = time(NULL);
402         }
403
404         tree = parse_tree_indirect(&oid);
405         if (tree == NULL)
406                 die("not a tree object");
407
408         if (prefix) {
409                 struct object_id tree_oid;
410                 unsigned int mode;
411                 int err;
412
413                 err = get_tree_entry(&tree->object.oid, prefix, &tree_oid,
414                                      &mode);
415                 if (err || !S_ISDIR(mode))
416                         die("current working directory is untracked");
417
418                 tree = parse_tree_indirect(&tree_oid);
419         }
420         ar_args->tree = tree;
421         ar_args->commit_sha1 = commit_sha1;
422         ar_args->commit = commit;
423         ar_args->time = archive_time;
424 }
425
426 #define OPT__COMPR(s, v, h, p) \
427         OPT_SET_INT_F(s, NULL, v, h, p, PARSE_OPT_NONEG)
428 #define OPT__COMPR_HIDDEN(s, v, p) \
429         OPT_SET_INT_F(s, NULL, v, "", p, PARSE_OPT_NONEG | PARSE_OPT_HIDDEN)
430
431 static int parse_archive_args(int argc, const char **argv,
432                 const struct archiver **ar, struct archiver_args *args,
433                 const char *name_hint, int is_remote)
434 {
435         const char *format = NULL;
436         const char *base = NULL;
437         const char *remote = NULL;
438         const char *exec = NULL;
439         const char *output = NULL;
440         int compression_level = -1;
441         int verbose = 0;
442         int i;
443         int list = 0;
444         int worktree_attributes = 0;
445         struct option opts[] = {
446                 OPT_GROUP(""),
447                 OPT_STRING(0, "format", &format, N_("fmt"), N_("archive format")),
448                 OPT_STRING(0, "prefix", &base, N_("prefix"),
449                         N_("prepend prefix to each pathname in the archive")),
450                 OPT_STRING('o', "output", &output, N_("file"),
451                         N_("write the archive to this file")),
452                 OPT_BOOL(0, "worktree-attributes", &worktree_attributes,
453                         N_("read .gitattributes in working directory")),
454                 OPT__VERBOSE(&verbose, N_("report archived files on stderr")),
455                 OPT__COMPR('0', &compression_level, N_("store only"), 0),
456                 OPT__COMPR('1', &compression_level, N_("compress faster"), 1),
457                 OPT__COMPR_HIDDEN('2', &compression_level, 2),
458                 OPT__COMPR_HIDDEN('3', &compression_level, 3),
459                 OPT__COMPR_HIDDEN('4', &compression_level, 4),
460                 OPT__COMPR_HIDDEN('5', &compression_level, 5),
461                 OPT__COMPR_HIDDEN('6', &compression_level, 6),
462                 OPT__COMPR_HIDDEN('7', &compression_level, 7),
463                 OPT__COMPR_HIDDEN('8', &compression_level, 8),
464                 OPT__COMPR('9', &compression_level, N_("compress better"), 9),
465                 OPT_GROUP(""),
466                 OPT_BOOL('l', "list", &list,
467                         N_("list supported archive formats")),
468                 OPT_GROUP(""),
469                 OPT_STRING(0, "remote", &remote, N_("repo"),
470                         N_("retrieve the archive from remote repository <repo>")),
471                 OPT_STRING(0, "exec", &exec, N_("command"),
472                         N_("path to the remote git-upload-archive command")),
473                 OPT_END()
474         };
475
476         argc = parse_options(argc, argv, NULL, opts, archive_usage, 0);
477
478         if (remote)
479                 die(_("Unexpected option --remote"));
480         if (exec)
481                 die(_("Option --exec can only be used together with --remote"));
482         if (output)
483                 die(_("Unexpected option --output"));
484
485         if (!base)
486                 base = "";
487
488         if (list) {
489                 for (i = 0; i < nr_archivers; i++)
490                         if (!is_remote || archivers[i]->flags & ARCHIVER_REMOTE)
491                                 printf("%s\n", archivers[i]->name);
492                 exit(0);
493         }
494
495         if (!format && name_hint)
496                 format = archive_format_from_filename(name_hint);
497         if (!format)
498                 format = "tar";
499
500         /* We need at least one parameter -- tree-ish */
501         if (argc < 1)
502                 usage_with_options(archive_usage, opts);
503         *ar = lookup_archiver(format);
504         if (!*ar || (is_remote && !((*ar)->flags & ARCHIVER_REMOTE)))
505                 die(_("Unknown archive format '%s'"), format);
506
507         args->compression_level = Z_DEFAULT_COMPRESSION;
508         if (compression_level != -1) {
509                 if ((*ar)->flags & ARCHIVER_WANT_COMPRESSION_LEVELS)
510                         args->compression_level = compression_level;
511                 else {
512                         die(_("Argument not supported for format '%s': -%d"),
513                                         format, compression_level);
514                 }
515         }
516         args->verbose = verbose;
517         args->base = base;
518         args->baselen = strlen(base);
519         args->worktree_attributes = worktree_attributes;
520
521         return argc;
522 }
523
524 int write_archive(int argc, const char **argv, const char *prefix,
525                   struct repository *repo,
526                   const char *name_hint, int remote)
527 {
528         const struct archiver *ar = NULL;
529         struct archiver_args args;
530
531         git_config_get_bool("uploadarchive.allowunreachable", &remote_allow_unreachable);
532         git_config(git_default_config, NULL);
533
534         init_tar_archiver();
535         init_zip_archiver();
536
537         args.repo = repo;
538         argc = parse_archive_args(argc, argv, &ar, &args, name_hint, remote);
539         if (!startup_info->have_repository) {
540                 /*
541                  * We know this will die() with an error, so we could just
542                  * die ourselves; but its error message will be more specific
543                  * than what we could write here.
544                  */
545                 setup_git_directory();
546         }
547
548         parse_treeish_arg(argv, &args, prefix, remote);
549         parse_pathspec_arg(argv + 1, &args);
550
551         return ar->write_archive(ar, &args);
552 }
553
554 static int match_extension(const char *filename, const char *ext)
555 {
556         int prefixlen = strlen(filename) - strlen(ext);
557
558         /*
559          * We need 1 character for the '.', and 1 character to ensure that the
560          * prefix is non-empty (k.e., we don't match .tar.gz with no actual
561          * filename).
562          */
563         if (prefixlen < 2 || filename[prefixlen - 1] != '.')
564                 return 0;
565         return !strcmp(filename + prefixlen, ext);
566 }
567
568 const char *archive_format_from_filename(const char *filename)
569 {
570         int i;
571
572         for (i = 0; i < nr_archivers; i++)
573                 if (match_extension(filename, archivers[i]->name))
574                         return archivers[i]->name;
575         return NULL;
576 }