t5300: abstract away SHA-1-specific constants
[git/git.git] / builtin / cat-file.c
1 /*
2 * GIT - The information manager from hell
3 *
4 * Copyright (C) Linus Torvalds, 2005
5 */
6 #include "cache.h"
7 #include "config.h"
8 #include "builtin.h"
9 #include "diff.h"
10 #include "parse-options.h"
11 #include "userdiff.h"
12 #include "streaming.h"
13 #include "tree-walk.h"
14 #include "sha1-array.h"
15 #include "packfile.h"
16
17 struct batch_options {
18 int enabled;
19 int follow_symlinks;
20 int print_contents;
21 int buffer_output;
22 int all_objects;
23 int cmdmode; /* may be 'w' or 'c' for --filters or --textconv */
24 const char *format;
25 };
26
27 static const char *force_path;
28
29 static int filter_object(const char *path, unsigned mode,
30 const struct object_id *oid,
31 char **buf, unsigned long *size)
32 {
33 enum object_type type;
34
35 *buf = read_object_file(oid, &type, size);
36 if (!*buf)
37 return error(_("cannot read object %s '%s'"),
38 oid_to_hex(oid), path);
39 if ((type == OBJ_BLOB) && S_ISREG(mode)) {
40 struct strbuf strbuf = STRBUF_INIT;
41 if (convert_to_working_tree(path, *buf, *size, &strbuf)) {
42 free(*buf);
43 *size = strbuf.len;
44 *buf = strbuf_detach(&strbuf, NULL);
45 }
46 }
47
48 return 0;
49 }
50
51 static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
52 int unknown_type)
53 {
54 struct object_id oid;
55 enum object_type type;
56 char *buf;
57 unsigned long size;
58 struct object_context obj_context;
59 struct object_info oi = OBJECT_INFO_INIT;
60 struct strbuf sb = STRBUF_INIT;
61 unsigned flags = OBJECT_INFO_LOOKUP_REPLACE;
62 const char *path = force_path;
63
64 if (unknown_type)
65 flags |= OBJECT_INFO_ALLOW_UNKNOWN_TYPE;
66
67 if (get_oid_with_context(obj_name, GET_OID_RECORD_PATH,
68 &oid, &obj_context))
69 die("Not a valid object name %s", obj_name);
70
71 if (!path)
72 path = obj_context.path;
73 if (obj_context.mode == S_IFINVALID)
74 obj_context.mode = 0100644;
75
76 buf = NULL;
77 switch (opt) {
78 case 't':
79 oi.type_name = &sb;
80 if (oid_object_info_extended(&oid, &oi, flags) < 0)
81 die("git cat-file: could not get object info");
82 if (sb.len) {
83 printf("%s\n", sb.buf);
84 strbuf_release(&sb);
85 return 0;
86 }
87 break;
88
89 case 's':
90 oi.sizep = &size;
91 if (oid_object_info_extended(&oid, &oi, flags) < 0)
92 die("git cat-file: could not get object info");
93 printf("%lu\n", size);
94 return 0;
95
96 case 'e':
97 return !has_object_file(&oid);
98
99 case 'w':
100 if (!path)
101 die("git cat-file --filters %s: <object> must be "
102 "<sha1:path>", obj_name);
103
104 if (filter_object(path, obj_context.mode,
105 &oid, &buf, &size))
106 return -1;
107 break;
108
109 case 'c':
110 if (!path)
111 die("git cat-file --textconv %s: <object> must be <sha1:path>",
112 obj_name);
113
114 if (textconv_object(path, obj_context.mode, &oid, 1, &buf, &size))
115 break;
116 /* else fallthrough */
117
118 case 'p':
119 type = oid_object_info(&oid, NULL);
120 if (type < 0)
121 die("Not a valid object name %s", obj_name);
122
123 /* custom pretty-print here */
124 if (type == OBJ_TREE) {
125 const char *ls_args[3] = { NULL };
126 ls_args[0] = "ls-tree";
127 ls_args[1] = obj_name;
128 return cmd_ls_tree(2, ls_args, NULL);
129 }
130
131 if (type == OBJ_BLOB)
132 return stream_blob_to_fd(1, &oid, NULL, 0);
133 buf = read_object_file(&oid, &type, &size);
134 if (!buf)
135 die("Cannot read object %s", obj_name);
136
137 /* otherwise just spit out the data */
138 break;
139
140 case 0:
141 if (type_from_string(exp_type) == OBJ_BLOB) {
142 struct object_id blob_oid;
143 if (oid_object_info(&oid, NULL) == OBJ_TAG) {
144 char *buffer = read_object_file(&oid, &type,
145 &size);
146 const char *target;
147 if (!skip_prefix(buffer, "object ", &target) ||
148 get_oid_hex(target, &blob_oid))
149 die("%s not a valid tag", oid_to_hex(&oid));
150 free(buffer);
151 } else
152 oidcpy(&blob_oid, &oid);
153
154 if (oid_object_info(&blob_oid, NULL) == OBJ_BLOB)
155 return stream_blob_to_fd(1, &blob_oid, NULL, 0);
156 /*
157 * we attempted to dereference a tag to a blob
158 * and failed; there may be new dereference
159 * mechanisms this code is not aware of.
160 * fall-back to the usual case.
161 */
162 }
163 buf = read_object_with_reference(&oid, exp_type, &size, NULL);
164 break;
165
166 default:
167 die("git cat-file: unknown option: %s", exp_type);
168 }
169
170 if (!buf)
171 die("git cat-file %s: bad file", obj_name);
172
173 write_or_die(1, buf, size);
174 free(buf);
175 free(obj_context.path);
176 return 0;
177 }
178
179 struct expand_data {
180 struct object_id oid;
181 enum object_type type;
182 unsigned long size;
183 off_t disk_size;
184 const char *rest;
185 struct object_id delta_base_oid;
186
187 /*
188 * If mark_query is true, we do not expand anything, but rather
189 * just mark the object_info with items we wish to query.
190 */
191 int mark_query;
192
193 /*
194 * Whether to split the input on whitespace before feeding it to
195 * get_sha1; this is decided during the mark_query phase based on
196 * whether we have a %(rest) token in our format.
197 */
198 int split_on_whitespace;
199
200 /*
201 * After a mark_query run, this object_info is set up to be
202 * passed to sha1_object_info_extended. It will point to the data
203 * elements above, so you can retrieve the response from there.
204 */
205 struct object_info info;
206
207 /*
208 * This flag will be true if the requested batch format and options
209 * don't require us to call sha1_object_info, which can then be
210 * optimized out.
211 */
212 unsigned skip_object_info : 1;
213 };
214
215 static int is_atom(const char *atom, const char *s, int slen)
216 {
217 int alen = strlen(atom);
218 return alen == slen && !memcmp(atom, s, alen);
219 }
220
221 static void expand_atom(struct strbuf *sb, const char *atom, int len,
222 void *vdata)
223 {
224 struct expand_data *data = vdata;
225
226 if (is_atom("objectname", atom, len)) {
227 if (!data->mark_query)
228 strbuf_addstr(sb, oid_to_hex(&data->oid));
229 } else if (is_atom("objecttype", atom, len)) {
230 if (data->mark_query)
231 data->info.typep = &data->type;
232 else
233 strbuf_addstr(sb, type_name(data->type));
234 } else if (is_atom("objectsize", atom, len)) {
235 if (data->mark_query)
236 data->info.sizep = &data->size;
237 else
238 strbuf_addf(sb, "%lu", data->size);
239 } else if (is_atom("objectsize:disk", atom, len)) {
240 if (data->mark_query)
241 data->info.disk_sizep = &data->disk_size;
242 else
243 strbuf_addf(sb, "%"PRIuMAX, (uintmax_t)data->disk_size);
244 } else if (is_atom("rest", atom, len)) {
245 if (data->mark_query)
246 data->split_on_whitespace = 1;
247 else if (data->rest)
248 strbuf_addstr(sb, data->rest);
249 } else if (is_atom("deltabase", atom, len)) {
250 if (data->mark_query)
251 data->info.delta_base_sha1 = data->delta_base_oid.hash;
252 else
253 strbuf_addstr(sb,
254 oid_to_hex(&data->delta_base_oid));
255 } else
256 die("unknown format element: %.*s", len, atom);
257 }
258
259 static size_t expand_format(struct strbuf *sb, const char *start, void *data)
260 {
261 const char *end;
262
263 if (*start != '(')
264 return 0;
265 end = strchr(start + 1, ')');
266 if (!end)
267 die("format element '%s' does not end in ')'", start);
268
269 expand_atom(sb, start + 1, end - start - 1, data);
270
271 return end - start + 1;
272 }
273
274 static void batch_write(struct batch_options *opt, const void *data, int len)
275 {
276 if (opt->buffer_output) {
277 if (fwrite(data, 1, len, stdout) != len)
278 die_errno("unable to write to stdout");
279 } else
280 write_or_die(1, data, len);
281 }
282
283 static void print_object_or_die(struct batch_options *opt, struct expand_data *data)
284 {
285 const struct object_id *oid = &data->oid;
286
287 assert(data->info.typep);
288
289 if (data->type == OBJ_BLOB) {
290 if (opt->buffer_output)
291 fflush(stdout);
292 if (opt->cmdmode) {
293 char *contents;
294 unsigned long size;
295
296 if (!data->rest)
297 die("missing path for '%s'", oid_to_hex(oid));
298
299 if (opt->cmdmode == 'w') {
300 if (filter_object(data->rest, 0100644, oid,
301 &contents, &size))
302 die("could not convert '%s' %s",
303 oid_to_hex(oid), data->rest);
304 } else if (opt->cmdmode == 'c') {
305 enum object_type type;
306 if (!textconv_object(data->rest, 0100644, oid,
307 1, &contents, &size))
308 contents = read_object_file(oid,
309 &type,
310 &size);
311 if (!contents)
312 die("could not convert '%s' %s",
313 oid_to_hex(oid), data->rest);
314 } else
315 die("BUG: invalid cmdmode: %c", opt->cmdmode);
316 batch_write(opt, contents, size);
317 free(contents);
318 } else if (stream_blob_to_fd(1, oid, NULL, 0) < 0)
319 die("unable to stream %s to stdout", oid_to_hex(oid));
320 }
321 else {
322 enum object_type type;
323 unsigned long size;
324 void *contents;
325
326 contents = read_object_file(oid, &type, &size);
327 if (!contents)
328 die("object %s disappeared", oid_to_hex(oid));
329 if (type != data->type)
330 die("object %s changed type!?", oid_to_hex(oid));
331 if (data->info.sizep && size != data->size)
332 die("object %s changed size!?", oid_to_hex(oid));
333
334 batch_write(opt, contents, size);
335 free(contents);
336 }
337 }
338
339 static void batch_object_write(const char *obj_name, struct batch_options *opt,
340 struct expand_data *data)
341 {
342 struct strbuf buf = STRBUF_INIT;
343
344 if (!data->skip_object_info &&
345 oid_object_info_extended(&data->oid, &data->info,
346 OBJECT_INFO_LOOKUP_REPLACE) < 0) {
347 printf("%s missing\n",
348 obj_name ? obj_name : oid_to_hex(&data->oid));
349 fflush(stdout);
350 return;
351 }
352
353 strbuf_expand(&buf, opt->format, expand_format, data);
354 strbuf_addch(&buf, '\n');
355 batch_write(opt, buf.buf, buf.len);
356 strbuf_release(&buf);
357
358 if (opt->print_contents) {
359 print_object_or_die(opt, data);
360 batch_write(opt, "\n", 1);
361 }
362 }
363
364 static void batch_one_object(const char *obj_name, struct batch_options *opt,
365 struct expand_data *data)
366 {
367 struct object_context ctx;
368 int flags = opt->follow_symlinks ? GET_OID_FOLLOW_SYMLINKS : 0;
369 enum follow_symlinks_result result;
370
371 result = get_oid_with_context(obj_name, flags, &data->oid, &ctx);
372 if (result != FOUND) {
373 switch (result) {
374 case MISSING_OBJECT:
375 printf("%s missing\n", obj_name);
376 break;
377 case DANGLING_SYMLINK:
378 printf("dangling %"PRIuMAX"\n%s\n",
379 (uintmax_t)strlen(obj_name), obj_name);
380 break;
381 case SYMLINK_LOOP:
382 printf("loop %"PRIuMAX"\n%s\n",
383 (uintmax_t)strlen(obj_name), obj_name);
384 break;
385 case NOT_DIR:
386 printf("notdir %"PRIuMAX"\n%s\n",
387 (uintmax_t)strlen(obj_name), obj_name);
388 break;
389 default:
390 die("BUG: unknown get_sha1_with_context result %d\n",
391 result);
392 break;
393 }
394 fflush(stdout);
395 return;
396 }
397
398 if (ctx.mode == 0) {
399 printf("symlink %"PRIuMAX"\n%s\n",
400 (uintmax_t)ctx.symlink_path.len,
401 ctx.symlink_path.buf);
402 fflush(stdout);
403 return;
404 }
405
406 batch_object_write(obj_name, opt, data);
407 }
408
409 struct object_cb_data {
410 struct batch_options *opt;
411 struct expand_data *expand;
412 };
413
414 static int batch_object_cb(const struct object_id *oid, void *vdata)
415 {
416 struct object_cb_data *data = vdata;
417 oidcpy(&data->expand->oid, oid);
418 batch_object_write(NULL, data->opt, data->expand);
419 return 0;
420 }
421
422 static int batch_loose_object(const struct object_id *oid,
423 const char *path,
424 void *data)
425 {
426 oid_array_append(data, oid);
427 return 0;
428 }
429
430 static int batch_packed_object(const struct object_id *oid,
431 struct packed_git *pack,
432 uint32_t pos,
433 void *data)
434 {
435 oid_array_append(data, oid);
436 return 0;
437 }
438
439 static int batch_objects(struct batch_options *opt)
440 {
441 struct strbuf buf = STRBUF_INIT;
442 struct expand_data data;
443 int save_warning;
444 int retval = 0;
445
446 if (!opt->format)
447 opt->format = "%(objectname) %(objecttype) %(objectsize)";
448
449 /*
450 * Expand once with our special mark_query flag, which will prime the
451 * object_info to be handed to sha1_object_info_extended for each
452 * object.
453 */
454 memset(&data, 0, sizeof(data));
455 data.mark_query = 1;
456 strbuf_expand(&buf, opt->format, expand_format, &data);
457 data.mark_query = 0;
458 if (opt->cmdmode)
459 data.split_on_whitespace = 1;
460
461 if (opt->all_objects) {
462 struct object_info empty = OBJECT_INFO_INIT;
463 if (!memcmp(&data.info, &empty, sizeof(empty)))
464 data.skip_object_info = 1;
465 }
466
467 /*
468 * If we are printing out the object, then always fill in the type,
469 * since we will want to decide whether or not to stream.
470 */
471 if (opt->print_contents)
472 data.info.typep = &data.type;
473
474 if (opt->all_objects) {
475 struct oid_array sa = OID_ARRAY_INIT;
476 struct object_cb_data cb;
477
478 for_each_loose_object(batch_loose_object, &sa, 0);
479 for_each_packed_object(batch_packed_object, &sa, 0);
480 if (repository_format_partial_clone)
481 warning("This repository has extensions.partialClone set. Some objects may not be loaded.");
482
483 cb.opt = opt;
484 cb.expand = &data;
485 oid_array_for_each_unique(&sa, batch_object_cb, &cb);
486
487 oid_array_clear(&sa);
488 return 0;
489 }
490
491 /*
492 * We are going to call get_sha1 on a potentially very large number of
493 * objects. In most large cases, these will be actual object sha1s. The
494 * cost to double-check that each one is not also a ref (just so we can
495 * warn) ends up dwarfing the actual cost of the object lookups
496 * themselves. We can work around it by just turning off the warning.
497 */
498 save_warning = warn_on_object_refname_ambiguity;
499 warn_on_object_refname_ambiguity = 0;
500
501 while (strbuf_getline(&buf, stdin) != EOF) {
502 if (data.split_on_whitespace) {
503 /*
504 * Split at first whitespace, tying off the beginning
505 * of the string and saving the remainder (or NULL) in
506 * data.rest.
507 */
508 char *p = strpbrk(buf.buf, " \t");
509 if (p) {
510 while (*p && strchr(" \t", *p))
511 *p++ = '\0';
512 }
513 data.rest = p;
514 }
515
516 batch_one_object(buf.buf, opt, &data);
517 }
518
519 strbuf_release(&buf);
520 warn_on_object_refname_ambiguity = save_warning;
521 return retval;
522 }
523
524 static const char * const cat_file_usage[] = {
525 N_("git cat-file (-t [--allow-unknown-type] | -s [--allow-unknown-type] | -e | -p | <type> | --textconv | --filters) [--path=<path>] <object>"),
526 N_("git cat-file (--batch | --batch-check) [--follow-symlinks] [--textconv | --filters]"),
527 NULL
528 };
529
530 static int git_cat_file_config(const char *var, const char *value, void *cb)
531 {
532 if (userdiff_config(var, value) < 0)
533 return -1;
534
535 return git_default_config(var, value, cb);
536 }
537
538 static int batch_option_callback(const struct option *opt,
539 const char *arg,
540 int unset)
541 {
542 struct batch_options *bo = opt->value;
543
544 if (bo->enabled) {
545 return 1;
546 }
547
548 bo->enabled = 1;
549 bo->print_contents = !strcmp(opt->long_name, "batch");
550 bo->format = arg;
551
552 return 0;
553 }
554
555 int cmd_cat_file(int argc, const char **argv, const char *prefix)
556 {
557 int opt = 0;
558 const char *exp_type = NULL, *obj_name = NULL;
559 struct batch_options batch = {0};
560 int unknown_type = 0;
561
562 const struct option options[] = {
563 OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
564 OPT_CMDMODE('t', NULL, &opt, N_("show object type"), 't'),
565 OPT_CMDMODE('s', NULL, &opt, N_("show object size"), 's'),
566 OPT_CMDMODE('e', NULL, &opt,
567 N_("exit with zero when there's no error"), 'e'),
568 OPT_CMDMODE('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
569 OPT_CMDMODE(0, "textconv", &opt,
570 N_("for blob objects, run textconv on object's content"), 'c'),
571 OPT_CMDMODE(0, "filters", &opt,
572 N_("for blob objects, run filters on object's content"), 'w'),
573 OPT_STRING(0, "path", &force_path, N_("blob"),
574 N_("use a specific path for --textconv/--filters")),
575 OPT_BOOL(0, "allow-unknown-type", &unknown_type,
576 N_("allow -s and -t to work with broken/corrupt objects")),
577 OPT_BOOL(0, "buffer", &batch.buffer_output, N_("buffer --batch output")),
578 { OPTION_CALLBACK, 0, "batch", &batch, "format",
579 N_("show info and content of objects fed from the standard input"),
580 PARSE_OPT_OPTARG, batch_option_callback },
581 { OPTION_CALLBACK, 0, "batch-check", &batch, "format",
582 N_("show info about objects fed from the standard input"),
583 PARSE_OPT_OPTARG, batch_option_callback },
584 OPT_BOOL(0, "follow-symlinks", &batch.follow_symlinks,
585 N_("follow in-tree symlinks (used with --batch or --batch-check)")),
586 OPT_BOOL(0, "batch-all-objects", &batch.all_objects,
587 N_("show all objects with --batch or --batch-check")),
588 OPT_END()
589 };
590
591 git_config(git_cat_file_config, NULL);
592
593 batch.buffer_output = -1;
594 argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
595
596 if (opt) {
597 if (batch.enabled && (opt == 'c' || opt == 'w'))
598 batch.cmdmode = opt;
599 else if (argc == 1)
600 obj_name = argv[0];
601 else
602 usage_with_options(cat_file_usage, options);
603 }
604 if (!opt && !batch.enabled) {
605 if (argc == 2) {
606 exp_type = argv[0];
607 obj_name = argv[1];
608 } else
609 usage_with_options(cat_file_usage, options);
610 }
611 if (batch.enabled) {
612 if (batch.cmdmode != opt || argc)
613 usage_with_options(cat_file_usage, options);
614 if (batch.cmdmode && batch.all_objects)
615 die("--batch-all-objects cannot be combined with "
616 "--textconv nor with --filters");
617 }
618
619 if ((batch.follow_symlinks || batch.all_objects) && !batch.enabled) {
620 usage_with_options(cat_file_usage, options);
621 }
622
623 if (force_path && opt != 'c' && opt != 'w') {
624 error("--path=<path> needs --textconv or --filters");
625 usage_with_options(cat_file_usage, options);
626 }
627
628 if (force_path && batch.enabled) {
629 error("--path=<path> incompatible with --batch");
630 usage_with_options(cat_file_usage, options);
631 }
632
633 if (batch.buffer_output < 0)
634 batch.buffer_output = batch.all_objects;
635
636 if (batch.enabled)
637 return batch_objects(&batch);
638
639 if (unknown_type && opt != 't' && opt != 's')
640 die("git cat-file --allow-unknown-type: use with -s or -t");
641 return cat_one_file(opt, exp_type, obj_name, unknown_type);
642 }