Sync with Git 2.14.4
[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_sha1_file(oid->hash, &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.typename = &sb;
80                 if (sha1_object_info_extended(oid.hash, &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 (sha1_object_info_extended(oid.hash, &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 = sha1_object_info(oid.hash, 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_sha1_file(oid.hash, &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 (sha1_object_info(oid.hash, NULL) == OBJ_TAG) {
144                                 char *buffer = read_sha1_file(oid.hash, &type, &size);
145                                 const char *target;
146                                 if (!skip_prefix(buffer, "object ", &target) ||
147                                     get_oid_hex(target, &blob_oid))
148                                         die("%s not a valid tag", oid_to_hex(&oid));
149                                 free(buffer);
150                         } else
151                                 oidcpy(&blob_oid, &oid);
152
153                         if (sha1_object_info(blob_oid.hash, NULL) == OBJ_BLOB)
154                                 return stream_blob_to_fd(1, &blob_oid, NULL, 0);
155                         /*
156                          * we attempted to dereference a tag to a blob
157                          * and failed; there may be new dereference
158                          * mechanisms this code is not aware of.
159                          * fall-back to the usual case.
160                          */
161                 }
162                 buf = read_object_with_reference(oid.hash, exp_type, &size, NULL);
163                 break;
164
165         default:
166                 die("git cat-file: unknown option: %s", exp_type);
167         }
168
169         if (!buf)
170                 die("git cat-file %s: bad file", obj_name);
171
172         write_or_die(1, buf, size);
173         free(buf);
174         free(obj_context.path);
175         return 0;
176 }
177
178 struct expand_data {
179         struct object_id oid;
180         enum object_type type;
181         unsigned long size;
182         off_t disk_size;
183         const char *rest;
184         struct object_id delta_base_oid;
185
186         /*
187          * If mark_query is true, we do not expand anything, but rather
188          * just mark the object_info with items we wish to query.
189          */
190         int mark_query;
191
192         /*
193          * Whether to split the input on whitespace before feeding it to
194          * get_sha1; this is decided during the mark_query phase based on
195          * whether we have a %(rest) token in our format.
196          */
197         int split_on_whitespace;
198
199         /*
200          * After a mark_query run, this object_info is set up to be
201          * passed to sha1_object_info_extended. It will point to the data
202          * elements above, so you can retrieve the response from there.
203          */
204         struct object_info info;
205
206         /*
207          * This flag will be true if the requested batch format and options
208          * don't require us to call sha1_object_info, which can then be
209          * optimized out.
210          */
211         unsigned skip_object_info : 1;
212 };
213
214 static int is_atom(const char *atom, const char *s, int slen)
215 {
216         int alen = strlen(atom);
217         return alen == slen && !memcmp(atom, s, alen);
218 }
219
220 static void expand_atom(struct strbuf *sb, const char *atom, int len,
221                         void *vdata)
222 {
223         struct expand_data *data = vdata;
224
225         if (is_atom("objectname", atom, len)) {
226                 if (!data->mark_query)
227                         strbuf_addstr(sb, oid_to_hex(&data->oid));
228         } else if (is_atom("objecttype", atom, len)) {
229                 if (data->mark_query)
230                         data->info.typep = &data->type;
231                 else
232                         strbuf_addstr(sb, typename(data->type));
233         } else if (is_atom("objectsize", atom, len)) {
234                 if (data->mark_query)
235                         data->info.sizep = &data->size;
236                 else
237                         strbuf_addf(sb, "%lu", data->size);
238         } else if (is_atom("objectsize:disk", atom, len)) {
239                 if (data->mark_query)
240                         data->info.disk_sizep = &data->disk_size;
241                 else
242                         strbuf_addf(sb, "%"PRIuMAX, (uintmax_t)data->disk_size);
243         } else if (is_atom("rest", atom, len)) {
244                 if (data->mark_query)
245                         data->split_on_whitespace = 1;
246                 else if (data->rest)
247                         strbuf_addstr(sb, data->rest);
248         } else if (is_atom("deltabase", atom, len)) {
249                 if (data->mark_query)
250                         data->info.delta_base_sha1 = data->delta_base_oid.hash;
251                 else
252                         strbuf_addstr(sb,
253                                       oid_to_hex(&data->delta_base_oid));
254         } else
255                 die("unknown format element: %.*s", len, atom);
256 }
257
258 static size_t expand_format(struct strbuf *sb, const char *start, void *data)
259 {
260         const char *end;
261
262         if (*start != '(')
263                 return 0;
264         end = strchr(start + 1, ')');
265         if (!end)
266                 die("format element '%s' does not end in ')'", start);
267
268         expand_atom(sb, start + 1, end - start - 1, data);
269
270         return end - start + 1;
271 }
272
273 static void batch_write(struct batch_options *opt, const void *data, int len)
274 {
275         if (opt->buffer_output) {
276                 if (fwrite(data, 1, len, stdout) != len)
277                         die_errno("unable to write to stdout");
278         } else
279                 write_or_die(1, data, len);
280 }
281
282 static void print_object_or_die(struct batch_options *opt, struct expand_data *data)
283 {
284         const struct object_id *oid = &data->oid;
285
286         assert(data->info.typep);
287
288         if (data->type == OBJ_BLOB) {
289                 if (opt->buffer_output)
290                         fflush(stdout);
291                 if (opt->cmdmode) {
292                         char *contents;
293                         unsigned long size;
294
295                         if (!data->rest)
296                                 die("missing path for '%s'", oid_to_hex(oid));
297
298                         if (opt->cmdmode == 'w') {
299                                 if (filter_object(data->rest, 0100644, oid,
300                                                   &contents, &size))
301                                         die("could not convert '%s' %s",
302                                             oid_to_hex(oid), data->rest);
303                         } else if (opt->cmdmode == 'c') {
304                                 enum object_type type;
305                                 if (!textconv_object(data->rest, 0100644, oid,
306                                                      1, &contents, &size))
307                                         contents = read_sha1_file(oid->hash, &type,
308                                                                   &size);
309                                 if (!contents)
310                                         die("could not convert '%s' %s",
311                                             oid_to_hex(oid), data->rest);
312                         } else
313                                 die("BUG: invalid cmdmode: %c", opt->cmdmode);
314                         batch_write(opt, contents, size);
315                         free(contents);
316                 } else if (stream_blob_to_fd(1, oid, NULL, 0) < 0)
317                         die("unable to stream %s to stdout", oid_to_hex(oid));
318         }
319         else {
320                 enum object_type type;
321                 unsigned long size;
322                 void *contents;
323
324                 contents = read_sha1_file(oid->hash, &type, &size);
325                 if (!contents)
326                         die("object %s disappeared", oid_to_hex(oid));
327                 if (type != data->type)
328                         die("object %s changed type!?", oid_to_hex(oid));
329                 if (data->info.sizep && size != data->size)
330                         die("object %s changed size!?", oid_to_hex(oid));
331
332                 batch_write(opt, contents, size);
333                 free(contents);
334         }
335 }
336
337 static void batch_object_write(const char *obj_name, struct batch_options *opt,
338                                struct expand_data *data)
339 {
340         struct strbuf buf = STRBUF_INIT;
341
342         if (!data->skip_object_info &&
343             sha1_object_info_extended(data->oid.hash, &data->info,
344                                       OBJECT_INFO_LOOKUP_REPLACE) < 0) {
345                 printf("%s missing\n",
346                        obj_name ? obj_name : oid_to_hex(&data->oid));
347                 fflush(stdout);
348                 return;
349         }
350
351         strbuf_expand(&buf, opt->format, expand_format, data);
352         strbuf_addch(&buf, '\n');
353         batch_write(opt, buf.buf, buf.len);
354         strbuf_release(&buf);
355
356         if (opt->print_contents) {
357                 print_object_or_die(opt, data);
358                 batch_write(opt, "\n", 1);
359         }
360 }
361
362 static void batch_one_object(const char *obj_name, struct batch_options *opt,
363                              struct expand_data *data)
364 {
365         struct object_context ctx;
366         int flags = opt->follow_symlinks ? GET_OID_FOLLOW_SYMLINKS : 0;
367         enum follow_symlinks_result result;
368
369         result = get_oid_with_context(obj_name, flags, &data->oid, &ctx);
370         if (result != FOUND) {
371                 switch (result) {
372                 case MISSING_OBJECT:
373                         printf("%s missing\n", obj_name);
374                         break;
375                 case DANGLING_SYMLINK:
376                         printf("dangling %"PRIuMAX"\n%s\n",
377                                (uintmax_t)strlen(obj_name), obj_name);
378                         break;
379                 case SYMLINK_LOOP:
380                         printf("loop %"PRIuMAX"\n%s\n",
381                                (uintmax_t)strlen(obj_name), obj_name);
382                         break;
383                 case NOT_DIR:
384                         printf("notdir %"PRIuMAX"\n%s\n",
385                                (uintmax_t)strlen(obj_name), obj_name);
386                         break;
387                 default:
388                         die("BUG: unknown get_sha1_with_context result %d\n",
389                                result);
390                         break;
391                 }
392                 fflush(stdout);
393                 return;
394         }
395
396         if (ctx.mode == 0) {
397                 printf("symlink %"PRIuMAX"\n%s\n",
398                        (uintmax_t)ctx.symlink_path.len,
399                        ctx.symlink_path.buf);
400                 fflush(stdout);
401                 return;
402         }
403
404         batch_object_write(obj_name, opt, data);
405 }
406
407 struct object_cb_data {
408         struct batch_options *opt;
409         struct expand_data *expand;
410 };
411
412 static int batch_object_cb(const struct object_id *oid, void *vdata)
413 {
414         struct object_cb_data *data = vdata;
415         oidcpy(&data->expand->oid, oid);
416         batch_object_write(NULL, data->opt, data->expand);
417         return 0;
418 }
419
420 static int batch_loose_object(const struct object_id *oid,
421                               const char *path,
422                               void *data)
423 {
424         oid_array_append(data, oid);
425         return 0;
426 }
427
428 static int batch_packed_object(const struct object_id *oid,
429                                struct packed_git *pack,
430                                uint32_t pos,
431                                void *data)
432 {
433         oid_array_append(data, oid);
434         return 0;
435 }
436
437 static int batch_objects(struct batch_options *opt)
438 {
439         struct strbuf buf = STRBUF_INIT;
440         struct expand_data data;
441         int save_warning;
442         int retval = 0;
443
444         if (!opt->format)
445                 opt->format = "%(objectname) %(objecttype) %(objectsize)";
446
447         /*
448          * Expand once with our special mark_query flag, which will prime the
449          * object_info to be handed to sha1_object_info_extended for each
450          * object.
451          */
452         memset(&data, 0, sizeof(data));
453         data.mark_query = 1;
454         strbuf_expand(&buf, opt->format, expand_format, &data);
455         data.mark_query = 0;
456         if (opt->cmdmode)
457                 data.split_on_whitespace = 1;
458
459         if (opt->all_objects) {
460                 struct object_info empty = OBJECT_INFO_INIT;
461                 if (!memcmp(&data.info, &empty, sizeof(empty)))
462                         data.skip_object_info = 1;
463         }
464
465         /*
466          * If we are printing out the object, then always fill in the type,
467          * since we will want to decide whether or not to stream.
468          */
469         if (opt->print_contents)
470                 data.info.typep = &data.type;
471
472         if (opt->all_objects) {
473                 struct oid_array sa = OID_ARRAY_INIT;
474                 struct object_cb_data cb;
475
476                 for_each_loose_object(batch_loose_object, &sa, 0);
477                 for_each_packed_object(batch_packed_object, &sa, 0);
478
479                 cb.opt = opt;
480                 cb.expand = &data;
481                 oid_array_for_each_unique(&sa, batch_object_cb, &cb);
482
483                 oid_array_clear(&sa);
484                 return 0;
485         }
486
487         /*
488          * We are going to call get_sha1 on a potentially very large number of
489          * objects. In most large cases, these will be actual object sha1s. The
490          * cost to double-check that each one is not also a ref (just so we can
491          * warn) ends up dwarfing the actual cost of the object lookups
492          * themselves. We can work around it by just turning off the warning.
493          */
494         save_warning = warn_on_object_refname_ambiguity;
495         warn_on_object_refname_ambiguity = 0;
496
497         while (strbuf_getline(&buf, stdin) != EOF) {
498                 if (data.split_on_whitespace) {
499                         /*
500                          * Split at first whitespace, tying off the beginning
501                          * of the string and saving the remainder (or NULL) in
502                          * data.rest.
503                          */
504                         char *p = strpbrk(buf.buf, " \t");
505                         if (p) {
506                                 while (*p && strchr(" \t", *p))
507                                         *p++ = '\0';
508                         }
509                         data.rest = p;
510                 }
511
512                 batch_one_object(buf.buf, opt, &data);
513         }
514
515         strbuf_release(&buf);
516         warn_on_object_refname_ambiguity = save_warning;
517         return retval;
518 }
519
520 static const char * const cat_file_usage[] = {
521         N_("git cat-file (-t [--allow-unknown-type] | -s [--allow-unknown-type] | -e | -p | <type> | --textconv | --filters) [--path=<path>] <object>"),
522         N_("git cat-file (--batch | --batch-check) [--follow-symlinks] [--textconv | --filters]"),
523         NULL
524 };
525
526 static int git_cat_file_config(const char *var, const char *value, void *cb)
527 {
528         if (userdiff_config(var, value) < 0)
529                 return -1;
530
531         return git_default_config(var, value, cb);
532 }
533
534 static int batch_option_callback(const struct option *opt,
535                                  const char *arg,
536                                  int unset)
537 {
538         struct batch_options *bo = opt->value;
539
540         if (bo->enabled) {
541                 return 1;
542         }
543
544         bo->enabled = 1;
545         bo->print_contents = !strcmp(opt->long_name, "batch");
546         bo->format = arg;
547
548         return 0;
549 }
550
551 int cmd_cat_file(int argc, const char **argv, const char *prefix)
552 {
553         int opt = 0;
554         const char *exp_type = NULL, *obj_name = NULL;
555         struct batch_options batch = {0};
556         int unknown_type = 0;
557
558         const struct option options[] = {
559                 OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
560                 OPT_CMDMODE('t', NULL, &opt, N_("show object type"), 't'),
561                 OPT_CMDMODE('s', NULL, &opt, N_("show object size"), 's'),
562                 OPT_CMDMODE('e', NULL, &opt,
563                             N_("exit with zero when there's no error"), 'e'),
564                 OPT_CMDMODE('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
565                 OPT_CMDMODE(0, "textconv", &opt,
566                             N_("for blob objects, run textconv on object's content"), 'c'),
567                 OPT_CMDMODE(0, "filters", &opt,
568                             N_("for blob objects, run filters on object's content"), 'w'),
569                 OPT_STRING(0, "path", &force_path, N_("blob"),
570                            N_("use a specific path for --textconv/--filters")),
571                 OPT_BOOL(0, "allow-unknown-type", &unknown_type,
572                           N_("allow -s and -t to work with broken/corrupt objects")),
573                 OPT_BOOL(0, "buffer", &batch.buffer_output, N_("buffer --batch output")),
574                 { OPTION_CALLBACK, 0, "batch", &batch, "format",
575                         N_("show info and content of objects fed from the standard input"),
576                         PARSE_OPT_OPTARG, batch_option_callback },
577                 { OPTION_CALLBACK, 0, "batch-check", &batch, "format",
578                         N_("show info about objects fed from the standard input"),
579                         PARSE_OPT_OPTARG, batch_option_callback },
580                 OPT_BOOL(0, "follow-symlinks", &batch.follow_symlinks,
581                          N_("follow in-tree symlinks (used with --batch or --batch-check)")),
582                 OPT_BOOL(0, "batch-all-objects", &batch.all_objects,
583                          N_("show all objects with --batch or --batch-check")),
584                 OPT_END()
585         };
586
587         git_config(git_cat_file_config, NULL);
588
589         batch.buffer_output = -1;
590         argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
591
592         if (opt) {
593                 if (batch.enabled && (opt == 'c' || opt == 'w'))
594                         batch.cmdmode = opt;
595                 else if (argc == 1)
596                         obj_name = argv[0];
597                 else
598                         usage_with_options(cat_file_usage, options);
599         }
600         if (!opt && !batch.enabled) {
601                 if (argc == 2) {
602                         exp_type = argv[0];
603                         obj_name = argv[1];
604                 } else
605                         usage_with_options(cat_file_usage, options);
606         }
607         if (batch.enabled) {
608                 if (batch.cmdmode != opt || argc)
609                         usage_with_options(cat_file_usage, options);
610                 if (batch.cmdmode && batch.all_objects)
611                         die("--batch-all-objects cannot be combined with "
612                             "--textconv nor with --filters");
613         }
614
615         if ((batch.follow_symlinks || batch.all_objects) && !batch.enabled) {
616                 usage_with_options(cat_file_usage, options);
617         }
618
619         if (force_path && opt != 'c' && opt != 'w') {
620                 error("--path=<path> needs --textconv or --filters");
621                 usage_with_options(cat_file_usage, options);
622         }
623
624         if (force_path && batch.enabled) {
625                 error("--path=<path> incompatible with --batch");
626                 usage_with_options(cat_file_usage, options);
627         }
628
629         if (batch.buffer_output < 0)
630                 batch.buffer_output = batch.all_objects;
631
632         if (batch.enabled)
633                 return batch_objects(&batch);
634
635         if (unknown_type && opt != 't' && opt != 's')
636                 die("git cat-file --allow-unknown-type: use with -s or -t");
637         return cat_one_file(opt, exp_type, obj_name, unknown_type);
638 }