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 #include "object-store.h"
  17
  18 struct batch_options {
  19         int enabled;
  20         int follow_symlinks;
  21         int print_contents;
  22         int buffer_output;
  23         int all_objects;
  24         int cmdmode; /* may be 'w' or 'c' for --filters or --textconv */
  25         const char *format;
  26 };
  27
  28 static const char *force_path;
  29
  30 static int filter_object(const char *path, unsigned mode,
  31                          const struct object_id *oid,
  32                          char **buf, unsigned long *size)
  33 {
  34         enum object_type type;
  35
  36         *buf = read_object_file(oid, &type, size);
  37         if (!*buf)
  38                 return error(_("cannot read object %s '%s'"),
  39                              oid_to_hex(oid), path);
  40         if ((type == OBJ_BLOB) && S_ISREG(mode)) {
  41                 struct strbuf strbuf = STRBUF_INIT;
  42                 if (convert_to_working_tree(path, *buf, *size, &strbuf)) {
  43                         free(*buf);
  44                         *size = strbuf.len;
  45                         *buf = strbuf_detach(&strbuf, NULL);
  46                 }
  47         }
  48
  49         return 0;
  50 }
  51
  52 static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
  53                         int unknown_type)
  54 {
  55         struct object_id oid;
  56         enum object_type type;
  57         char *buf;
  58         unsigned long size;
  59         struct object_context obj_context;
  60         struct object_info oi = OBJECT_INFO_INIT;
  61         struct strbuf sb = STRBUF_INIT;
  62         unsigned flags = OBJECT_INFO_LOOKUP_REPLACE;
  63         const char *path = force_path;
  64
  65         if (unknown_type)
  66                 flags |= OBJECT_INFO_ALLOW_UNKNOWN_TYPE;
  67
  68         if (get_oid_with_context(obj_name, GET_OID_RECORD_PATH,
  69                                  &oid, &obj_context))
  70                 die("Not a valid object name %s", obj_name);
  71
  72         if (!path)
  73                 path = obj_context.path;
  74         if (obj_context.mode == S_IFINVALID)
  75                 obj_context.mode = 0100644;
  76
  77         buf = NULL;
  78         switch (opt) {
  79         case 't':
  80                 oi.type_name = &sb;
  81                 if (oid_object_info_extended(the_repository, &oid, &oi, flags) < 0)
  82                         die("git cat-file: could not get object info");
  83                 if (sb.len) {
  84                         printf("%s\n", sb.buf);
  85                         strbuf_release(&sb);
  86                         return 0;
  87                 }
  88                 break;
  89
  90         case 's':
  91                 oi.sizep = &size;
  92                 if (oid_object_info_extended(the_repository, &oid, &oi, flags) < 0)
  93                         die("git cat-file: could not get object info");
  94                 printf("%lu\n", size);
  95                 return 0;
  96
  97         case 'e':
  98                 return !has_object_file(&oid);
  99
 100         case 'w':
 101                 if (!path)
 102                         die("git cat-file --filters %s: <object> must be "
 103                             "<sha1:path>", obj_name);
 104
 105                 if (filter_object(path, obj_context.mode,
 106                                   &oid, &buf, &size))
 107                         return -1;
 108                 break;
 109
 110         case 'c':
 111                 if (!path)
 112                         die("git cat-file --textconv %s: <object> must be <sha1:path>",
 113                             obj_name);
 114
 115                 if (textconv_object(path, obj_context.mode, &oid, 1, &buf, &size))
 116                         break;
 117                 /* else fallthrough */
 118
 119         case 'p':
 120                 type = oid_object_info(the_repository, &oid, NULL);
 121                 if (type < 0)
 122                         die("Not a valid object name %s", obj_name);
 123
 124                 /* custom pretty-print here */
 125                 if (type == OBJ_TREE) {
 126                         const char *ls_args[3] = { NULL };
 127                         ls_args[0] =  "ls-tree";
 128                         ls_args[1] =  obj_name;
 129                         return cmd_ls_tree(2, ls_args, NULL);
 130                 }
 131
 132                 if (type == OBJ_BLOB)
 133                         return stream_blob_to_fd(1, &oid, NULL, 0);
 134                 buf = read_object_file(&oid, &type, &size);
 135                 if (!buf)
 136                         die("Cannot read object %s", obj_name);
 137
 138                 /* otherwise just spit out the data */
 139                 break;
 140
 141         case 0:
 142                 if (type_from_string(exp_type) == OBJ_BLOB) {
 143                         struct object_id blob_oid;
 144                         if (oid_object_info(the_repository, &oid, NULL) == OBJ_TAG) {
 145                                 char *buffer = read_object_file(&oid, &type,
 146                                                                 &size);
 147                                 const char *target;
 148                                 if (!skip_prefix(buffer, "object ", &target) ||
 149                                     get_oid_hex(target, &blob_oid))
 150                                         die("%s not a valid tag", oid_to_hex(&oid));
 151                                 free(buffer);
 152                         } else
 153                                 oidcpy(&blob_oid, &oid);
 154
 155                         if (oid_object_info(the_repository, &blob_oid, NULL) == OBJ_BLOB)
 156                                 return stream_blob_to_fd(1, &blob_oid, NULL, 0);
 157                         /*
 158                          * we attempted to dereference a tag to a blob
 159                          * and failed; there may be new dereference
 160                          * mechanisms this code is not aware of.
 161                          * fall-back to the usual case.
 162                          */
 163                 }
 164                 buf = read_object_with_reference(&oid, exp_type, &size, NULL);
 165                 break;
 166
 167         default:
 168                 die("git cat-file: unknown option: %s", exp_type);
 169         }
 170
 171         if (!buf)
 172                 die("git cat-file %s: bad file", obj_name);
 173
 174         write_or_die(1, buf, size);
 175         free(buf);
 176         free(obj_context.path);
 177         return 0;
 178 }
 179
 180 struct expand_data {
 181         struct object_id oid;
 182         enum object_type type;
 183         unsigned long size;
 184         off_t disk_size;
 185         const char *rest;
 186         struct object_id delta_base_oid;
 187
 188         /*
 189          * If mark_query is true, we do not expand anything, but rather
 190          * just mark the object_info with items we wish to query.
 191          */
 192         int mark_query;
 193
 194         /*
 195          * Whether to split the input on whitespace before feeding it to
 196          * get_sha1; this is decided during the mark_query phase based on
 197          * whether we have a %(rest) token in our format.
 198          */
 199         int split_on_whitespace;
 200
 201         /*
 202          * After a mark_query run, this object_info is set up to be
 203          * passed to sha1_object_info_extended. It will point to the data
 204          * elements above, so you can retrieve the response from there.
 205          */
 206         struct object_info info;
 207
 208         /*
 209          * This flag will be true if the requested batch format and options
 210          * don't require us to call sha1_object_info, which can then be
 211          * optimized out.
 212          */
 213         unsigned skip_object_info : 1;
 214 };
 215
 216 static int is_atom(const char *atom, const char *s, int slen)
 217 {
 218         int alen = strlen(atom);
 219         return alen == slen && !memcmp(atom, s, alen);
 220 }
 221
 222 static void expand_atom(struct strbuf *sb, const char *atom, int len,
 223                         void *vdata)
 224 {
 225         struct expand_data *data = vdata;
 226
 227         if (is_atom("objectname", atom, len)) {
 228                 if (!data->mark_query)
 229                         strbuf_addstr(sb, oid_to_hex(&data->oid));
 230         } else if (is_atom("objecttype", atom, len)) {
 231                 if (data->mark_query)
 232                         data->info.typep = &data->type;
 233                 else
 234                         strbuf_addstr(sb, type_name(data->type));
 235         } else if (is_atom("objectsize", atom, len)) {
 236                 if (data->mark_query)
 237                         data->info.sizep = &data->size;
 238                 else
 239                         strbuf_addf(sb, "%lu", data->size);
 240         } else if (is_atom("objectsize:disk", atom, len)) {
 241                 if (data->mark_query)
 242                         data->info.disk_sizep = &data->disk_size;
 243                 else
 244                         strbuf_addf(sb, "%"PRIuMAX, (uintmax_t)data->disk_size);
 245         } else if (is_atom("rest", atom, len)) {
 246                 if (data->mark_query)
 247                         data->split_on_whitespace = 1;
 248                 else if (data->rest)
 249                         strbuf_addstr(sb, data->rest);
 250         } else if (is_atom("deltabase", atom, len)) {
 251                 if (data->mark_query)
 252                         data->info.delta_base_sha1 = data->delta_base_oid.hash;
 253                 else
 254                         strbuf_addstr(sb,
 255                                       oid_to_hex(&data->delta_base_oid));
 256         } else
 257                 die("unknown format element: %.*s", len, atom);
 258 }
 259
 260 static size_t expand_format(struct strbuf *sb, const char *start, void *data)
 261 {
 262         const char *end;
 263
 264         if (*start != '(')
 265                 return 0;
 266         end = strchr(start + 1, ')');
 267         if (!end)
 268                 die("format element '%s' does not end in ')'", start);
 269
 270         expand_atom(sb, start + 1, end - start - 1, data);
 271
 272         return end - start + 1;
 273 }
 274
 275 static void batch_write(struct batch_options *opt, const void *data, int len)
 276 {
 277         if (opt->buffer_output) {
 278                 if (fwrite(data, 1, len, stdout) != len)
 279                         die_errno("unable to write to stdout");
 280         } else
 281                 write_or_die(1, data, len);
 282 }
 283
 284 static void print_object_or_die(struct batch_options *opt, struct expand_data *data)
 285 {
 286         const struct object_id *oid = &data->oid;
 287
 288         assert(data->info.typep);
 289
 290         if (data->type == OBJ_BLOB) {
 291                 if (opt->buffer_output)
 292                         fflush(stdout);
 293                 if (opt->cmdmode) {
 294                         char *contents;
 295                         unsigned long size;
 296
 297                         if (!data->rest)
 298                                 die("missing path for '%s'", oid_to_hex(oid));
 299
 300                         if (opt->cmdmode == 'w') {
 301                                 if (filter_object(data->rest, 0100644, oid,
 302                                                   &contents, &size))
 303                                         die("could not convert '%s' %s",
 304                                             oid_to_hex(oid), data->rest);
 305                         } else if (opt->cmdmode == 'c') {
 306                                 enum object_type type;
 307                                 if (!textconv_object(data->rest, 0100644, oid,
 308                                                      1, &contents, &size))
 309                                         contents = read_object_file(oid,
 310                                                                     &type,
 311                                                                     &size);
 312                                 if (!contents)
 313                                         die("could not convert '%s' %s",
 314                                             oid_to_hex(oid), data->rest);
 315                         } else
 316                                 BUG("invalid cmdmode: %c", opt->cmdmode);
 317                         batch_write(opt, contents, size);
 318                         free(contents);
 319                 } else if (stream_blob_to_fd(1, oid, NULL, 0) < 0)
 320                         die("unable to stream %s to stdout", oid_to_hex(oid));
 321         }
 322         else {
 323                 enum object_type type;
 324                 unsigned long size;
 325                 void *contents;
 326
 327                 contents = read_object_file(oid, &type, &size);
 328                 if (!contents)
 329                         die("object %s disappeared", oid_to_hex(oid));
 330                 if (type != data->type)
 331                         die("object %s changed type!?", oid_to_hex(oid));
 332                 if (data->info.sizep && size != data->size)
 333                         die("object %s changed size!?", oid_to_hex(oid));
 334
 335                 batch_write(opt, contents, size);
 336                 free(contents);
 337         }
 338 }
 339
 340 static void batch_object_write(const char *obj_name, struct batch_options *opt,
 341                                struct expand_data *data)
 342 {
 343         struct strbuf buf = STRBUF_INIT;
 344
 345         if (!data->skip_object_info &&
 346             oid_object_info_extended(the_repository, &data->oid, &data->info,
 347                                      OBJECT_INFO_LOOKUP_REPLACE) < 0) {
 348                 printf("%s missing\n",
 349                        obj_name ? obj_name : oid_to_hex(&data->oid));
 350                 fflush(stdout);
 351                 return;
 352         }
 353
 354         strbuf_expand(&buf, opt->format, expand_format, data);
 355         strbuf_addch(&buf, '\n');
 356         batch_write(opt, buf.buf, buf.len);
 357         strbuf_release(&buf);
 358
 359         if (opt->print_contents) {
 360                 print_object_or_die(opt, data);
 361                 batch_write(opt, "\n", 1);
 362         }
 363 }
 364
 365 static void batch_one_object(const char *obj_name, struct batch_options *opt,
 366                              struct expand_data *data)
 367 {
 368         struct object_context ctx;
 369         int flags = opt->follow_symlinks ? GET_OID_FOLLOW_SYMLINKS : 0;
 370         enum follow_symlinks_result result;
 371
 372         result = get_oid_with_context(obj_name, flags, &data->oid, &ctx);
 373         if (result != FOUND) {
 374                 switch (result) {
 375                 case MISSING_OBJECT:
 376                         printf("%s missing\n", obj_name);
 377                         break;
 378                 case DANGLING_SYMLINK:
 379                         printf("dangling %"PRIuMAX"\n%s\n",
 380                                (uintmax_t)strlen(obj_name), obj_name);
 381                         break;
 382                 case SYMLINK_LOOP:
 383                         printf("loop %"PRIuMAX"\n%s\n",
 384                                (uintmax_t)strlen(obj_name), obj_name);
 385                         break;
 386                 case NOT_DIR:
 387                         printf("notdir %"PRIuMAX"\n%s\n",
 388                                (uintmax_t)strlen(obj_name), obj_name);
 389                         break;
 390                 default:
 391                         BUG("unknown get_sha1_with_context result %d\n",
 392                                result);
 393                         break;
 394                 }
 395                 fflush(stdout);
 396                 return;
 397         }
 398
 399         if (ctx.mode == 0) {
 400                 printf("symlink %"PRIuMAX"\n%s\n",
 401                        (uintmax_t)ctx.symlink_path.len,
 402                        ctx.symlink_path.buf);
 403                 fflush(stdout);
 404                 return;
 405         }
 406
 407         batch_object_write(obj_name, opt, data);
 408 }
 409
 410 struct object_cb_data {
 411         struct batch_options *opt;
 412         struct expand_data *expand;
 413 };
 414
 415 static int batch_object_cb(const struct object_id *oid, void *vdata)
 416 {
 417         struct object_cb_data *data = vdata;
 418         oidcpy(&data->expand->oid, oid);
 419         batch_object_write(NULL, data->opt, data->expand);
 420         return 0;
 421 }
 422
 423 static int batch_loose_object(const struct object_id *oid,
 424                               const char *path,
 425                               void *data)
 426 {
 427         oid_array_append(data, oid);
 428         return 0;
 429 }
 430
 431 static int batch_packed_object(const struct object_id *oid,
 432                                struct packed_git *pack,
 433                                uint32_t pos,
 434                                void *data)
 435 {
 436         oid_array_append(data, oid);
 437         return 0;
 438 }
 439
 440 static int batch_objects(struct batch_options *opt)
 441 {
 442         struct strbuf buf = STRBUF_INIT;
 443         struct expand_data data;
 444         int save_warning;
 445         int retval = 0;
 446
 447         if (!opt->format)
 448                 opt->format = "%(objectname) %(objecttype) %(objectsize)";
 449
 450         /*
 451          * Expand once with our special mark_query flag, which will prime the
 452          * object_info to be handed to sha1_object_info_extended for each
 453          * object.
 454          */
 455         memset(&data, 0, sizeof(data));
 456         data.mark_query = 1;
 457         strbuf_expand(&buf, opt->format, expand_format, &data);
 458         data.mark_query = 0;
 459         if (opt->cmdmode)
 460                 data.split_on_whitespace = 1;
 461
 462         if (opt->all_objects) {
 463                 struct object_info empty = OBJECT_INFO_INIT;
 464                 if (!memcmp(&data.info, &empty, sizeof(empty)))
 465                         data.skip_object_info = 1;
 466         }
 467
 468         /*
 469          * If we are printing out the object, then always fill in the type,
 470          * since we will want to decide whether or not to stream.
 471          */
 472         if (opt->print_contents)
 473                 data.info.typep = &data.type;
 474
 475         if (opt->all_objects) {
 476                 struct oid_array sa = OID_ARRAY_INIT;
 477                 struct object_cb_data cb;
 478
 479                 for_each_loose_object(batch_loose_object, &sa, 0);
 480                 for_each_packed_object(batch_packed_object, &sa, 0);
 481                 if (repository_format_partial_clone)
 482                         warning("This repository has extensions.partialClone set. Some objects may not be loaded.");
 483
 484                 cb.opt = opt;
 485                 cb.expand = &data;
 486                 oid_array_for_each_unique(&sa, batch_object_cb, &cb);
 487
 488                 oid_array_clear(&sa);
 489                 return 0;
 490         }
 491
 492         /*
 493          * We are going to call get_sha1 on a potentially very large number of
 494          * objects. In most large cases, these will be actual object sha1s. The
 495          * cost to double-check that each one is not also a ref (just so we can
 496          * warn) ends up dwarfing the actual cost of the object lookups
 497          * themselves. We can work around it by just turning off the warning.
 498          */
 499         save_warning = warn_on_object_refname_ambiguity;
 500         warn_on_object_refname_ambiguity = 0;
 501
 502         while (strbuf_getline(&buf, stdin) != EOF) {
 503                 if (data.split_on_whitespace) {
 504                         /*
 505                          * Split at first whitespace, tying off the beginning
 506                          * of the string and saving the remainder (or NULL) in
 507                          * data.rest.
 508                          */
 509                         char *p = strpbrk(buf.buf, " \t");
 510                         if (p) {
 511                                 while (*p && strchr(" \t", *p))
 512                                         *p++ = '\0';
 513                         }
 514                         data.rest = p;
 515                 }
 516
 517                 batch_one_object(buf.buf, opt, &data);
 518         }
 519
 520         strbuf_release(&buf);
 521         warn_on_object_refname_ambiguity = save_warning;
 522         return retval;
 523 }
 524
 525 static const char * const cat_file_usage[] = {
 526         N_("git cat-file (-t [--allow-unknown-type] | -s [--allow-unknown-type] | -e | -p | <type> | --textconv | --filters) [--path=<path>] <object>"),
 527         N_("git cat-file (--batch | --batch-check) [--follow-symlinks] [--textconv | --filters]"),
 528         NULL
 529 };
 530
 531 static int git_cat_file_config(const char *var, const char *value, void *cb)
 532 {
 533         if (userdiff_config(var, value) < 0)
 534                 return -1;
 535
 536         return git_default_config(var, value, cb);
 537 }
 538
 539 static int batch_option_callback(const struct option *opt,
 540                                  const char *arg,
 541                                  int unset)
 542 {
 543         struct batch_options *bo = opt->value;
 544
 545         if (bo->enabled) {
 546                 return 1;
 547         }
 548
 549         bo->enabled = 1;
 550         bo->print_contents = !strcmp(opt->long_name, "batch");
 551         bo->format = arg;
 552
 553         return 0;
 554 }
 555
 556 int cmd_cat_file(int argc, const char **argv, const char *prefix)
 557 {
 558         int opt = 0;
 559         const char *exp_type = NULL, *obj_name = NULL;
 560         struct batch_options batch = {0};
 561         int unknown_type = 0;
 562
 563         const struct option options[] = {
 564                 OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
 565                 OPT_CMDMODE('t', NULL, &opt, N_("show object type"), 't'),
 566                 OPT_CMDMODE('s', NULL, &opt, N_("show object size"), 's'),
 567                 OPT_CMDMODE('e', NULL, &opt,
 568                             N_("exit with zero when there's no error"), 'e'),
 569                 OPT_CMDMODE('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
 570                 OPT_CMDMODE(0, "textconv", &opt,
 571                             N_("for blob objects, run textconv on object's content"), 'c'),
 572                 OPT_CMDMODE(0, "filters", &opt,
 573                             N_("for blob objects, run filters on object's content"), 'w'),
 574                 OPT_STRING(0, "path", &force_path, N_("blob"),
 575                            N_("use a specific path for --textconv/--filters")),
 576                 OPT_BOOL(0, "allow-unknown-type", &unknown_type,
 577                           N_("allow -s and -t to work with broken/corrupt objects")),
 578                 OPT_BOOL(0, "buffer", &batch.buffer_output, N_("buffer --batch output")),
 579                 { OPTION_CALLBACK, 0, "batch", &batch, "format",
 580                         N_("show info and content of objects fed from the standard input"),
 581                         PARSE_OPT_OPTARG, batch_option_callback },
 582                 { OPTION_CALLBACK, 0, "batch-check", &batch, "format",
 583                         N_("show info about objects fed from the standard input"),
 584                         PARSE_OPT_OPTARG, batch_option_callback },
 585                 OPT_BOOL(0, "follow-symlinks", &batch.follow_symlinks,
 586                          N_("follow in-tree symlinks (used with --batch or --batch-check)")),
 587                 OPT_BOOL(0, "batch-all-objects", &batch.all_objects,
 588                          N_("show all objects with --batch or --batch-check")),
 589                 OPT_END()
 590         };
 591
 592         git_config(git_cat_file_config, NULL);
 593
 594         batch.buffer_output = -1;
 595         argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
 596
 597         if (opt) {
 598                 if (batch.enabled && (opt == 'c' || opt == 'w'))
 599                         batch.cmdmode = opt;
 600                 else if (argc == 1)
 601                         obj_name = argv[0];
 602                 else
 603                         usage_with_options(cat_file_usage, options);
 604         }
 605         if (!opt && !batch.enabled) {
 606                 if (argc == 2) {
 607                         exp_type = argv[0];
 608                         obj_name = argv[1];
 609                 } else
 610                         usage_with_options(cat_file_usage, options);
 611         }
 612         if (batch.enabled) {
 613                 if (batch.cmdmode != opt || argc)
 614                         usage_with_options(cat_file_usage, options);
 615                 if (batch.cmdmode && batch.all_objects)
 616                         die("--batch-all-objects cannot be combined with "
 617                             "--textconv nor with --filters");
 618         }
 619
 620         if ((batch.follow_symlinks || batch.all_objects) && !batch.enabled) {
 621                 usage_with_options(cat_file_usage, options);
 622         }
 623
 624         if (force_path && opt != 'c' && opt != 'w') {
 625                 error("--path=<path> needs --textconv or --filters");
 626                 usage_with_options(cat_file_usage, options);
 627         }
 628
 629         if (force_path && batch.enabled) {
 630                 error("--path=<path> incompatible with --batch");
 631                 usage_with_options(cat_file_usage, options);
 632         }
 633
 634         if (batch.buffer_output < 0)
 635                 batch.buffer_output = batch.all_objects;
 636
 637         if (batch.enabled)
 638                 return batch_objects(&batch);
 639
 640         if (unknown_type && opt != 't' && opt != 's')
 641                 die("git cat-file --allow-unknown-type: use with -s or -t");
 642         return cat_one_file(opt, exp_type, obj_name, unknown_type);
 643 }