git.oblomov.eu Git - git/blob - 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 "builtin.h"
   8 #include "parse-options.h"
   9 #include "userdiff.h"
  10 #include "streaming.h"
  11 #include "tree-walk.h"
  12 #include "sha1-array.h"
  13
  14 struct batch_options {
  15         int enabled;
  16         int follow_symlinks;
  17         int print_contents;
  18         int buffer_output;
  19         int all_objects;
  20         const char *format;
  21 };
  22
  23 static int filter_object(const char *path, unsigned mode,
  24                          const unsigned char *sha1,
  25                          char **buf, unsigned long *size)
  26 {
  27         enum object_type type;
  28
  29         *buf = read_sha1_file(sha1, &type, size);
  30         if (!*buf)
  31                 return error(_("cannot read object %s '%s'"),
  32                         sha1_to_hex(sha1), path);
  33         if ((type == OBJ_BLOB) && S_ISREG(mode)) {
  34                 struct strbuf strbuf = STRBUF_INIT;
  35                 if (convert_to_working_tree(path, *buf, *size, &strbuf)) {
  36                         free(*buf);
  37                         *size = strbuf.len;
  38                         *buf = strbuf_detach(&strbuf, NULL);
  39                 }
  40         }
  41
  42         return 0;
  43 }
  44
  45 static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
  46                         int unknown_type)
  47 {
  48         unsigned char sha1[20];
  49         enum object_type type;
  50         char *buf;
  51         unsigned long size;
  52         struct object_context obj_context;
  53         struct object_info oi = {NULL};
  54         struct strbuf sb = STRBUF_INIT;
  55         unsigned flags = LOOKUP_REPLACE_OBJECT;
  56
  57         if (unknown_type)
  58                 flags |= LOOKUP_UNKNOWN_OBJECT;
  59
  60         if (get_sha1_with_context(obj_name, 0, sha1, &obj_context))
  61                 die("Not a valid object name %s", obj_name);
  62
  63         buf = NULL;
  64         switch (opt) {
  65         case 't':
  66                 oi.typename = &sb;
  67                 if (sha1_object_info_extended(sha1, &oi, flags) < 0)
  68                         die("git cat-file: could not get object info");
  69                 if (sb.len) {
  70                         printf("%s\n", sb.buf);
  71                         strbuf_release(&sb);
  72                         return 0;
  73                 }
  74                 break;
  75
  76         case 's':
  77                 oi.sizep = &size;
  78                 if (sha1_object_info_extended(sha1, &oi, flags) < 0)
  79                         die("git cat-file: could not get object info");
  80                 printf("%lu\n", size);
  81                 return 0;
  82
  83         case 'e':
  84                 return !has_sha1_file(sha1);
  85
  86         case 'w':
  87                 if (!obj_context.path[0])
  88                         die("git cat-file --filters %s: <object> must be "
  89                             "<sha1:path>", obj_name);
  90
  91                 if (filter_object(obj_context.path, obj_context.mode,
  92                                   sha1, &buf, &size))
  93                         return -1;
  94                 break;
  95
  96         case 'c':
  97                 if (!obj_context.path[0])
  98                         die("git cat-file --textconv %s: <object> must be <sha1:path>",
  99                             obj_name);
 100
 101                 if (textconv_object(obj_context.path, obj_context.mode, sha1, 1, &buf, &size))
 102                         break;
 103
 104         case 'p':
 105                 type = sha1_object_info(sha1, NULL);
 106                 if (type < 0)
 107                         die("Not a valid object name %s", obj_name);
 108
 109                 /* custom pretty-print here */
 110                 if (type == OBJ_TREE) {
 111                         const char *ls_args[3] = { NULL };
 112                         ls_args[0] =  "ls-tree";
 113                         ls_args[1] =  obj_name;
 114                         return cmd_ls_tree(2, ls_args, NULL);
 115                 }
 116
 117                 if (type == OBJ_BLOB)
 118                         return stream_blob_to_fd(1, sha1, NULL, 0);
 119                 buf = read_sha1_file(sha1, &type, &size);
 120                 if (!buf)
 121                         die("Cannot read object %s", obj_name);
 122
 123                 /* otherwise just spit out the data */
 124                 break;
 125
 126         case 0:
 127                 if (type_from_string(exp_type) == OBJ_BLOB) {
 128                         unsigned char blob_sha1[20];
 129                         if (sha1_object_info(sha1, NULL) == OBJ_TAG) {
 130                                 char *buffer = read_sha1_file(sha1, &type, &size);
 131                                 const char *target;
 132                                 if (!skip_prefix(buffer, "object ", &target) ||
 133                                     get_sha1_hex(target, blob_sha1))
 134                                         die("%s not a valid tag", sha1_to_hex(sha1));
 135                                 free(buffer);
 136                         } else
 137                                 hashcpy(blob_sha1, sha1);
 138
 139                         if (sha1_object_info(blob_sha1, NULL) == OBJ_BLOB)
 140                                 return stream_blob_to_fd(1, blob_sha1, NULL, 0);
 141                         /*
 142                          * we attempted to dereference a tag to a blob
 143                          * and failed; there may be new dereference
 144                          * mechanisms this code is not aware of.
 145                          * fall-back to the usual case.
 146                          */
 147                 }
 148                 buf = read_object_with_reference(sha1, exp_type, &size, NULL);
 149                 break;
 150
 151         default:
 152                 die("git cat-file: unknown option: %s", exp_type);
 153         }
 154
 155         if (!buf)
 156                 die("git cat-file %s: bad file", obj_name);
 157
 158         write_or_die(1, buf, size);
 159         return 0;
 160 }
 161
 162 struct expand_data {
 163         unsigned char sha1[20];
 164         enum object_type type;
 165         unsigned long size;
 166         off_t disk_size;
 167         const char *rest;
 168         unsigned char delta_base_sha1[20];
 169
 170         /*
 171          * If mark_query is true, we do not expand anything, but rather
 172          * just mark the object_info with items we wish to query.
 173          */
 174         int mark_query;
 175
 176         /*
 177          * Whether to split the input on whitespace before feeding it to
 178          * get_sha1; this is decided during the mark_query phase based on
 179          * whether we have a %(rest) token in our format.
 180          */
 181         int split_on_whitespace;
 182
 183         /*
 184          * After a mark_query run, this object_info is set up to be
 185          * passed to sha1_object_info_extended. It will point to the data
 186          * elements above, so you can retrieve the response from there.
 187          */
 188         struct object_info info;
 189
 190         /*
 191          * This flag will be true if the requested batch format and options
 192          * don't require us to call sha1_object_info, which can then be
 193          * optimized out.
 194          */
 195         unsigned skip_object_info : 1;
 196 };
 197
 198 static int is_atom(const char *atom, const char *s, int slen)
 199 {
 200         int alen = strlen(atom);
 201         return alen == slen && !memcmp(atom, s, alen);
 202 }
 203
 204 static void expand_atom(struct strbuf *sb, const char *atom, int len,
 205                         void *vdata)
 206 {
 207         struct expand_data *data = vdata;
 208
 209         if (is_atom("objectname", atom, len)) {
 210                 if (!data->mark_query)
 211                         strbuf_addstr(sb, sha1_to_hex(data->sha1));
 212         } else if (is_atom("objecttype", atom, len)) {
 213                 if (data->mark_query)
 214                         data->info.typep = &data->type;
 215                 else
 216                         strbuf_addstr(sb, typename(data->type));
 217         } else if (is_atom("objectsize", atom, len)) {
 218                 if (data->mark_query)
 219                         data->info.sizep = &data->size;
 220                 else
 221                         strbuf_addf(sb, "%lu", data->size);
 222         } else if (is_atom("objectsize:disk", atom, len)) {
 223                 if (data->mark_query)
 224                         data->info.disk_sizep = &data->disk_size;
 225                 else
 226                         strbuf_addf(sb, "%"PRIuMAX, (uintmax_t)data->disk_size);
 227         } else if (is_atom("rest", atom, len)) {
 228                 if (data->mark_query)
 229                         data->split_on_whitespace = 1;
 230                 else if (data->rest)
 231                         strbuf_addstr(sb, data->rest);
 232         } else if (is_atom("deltabase", atom, len)) {
 233                 if (data->mark_query)
 234                         data->info.delta_base_sha1 = data->delta_base_sha1;
 235                 else
 236                         strbuf_addstr(sb, sha1_to_hex(data->delta_base_sha1));
 237         } else
 238                 die("unknown format element: %.*s", len, atom);
 239 }
 240
 241 static size_t expand_format(struct strbuf *sb, const char *start, void *data)
 242 {
 243         const char *end;
 244
 245         if (*start != '(')
 246                 return 0;
 247         end = strchr(start + 1, ')');
 248         if (!end)
 249                 die("format element '%s' does not end in ')'", start);
 250
 251         expand_atom(sb, start + 1, end - start - 1, data);
 252
 253         return end - start + 1;
 254 }
 255
 256 static void batch_write(struct batch_options *opt, const void *data, int len)
 257 {
 258         if (opt->buffer_output) {
 259                 if (fwrite(data, 1, len, stdout) != len)
 260                         die_errno("unable to write to stdout");
 261         } else
 262                 write_or_die(1, data, len);
 263 }
 264
 265 static void print_object_or_die(struct batch_options *opt, struct expand_data *data)
 266 {
 267         const unsigned char *sha1 = data->sha1;
 268
 269         assert(data->info.typep);
 270
 271         if (data->type == OBJ_BLOB) {
 272                 if (opt->buffer_output)
 273                         fflush(stdout);
 274                 if (stream_blob_to_fd(1, sha1, NULL, 0) < 0)
 275                         die("unable to stream %s to stdout", sha1_to_hex(sha1));
 276         }
 277         else {
 278                 enum object_type type;
 279                 unsigned long size;
 280                 void *contents;
 281
 282                 contents = read_sha1_file(sha1, &type, &size);
 283                 if (!contents)
 284                         die("object %s disappeared", sha1_to_hex(sha1));
 285                 if (type != data->type)
 286                         die("object %s changed type!?", sha1_to_hex(sha1));
 287                 if (data->info.sizep && size != data->size)
 288                         die("object %s changed size!?", sha1_to_hex(sha1));
 289
 290                 batch_write(opt, contents, size);
 291                 free(contents);
 292         }
 293 }
 294
 295 static void batch_object_write(const char *obj_name, struct batch_options *opt,
 296                                struct expand_data *data)
 297 {
 298         struct strbuf buf = STRBUF_INIT;
 299
 300         if (!data->skip_object_info &&
 301             sha1_object_info_extended(data->sha1, &data->info, LOOKUP_REPLACE_OBJECT) < 0) {
 302                 printf("%s missing\n", obj_name ? obj_name : sha1_to_hex(data->sha1));
 303                 fflush(stdout);
 304                 return;
 305         }
 306
 307         strbuf_expand(&buf, opt->format, expand_format, data);
 308         strbuf_addch(&buf, '\n');
 309         batch_write(opt, buf.buf, buf.len);
 310         strbuf_release(&buf);
 311
 312         if (opt->print_contents) {
 313                 print_object_or_die(opt, data);
 314                 batch_write(opt, "\n", 1);
 315         }
 316 }
 317
 318 static void batch_one_object(const char *obj_name, struct batch_options *opt,
 319                              struct expand_data *data)
 320 {
 321         struct object_context ctx;
 322         int flags = opt->follow_symlinks ? GET_SHA1_FOLLOW_SYMLINKS : 0;
 323         enum follow_symlinks_result result;
 324
 325         result = get_sha1_with_context(obj_name, flags, data->sha1, &ctx);
 326         if (result != FOUND) {
 327                 switch (result) {
 328                 case MISSING_OBJECT:
 329                         printf("%s missing\n", obj_name);
 330                         break;
 331                 case DANGLING_SYMLINK:
 332                         printf("dangling %"PRIuMAX"\n%s\n",
 333                                (uintmax_t)strlen(obj_name), obj_name);
 334                         break;
 335                 case SYMLINK_LOOP:
 336                         printf("loop %"PRIuMAX"\n%s\n",
 337                                (uintmax_t)strlen(obj_name), obj_name);
 338                         break;
 339                 case NOT_DIR:
 340                         printf("notdir %"PRIuMAX"\n%s\n",
 341                                (uintmax_t)strlen(obj_name), obj_name);
 342                         break;
 343                 default:
 344                         die("BUG: unknown get_sha1_with_context result %d\n",
 345                                result);
 346                         break;
 347                 }
 348                 fflush(stdout);
 349                 return;
 350         }
 351
 352         if (ctx.mode == 0) {
 353                 printf("symlink %"PRIuMAX"\n%s\n",
 354                        (uintmax_t)ctx.symlink_path.len,
 355                        ctx.symlink_path.buf);
 356                 fflush(stdout);
 357                 return;
 358         }
 359
 360         batch_object_write(obj_name, opt, data);
 361 }
 362
 363 struct object_cb_data {
 364         struct batch_options *opt;
 365         struct expand_data *expand;
 366 };
 367
 368 static void batch_object_cb(const unsigned char sha1[20], void *vdata)
 369 {
 370         struct object_cb_data *data = vdata;
 371         hashcpy(data->expand->sha1, sha1);
 372         batch_object_write(NULL, data->opt, data->expand);
 373 }
 374
 375 static int batch_loose_object(const unsigned char *sha1,
 376                               const char *path,
 377                               void *data)
 378 {
 379         sha1_array_append(data, sha1);
 380         return 0;
 381 }
 382
 383 static int batch_packed_object(const unsigned char *sha1,
 384                                struct packed_git *pack,
 385                                uint32_t pos,
 386                                void *data)
 387 {
 388         sha1_array_append(data, sha1);
 389         return 0;
 390 }
 391
 392 static int batch_objects(struct batch_options *opt)
 393 {
 394         struct strbuf buf = STRBUF_INIT;
 395         struct expand_data data;
 396         int save_warning;
 397         int retval = 0;
 398
 399         if (!opt->format)
 400                 opt->format = "%(objectname) %(objecttype) %(objectsize)";
 401
 402         /*
 403          * Expand once with our special mark_query flag, which will prime the
 404          * object_info to be handed to sha1_object_info_extended for each
 405          * object.
 406          */
 407         memset(&data, 0, sizeof(data));
 408         data.mark_query = 1;
 409         strbuf_expand(&buf, opt->format, expand_format, &data);
 410         data.mark_query = 0;
 411
 412         if (opt->all_objects) {
 413                 struct object_info empty;
 414                 memset(&empty, 0, sizeof(empty));
 415                 if (!memcmp(&data.info, &empty, sizeof(empty)))
 416                         data.skip_object_info = 1;
 417         }
 418
 419         /*
 420          * If we are printing out the object, then always fill in the type,
 421          * since we will want to decide whether or not to stream.
 422          */
 423         if (opt->print_contents)
 424                 data.info.typep = &data.type;
 425
 426         if (opt->all_objects) {
 427                 struct sha1_array sa = SHA1_ARRAY_INIT;
 428                 struct object_cb_data cb;
 429
 430                 for_each_loose_object(batch_loose_object, &sa, 0);
 431                 for_each_packed_object(batch_packed_object, &sa, 0);
 432
 433                 cb.opt = opt;
 434                 cb.expand = &data;
 435                 sha1_array_for_each_unique(&sa, batch_object_cb, &cb);
 436
 437                 sha1_array_clear(&sa);
 438                 return 0;
 439         }
 440
 441         /*
 442          * We are going to call get_sha1 on a potentially very large number of
 443          * objects. In most large cases, these will be actual object sha1s. The
 444          * cost to double-check that each one is not also a ref (just so we can
 445          * warn) ends up dwarfing the actual cost of the object lookups
 446          * themselves. We can work around it by just turning off the warning.
 447          */
 448         save_warning = warn_on_object_refname_ambiguity;
 449         warn_on_object_refname_ambiguity = 0;
 450
 451         while (strbuf_getline(&buf, stdin) != EOF) {
 452                 if (data.split_on_whitespace) {
 453                         /*
 454                          * Split at first whitespace, tying off the beginning
 455                          * of the string and saving the remainder (or NULL) in
 456                          * data.rest.
 457                          */
 458                         char *p = strpbrk(buf.buf, " \t");
 459                         if (p) {
 460                                 while (*p && strchr(" \t", *p))
 461                                         *p++ = '\0';
 462                         }
 463                         data.rest = p;
 464                 }
 465
 466                 batch_one_object(buf.buf, opt, &data);
 467         }
 468
 469         strbuf_release(&buf);
 470         warn_on_object_refname_ambiguity = save_warning;
 471         return retval;
 472 }
 473
 474 static const char * const cat_file_usage[] = {
 475         N_("git cat-file (-t [--allow-unknown-type]|-s [--allow-unknown-type]|-e|-p|<type>|--textconv|--filters) <object>"),
 476         N_("git cat-file (--batch | --batch-check) [--follow-symlinks]"),
 477         NULL
 478 };
 479
 480 static int git_cat_file_config(const char *var, const char *value, void *cb)
 481 {
 482         if (userdiff_config(var, value) < 0)
 483                 return -1;
 484
 485         return git_default_config(var, value, cb);
 486 }
 487
 488 static int batch_option_callback(const struct option *opt,
 489                                  const char *arg,
 490                                  int unset)
 491 {
 492         struct batch_options *bo = opt->value;
 493
 494         if (bo->enabled) {
 495                 return 1;
 496         }
 497
 498         bo->enabled = 1;
 499         bo->print_contents = !strcmp(opt->long_name, "batch");
 500         bo->format = arg;
 501
 502         return 0;
 503 }
 504
 505 int cmd_cat_file(int argc, const char **argv, const char *prefix)
 506 {
 507         int opt = 0;
 508         const char *exp_type = NULL, *obj_name = NULL;
 509         struct batch_options batch = {0};
 510         int unknown_type = 0;
 511
 512         const struct option options[] = {
 513                 OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
 514                 OPT_CMDMODE('t', NULL, &opt, N_("show object type"), 't'),
 515                 OPT_CMDMODE('s', NULL, &opt, N_("show object size"), 's'),
 516                 OPT_CMDMODE('e', NULL, &opt,
 517                             N_("exit with zero when there's no error"), 'e'),
 518                 OPT_CMDMODE('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
 519                 OPT_CMDMODE(0, "textconv", &opt,
 520                             N_("for blob objects, run textconv on object's content"), 'c'),
 521                 OPT_CMDMODE(0, "filters", &opt,
 522                             N_("for blob objects, run filters on object's content"), 'w'),
 523                 OPT_BOOL(0, "allow-unknown-type", &unknown_type,
 524                           N_("allow -s and -t to work with broken/corrupt objects")),
 525                 OPT_BOOL(0, "buffer", &batch.buffer_output, N_("buffer --batch output")),
 526                 { OPTION_CALLBACK, 0, "batch", &batch, "format",
 527                         N_("show info and content of objects fed from the standard input"),
 528                         PARSE_OPT_OPTARG, batch_option_callback },
 529                 { OPTION_CALLBACK, 0, "batch-check", &batch, "format",
 530                         N_("show info about objects fed from the standard input"),
 531                         PARSE_OPT_OPTARG, batch_option_callback },
 532                 OPT_BOOL(0, "follow-symlinks", &batch.follow_symlinks,
 533                          N_("follow in-tree symlinks (used with --batch or --batch-check)")),
 534                 OPT_BOOL(0, "batch-all-objects", &batch.all_objects,
 535                          N_("show all objects with --batch or --batch-check")),
 536                 OPT_END()
 537         };
 538
 539         git_config(git_cat_file_config, NULL);
 540
 541         batch.buffer_output = -1;
 542         argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
 543
 544         if (opt) {
 545                 if (argc == 1)
 546                         obj_name = argv[0];
 547                 else
 548                         usage_with_options(cat_file_usage, options);
 549         }
 550         if (!opt && !batch.enabled) {
 551                 if (argc == 2) {
 552                         exp_type = argv[0];
 553                         obj_name = argv[1];
 554                 } else
 555                         usage_with_options(cat_file_usage, options);
 556         }
 557         if (batch.enabled && (opt || argc)) {
 558                 usage_with_options(cat_file_usage, options);
 559         }
 560
 561         if ((batch.follow_symlinks || batch.all_objects) && !batch.enabled) {
 562                 usage_with_options(cat_file_usage, options);
 563         }
 564
 565         if (batch.buffer_output < 0)
 566                 batch.buffer_output = batch.all_objects;
 567
 568         if (batch.enabled)
 569                 return batch_objects(&batch);
 570
 571         if (unknown_type && opt != 't' && opt != 's')
 572                 die("git cat-file --allow-unknown-type: use with -s or -t");
 573         return cat_one_file(opt, exp_type, obj_name, unknown_type);
 574 }