Andrew's git / gitweb.git / builtin/cat-file.c
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builtin / cat-file.con commit submodule: port resolve_relative_url from shell to C (63e95be)
   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
  14struct 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
  23static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
  24                        int unknown_type)
  25{
  26        unsigned char sha1[20];
  27        enum object_type type;
  28        char *buf;
  29        unsigned long size;
  30        struct object_context obj_context;
  31        struct object_info oi = {NULL};
  32        struct strbuf sb = STRBUF_INIT;
  33        unsigned flags = LOOKUP_REPLACE_OBJECT;
  34
  35        if (unknown_type)
  36                flags |= LOOKUP_UNKNOWN_OBJECT;
  37
  38        if (get_sha1_with_context(obj_name, 0, sha1, &obj_context))
  39                die("Not a valid object name %s", obj_name);
  40
  41        buf = NULL;
  42        switch (opt) {
  43        case 't':
  44                oi.typename = &sb;
  45                if (sha1_object_info_extended(sha1, &oi, flags) < 0)
  46                        die("git cat-file: could not get object info");
  47                if (sb.len) {
  48                        printf("%s\n", sb.buf);
  49                        strbuf_release(&sb);
  50                        return 0;
  51                }
  52                break;
  53
  54        case 's':
  55                oi.sizep = &size;
  56                if (sha1_object_info_extended(sha1, &oi, flags) < 0)
  57                        die("git cat-file: could not get object info");
  58                printf("%lu\n", size);
  59                return 0;
  60
  61        case 'e':
  62                return !has_sha1_file(sha1);
  63
  64        case 'c':
  65                if (!obj_context.path[0])
  66                        die("git cat-file --textconv %s: <object> must be <sha1:path>",
  67                            obj_name);
  68
  69                if (textconv_object(obj_context.path, obj_context.mode, sha1, 1, &buf, &size))
  70                        break;
  71
  72        case 'p':
  73                type = sha1_object_info(sha1, NULL);
  74                if (type < 0)
  75                        die("Not a valid object name %s", obj_name);
  76
  77                /* custom pretty-print here */
  78                if (type == OBJ_TREE) {
  79                        const char *ls_args[3] = { NULL };
  80                        ls_args[0] =  "ls-tree";
  81                        ls_args[1] =  obj_name;
  82                        return cmd_ls_tree(2, ls_args, NULL);
  83                }
  84
  85                if (type == OBJ_BLOB)
  86                        return stream_blob_to_fd(1, sha1, NULL, 0);
  87                buf = read_sha1_file(sha1, &type, &size);
  88                if (!buf)
  89                        die("Cannot read object %s", obj_name);
  90
  91                /* otherwise just spit out the data */
  92                break;
  93
  94        case 0:
  95                if (type_from_string(exp_type) == OBJ_BLOB) {
  96                        unsigned char blob_sha1[20];
  97                        if (sha1_object_info(sha1, NULL) == OBJ_TAG) {
  98                                char *buffer = read_sha1_file(sha1, &type, &size);
  99                                const char *target;
 100                                if (!skip_prefix(buffer, "object ", &target) ||
 101                                    get_sha1_hex(target, blob_sha1))
 102                                        die("%s not a valid tag", sha1_to_hex(sha1));
 103                                free(buffer);
 104                        } else
 105                                hashcpy(blob_sha1, sha1);
 106
 107                        if (sha1_object_info(blob_sha1, NULL) == OBJ_BLOB)
 108                                return stream_blob_to_fd(1, blob_sha1, NULL, 0);
 109                        /*
 110                         * we attempted to dereference a tag to a blob
 111                         * and failed; there may be new dereference
 112                         * mechanisms this code is not aware of.
 113                         * fall-back to the usual case.
 114                         */
 115                }
 116                buf = read_object_with_reference(sha1, exp_type, &size, NULL);
 117                break;
 118
 119        default:
 120                die("git cat-file: unknown option: %s", exp_type);
 121        }
 122
 123        if (!buf)
 124                die("git cat-file %s: bad file", obj_name);
 125
 126        write_or_die(1, buf, size);
 127        return 0;
 128}
 129
 130struct expand_data {
 131        unsigned char sha1[20];
 132        enum object_type type;
 133        unsigned long size;
 134        unsigned long disk_size;
 135        const char *rest;
 136        unsigned char delta_base_sha1[20];
 137
 138        /*
 139         * If mark_query is true, we do not expand anything, but rather
 140         * just mark the object_info with items we wish to query.
 141         */
 142        int mark_query;
 143
 144        /*
 145         * Whether to split the input on whitespace before feeding it to
 146         * get_sha1; this is decided during the mark_query phase based on
 147         * whether we have a %(rest) token in our format.
 148         */
 149        int split_on_whitespace;
 150
 151        /*
 152         * After a mark_query run, this object_info is set up to be
 153         * passed to sha1_object_info_extended. It will point to the data
 154         * elements above, so you can retrieve the response from there.
 155         */
 156        struct object_info info;
 157};
 158
 159static int is_atom(const char *atom, const char *s, int slen)
 160{
 161        int alen = strlen(atom);
 162        return alen == slen && !memcmp(atom, s, alen);
 163}
 164
 165static void expand_atom(struct strbuf *sb, const char *atom, int len,
 166                        void *vdata)
 167{
 168        struct expand_data *data = vdata;
 169
 170        if (is_atom("objectname", atom, len)) {
 171                if (!data->mark_query)
 172                        strbuf_addstr(sb, sha1_to_hex(data->sha1));
 173        } else if (is_atom("objecttype", atom, len)) {
 174                if (data->mark_query)
 175                        data->info.typep = &data->type;
 176                else
 177                        strbuf_addstr(sb, typename(data->type));
 178        } else if (is_atom("objectsize", atom, len)) {
 179                if (data->mark_query)
 180                        data->info.sizep = &data->size;
 181                else
 182                        strbuf_addf(sb, "%lu", data->size);
 183        } else if (is_atom("objectsize:disk", atom, len)) {
 184                if (data->mark_query)
 185                        data->info.disk_sizep = &data->disk_size;
 186                else
 187                        strbuf_addf(sb, "%lu", data->disk_size);
 188        } else if (is_atom("rest", atom, len)) {
 189                if (data->mark_query)
 190                        data->split_on_whitespace = 1;
 191                else if (data->rest)
 192                        strbuf_addstr(sb, data->rest);
 193        } else if (is_atom("deltabase", atom, len)) {
 194                if (data->mark_query)
 195                        data->info.delta_base_sha1 = data->delta_base_sha1;
 196                else
 197                        strbuf_addstr(sb, sha1_to_hex(data->delta_base_sha1));
 198        } else
 199                die("unknown format element: %.*s", len, atom);
 200}
 201
 202static size_t expand_format(struct strbuf *sb, const char *start, void *data)
 203{
 204        const char *end;
 205
 206        if (*start != '(')
 207                return 0;
 208        end = strchr(start + 1, ')');
 209        if (!end)
 210                die("format element '%s' does not end in ')'", start);
 211
 212        expand_atom(sb, start + 1, end - start - 1, data);
 213
 214        return end - start + 1;
 215}
 216
 217static void batch_write(struct batch_options *opt, const void *data, int len)
 218{
 219        if (opt->buffer_output) {
 220                if (fwrite(data, 1, len, stdout) != len)
 221                        die_errno("unable to write to stdout");
 222        } else
 223                write_or_die(1, data, len);
 224}
 225
 226static void print_object_or_die(struct batch_options *opt, struct expand_data *data)
 227{
 228        const unsigned char *sha1 = data->sha1;
 229
 230        assert(data->info.typep);
 231
 232        if (data->type == OBJ_BLOB) {
 233                if (opt->buffer_output)
 234                        fflush(stdout);
 235                if (stream_blob_to_fd(1, sha1, NULL, 0) < 0)
 236                        die("unable to stream %s to stdout", sha1_to_hex(sha1));
 237        }
 238        else {
 239                enum object_type type;
 240                unsigned long size;
 241                void *contents;
 242
 243                contents = read_sha1_file(sha1, &type, &size);
 244                if (!contents)
 245                        die("object %s disappeared", sha1_to_hex(sha1));
 246                if (type != data->type)
 247                        die("object %s changed type!?", sha1_to_hex(sha1));
 248                if (data->info.sizep && size != data->size)
 249                        die("object %s changed size!?", sha1_to_hex(sha1));
 250
 251                batch_write(opt, contents, size);
 252                free(contents);
 253        }
 254}
 255
 256static void batch_object_write(const char *obj_name, struct batch_options *opt,
 257                               struct expand_data *data)
 258{
 259        struct strbuf buf = STRBUF_INIT;
 260
 261        if (sha1_object_info_extended(data->sha1, &data->info, LOOKUP_REPLACE_OBJECT) < 0) {
 262                printf("%s missing\n", obj_name ? obj_name : sha1_to_hex(data->sha1));
 263                fflush(stdout);
 264                return;
 265        }
 266
 267        strbuf_expand(&buf, opt->format, expand_format, data);
 268        strbuf_addch(&buf, '\n');
 269        batch_write(opt, buf.buf, buf.len);
 270        strbuf_release(&buf);
 271
 272        if (opt->print_contents) {
 273                print_object_or_die(opt, data);
 274                batch_write(opt, "\n", 1);
 275        }
 276}
 277
 278static void batch_one_object(const char *obj_name, struct batch_options *opt,
 279                             struct expand_data *data)
 280{
 281        struct object_context ctx;
 282        int flags = opt->follow_symlinks ? GET_SHA1_FOLLOW_SYMLINKS : 0;
 283        enum follow_symlinks_result result;
 284
 285        result = get_sha1_with_context(obj_name, flags, data->sha1, &ctx);
 286        if (result != FOUND) {
 287                switch (result) {
 288                case MISSING_OBJECT:
 289                        printf("%s missing\n", obj_name);
 290                        break;
 291                case DANGLING_SYMLINK:
 292                        printf("dangling %"PRIuMAX"\n%s\n",
 293                               (uintmax_t)strlen(obj_name), obj_name);
 294                        break;
 295                case SYMLINK_LOOP:
 296                        printf("loop %"PRIuMAX"\n%s\n",
 297                               (uintmax_t)strlen(obj_name), obj_name);
 298                        break;
 299                case NOT_DIR:
 300                        printf("notdir %"PRIuMAX"\n%s\n",
 301                               (uintmax_t)strlen(obj_name), obj_name);
 302                        break;
 303                default:
 304                        die("BUG: unknown get_sha1_with_context result %d\n",
 305                               result);
 306                        break;
 307                }
 308                fflush(stdout);
 309                return;
 310        }
 311
 312        if (ctx.mode == 0) {
 313                printf("symlink %"PRIuMAX"\n%s\n",
 314                       (uintmax_t)ctx.symlink_path.len,
 315                       ctx.symlink_path.buf);
 316                fflush(stdout);
 317                return;
 318        }
 319
 320        batch_object_write(obj_name, opt, data);
 321}
 322
 323struct object_cb_data {
 324        struct batch_options *opt;
 325        struct expand_data *expand;
 326};
 327
 328static void batch_object_cb(const unsigned char sha1[20], void *vdata)
 329{
 330        struct object_cb_data *data = vdata;
 331        hashcpy(data->expand->sha1, sha1);
 332        batch_object_write(NULL, data->opt, data->expand);
 333}
 334
 335static int batch_loose_object(const unsigned char *sha1,
 336                              const char *path,
 337                              void *data)
 338{
 339        sha1_array_append(data, sha1);
 340        return 0;
 341}
 342
 343static int batch_packed_object(const unsigned char *sha1,
 344                               struct packed_git *pack,
 345                               uint32_t pos,
 346                               void *data)
 347{
 348        sha1_array_append(data, sha1);
 349        return 0;
 350}
 351
 352static int batch_objects(struct batch_options *opt)
 353{
 354        struct strbuf buf = STRBUF_INIT;
 355        struct expand_data data;
 356        int save_warning;
 357        int retval = 0;
 358
 359        if (!opt->format)
 360                opt->format = "%(objectname) %(objecttype) %(objectsize)";
 361
 362        /*
 363         * Expand once with our special mark_query flag, which will prime the
 364         * object_info to be handed to sha1_object_info_extended for each
 365         * object.
 366         */
 367        memset(&data, 0, sizeof(data));
 368        data.mark_query = 1;
 369        strbuf_expand(&buf, opt->format, expand_format, &data);
 370        data.mark_query = 0;
 371
 372        /*
 373         * If we are printing out the object, then always fill in the type,
 374         * since we will want to decide whether or not to stream.
 375         */
 376        if (opt->print_contents)
 377                data.info.typep = &data.type;
 378
 379        if (opt->all_objects) {
 380                struct sha1_array sa = SHA1_ARRAY_INIT;
 381                struct object_cb_data cb;
 382
 383                for_each_loose_object(batch_loose_object, &sa, 0);
 384                for_each_packed_object(batch_packed_object, &sa, 0);
 385
 386                cb.opt = opt;
 387                cb.expand = &data;
 388                sha1_array_for_each_unique(&sa, batch_object_cb, &cb);
 389
 390                sha1_array_clear(&sa);
 391                return 0;
 392        }
 393
 394        /*
 395         * We are going to call get_sha1 on a potentially very large number of
 396         * objects. In most large cases, these will be actual object sha1s. The
 397         * cost to double-check that each one is not also a ref (just so we can
 398         * warn) ends up dwarfing the actual cost of the object lookups
 399         * themselves. We can work around it by just turning off the warning.
 400         */
 401        save_warning = warn_on_object_refname_ambiguity;
 402        warn_on_object_refname_ambiguity = 0;
 403
 404        while (strbuf_getline(&buf, stdin) != EOF) {
 405                if (data.split_on_whitespace) {
 406                        /*
 407                         * Split at first whitespace, tying off the beginning
 408                         * of the string and saving the remainder (or NULL) in
 409                         * data.rest.
 410                         */
 411                        char *p = strpbrk(buf.buf, " \t");
 412                        if (p) {
 413                                while (*p && strchr(" \t", *p))
 414                                        *p++ = '\0';
 415                        }
 416                        data.rest = p;
 417                }
 418
 419                batch_one_object(buf.buf, opt, &data);
 420        }
 421
 422        strbuf_release(&buf);
 423        warn_on_object_refname_ambiguity = save_warning;
 424        return retval;
 425}
 426
 427static const char * const cat_file_usage[] = {
 428        N_("git cat-file (-t [--allow-unknown-type]|-s [--allow-unknown-type]|-e|-p|<type>|--textconv) <object>"),
 429        N_("git cat-file (--batch | --batch-check) [--follow-symlinks]"),
 430        NULL
 431};
 432
 433static int git_cat_file_config(const char *var, const char *value, void *cb)
 434{
 435        if (userdiff_config(var, value) < 0)
 436                return -1;
 437
 438        return git_default_config(var, value, cb);
 439}
 440
 441static int batch_option_callback(const struct option *opt,
 442                                 const char *arg,
 443                                 int unset)
 444{
 445        struct batch_options *bo = opt->value;
 446
 447        if (bo->enabled) {
 448                return 1;
 449        }
 450
 451        bo->enabled = 1;
 452        bo->print_contents = !strcmp(opt->long_name, "batch");
 453        bo->format = arg;
 454
 455        return 0;
 456}
 457
 458int cmd_cat_file(int argc, const char **argv, const char *prefix)
 459{
 460        int opt = 0;
 461        const char *exp_type = NULL, *obj_name = NULL;
 462        struct batch_options batch = {0};
 463        int unknown_type = 0;
 464
 465        const struct option options[] = {
 466                OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
 467                OPT_CMDMODE('t', NULL, &opt, N_("show object type"), 't'),
 468                OPT_CMDMODE('s', NULL, &opt, N_("show object size"), 's'),
 469                OPT_CMDMODE('e', NULL, &opt,
 470                            N_("exit with zero when there's no error"), 'e'),
 471                OPT_CMDMODE('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
 472                OPT_CMDMODE(0, "textconv", &opt,
 473                            N_("for blob objects, run textconv on object's content"), 'c'),
 474                OPT_BOOL(0, "allow-unknown-type", &unknown_type,
 475                          N_("allow -s and -t to work with broken/corrupt objects")),
 476                OPT_BOOL(0, "buffer", &batch.buffer_output, N_("buffer --batch output")),
 477                { OPTION_CALLBACK, 0, "batch", &batch, "format",
 478                        N_("show info and content of objects fed from the standard input"),
 479                        PARSE_OPT_OPTARG, batch_option_callback },
 480                { OPTION_CALLBACK, 0, "batch-check", &batch, "format",
 481                        N_("show info about objects fed from the standard input"),
 482                        PARSE_OPT_OPTARG, batch_option_callback },
 483                OPT_BOOL(0, "follow-symlinks", &batch.follow_symlinks,
 484                         N_("follow in-tree symlinks (used with --batch or --batch-check)")),
 485                OPT_BOOL(0, "batch-all-objects", &batch.all_objects,
 486                         N_("show all objects with --batch or --batch-check")),
 487                OPT_END()
 488        };
 489
 490        git_config(git_cat_file_config, NULL);
 491
 492        argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
 493
 494        if (opt) {
 495                if (argc == 1)
 496                        obj_name = argv[0];
 497                else
 498                        usage_with_options(cat_file_usage, options);
 499        }
 500        if (!opt && !batch.enabled) {
 501                if (argc == 2) {
 502                        exp_type = argv[0];
 503                        obj_name = argv[1];
 504                } else
 505                        usage_with_options(cat_file_usage, options);
 506        }
 507        if (batch.enabled && (opt || argc)) {
 508                usage_with_options(cat_file_usage, options);
 509        }
 510
 511        if ((batch.follow_symlinks || batch.all_objects) && !batch.enabled) {
 512                usage_with_options(cat_file_usage, options);
 513        }
 514
 515        if (batch.enabled)
 516                return batch_objects(&batch);
 517
 518        if (unknown_type && opt != 't' && opt != 's')
 519                die("git cat-file --allow-unknown-type: use with -s or -t");
 520        return cat_one_file(opt, exp_type, obj_name, unknown_type);
 521}