Andrew's git - gitweb.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
  12static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
  13                        int unknown_type)
  14{
  15        unsigned char sha1[20];
  16        enum object_type type;
  17        char *buf;
  18        unsigned long size;
  19        struct object_context obj_context;
  20        struct object_info oi = {NULL};
  21        struct strbuf sb = STRBUF_INIT;
  22        unsigned flags = LOOKUP_REPLACE_OBJECT;
  23
  24        if (unknown_type)
  25                flags |= LOOKUP_UNKNOWN_OBJECT;
  26
  27        if (get_sha1_with_context(obj_name, 0, sha1, &obj_context))
  28                die("Not a valid object name %s", obj_name);
  29
  30        buf = NULL;
  31        switch (opt) {
  32        case 't':
  33                oi.typename = &sb;
  34                if (sha1_object_info_extended(sha1, &oi, flags) < 0)
  35                        die("git cat-file: could not get object info");
  36                if (sb.len) {
  37                        printf("%s\n", sb.buf);
  38                        strbuf_release(&sb);
  39                        return 0;
  40                }
  41                break;
  42
  43        case 's':
  44                oi.sizep = &size;
  45                if (sha1_object_info_extended(sha1, &oi, flags) < 0)
  46                        die("git cat-file: could not get object info");
  47                printf("%lu\n", size);
  48                return 0;
  49
  50        case 'e':
  51                return !has_sha1_file(sha1);
  52
  53        case 'c':
  54                if (!obj_context.path[0])
  55                        die("git cat-file --textconv %s: <object> must be <sha1:path>",
  56                            obj_name);
  57
  58                if (textconv_object(obj_context.path, obj_context.mode, sha1, 1, &buf, &size))
  59                        break;
  60
  61        case 'p':
  62                type = sha1_object_info(sha1, NULL);
  63                if (type < 0)
  64                        die("Not a valid object name %s", obj_name);
  65
  66                /* custom pretty-print here */
  67                if (type == OBJ_TREE) {
  68                        const char *ls_args[3] = { NULL };
  69                        ls_args[0] =  "ls-tree";
  70                        ls_args[1] =  obj_name;
  71                        return cmd_ls_tree(2, ls_args, NULL);
  72                }
  73
  74                if (type == OBJ_BLOB)
  75                        return stream_blob_to_fd(1, sha1, NULL, 0);
  76                buf = read_sha1_file(sha1, &type, &size);
  77                if (!buf)
  78                        die("Cannot read object %s", obj_name);
  79
  80                /* otherwise just spit out the data */
  81                break;
  82
  83        case 0:
  84                if (type_from_string(exp_type) == OBJ_BLOB) {
  85                        unsigned char blob_sha1[20];
  86                        if (sha1_object_info(sha1, NULL) == OBJ_TAG) {
  87                                char *buffer = read_sha1_file(sha1, &type, &size);
  88                                const char *target;
  89                                if (!skip_prefix(buffer, "object ", &target) ||
  90                                    get_sha1_hex(target, blob_sha1))
  91                                        die("%s not a valid tag", sha1_to_hex(sha1));
  92                                free(buffer);
  93                        } else
  94                                hashcpy(blob_sha1, sha1);
  95
  96                        if (sha1_object_info(blob_sha1, NULL) == OBJ_BLOB)
  97                                return stream_blob_to_fd(1, blob_sha1, NULL, 0);
  98                        /*
  99                         * we attempted to dereference a tag to a blob
 100                         * and failed; there may be new dereference
 101                         * mechanisms this code is not aware of.
 102                         * fall-back to the usual case.
 103                         */
 104                }
 105                buf = read_object_with_reference(sha1, exp_type, &size, NULL);
 106                break;
 107
 108        default:
 109                die("git cat-file: unknown option: %s", exp_type);
 110        }
 111
 112        if (!buf)
 113                die("git cat-file %s: bad file", obj_name);
 114
 115        write_or_die(1, buf, size);
 116        return 0;
 117}
 118
 119struct expand_data {
 120        unsigned char sha1[20];
 121        enum object_type type;
 122        unsigned long size;
 123        unsigned long disk_size;
 124        const char *rest;
 125        unsigned char delta_base_sha1[20];
 126
 127        /*
 128         * If mark_query is true, we do not expand anything, but rather
 129         * just mark the object_info with items we wish to query.
 130         */
 131        int mark_query;
 132
 133        /*
 134         * Whether to split the input on whitespace before feeding it to
 135         * get_sha1; this is decided during the mark_query phase based on
 136         * whether we have a %(rest) token in our format.
 137         */
 138        int split_on_whitespace;
 139
 140        /*
 141         * After a mark_query run, this object_info is set up to be
 142         * passed to sha1_object_info_extended. It will point to the data
 143         * elements above, so you can retrieve the response from there.
 144         */
 145        struct object_info info;
 146};
 147
 148static int is_atom(const char *atom, const char *s, int slen)
 149{
 150        int alen = strlen(atom);
 151        return alen == slen && !memcmp(atom, s, alen);
 152}
 153
 154static void expand_atom(struct strbuf *sb, const char *atom, int len,
 155                        void *vdata)
 156{
 157        struct expand_data *data = vdata;
 158
 159        if (is_atom("objectname", atom, len)) {
 160                if (!data->mark_query)
 161                        strbuf_addstr(sb, sha1_to_hex(data->sha1));
 162        } else if (is_atom("objecttype", atom, len)) {
 163                if (data->mark_query)
 164                        data->info.typep = &data->type;
 165                else
 166                        strbuf_addstr(sb, typename(data->type));
 167        } else if (is_atom("objectsize", atom, len)) {
 168                if (data->mark_query)
 169                        data->info.sizep = &data->size;
 170                else
 171                        strbuf_addf(sb, "%lu", data->size);
 172        } else if (is_atom("objectsize:disk", atom, len)) {
 173                if (data->mark_query)
 174                        data->info.disk_sizep = &data->disk_size;
 175                else
 176                        strbuf_addf(sb, "%lu", data->disk_size);
 177        } else if (is_atom("rest", atom, len)) {
 178                if (data->mark_query)
 179                        data->split_on_whitespace = 1;
 180                else if (data->rest)
 181                        strbuf_addstr(sb, data->rest);
 182        } else if (is_atom("deltabase", atom, len)) {
 183                if (data->mark_query)
 184                        data->info.delta_base_sha1 = data->delta_base_sha1;
 185                else
 186                        strbuf_addstr(sb, sha1_to_hex(data->delta_base_sha1));
 187        } else
 188                die("unknown format element: %.*s", len, atom);
 189}
 190
 191static size_t expand_format(struct strbuf *sb, const char *start, void *data)
 192{
 193        const char *end;
 194
 195        if (*start != '(')
 196                return 0;
 197        end = strchr(start + 1, ')');
 198        if (!end)
 199                die("format element '%s' does not end in ')'", start);
 200
 201        expand_atom(sb, start + 1, end - start - 1, data);
 202
 203        return end - start + 1;
 204}
 205
 206static void print_object_or_die(int fd, struct expand_data *data)
 207{
 208        const unsigned char *sha1 = data->sha1;
 209
 210        assert(data->info.typep);
 211
 212        if (data->type == OBJ_BLOB) {
 213                if (stream_blob_to_fd(fd, sha1, NULL, 0) < 0)
 214                        die("unable to stream %s to stdout", sha1_to_hex(sha1));
 215        }
 216        else {
 217                enum object_type type;
 218                unsigned long size;
 219                void *contents;
 220
 221                contents = read_sha1_file(sha1, &type, &size);
 222                if (!contents)
 223                        die("object %s disappeared", sha1_to_hex(sha1));
 224                if (type != data->type)
 225                        die("object %s changed type!?", sha1_to_hex(sha1));
 226                if (data->info.sizep && size != data->size)
 227                        die("object %s changed size!?", sha1_to_hex(sha1));
 228
 229                write_or_die(fd, contents, size);
 230                free(contents);
 231        }
 232}
 233
 234struct batch_options {
 235        int enabled;
 236        int print_contents;
 237        const char *format;
 238};
 239
 240static int batch_one_object(const char *obj_name, struct batch_options *opt,
 241                            struct expand_data *data)
 242{
 243        struct strbuf buf = STRBUF_INIT;
 244
 245        if (!obj_name)
 246           return 1;
 247
 248        if (get_sha1(obj_name, data->sha1)) {
 249                printf("%s missing\n", obj_name);
 250                fflush(stdout);
 251                return 0;
 252        }
 253
 254        if (sha1_object_info_extended(data->sha1, &data->info, LOOKUP_REPLACE_OBJECT) < 0) {
 255                printf("%s missing\n", obj_name);
 256                fflush(stdout);
 257                return 0;
 258        }
 259
 260        strbuf_expand(&buf, opt->format, expand_format, data);
 261        strbuf_addch(&buf, '\n');
 262        write_or_die(1, buf.buf, buf.len);
 263        strbuf_release(&buf);
 264
 265        if (opt->print_contents) {
 266                print_object_or_die(1, data);
 267                write_or_die(1, "\n", 1);
 268        }
 269        return 0;
 270}
 271
 272static int batch_objects(struct batch_options *opt)
 273{
 274        struct strbuf buf = STRBUF_INIT;
 275        struct expand_data data;
 276        int save_warning;
 277        int retval = 0;
 278
 279        if (!opt->format)
 280                opt->format = "%(objectname) %(objecttype) %(objectsize)";
 281
 282        /*
 283         * Expand once with our special mark_query flag, which will prime the
 284         * object_info to be handed to sha1_object_info_extended for each
 285         * object.
 286         */
 287        memset(&data, 0, sizeof(data));
 288        data.mark_query = 1;
 289        strbuf_expand(&buf, opt->format, expand_format, &data);
 290        data.mark_query = 0;
 291
 292        /*
 293         * If we are printing out the object, then always fill in the type,
 294         * since we will want to decide whether or not to stream.
 295         */
 296        if (opt->print_contents)
 297                data.info.typep = &data.type;
 298
 299        /*
 300         * We are going to call get_sha1 on a potentially very large number of
 301         * objects. In most large cases, these will be actual object sha1s. The
 302         * cost to double-check that each one is not also a ref (just so we can
 303         * warn) ends up dwarfing the actual cost of the object lookups
 304         * themselves. We can work around it by just turning off the warning.
 305         */
 306        save_warning = warn_on_object_refname_ambiguity;
 307        warn_on_object_refname_ambiguity = 0;
 308
 309        while (strbuf_getline(&buf, stdin, '\n') != EOF) {
 310                if (data.split_on_whitespace) {
 311                        /*
 312                         * Split at first whitespace, tying off the beginning
 313                         * of the string and saving the remainder (or NULL) in
 314                         * data.rest.
 315                         */
 316                        char *p = strpbrk(buf.buf, " \t");
 317                        if (p) {
 318                                while (*p && strchr(" \t", *p))
 319                                        *p++ = '\0';
 320                        }
 321                        data.rest = p;
 322                }
 323
 324                retval = batch_one_object(buf.buf, opt, &data);
 325                if (retval)
 326                        break;
 327        }
 328
 329        strbuf_release(&buf);
 330        warn_on_object_refname_ambiguity = save_warning;
 331        return retval;
 332}
 333
 334static const char * const cat_file_usage[] = {
 335        N_("git cat-file (-t [--allow-unknown-type]|-s [--allow-unknown-type]|-e|-p|<type>|--textconv) <object>"),
 336        N_("git cat-file (--batch | --batch-check) < <list-of-objects>"),
 337        NULL
 338};
 339
 340static int git_cat_file_config(const char *var, const char *value, void *cb)
 341{
 342        if (userdiff_config(var, value) < 0)
 343                return -1;
 344
 345        return git_default_config(var, value, cb);
 346}
 347
 348static int batch_option_callback(const struct option *opt,
 349                                 const char *arg,
 350                                 int unset)
 351{
 352        struct batch_options *bo = opt->value;
 353
 354        if (unset) {
 355                memset(bo, 0, sizeof(*bo));
 356                return 0;
 357        }
 358
 359        bo->enabled = 1;
 360        bo->print_contents = !strcmp(opt->long_name, "batch");
 361        bo->format = arg;
 362
 363        return 0;
 364}
 365
 366int cmd_cat_file(int argc, const char **argv, const char *prefix)
 367{
 368        int opt = 0;
 369        const char *exp_type = NULL, *obj_name = NULL;
 370        struct batch_options batch = {0};
 371        int unknown_type = 0;
 372
 373        const struct option options[] = {
 374                OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
 375                OPT_CMDMODE('t', NULL, &opt, N_("show object type"), 't'),
 376                OPT_CMDMODE('s', NULL, &opt, N_("show object size"), 's'),
 377                OPT_CMDMODE('e', NULL, &opt,
 378                            N_("exit with zero when there's no error"), 'e'),
 379                OPT_CMDMODE('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
 380                OPT_CMDMODE(0, "textconv", &opt,
 381                            N_("for blob objects, run textconv on object's content"), 'c'),
 382                OPT_BOOL( 0, "allow-unknown-type", &unknown_type,
 383                          N_("allow -s and -t to work with broken/corrupt objects")),
 384                { OPTION_CALLBACK, 0, "batch", &batch, "format",
 385                        N_("show info and content of objects fed from the standard input"),
 386                        PARSE_OPT_OPTARG, batch_option_callback },
 387                { OPTION_CALLBACK, 0, "batch-check", &batch, "format",
 388                        N_("show info about objects fed from the standard input"),
 389                        PARSE_OPT_OPTARG, batch_option_callback },
 390                OPT_END()
 391        };
 392
 393        git_config(git_cat_file_config, NULL);
 394
 395        argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
 396
 397        if (opt) {
 398                if (argc == 1)
 399                        obj_name = argv[0];
 400                else
 401                        usage_with_options(cat_file_usage, options);
 402        }
 403        if (!opt && !batch.enabled) {
 404                if (argc == 2) {
 405                        exp_type = argv[0];
 406                        obj_name = argv[1];
 407                } else
 408                        usage_with_options(cat_file_usage, options);
 409        }
 410        if (batch.enabled && (opt || argc)) {
 411                usage_with_options(cat_file_usage, options);
 412        }
 413
 414        if (batch.enabled)
 415                return batch_objects(&batch);
 416
 417        if (unknown_type && opt != 't' && opt != 's')
 418                die("git cat-file --allow-unknown-type: use with -s or -t");
 419        return cat_one_file(opt, exp_type, obj_name, unknown_type);
 420}