Andrew's git - gitweb.git/blob

   1#include "cache.h"
   2#include "object.h"
   3#include "commit.h"
   4#include "diff.h"
   5#include "revision.h"
   6#include "list-objects.h"
   7#include "exec_cmd.h"
   8
   9/*
  10 * Basic handler for bundle files to connect repositories via sneakernet.
  11 * Invocation must include action.
  12 * This function can create a bundle or provide information on an existing
  13 * bundle supporting git-fetch, git-pull, and git-ls-remote
  14 */
  15
  16static const char *bundle_usage="git-bundle (--create <bundle> <git-rev-list args> | --verify <bundle> | --list-heads <bundle> [refname]... | --unbundle <bundle> [refname]... )";
  17
  18static const char bundle_signature[] = "# v2 git bundle\n";
  19
  20struct ref_list {
  21        unsigned int nr, alloc;
  22        struct {
  23                unsigned char sha1[20];
  24                char *name;
  25        } *list;
  26};
  27
  28static void add_to_ref_list(const unsigned char *sha1, const char *name,
  29                struct ref_list *list)
  30{
  31        if (list->nr + 1 >= list->alloc) {
  32                list->alloc = alloc_nr(list->nr + 1);
  33                list->list = xrealloc(list->list,
  34                                list->alloc * sizeof(list->list[0]));
  35        }
  36        memcpy(list->list[list->nr].sha1, sha1, 20);
  37        list->list[list->nr].name = xstrdup(name);
  38        list->nr++;
  39}
  40
  41struct bundle_header {
  42        struct ref_list prerequisites, references;
  43};
  44
  45/* this function returns the length of the string */
  46static int read_string(int fd, char *buffer, int size)
  47{
  48        int i;
  49        for (i = 0; i < size - 1; i++) {
  50                int count = read(fd, buffer + i, 1);
  51                if (count < 0)
  52                        return error("Read error: %s", strerror(errno));
  53                if (count == 0) {
  54                        i--;
  55                        break;
  56                }
  57                if (buffer[i] == '\n')
  58                        break;
  59        }
  60        buffer[i + 1] = '\0';
  61        return i + 1;
  62}
  63
  64/* returns an fd */
  65static int read_header(const char *path, struct bundle_header *header) {
  66        char buffer[1024];
  67        int fd = open(path, O_RDONLY);
  68
  69        if (fd < 0)
  70                return error("could not open '%s'", path);
  71        if (read_string(fd, buffer, sizeof(buffer)) < 0 ||
  72                        strcmp(buffer, bundle_signature)) {
  73                close(fd);
  74                return error("'%s' does not look like a v2 bundle file", path);
  75        }
  76        while (read_string(fd, buffer, sizeof(buffer)) > 0
  77                        && buffer[0] != '\n') {
  78                int offset = buffer[0] == '-' ? 1 : 0;
  79                int len = strlen(buffer);
  80                unsigned char sha1[20];
  81                struct ref_list *list = offset ? &header->prerequisites
  82                        : &header->references;
  83                if (get_sha1_hex(buffer + offset, sha1)) {
  84                        close(fd);
  85                        return error("invalid SHA1: %s", buffer);
  86                }
  87                if (buffer[len - 1] == '\n')
  88                        buffer[len - 1] = '\0';
  89                add_to_ref_list(sha1, buffer + 41 + offset, list);
  90        }
  91        return fd;
  92}
  93
  94/* if in && *in >= 0, take that as input file descriptor instead */
  95static int fork_with_pipe(const char **argv, int *in, int *out)
  96{
  97        int needs_in, needs_out;
  98        int fdin[2], fdout[2], pid;
  99
 100        needs_in = in && *in < 0;
 101        if (needs_in) {
 102                if (pipe(fdin) < 0)
 103                        return error("could not setup pipe");
 104                *in = fdin[1];
 105        }
 106
 107        needs_out = out && *out < 0;
 108        if (needs_out) {
 109                if (pipe(fdout) < 0)
 110                        return error("could not setup pipe");
 111                *out = fdout[0];
 112        }
 113
 114        if ((pid = fork()) < 0) {
 115                if (needs_in) {
 116                        close(fdin[0]);
 117                        close(fdin[1]);
 118                }
 119                if (needs_out) {
 120                        close(fdout[0]);
 121                        close(fdout[1]);
 122                }
 123                return error("could not fork");
 124        }
 125        if (!pid) {
 126                if (needs_in) {
 127                        dup2(fdin[0], 0);
 128                        close(fdin[0]);
 129                        close(fdin[1]);
 130                } else if (in)
 131                        dup2(*in, 0);
 132                if (needs_out) {
 133                        dup2(fdout[1], 1);
 134                        close(fdout[0]);
 135                        close(fdout[1]);
 136                } else if (out)
 137                        dup2(*out, 1);
 138                exit(execv_git_cmd(argv));
 139        }
 140        if (needs_in)
 141                close(fdin[0]);
 142        if (needs_out)
 143                close(fdout[1]);
 144        return pid;
 145}
 146
 147static int verify_bundle(struct bundle_header *header)
 148{
 149        /*
 150         * Do fast check, then if any prereqs are missing then go line by line
 151         * to be verbose about the errors
 152         */
 153        struct ref_list *p = &header->prerequisites;
 154        const char *argv[5] = {"rev-list", "--stdin", "--not", "--all", NULL};
 155        int pid, in, out, i, ret = 0;
 156        char buffer[1024];
 157
 158        in = out = -1;
 159        pid = fork_with_pipe(argv, &in, &out);
 160        if (pid < 0)
 161                return error("Could not fork rev-list");
 162        if (!fork()) {
 163                for (i = 0; i < p->nr; i++) {
 164                        write(in, sha1_to_hex(p->list[i].sha1), 40);
 165                        write(in, "\n", 1);
 166                }
 167                close(in);
 168                exit(0);
 169        }
 170        close(in);
 171        while (read_string(out, buffer, sizeof(buffer)) > 0) {
 172                if (ret++ == 0)
 173                        error ("The bundle requires the following commits you lack:");
 174                fprintf(stderr, "%s", buffer);
 175        }
 176        close(out);
 177        while (waitpid(pid, &i, 0) < 0)
 178                if (errno != EINTR)
 179                        return -1;
 180        if (!ret && (!WIFEXITED(i) || WEXITSTATUS(i)))
 181                return error("At least one prerequisite is lacking.");
 182
 183        return ret;
 184}
 185
 186static int list_heads(struct bundle_header *header, int argc, const char **argv)
 187{
 188        int i;
 189        struct ref_list *r = &header->references;
 190
 191        for (i = 0; i < r->nr; i++) {
 192                if (argc > 1) {
 193                        int j;
 194                        for (j = 1; j < argc; j++)
 195                                if (!strcmp(r->list[i].name, argv[j]))
 196                                        break;
 197                        if (j == argc)
 198                                continue;
 199                }
 200                printf("%s %s\n", sha1_to_hex(r->list[i].sha1),
 201                                r->list[i].name);
 202        }
 203        return 0;
 204}
 205
 206static void show_commit(struct commit *commit)
 207{
 208        write(1, sha1_to_hex(commit->object.sha1), 40);
 209        write(1, "\n", 1);
 210        if (commit->parents) {
 211                free_commit_list(commit->parents);
 212                commit->parents = NULL;
 213        }
 214}
 215
 216static void show_object(struct object_array_entry *p)
 217{
 218        /* An object with name "foo\n0000000..." can be used to
 219         *          * confuse downstream git-pack-objects very badly.
 220         *                   */
 221        const char *ep = strchr(p->name, '\n');
 222        int len = ep ? ep - p->name : strlen(p->name);
 223        write(1, sha1_to_hex(p->item->sha1), 40);
 224        write(1, " ", 1);
 225        if (len)
 226                write(1, p->name, len);
 227        write(1, "\n", 1);
 228}
 229
 230static int create_bundle(struct bundle_header *header, const char *path,
 231                int argc, const char **argv)
 232{
 233        int bundle_fd = -1;
 234        const char **argv_boundary = xmalloc((argc + 3) * sizeof(const char *));
 235        const char **argv_pack = xmalloc(4 * sizeof(const char *));
 236        int pid, in, out, i, status;
 237        char buffer[1024];
 238        struct rev_info revs;
 239
 240        bundle_fd = (!strcmp(path, "-") ? 1 :
 241                        open(path, O_CREAT | O_WRONLY, 0666));
 242        if (bundle_fd < 0)
 243                return error("Could not write to '%s'", path);
 244
 245        /* write signature */
 246        write(bundle_fd, bundle_signature, strlen(bundle_signature));
 247
 248        /* write prerequisites */
 249        memcpy(argv_boundary + 2, argv + 1, argc * sizeof(const char *));
 250        argv_boundary[0] = "rev-list";
 251        argv_boundary[1] = "--boundary";
 252        argv_boundary[argc + 1] = NULL;
 253        out = -1;
 254        pid = fork_with_pipe(argv_boundary, NULL, &out);
 255        if (pid < 0)
 256                return -1;
 257        while ((i = read_string(out, buffer, sizeof(buffer))) > 0)
 258                if (buffer[0] == '-')
 259                        write(bundle_fd, buffer, i);
 260        while ((i = waitpid(pid, &status, 0)) < 0)
 261                if (errno != EINTR)
 262                        return error("rev-list died");
 263        if (!WIFEXITED(status) || WEXITSTATUS(status))
 264                return error("rev-list died %d", WEXITSTATUS(status));
 265
 266        /* write references */
 267        save_commit_buffer = 0;
 268        init_revisions(&revs, NULL);
 269        revs.tag_objects = 1;
 270        revs.tree_objects = 1;
 271        revs.blob_objects = 1;
 272        argc = setup_revisions(argc, argv, &revs, NULL);
 273        if (argc > 1)
 274                return error("unrecognized argument: %s'", argv[1]);
 275        for (i = 0; i < revs.pending.nr; i++) {
 276                struct object_array_entry *e = revs.pending.objects + i;
 277                if (!(e->item->flags & UNINTERESTING)) {
 278                        unsigned char sha1[20];
 279                        char *ref;
 280                        if (dwim_ref(e->name, strlen(e->name), sha1, &ref) != 1)
 281                                continue;
 282                        write(bundle_fd, sha1_to_hex(e->item->sha1), 40);
 283                        write(bundle_fd, " ", 1);
 284                        write(bundle_fd, ref, strlen(ref));
 285                        write(bundle_fd, "\n", 1);
 286                        free(ref);
 287                }
 288        }
 289
 290        /* end header */
 291        write(bundle_fd, "\n", 1);
 292
 293        /* write pack */
 294        argv_pack[0] = "pack-objects";
 295        argv_pack[1] = "--all-progress";
 296        argv_pack[2] = "--stdout";
 297        argv_pack[3] = NULL;
 298        in = -1;
 299        out = bundle_fd;
 300        pid = fork_with_pipe(argv_pack, &in, &out);
 301        if (pid < 0)
 302                return error("Could not spawn pack-objects");
 303        close(1);
 304        close(bundle_fd);
 305        dup2(in, 1);
 306        close(in);
 307        prepare_revision_walk(&revs);
 308        traverse_commit_list(&revs, show_commit, show_object);
 309        close(1);
 310        while (waitpid(pid, &status, 0) < 0)
 311                if (errno != EINTR)
 312                        return -1;
 313        if (!WIFEXITED(status) || WEXITSTATUS(status))
 314                return error ("pack-objects died");
 315        return 0;
 316}
 317
 318static int unbundle(struct bundle_header *header, int bundle_fd,
 319                int argc, const char **argv)
 320{
 321        const char *argv_index_pack[] = {"index-pack", "--stdin", NULL};
 322        int pid, status, dev_null;
 323
 324        if (verify_bundle(header))
 325                return -1;
 326        dev_null = open("/dev/null", O_WRONLY);
 327        pid = fork_with_pipe(argv_index_pack, &bundle_fd, &dev_null);
 328        if (pid < 0)
 329                return error("Could not spawn index-pack");
 330        close(bundle_fd);
 331        while (waitpid(pid, &status, 0) < 0)
 332                if (errno != EINTR)
 333                        return error("index-pack died");
 334        if (!WIFEXITED(status) || WEXITSTATUS(status))
 335                return error("index-pack exited with status %d",
 336                                WEXITSTATUS(status));
 337        return list_heads(header, argc, argv);
 338}
 339
 340int cmd_bundle(int argc, const char **argv, const char *prefix)
 341{
 342        struct bundle_header header;
 343        int nongit = 0;
 344        const char *cmd, *bundle_file;
 345        int bundle_fd = -1;
 346        char buffer[PATH_MAX];
 347
 348        if (argc < 3)
 349                usage(bundle_usage);
 350
 351        cmd = argv[1];
 352        bundle_file = argv[2];
 353        argc -= 2;
 354        argv += 2;
 355
 356        prefix = setup_git_directory_gently(&nongit);
 357        if (prefix && bundle_file[0] != '/') {
 358                snprintf(buffer, sizeof(buffer), "%s/%s", prefix, bundle_file);
 359                bundle_file = buffer;
 360        }
 361
 362        memset(&header, 0, sizeof(header));
 363        if (strcmp(cmd, "create") &&
 364                        !(bundle_fd = read_header(bundle_file, &header)))
 365                return 1;
 366
 367        if (!strcmp(cmd, "verify")) {
 368                close(bundle_fd);
 369                if (verify_bundle(&header))
 370                        return 1;
 371                fprintf(stderr, "%s is okay\n", bundle_file);
 372                return 0;
 373        }
 374        if (!strcmp(cmd, "list-heads")) {
 375                close(bundle_fd);
 376                return !!list_heads(&header, argc, argv);
 377        }
 378        if (!strcmp(cmd, "create")) {
 379                if (nongit)
 380                        die("Need a repository to create a bundle.");
 381                return !!create_bundle(&header, bundle_file, argc, argv);
 382        } else if (!strcmp(cmd, "unbundle")) {
 383                if (nongit)
 384                        die("Need a repository to unbundle.");
 385                return !!unbundle(&header, bundle_fd, argc, argv);
 386        } else
 387                usage(bundle_usage);
 388}
 389