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;
  43        struct ref_list references;
  44};
  45
  46/* this function returns the length of the string */
  47static int read_string(int fd, char *buffer, int size)
  48{
  49        int i;
  50        for (i = 0; i < size - 1; i++) {
  51                int count = xread(fd, buffer + i, 1);
  52                if (count < 0)
  53                        return error("Read error: %s", strerror(errno));
  54                if (count == 0) {
  55                        i--;
  56                        break;
  57                }
  58                if (buffer[i] == '\n')
  59                        break;
  60        }
  61        buffer[i + 1] = '\0';
  62        return i + 1;
  63}
  64
  65/* returns an fd */
  66static int read_header(const char *path, struct bundle_header *header) {
  67        char buffer[1024];
  68        int fd = open(path, O_RDONLY);
  69
  70        if (fd < 0)
  71                return error("could not open '%s'", path);
  72        if (read_string(fd, buffer, sizeof(buffer)) < 0 ||
  73                        strcmp(buffer, bundle_signature)) {
  74                close(fd);
  75                return error("'%s' does not look like a v2 bundle file", path);
  76        }
  77        while (read_string(fd, buffer, sizeof(buffer)) > 0
  78                        && buffer[0] != '\n') {
  79                int is_prereq = buffer[0] == '-';
  80                int offset = is_prereq ? 1 : 0;
  81                int len = strlen(buffer);
  82                unsigned char sha1[20];
  83                struct ref_list *list = is_prereq ? &header->prerequisites
  84                        : &header->references;
  85                char delim;
  86
  87                if (buffer[len - 1] == '\n')
  88                        buffer[len - 1] = '\0';
  89                if (get_sha1_hex(buffer + offset, sha1)) {
  90                        warn("unrecognized header: %s", buffer);
  91                        continue;
  92                }
  93                delim = buffer[40 + offset];
  94                if (!isspace(delim) && (delim != '\0' || !is_prereq))
  95                        die ("invalid header: %s", buffer);
  96                add_to_ref_list(sha1, isspace(delim) ?
  97                                buffer + 41 + offset : "", list);
  98        }
  99        return fd;
 100}
 101
 102/* if in && *in >= 0, take that as input file descriptor instead */
 103static int fork_with_pipe(const char **argv, int *in, int *out)
 104{
 105        int needs_in, needs_out;
 106        int fdin[2], fdout[2], pid;
 107
 108        needs_in = in && *in < 0;
 109        if (needs_in) {
 110                if (pipe(fdin) < 0)
 111                        return error("could not setup pipe");
 112                *in = fdin[1];
 113        }
 114
 115        needs_out = out && *out < 0;
 116        if (needs_out) {
 117                if (pipe(fdout) < 0)
 118                        return error("could not setup pipe");
 119                *out = fdout[0];
 120        }
 121
 122        if ((pid = fork()) < 0) {
 123                if (needs_in) {
 124                        close(fdin[0]);
 125                        close(fdin[1]);
 126                }
 127                if (needs_out) {
 128                        close(fdout[0]);
 129                        close(fdout[1]);
 130                }
 131                return error("could not fork");
 132        }
 133        if (!pid) {
 134                if (needs_in) {
 135                        dup2(fdin[0], 0);
 136                        close(fdin[0]);
 137                        close(fdin[1]);
 138                } else if (in) {
 139                        dup2(*in, 0);
 140                        close(*in);
 141                }
 142                if (needs_out) {
 143                        dup2(fdout[1], 1);
 144                        close(fdout[0]);
 145                        close(fdout[1]);
 146                } else if (out) {
 147                        dup2(*out, 1);
 148                        close(*out);
 149                }
 150                exit(execv_git_cmd(argv));
 151        }
 152        if (needs_in)
 153                close(fdin[0]);
 154        else if (in)
 155                close(*in);
 156        if (needs_out)
 157                close(fdout[1]);
 158        else if (out)
 159                close(*out);
 160        return pid;
 161}
 162
 163static int verify_bundle(struct bundle_header *header)
 164{
 165        /*
 166         * Do fast check, then if any prereqs are missing then go line by line
 167         * to be verbose about the errors
 168         */
 169        struct ref_list *p = &header->prerequisites;
 170        char **argv;
 171        int pid, out, i, ret = 0;
 172        char buffer[1024];
 173
 174        argv = xmalloc((p->nr + 4) * sizeof(const char *));
 175        argv[0] = "rev-list";
 176        argv[1] = "--not";
 177        argv[2] = "--all";
 178        for (i = 0; i < p->nr; i++)
 179                argv[i + 3] = xstrdup(sha1_to_hex(p->list[i].sha1));
 180        argv[p->nr + 3] = NULL;
 181        out = -1;
 182        pid = fork_with_pipe((const char **)argv, NULL, &out);
 183        if (pid < 0)
 184                return error("Could not fork rev-list");
 185        while (read_string(out, buffer, sizeof(buffer)) > 0)
 186                ; /* do nothing */
 187        close(out);
 188        for (i = 0; i < p->nr; i++)
 189                free(argv[i + 3]);
 190        free(argv);
 191
 192        while (waitpid(pid, &i, 0) < 0)
 193                if (errno != EINTR)
 194                        return -1;
 195        if (!ret && (!WIFEXITED(i) || WEXITSTATUS(i)))
 196                return error("At least one prerequisite is lacking.");
 197
 198        return ret;
 199}
 200
 201static int list_heads(struct bundle_header *header, int argc, const char **argv)
 202{
 203        int i;
 204        struct ref_list *r = &header->references;
 205
 206        for (i = 0; i < r->nr; i++) {
 207                if (argc > 1) {
 208                        int j;
 209                        for (j = 1; j < argc; j++)
 210                                if (!strcmp(r->list[i].name, argv[j]))
 211                                        break;
 212                        if (j == argc)
 213                                continue;
 214                }
 215                printf("%s %s\n", sha1_to_hex(r->list[i].sha1),
 216                                r->list[i].name);
 217        }
 218        return 0;
 219}
 220
 221static void show_commit(struct commit *commit)
 222{
 223        write_or_die(1, sha1_to_hex(commit->object.sha1), 40);
 224        write_or_die(1, "\n", 1);
 225        if (commit->parents) {
 226                free_commit_list(commit->parents);
 227                commit->parents = NULL;
 228        }
 229}
 230
 231static void show_object(struct object_array_entry *p)
 232{
 233        /* An object with name "foo\n0000000..." can be used to
 234         * confuse downstream git-pack-objects very badly.
 235         */
 236        const char *ep = strchr(p->name, '\n');
 237        int len = ep ? ep - p->name : strlen(p->name);
 238        write_or_die(1, sha1_to_hex(p->item->sha1), 40);
 239        write_or_die(1, " ", 1);
 240        if (len)
 241                write_or_die(1, p->name, len);
 242        write_or_die(1, "\n", 1);
 243}
 244
 245static int create_bundle(struct bundle_header *header, const char *path,
 246                int argc, const char **argv)
 247{
 248        int bundle_fd = -1;
 249        const char **argv_boundary = xmalloc((argc + 3) * sizeof(const char *));
 250        const char **argv_pack = xmalloc(4 * sizeof(const char *));
 251        int pid, in, out, i, status;
 252        char buffer[1024];
 253        struct rev_info revs;
 254
 255        bundle_fd = (!strcmp(path, "-") ? 1 :
 256                        open(path, O_CREAT | O_WRONLY, 0666));
 257        if (bundle_fd < 0)
 258                return error("Could not write to '%s'", path);
 259
 260        /* write signature */
 261        write_or_die(bundle_fd, bundle_signature, strlen(bundle_signature));
 262
 263        /* write prerequisites */
 264        memcpy(argv_boundary + 2, argv + 1, argc * sizeof(const char *));
 265        argv_boundary[0] = "rev-list";
 266        argv_boundary[1] = "--boundary";
 267        argv_boundary[argc + 1] = NULL;
 268        out = -1;
 269        pid = fork_with_pipe(argv_boundary, NULL, &out);
 270        if (pid < 0)
 271                return -1;
 272        while ((i = read_string(out, buffer, sizeof(buffer))) > 0)
 273                if (buffer[0] == '-')
 274                        write_or_die(bundle_fd, buffer, i);
 275        while ((i = waitpid(pid, &status, 0)) < 0)
 276                if (errno != EINTR)
 277                        return error("rev-list died");
 278        if (!WIFEXITED(status) || WEXITSTATUS(status))
 279                return error("rev-list died %d", WEXITSTATUS(status));
 280
 281        /* write references */
 282        save_commit_buffer = 0;
 283        init_revisions(&revs, NULL);
 284        revs.tag_objects = 1;
 285        revs.tree_objects = 1;
 286        revs.blob_objects = 1;
 287        argc = setup_revisions(argc, argv, &revs, NULL);
 288        if (argc > 1)
 289                return error("unrecognized argument: %s'", argv[1]);
 290        for (i = 0; i < revs.pending.nr; i++) {
 291                struct object_array_entry *e = revs.pending.objects + i;
 292                if (!(e->item->flags & UNINTERESTING)) {
 293                        unsigned char sha1[20];
 294                        char *ref;
 295                        if (dwim_ref(e->name, strlen(e->name), sha1, &ref) != 1)
 296                                continue;
 297                        write_or_die(bundle_fd, sha1_to_hex(e->item->sha1), 40);
 298                        write_or_die(bundle_fd, " ", 1);
 299                        write_or_die(bundle_fd, ref, strlen(ref));
 300                        write_or_die(bundle_fd, "\n", 1);
 301                        free(ref);
 302                }
 303        }
 304
 305        /* end header */
 306        write_or_die(bundle_fd, "\n", 1);
 307
 308        /* write pack */
 309        argv_pack[0] = "pack-objects";
 310        argv_pack[1] = "--all-progress";
 311        argv_pack[2] = "--stdout";
 312        argv_pack[3] = NULL;
 313        in = -1;
 314        out = bundle_fd;
 315        pid = fork_with_pipe(argv_pack, &in, &out);
 316        if (pid < 0)
 317                return error("Could not spawn pack-objects");
 318        close(1);
 319        dup2(in, 1);
 320        close(in);
 321        prepare_revision_walk(&revs);
 322        traverse_commit_list(&revs, show_commit, show_object);
 323        close(1);
 324        while (waitpid(pid, &status, 0) < 0)
 325                if (errno != EINTR)
 326                        return -1;
 327        if (!WIFEXITED(status) || WEXITSTATUS(status))
 328                return error ("pack-objects died");
 329        return 0;
 330}
 331
 332static int unbundle(struct bundle_header *header, int bundle_fd,
 333                int argc, const char **argv)
 334{
 335        const char *argv_index_pack[] = {"index-pack", "--stdin", NULL};
 336        int pid, status, dev_null;
 337
 338        if (verify_bundle(header))
 339                return -1;
 340        dev_null = open("/dev/null", O_WRONLY);
 341        pid = fork_with_pipe(argv_index_pack, &bundle_fd, &dev_null);
 342        if (pid < 0)
 343                return error("Could not spawn index-pack");
 344        while (waitpid(pid, &status, 0) < 0)
 345                if (errno != EINTR)
 346                        return error("index-pack died");
 347        if (!WIFEXITED(status) || WEXITSTATUS(status))
 348                return error("index-pack exited with status %d",
 349                                WEXITSTATUS(status));
 350        return list_heads(header, argc, argv);
 351}
 352
 353int cmd_bundle(int argc, const char **argv, const char *prefix)
 354{
 355        struct bundle_header header;
 356        int nongit = 0;
 357        const char *cmd, *bundle_file;
 358        int bundle_fd = -1;
 359        char buffer[PATH_MAX];
 360
 361        if (argc < 3)
 362                usage(bundle_usage);
 363
 364        cmd = argv[1];
 365        bundle_file = argv[2];
 366        argc -= 2;
 367        argv += 2;
 368
 369        prefix = setup_git_directory_gently(&nongit);
 370        if (prefix && bundle_file[0] != '/') {
 371                snprintf(buffer, sizeof(buffer), "%s/%s", prefix, bundle_file);
 372                bundle_file = buffer;
 373        }
 374
 375        memset(&header, 0, sizeof(header));
 376        if (strcmp(cmd, "create") &&
 377                        !(bundle_fd = read_header(bundle_file, &header)))
 378                return 1;
 379
 380        if (!strcmp(cmd, "verify")) {
 381                close(bundle_fd);
 382                if (verify_bundle(&header))
 383                        return 1;
 384                fprintf(stderr, "%s is okay\n", bundle_file);
 385                return 0;
 386        }
 387        if (!strcmp(cmd, "list-heads")) {
 388                close(bundle_fd);
 389                return !!list_heads(&header, argc, argv);
 390        }
 391        if (!strcmp(cmd, "create")) {
 392                if (nongit)
 393                        die("Need a repository to create a bundle.");
 394                return !!create_bundle(&header, bundle_file, argc, argv);
 395        } else if (!strcmp(cmd, "unbundle")) {
 396                if (nongit)
 397                        die("Need a repository to unbundle.");
 398                return !!unbundle(&header, bundle_fd, argc, argv);
 399        } else
 400                usage(bundle_usage);
 401}
 402