Andrew's git - gitweb.git/blob

   1#include "cache.h"
   2#include "commit.h"
   3#include "tag.h"
   4#include "refs.h"
   5#include "pkt-line.h"
   6
   7static const char send_pack_usage[] =
   8"git-send-pack [--all] [--exec=git-receive-pack] <remote> [<head>...]\n"
   9"  --all and explicit <head> specification are mutually exclusive.";
  10static const char *exec = "git-receive-pack";
  11static int send_all = 0;
  12static int force_update = 0;
  13
  14static int is_zero_sha1(const unsigned char *sha1)
  15{
  16        int i;
  17
  18        for (i = 0; i < 20; i++) {
  19                if (*sha1++)
  20                        return 0;
  21        }
  22        return 1;
  23}
  24
  25static void exec_pack_objects(void)
  26{
  27        static char *args[] = {
  28                "git-pack-objects",
  29                "--stdout",
  30                NULL
  31        };
  32        execvp("git-pack-objects", args);
  33        die("git-pack-objects exec failed (%s)", strerror(errno));
  34}
  35
  36static void exec_rev_list(struct ref *refs)
  37{
  38        static char *args[1000];
  39        int i = 0;
  40
  41        args[i++] = "git-rev-list";     /* 0 */
  42        args[i++] = "--objects";        /* 1 */
  43        while (refs) {
  44                char *buf = malloc(100);
  45                if (i > 900)
  46                        die("git-rev-list environment overflow");
  47                if (!is_zero_sha1(refs->old_sha1) &&
  48                    has_sha1_file(refs->old_sha1)) {
  49                        args[i++] = buf;
  50                        snprintf(buf, 50, "^%s", sha1_to_hex(refs->old_sha1));
  51                        buf += 50;
  52                }
  53                if (!is_zero_sha1(refs->new_sha1)) {
  54                        args[i++] = buf;
  55                        snprintf(buf, 50, "%s", sha1_to_hex(refs->new_sha1));
  56                }
  57                refs = refs->next;
  58        }
  59        args[i] = NULL;
  60        execvp("git-rev-list", args);
  61        die("git-rev-list exec failed (%s)", strerror(errno));
  62}
  63
  64static void rev_list(int fd, struct ref *refs)
  65{
  66        int pipe_fd[2];
  67        pid_t pack_objects_pid;
  68
  69        if (pipe(pipe_fd) < 0)
  70                die("rev-list setup: pipe failed");
  71        pack_objects_pid = fork();
  72        if (!pack_objects_pid) {
  73                dup2(pipe_fd[0], 0);
  74                dup2(fd, 1);
  75                close(pipe_fd[0]);
  76                close(pipe_fd[1]);
  77                close(fd);
  78                exec_pack_objects();
  79                die("pack-objects setup failed");
  80        }
  81        if (pack_objects_pid < 0)
  82                die("pack-objects fork failed");
  83        dup2(pipe_fd[1], 1);
  84        close(pipe_fd[0]);
  85        close(pipe_fd[1]);
  86        close(fd);
  87        exec_rev_list(refs);
  88}
  89
  90static int pack_objects(int fd, struct ref *refs)
  91{
  92        pid_t rev_list_pid;
  93
  94        rev_list_pid = fork();
  95        if (!rev_list_pid) {
  96                rev_list(fd, refs);
  97                die("rev-list setup failed");
  98        }
  99        if (rev_list_pid < 0)
 100                die("rev-list fork failed");
 101        /*
 102         * We don't wait for the rev-list pipeline in the parent:
 103         * we end up waiting for the other end instead
 104         */
 105        return 0;
 106}
 107
 108static int ref_newer(const unsigned char *new_sha1,
 109                     const unsigned char *old_sha1)
 110{
 111        struct object *o;
 112        struct commit *old, *new;
 113        struct commit_list *list;
 114
 115        /* Both new and old must be commit-ish and new is descendant of
 116         * old.  Otherwise we require --force.
 117         */
 118        o = deref_tag(parse_object(old_sha1));
 119        if (!o || o->type != commit_type)
 120                return 0;
 121        old = (struct commit *) o;
 122
 123        o = deref_tag(parse_object(new_sha1));
 124        if (!o || o->type != commit_type)
 125                return 0;
 126        new = (struct commit *) o;
 127
 128        if (parse_commit(new) < 0)
 129                return 0;
 130        list = NULL;
 131        commit_list_insert(new, &list);
 132        while (list) {
 133                new = pop_most_recent_commit(&list, 1);
 134                if (new == old)
 135                        return 1;
 136        }
 137        return 0;
 138}
 139
 140static struct ref *local_refs, **local_tail;
 141static struct ref *remote_refs, **remote_tail;
 142
 143static int one_local_ref(const char *refname, const unsigned char *sha1)
 144{
 145        struct ref *ref;
 146        int len = strlen(refname) + 1;
 147        ref = xcalloc(1, sizeof(*ref) + len);
 148        memcpy(ref->new_sha1, sha1, 20);
 149        memcpy(ref->name, refname, len);
 150        *local_tail = ref;
 151        local_tail = &ref->next;
 152        return 0;
 153}
 154
 155static void get_local_heads(void)
 156{
 157        local_tail = &local_refs;
 158        for_each_ref(one_local_ref);
 159}
 160
 161static int send_pack(int in, int out, int nr_refspec, char **refspec)
 162{
 163        struct ref *ref;
 164        int new_refs;
 165
 166        /* No funny business with the matcher */
 167        remote_tail = get_remote_heads(in, &remote_refs, 0, NULL);
 168        get_local_heads();
 169
 170        /* match them up */
 171        if (!remote_tail)
 172                remote_tail = &remote_refs;
 173        if (match_refs(local_refs, remote_refs, &remote_tail,
 174                       nr_refspec, refspec, send_all))
 175                return -1;
 176        /*
 177         * Finally, tell the other end!
 178         */
 179        new_refs = 0;
 180        for (ref = remote_refs; ref; ref = ref->next) {
 181                char old_hex[60], *new_hex;
 182                if (!ref->peer_ref)
 183                        continue;
 184                if (!memcmp(ref->old_sha1, ref->peer_ref->new_sha1, 20)) {
 185                        fprintf(stderr, "'%s': up-to-date\n", ref->name);
 186                        continue;
 187                }
 188
 189                /* This part determines what can overwrite what.
 190                 * The rules are:
 191                 *
 192                 * (0) you can always use --force.
 193                 *
 194                 * (1) if the old thing does not exist, it is OK.
 195                 *
 196                 * (2) if you do not have the old thing, you are not allowed
 197                 *     to overwrite it; you would not know what you are losing
 198                 *     otherwise.
 199                 *
 200                 * (3) if both new and old are commit-ish, and new is a
 201                 *     descendant of old, it is OK.
 202                 */
 203
 204                if (!force_update && !is_zero_sha1(ref->old_sha1)) {
 205                        if (!has_sha1_file(ref->old_sha1)) {
 206                                error("remote '%s' object %s does not "
 207                                      "exist on local",
 208                                      ref->name, sha1_to_hex(ref->old_sha1));
 209                                continue;
 210                        }
 211                        /* We assume that local is fsck-clean.  Otherwise
 212                         * you _could_ have a old tag which points at
 213                         * something you do not have which may or may not
 214                         * be a commit.
 215                         */
 216                        if (!ref_newer(ref->peer_ref->new_sha1,
 217                                       ref->old_sha1)) {
 218                                error("remote ref '%s' is not a strict "
 219                                      "subset of local ref '%s'.", ref->name,
 220                                      ref->peer_ref->name);
 221                                continue;
 222                        }
 223                }
 224                memcpy(ref->new_sha1, ref->peer_ref->new_sha1, 20);
 225                if (is_zero_sha1(ref->new_sha1)) {
 226                        error("cannot happen anymore");
 227                        continue;
 228                }
 229                new_refs++;
 230                strcpy(old_hex, sha1_to_hex(ref->old_sha1));
 231                new_hex = sha1_to_hex(ref->new_sha1);
 232                packet_write(out, "%s %s %s", old_hex, new_hex, ref->name);
 233                fprintf(stderr, "updating '%s'", ref->name);
 234                if (strcmp(ref->name, ref->peer_ref->name))
 235                        fprintf(stderr, " using '%s'", ref->peer_ref->name);
 236                fprintf(stderr, "\n  from %s\n  to   %s\n", old_hex, new_hex);
 237        }
 238
 239        packet_flush(out);
 240        if (new_refs)
 241                pack_objects(out, remote_refs);
 242        close(out);
 243        return 0;
 244}
 245
 246
 247int main(int argc, char **argv)
 248{
 249        int i, nr_heads = 0;
 250        char *dest = NULL;
 251        char **heads = NULL;
 252        int fd[2], ret;
 253        pid_t pid;
 254
 255        argv++;
 256        for (i = 1; i < argc; i++, argv++) {
 257                char *arg = *argv;
 258
 259                if (*arg == '-') {
 260                        if (!strncmp(arg, "--exec=", 7)) {
 261                                exec = arg + 7;
 262                                continue;
 263                        }
 264                        if (!strcmp(arg, "--all")) {
 265                                send_all = 1;
 266                                continue;
 267                        }
 268                        if (!strcmp(arg, "--force")) {
 269                                force_update = 1;
 270                                continue;
 271                        }
 272                        usage(send_pack_usage);
 273                }
 274                if (!dest) {
 275                        dest = arg;
 276                        continue;
 277                }
 278                heads = argv;
 279                nr_heads = argc - i;
 280                break;
 281        }
 282        if (!dest)
 283                usage(send_pack_usage);
 284        if (heads && send_all)
 285                usage(send_pack_usage);
 286        pid = git_connect(fd, dest, exec);
 287        if (pid < 0)
 288                return 1;
 289        ret = send_pack(fd[0], fd[1], nr_heads, heads);
 290        close(fd[0]);
 291        close(fd[1]);
 292        finish_connect(pid);
 293        return ret;
 294}