upload-pack.c

   1 #include "cache.h"
   2 #include "refs.h"
   3 #include "pkt-line.h"
   4 #include "tag.h"
   5 #include "object.h"
   6 #include "commit.h"
   7
   8 static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
   9
  10 #define THEY_HAVE (1U << 0)
  11 #define OUR_REF (1U << 1)
  12 #define WANTED (1U << 2)
  13 #define MAX_HAS 256
  14 #define MAX_NEEDS 256
  15 static int nr_has = 0, nr_needs = 0, multi_ack = 0, nr_our_refs = 0;
  16 static unsigned char has_sha1[MAX_HAS][20];
  17 static unsigned char needs_sha1[MAX_NEEDS][20];
  18 static unsigned int timeout = 0;
  19
  20 static void reset_timeout(void)
  21 {
  22         alarm(timeout);
  23 }
  24
  25 static int strip(char *line, int len)
  26 {
  27         if (len && line[len-1] == '\n')
  28                 line[--len] = 0;
  29         return len;
  30 }
  31
  32 static void create_pack_file(void)
  33 {
  34         int fd[2];
  35         pid_t pid;
  36         int create_full_pack = (nr_our_refs == nr_needs && !nr_has);
  37
  38         if (pipe(fd) < 0)
  39                 die("git-upload-pack: unable to create pipe");
  40         pid = fork();
  41         if (pid < 0)
  42                 die("git-upload-pack: unable to fork git-rev-list");
  43
  44         if (!pid) {
  45                 int i;
  46                 int args;
  47                 char **argv;
  48                 char *buf;
  49                 char **p;
  50
  51                 if (create_full_pack)
  52                         args = 10;
  53                 else
  54                         args = nr_has + nr_needs + 5;
  55                 argv = xmalloc(args * sizeof(char *));
  56                 buf = xmalloc(args * 45);
  57                 p = argv;
  58
  59                 dup2(fd[1], 1);
  60                 close(0);
  61                 close(fd[0]);
  62                 close(fd[1]);
  63                 *p++ = "git-rev-list";
  64                 *p++ = "--objects";
  65                 if (create_full_pack || MAX_NEEDS <= nr_needs)
  66                         *p++ = "--all";
  67                 else {
  68                         for (i = 0; i < nr_needs; i++) {
  69                                 *p++ = buf;
  70                                 memcpy(buf, sha1_to_hex(needs_sha1[i]), 41);
  71                                 buf += 41;
  72                         }
  73                 }
  74                 if (!create_full_pack)
  75                         for (i = 0; i < nr_has; i++) {
  76                                 *p++ = buf;
  77                                 *buf++ = '^';
  78                                 memcpy(buf, sha1_to_hex(has_sha1[i]), 41);
  79                                 buf += 41;
  80                         }
  81                 *p++ = NULL;
  82                 execvp("git-rev-list", argv);
  83                 die("git-upload-pack: unable to exec git-rev-list");
  84         }
  85         dup2(fd[0], 0);
  86         close(fd[0]);
  87         close(fd[1]);
  88         execlp("git-pack-objects", "git-pack-objects", "--stdout", NULL);
  89         die("git-upload-pack: unable to exec git-pack-objects");
  90 }
  91
  92 static int got_sha1(char *hex, unsigned char *sha1)
  93 {
  94         if (get_sha1_hex(hex, sha1))
  95                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
  96         if (!has_sha1_file(sha1))
  97                 return 0;
  98         if (nr_has < MAX_HAS) {
  99                 struct object *o = lookup_object(sha1);
 100                 if (!(o && o->parsed))
 101                         o = parse_object(sha1);
 102                 if (!o)
 103                         die("oops (%s)", sha1_to_hex(sha1));
 104                 if (o->type == commit_type) {
 105                         struct commit_list *parents;
 106                         if (o->flags & THEY_HAVE)
 107                                 return 0;
 108                         o->flags |= THEY_HAVE;
 109                         for (parents = ((struct commit*)o)->parents;
 110                              parents;
 111                              parents = parents->next)
 112                                 parents->item->object.flags |= THEY_HAVE;
 113                 }
 114                 memcpy(has_sha1[nr_has++], sha1, 20);
 115         }
 116         return 1;
 117 }
 118
 119 static int get_common_commits(void)
 120 {
 121         static char line[1000];
 122         unsigned char sha1[20], last_sha1[20];
 123         int len;
 124
 125         track_object_refs = 0;
 126         save_commit_buffer = 0;
 127
 128         for(;;) {
 129                 len = packet_read_line(0, line, sizeof(line));
 130                 reset_timeout();
 131
 132                 if (!len) {
 133                         if (nr_has == 0 || multi_ack)
 134                                 packet_write(1, "NAK\n");
 135                         continue;
 136                 }
 137                 len = strip(line, len);
 138                 if (!strncmp(line, "have ", 5)) {
 139                         if (got_sha1(line+5, sha1) &&
 140                                         (multi_ack || nr_has == 1)) {
 141                                 if (nr_has >= MAX_HAS)
 142                                         multi_ack = 0;
 143                                 packet_write(1, "ACK %s%s\n",
 144                                         sha1_to_hex(sha1),
 145                                         multi_ack ?  " continue" : "");
 146                                 if (multi_ack)
 147                                         memcpy(last_sha1, sha1, 20);
 148                         }
 149                         continue;
 150                 }
 151                 if (!strcmp(line, "done")) {
 152                         if (nr_has > 0) {
 153                                 if (multi_ack)
 154                                         packet_write(1, "ACK %s\n",
 155                                                         sha1_to_hex(last_sha1));
 156                                 return 0;
 157                         }
 158                         packet_write(1, "NAK\n");
 159                         return -1;
 160                 }
 161                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
 162         }
 163 }
 164
 165 static int receive_needs(void)
 166 {
 167         static char line[1000];
 168         int len, needs;
 169
 170         needs = 0;
 171         for (;;) {
 172                 struct object *o;
 173                 unsigned char dummy[20], *sha1_buf;
 174                 len = packet_read_line(0, line, sizeof(line));
 175                 reset_timeout();
 176                 if (!len)
 177                         return needs;
 178
 179                 sha1_buf = dummy;
 180                 if (needs == MAX_NEEDS) {
 181                         fprintf(stderr,
 182                                 "warning: supporting only a max of %d requests. "
 183                                 "sending everything instead.\n",
 184                                 MAX_NEEDS);
 185                 }
 186                 else if (needs < MAX_NEEDS)
 187                         sha1_buf = needs_sha1[needs];
 188
 189                 if (strncmp("want ", line, 5) || get_sha1_hex(line+5, sha1_buf))
 190                         die("git-upload-pack: protocol error, "
 191                             "expected to get sha, not '%s'", line);
 192                 if (strstr(line+45, "multi_ack"))
 193                         multi_ack = 1;
 194
 195                 /* We have sent all our refs already, and the other end
 196                  * should have chosen out of them; otherwise they are
 197                  * asking for nonsense.
 198                  *
 199                  * Hmph.  We may later want to allow "want" line that
 200                  * asks for something like "master~10" (symbolic)...
 201                  * would it make sense?  I don't know.
 202                  */
 203                 o = lookup_object(sha1_buf);
 204                 if (!o || !(o->flags & OUR_REF))
 205                         die("git-upload-pack: not our ref %s", line+5);
 206                 if (!(o->flags & WANTED)) {
 207                         o->flags |= WANTED;
 208                         needs++;
 209                 }
 210         }
 211 }
 212
 213 static int send_ref(const char *refname, const unsigned char *sha1)
 214 {
 215         static char *capabilities = "multi_ack";
 216         struct object *o = parse_object(sha1);
 217
 218         if (capabilities)
 219                 packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
 220                         0, capabilities);
 221         else
 222                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 223         capabilities = NULL;
 224         if (!(o->flags & OUR_REF)) {
 225                 o->flags |= OUR_REF;
 226                 nr_our_refs++;
 227         }
 228         if (o->type == tag_type) {
 229                 o = deref_tag(o, refname, 0);
 230                 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 231         }
 232         return 0;
 233 }
 234
 235 static int upload_pack(void)
 236 {
 237         reset_timeout();
 238         head_ref(send_ref);
 239         for_each_ref(send_ref);
 240         packet_flush(1);
 241         nr_needs = receive_needs();
 242         if (!nr_needs)
 243                 return 0;
 244         get_common_commits();
 245         create_pack_file();
 246         return 0;
 247 }
 248
 249 int main(int argc, char **argv)
 250 {
 251         char *dir;
 252         int i;
 253         int strict = 0;
 254
 255         for (i = 1; i < argc; i++) {
 256                 char *arg = argv[i];
 257
 258                 if (arg[0] != '-')
 259                         break;
 260                 if (!strcmp(arg, "--strict")) {
 261                         strict = 1;
 262                         continue;
 263                 }
 264                 if (!strncmp(arg, "--timeout=", 10)) {
 265                         timeout = atoi(arg+10);
 266                         continue;
 267                 }
 268                 if (!strcmp(arg, "--")) {
 269                         i++;
 270                         break;
 271                 }
 272         }
 273
 274         if (i != argc-1)
 275                 usage(upload_pack_usage);
 276         dir = argv[i];
 277
 278         if (!enter_repo(dir, strict))
 279                 die("'%s': unable to chdir or not a git archive", dir);
 280
 281         upload_pack();
 282         return 0;
 283 }