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 #include "exec_cmd.h"
   8
   9 static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
  10
  11 #define THEY_HAVE (1U << 0)
  12 #define OUR_REF (1U << 1)
  13 #define WANTED (1U << 2)
  14 #define MAX_HAS 256
  15 #define MAX_NEEDS 256
  16 static int nr_has = 0, nr_needs = 0, multi_ack = 0, nr_our_refs = 0;
  17 static int use_thin_pack = 0;
  18 static unsigned char has_sha1[MAX_HAS][20];
  19 static unsigned char needs_sha1[MAX_NEEDS][20];
  20 static unsigned int timeout = 0;
  21
  22 static void reset_timeout(void)
  23 {
  24         alarm(timeout);
  25 }
  26
  27 static int strip(char *line, int len)
  28 {
  29         if (len && line[len-1] == '\n')
  30                 line[--len] = 0;
  31         return len;
  32 }
  33
  34 static void create_pack_file(void)
  35 {
  36         int fd[2];
  37         pid_t pid;
  38         int create_full_pack = (nr_our_refs == nr_needs && !nr_has);
  39
  40         if (pipe(fd) < 0)
  41                 die("git-upload-pack: unable to create pipe");
  42         pid = fork();
  43         if (pid < 0)
  44                 die("git-upload-pack: unable to fork git-rev-list");
  45
  46         if (!pid) {
  47                 int i;
  48                 int args;
  49                 const char **argv;
  50                 char *buf;
  51                 char **p;
  52
  53                 if (create_full_pack) {
  54                         args = 10;
  55                         use_thin_pack = 0; /* no point doing it */
  56                 }
  57                 else
  58                         args = nr_has + nr_needs + 5;
  59                 p = xmalloc(args * sizeof(char *));
  60                 argv = (const char **) p;
  61                 buf = xmalloc(args * 45);
  62
  63                 dup2(fd[1], 1);
  64                 close(0);
  65                 close(fd[0]);
  66                 close(fd[1]);
  67                 *p++ = "rev-list";
  68                 *p++ = use_thin_pack ? "--objects-edge" : "--objects";
  69                 if (create_full_pack || MAX_NEEDS <= nr_needs)
  70                         *p++ = "--all";
  71                 else {
  72                         for (i = 0; i < nr_needs; i++) {
  73                                 *p++ = buf;
  74                                 memcpy(buf, sha1_to_hex(needs_sha1[i]), 41);
  75                                 buf += 41;
  76                         }
  77                 }
  78                 if (!create_full_pack)
  79                         for (i = 0; i < nr_has; i++) {
  80                                 *p++ = buf;
  81                                 *buf++ = '^';
  82                                 memcpy(buf, sha1_to_hex(has_sha1[i]), 41);
  83                                 buf += 41;
  84                         }
  85                 *p++ = NULL;
  86                 execv_git_cmd(argv);
  87                 die("git-upload-pack: unable to exec git-rev-list");
  88         }
  89         dup2(fd[0], 0);
  90         close(fd[0]);
  91         close(fd[1]);
  92         execl_git_cmd("pack-objects", "--stdout", NULL);
  93         die("git-upload-pack: unable to exec git-pack-objects");
  94 }
  95
  96 static int got_sha1(char *hex, unsigned char *sha1)
  97 {
  98         if (get_sha1_hex(hex, sha1))
  99                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
 100         if (!has_sha1_file(sha1))
 101                 return 0;
 102         if (nr_has < MAX_HAS) {
 103                 struct object *o = lookup_object(sha1);
 104                 if (!(o && o->parsed))
 105                         o = parse_object(sha1);
 106                 if (!o)
 107                         die("oops (%s)", sha1_to_hex(sha1));
 108                 if (o->type == commit_type) {
 109                         struct commit_list *parents;
 110                         if (o->flags & THEY_HAVE)
 111                                 return 0;
 112                         o->flags |= THEY_HAVE;
 113                         for (parents = ((struct commit*)o)->parents;
 114                              parents;
 115                              parents = parents->next)
 116                                 parents->item->object.flags |= THEY_HAVE;
 117                 }
 118                 memcpy(has_sha1[nr_has++], sha1, 20);
 119         }
 120         return 1;
 121 }
 122
 123 static int get_common_commits(void)
 124 {
 125         static char line[1000];
 126         unsigned char sha1[20], last_sha1[20];
 127         int len;
 128
 129         track_object_refs = 0;
 130         save_commit_buffer = 0;
 131
 132         for(;;) {
 133                 len = packet_read_line(0, line, sizeof(line));
 134                 reset_timeout();
 135
 136                 if (!len) {
 137                         if (nr_has == 0 || multi_ack)
 138                                 packet_write(1, "NAK\n");
 139                         continue;
 140                 }
 141                 len = strip(line, len);
 142                 if (!strncmp(line, "have ", 5)) {
 143                         if (got_sha1(line+5, sha1) &&
 144                                         (multi_ack || nr_has == 1)) {
 145                                 if (nr_has >= MAX_HAS)
 146                                         multi_ack = 0;
 147                                 packet_write(1, "ACK %s%s\n",
 148                                         sha1_to_hex(sha1),
 149                                         multi_ack ?  " continue" : "");
 150                                 if (multi_ack)
 151                                         memcpy(last_sha1, sha1, 20);
 152                         }
 153                         continue;
 154                 }
 155                 if (!strcmp(line, "done")) {
 156                         if (nr_has > 0) {
 157                                 if (multi_ack)
 158                                         packet_write(1, "ACK %s\n",
 159                                                         sha1_to_hex(last_sha1));
 160                                 return 0;
 161                         }
 162                         packet_write(1, "NAK\n");
 163                         return -1;
 164                 }
 165                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
 166         }
 167 }
 168
 169 static int receive_needs(void)
 170 {
 171         static char line[1000];
 172         int len, needs;
 173
 174         needs = 0;
 175         for (;;) {
 176                 struct object *o;
 177                 unsigned char dummy[20], *sha1_buf;
 178                 len = packet_read_line(0, line, sizeof(line));
 179                 reset_timeout();
 180                 if (!len)
 181                         return needs;
 182
 183                 sha1_buf = dummy;
 184                 if (needs == MAX_NEEDS) {
 185                         fprintf(stderr,
 186                                 "warning: supporting only a max of %d requests. "
 187                                 "sending everything instead.\n",
 188                                 MAX_NEEDS);
 189                 }
 190                 else if (needs < MAX_NEEDS)
 191                         sha1_buf = needs_sha1[needs];
 192
 193                 if (strncmp("want ", line, 5) || get_sha1_hex(line+5, sha1_buf))
 194                         die("git-upload-pack: protocol error, "
 195                             "expected to get sha, not '%s'", line);
 196                 if (strstr(line+45, "multi_ack"))
 197                         multi_ack = 1;
 198                 if (strstr(line+45, "thin-pack"))
 199                         use_thin_pack = 1;
 200
 201                 /* We have sent all our refs already, and the other end
 202                  * should have chosen out of them; otherwise they are
 203                  * asking for nonsense.
 204                  *
 205                  * Hmph.  We may later want to allow "want" line that
 206                  * asks for something like "master~10" (symbolic)...
 207                  * would it make sense?  I don't know.
 208                  */
 209                 o = lookup_object(sha1_buf);
 210                 if (!o || !(o->flags & OUR_REF))
 211                         die("git-upload-pack: not our ref %s", line+5);
 212                 if (!(o->flags & WANTED)) {
 213                         o->flags |= WANTED;
 214                         needs++;
 215                 }
 216         }
 217 }
 218
 219 static int send_ref(const char *refname, const unsigned char *sha1)
 220 {
 221         static char *capabilities = "multi_ack thin-pack";
 222         struct object *o = parse_object(sha1);
 223
 224         if (!o)
 225                 die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
 226
 227         if (capabilities)
 228                 packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
 229                         0, capabilities);
 230         else
 231                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 232         capabilities = NULL;
 233         if (!(o->flags & OUR_REF)) {
 234                 o->flags |= OUR_REF;
 235                 nr_our_refs++;
 236         }
 237         if (o->type == tag_type) {
 238                 o = deref_tag(o, refname, 0);
 239                 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 240         }
 241         return 0;
 242 }
 243
 244 static int upload_pack(void)
 245 {
 246         reset_timeout();
 247         head_ref(send_ref);
 248         for_each_ref(send_ref);
 249         packet_flush(1);
 250         nr_needs = receive_needs();
 251         if (!nr_needs)
 252                 return 0;
 253         get_common_commits();
 254         create_pack_file();
 255         return 0;
 256 }
 257
 258 int main(int argc, char **argv)
 259 {
 260         char *dir;
 261         int i;
 262         int strict = 0;
 263
 264         for (i = 1; i < argc; i++) {
 265                 char *arg = argv[i];
 266
 267                 if (arg[0] != '-')
 268                         break;
 269                 if (!strcmp(arg, "--strict")) {
 270                         strict = 1;
 271                         continue;
 272                 }
 273                 if (!strncmp(arg, "--timeout=", 10)) {
 274                         timeout = atoi(arg+10);
 275                         continue;
 276                 }
 277                 if (!strcmp(arg, "--")) {
 278                         i++;
 279                         break;
 280                 }
 281         }
 282
 283         if (i != argc-1)
 284                 usage(upload_pack_usage);
 285         dir = argv[i];
 286
 287         if (!enter_repo(dir, strict))
 288                 die("'%s': unable to chdir or not a git archive", dir);
 289
 290         upload_pack();
 291         return 0;
 292 }