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
   7 static const char upload_pack_usage[] = "git-upload-pack <dir>";
   8
   9 #define MAX_HAS (16)
  10 #define MAX_NEEDS (256)
  11 static int nr_has = 0, nr_needs = 0;
  12 static unsigned char has_sha1[MAX_HAS][20];
  13 static unsigned char needs_sha1[MAX_NEEDS][20];
  14
  15 static int strip(char *line, int len)
  16 {
  17         if (len && line[len-1] == '\n')
  18                 line[--len] = 0;
  19         return len;
  20 }
  21
  22 static void create_pack_file(void)
  23 {
  24         int fd[2];
  25         pid_t pid;
  26
  27         if (pipe(fd) < 0)
  28                 die("git-upload-pack: unable to create pipe");
  29         pid = fork();
  30         if (pid < 0)
  31                 die("git-upload-pack: unable to fork git-rev-list");
  32
  33         if (!pid) {
  34                 int i;
  35                 int args;
  36                 char **argv;
  37                 char *buf;
  38                 char **p;
  39
  40                 if (MAX_NEEDS <= nr_needs)
  41                         args = nr_has + 10;
  42                 else
  43                         args = nr_has + nr_needs + 5;
  44                 argv = xmalloc(args * sizeof(char *));
  45                 buf = xmalloc(args * 45);
  46                 p = argv;
  47
  48                 dup2(fd[1], 1);
  49                 close(0);
  50                 close(fd[0]);
  51                 close(fd[1]);
  52                 *p++ = "git-rev-list";
  53                 *p++ = "--objects";
  54                 if (MAX_NEEDS <= nr_needs)
  55                         *p++ = "--all";
  56                 else {
  57                         for (i = 0; i < nr_needs; i++) {
  58                                 *p++ = buf;
  59                                 memcpy(buf, sha1_to_hex(needs_sha1[i]), 41);
  60                                 buf += 41;
  61                         }
  62                 }
  63                 for (i = 0; i < nr_has; i++) {
  64                         *p++ = buf;
  65                         *buf++ = '^';
  66                         memcpy(buf, sha1_to_hex(has_sha1[i]), 41);
  67                         buf += 41;
  68                 }
  69                 *p++ = NULL;
  70                 execvp("git-rev-list", argv);
  71                 die("git-upload-pack: unable to exec git-rev-list");
  72         }
  73         dup2(fd[0], 0);
  74         close(fd[0]);
  75         close(fd[1]);
  76         execlp("git-pack-objects", "git-pack-objects", "--stdout", NULL);
  77         die("git-upload-pack: unable to exec git-pack-objects");
  78 }
  79
  80 static int got_sha1(char *hex, unsigned char *sha1)
  81 {
  82         int nr;
  83         if (get_sha1_hex(hex, sha1))
  84                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
  85         if (!has_sha1_file(sha1))
  86                 return 0;
  87         nr = nr_has;
  88         if (nr < MAX_HAS) {
  89                 memcpy(has_sha1[nr], sha1, 20);
  90                 nr_has = nr+1;
  91         }
  92         return 1;
  93 }
  94
  95 static int get_common_commits(void)
  96 {
  97         static char line[1000];
  98         unsigned char sha1[20];
  99         int len;
 100
 101         for(;;) {
 102                 len = packet_read_line(0, line, sizeof(line));
 103
 104                 if (!len) {
 105                         packet_write(1, "NAK\n");
 106                         continue;
 107                 }
 108                 len = strip(line, len);
 109                 if (!strncmp(line, "have ", 5)) {
 110                         if (got_sha1(line+5, sha1)) {
 111                                 packet_write(1, "ACK %s\n", sha1_to_hex(sha1));
 112                                 break;
 113                         }
 114                         continue;
 115                 }
 116                 if (!strcmp(line, "done")) {
 117                         packet_write(1, "NAK\n");
 118                         return -1;
 119                 }
 120                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
 121         }
 122
 123         for (;;) {
 124                 len = packet_read_line(0, line, sizeof(line));
 125                 if (!len)
 126                         continue;
 127                 len = strip(line, len);
 128                 if (!strncmp(line, "have ", 5)) {
 129                         got_sha1(line+5, sha1);
 130                         continue;
 131                 }
 132                 if (!strcmp(line, "done"))
 133                         break;
 134                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
 135         }
 136         return 0;
 137 }
 138
 139 static int receive_needs(void)
 140 {
 141         static char line[1000];
 142         int len, needs;
 143
 144         needs = 0;
 145         for (;;) {
 146                 unsigned char dummy[20], *sha1_buf;
 147                 len = packet_read_line(0, line, sizeof(line));
 148                 if (!len)
 149                         return needs;
 150
 151                 sha1_buf = dummy;
 152                 if (needs == MAX_NEEDS) {
 153                         fprintf(stderr,
 154                                 "warning: supporting only a max of %d requests. "
 155                                 "sending everything instead.\n",
 156                                 MAX_NEEDS);
 157                 }
 158                 else if (needs < MAX_NEEDS)
 159                         sha1_buf = needs_sha1[needs];
 160
 161                 if (strncmp("want ", line, 5) || get_sha1_hex(line+5, sha1_buf))
 162                         die("git-upload-pack: protocol error, "
 163                             "expected to get sha, not '%s'", line);
 164                 needs++;
 165         }
 166 }
 167
 168 static int send_ref(const char *refname, const unsigned char *sha1)
 169 {
 170         struct object *o = parse_object(sha1);
 171
 172         packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 173         if (o->type == tag_type) {
 174                 o = deref_tag(o);
 175                 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 176         }
 177         return 0;
 178 }
 179
 180 static int upload_pack(void)
 181 {
 182         head_ref(send_ref);
 183         for_each_ref(send_ref);
 184         packet_flush(1);
 185         nr_needs = receive_needs();
 186         if (!nr_needs)
 187                 return 0;
 188         get_common_commits();
 189         create_pack_file();
 190         return 0;
 191 }
 192
 193 int main(int argc, char **argv)
 194 {
 195         const char *dir;
 196         if (argc != 2)
 197                 usage(upload_pack_usage);
 198         dir = argv[1];
 199
 200         /* chdir to the directory. If that fails, try appending ".git" */
 201         if (chdir(dir) < 0) {
 202                 if (chdir(mkpath("%s.git", dir)) < 0)
 203                         die("git-upload-pack unable to chdir to %s", dir);
 204         }
 205         chdir(".git");
 206         if (access("objects", X_OK) || access("refs", X_OK))
 207                 die("git-upload-pack: %s doesn't seem to be a git archive", dir);
 208         putenv("GIT_DIR=.");
 209         upload_pack();
 210         return 0;
 211 }