upload-pack.c

   1 #include "cache.h"
   2 #include "refs.h"
   3 #include "pkt-line.h"
   4
   5 static const char upload_pack_usage[] = "git-upload-pack <dir>";
   6
   7 #define MAX_HAS (16)
   8 #define MAX_NEEDS (256)
   9 static int nr_has = 0, nr_needs = 0;
  10 static unsigned char has_sha1[MAX_HAS][20];
  11 static unsigned char needs_sha1[MAX_NEEDS][20];
  12
  13 static int strip(char *line, int len)
  14 {
  15         if (len && line[len-1] == '\n')
  16                 line[--len] = 0;
  17         return len;
  18 }
  19
  20 static void create_pack_file(void)
  21 {
  22         int fd[2];
  23         pid_t pid;
  24
  25         if (pipe(fd) < 0)
  26                 die("git-upload-pack: unable to create pipe");
  27         pid = fork();
  28         if (pid < 0)
  29                 die("git-upload-pack: unable to fork git-rev-list");
  30
  31         if (!pid) {
  32                 int i;
  33                 int args;
  34                 char **argv;
  35                 char *buf;
  36                 char **p;
  37
  38                 if (MAX_NEEDS <= nr_needs)
  39                         args = nr_has + 10;
  40                 else
  41                         args = nr_has + nr_needs + 5;
  42                 argv = xmalloc(args * sizeof(char *));
  43                 buf = xmalloc(args * 45);
  44                 p = argv;
  45
  46                 dup2(fd[1], 1);
  47                 close(0);
  48                 close(fd[0]);
  49                 close(fd[1]);
  50                 *p++ = "git-rev-list";
  51                 *p++ = "--objects";
  52                 if (MAX_NEEDS <= nr_needs)
  53                         *p++ = "--all";
  54                 else {
  55                         for (i = 0; i < nr_needs; i++) {
  56                                 *p++ = buf;
  57                                 memcpy(buf, sha1_to_hex(needs_sha1[i]), 41);
  58                                 buf += 41;
  59                         }
  60                 }
  61                 for (i = 0; i < nr_has; i++) {
  62                         *p++ = buf;
  63                         *buf++ = '^';
  64                         memcpy(buf, sha1_to_hex(has_sha1[i]), 41);
  65                         buf += 41;
  66                 }
  67                 *p++ = NULL;
  68                 execvp("git-rev-list", argv);
  69                 die("git-upload-pack: unable to exec git-rev-list");
  70         }
  71         dup2(fd[0], 0);
  72         close(fd[0]);
  73         close(fd[1]);
  74         execlp("git-pack-objects", "git-pack-objects", "--stdout", NULL);
  75         die("git-upload-pack: unable to exec git-pack-objects");
  76 }
  77
  78 static int got_sha1(char *hex, unsigned char *sha1)
  79 {
  80         int nr;
  81         if (get_sha1_hex(hex, sha1))
  82                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
  83         if (!has_sha1_file(sha1))
  84                 return 0;
  85         nr = nr_has;
  86         if (nr < MAX_HAS) {
  87                 memcpy(has_sha1[nr], sha1, 20);
  88                 nr_has = nr+1;
  89         }
  90         return 1;
  91 }
  92
  93 static int get_common_commits(void)
  94 {
  95         static char line[1000];
  96         unsigned char sha1[20];
  97         int len;
  98
  99         for(;;) {
 100                 len = packet_read_line(0, line, sizeof(line));
 101
 102                 if (!len) {
 103                         packet_write(1, "NAK\n");
 104                         continue;
 105                 }
 106                 len = strip(line, len);
 107                 if (!strncmp(line, "have ", 5)) {
 108                         if (got_sha1(line+5, sha1)) {
 109                                 packet_write(1, "ACK %s\n", sha1_to_hex(sha1));
 110                                 break;
 111                         }
 112                         continue;
 113                 }
 114                 if (!strcmp(line, "done")) {
 115                         packet_write(1, "NAK\n");
 116                         return -1;
 117                 }
 118                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
 119         }
 120
 121         for (;;) {
 122                 len = packet_read_line(0, line, sizeof(line));
 123                 if (!len)
 124                         continue;
 125                 len = strip(line, len);
 126                 if (!strncmp(line, "have ", 5)) {
 127                         got_sha1(line+5, sha1);
 128                         continue;
 129                 }
 130                 if (!strcmp(line, "done"))
 131                         break;
 132                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
 133         }
 134         return 0;
 135 }
 136
 137 static int receive_needs(void)
 138 {
 139         static char line[1000];
 140         int len, needs;
 141
 142         needs = 0;
 143         for (;;) {
 144                 unsigned char dummy[20], *sha1_buf;
 145                 len = packet_read_line(0, line, sizeof(line));
 146                 if (!len)
 147                         return needs;
 148
 149                 sha1_buf = dummy;
 150                 if (needs == MAX_NEEDS) {
 151                         fprintf(stderr,
 152                                 "warning: supporting only a max of %d requests. "
 153                                 "sending everything instead.\n",
 154                                 MAX_NEEDS);
 155                 }
 156                 else if (needs < MAX_NEEDS)
 157                         sha1_buf = needs_sha1[needs];
 158
 159                 if (strncmp("want ", line, 5) || get_sha1_hex(line+5, sha1_buf))
 160                         die("git-upload-pack: protocol error, "
 161                             "expected to get sha, not '%s'", line);
 162                 needs++;
 163         }
 164 }
 165
 166 static int send_ref(const char *refname, const unsigned char *sha1)
 167 {
 168         packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 169         return 0;
 170 }
 171
 172 static int upload_pack(void)
 173 {
 174         head_ref(send_ref);
 175         for_each_ref(send_ref);
 176         packet_flush(1);
 177         nr_needs = receive_needs();
 178         if (!nr_needs)
 179                 return 0;
 180         get_common_commits();
 181         create_pack_file();
 182         return 0;
 183 }
 184
 185 int main(int argc, char **argv)
 186 {
 187         const char *dir;
 188         if (argc != 2)
 189                 usage(upload_pack_usage);
 190         dir = argv[1];
 191
 192         /* chdir to the directory. If that fails, try appending ".git" */
 193         if (chdir(dir) < 0) {
 194                 if (chdir(mkpath("%s.git", dir)) < 0)
 195                         die("git-upload-pack unable to chdir to %s", dir);
 196         }
 197         chdir(".git");
 198         if (access("objects", X_OK) || access("refs", X_OK))
 199                 die("git-upload-pack: %s doesn't seem to be a git archive", dir);
 200         putenv("GIT_DIR=.");
 201         upload_pack();
 202         return 0;
 203 }