Andrew's git - gitweb.git/blob

   1#include "cache.h"
   2#include "refs.h"
   3#include "pkt-line.h"
   4#include <sys/wait.h>
   5
   6static const char fetch_pack_usage[] = "git-fetch-pack [host:]directory [heads]* < mycommitlist";
   7static const char *exec = "git-upload-pack";
   8
   9static int find_common(int fd[2], unsigned char *result_sha1, unsigned char *remote)
  10{
  11        static char line[1000];
  12        int count = 0, flushes = 0, retval;
  13        FILE *revs;
  14
  15        revs = popen("git-rev-list $(git-rev-parse --all)", "r");
  16        if (!revs)
  17                die("unable to run 'git-rev-list'");
  18        packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
  19        packet_flush(fd[1]);
  20        flushes = 1;
  21        retval = -1;
  22        while (fgets(line, sizeof(line), revs) != NULL) {
  23                unsigned char sha1[20];
  24                if (get_sha1_hex(line, sha1))
  25                        die("git-fetch-pack: expected object name, got crud");
  26                packet_write(fd[1], "have %s\n", sha1_to_hex(sha1));
  27                if (!(31 & ++count)) {
  28                        packet_flush(fd[1]);
  29                        flushes++;
  30
  31                        /*
  32                         * We keep one window "ahead" of the other side, and
  33                         * will wait for an ACK only on the next one
  34                         */
  35                        if (count == 32)
  36                                continue;
  37                        if (get_ack(fd[0], result_sha1)) {
  38                                flushes = 0;
  39                                retval = 0;
  40                                break;
  41                        }
  42                        flushes--;
  43                }
  44        }
  45        pclose(revs);
  46        packet_write(fd[1], "done\n");
  47        while (flushes) {
  48                flushes--;
  49                if (get_ack(fd[0], result_sha1))
  50                        return 0;
  51        }
  52        return retval;
  53}
  54
  55static int get_remote_heads(int fd, int nr_match, char **match, unsigned char *result)
  56{
  57        int count = 0;
  58
  59        for (;;) {
  60                static char line[1000];
  61                unsigned char sha1[20];
  62                char *refname;
  63                int len;
  64
  65                len = packet_read_line(fd, line, sizeof(line));
  66                if (!len)
  67                        break;
  68                if (line[len-1] == '\n')
  69                        line[--len] = 0;
  70                if (len < 42 || get_sha1_hex(line, sha1))
  71                        die("git-fetch-pack: protocol error - expected ref descriptor, got '%s¤'", line);
  72                refname = line+41;
  73                if (nr_match && !path_match(refname, nr_match, match))
  74                        continue;
  75                count++;
  76                memcpy(result, sha1, 20);
  77        }
  78        return count;
  79}
  80
  81static int fetch_pack(int fd[2], int nr_match, char **match)
  82{
  83        unsigned char sha1[20], remote[20];
  84        int heads, status;
  85        pid_t pid;
  86
  87        heads = get_remote_heads(fd[0], nr_match, match, remote);
  88        if (heads != 1) {
  89                packet_flush(fd[1]);
  90                die(heads ? "multiple remote heads" : "no matching remote head");
  91        }
  92        if (find_common(fd, sha1, remote) < 0)
  93                die("git-fetch-pack: no common commits");
  94        pid = fork();
  95        if (pid < 0)
  96                die("git-fetch-pack: unable to fork off git-unpack-objects");
  97        if (!pid) {
  98                dup2(fd[0], 0);
  99                close(fd[0]);
 100                close(fd[1]);
 101                execlp("git-unpack-objects", "git-unpack-objects", NULL);
 102                die("git-unpack-objects exec failed");
 103        }
 104        close(fd[0]);
 105        close(fd[1]);
 106        while (waitpid(pid, &status, 0) < 0) {
 107                if (errno != EINTR)
 108                        die("waiting for git-unpack-objects: %s", strerror(errno));
 109        }
 110        if (WIFEXITED(status)) {
 111                int code = WEXITSTATUS(status);
 112                if (code)
 113                        die("git-unpack-objects died with error code %d", code);
 114                puts(sha1_to_hex(remote));
 115                return 0;
 116        }
 117        if (WIFSIGNALED(status)) {
 118                int sig = WTERMSIG(status);
 119                die("git-unpack-objects died of signal %d", sig);
 120        }
 121        die("Sherlock Holmes! git-unpack-objects died of unnatural causes %d!", status);
 122}
 123
 124int main(int argc, char **argv)
 125{
 126        int i, ret, nr_heads;
 127        char *dest = NULL, **heads;
 128        int fd[2];
 129        pid_t pid;
 130
 131        nr_heads = 0;
 132        heads = NULL;
 133        for (i = 1; i < argc; i++) {
 134                char *arg = argv[i];
 135
 136                if (*arg == '-') {
 137                        /* Arguments go here */
 138                        usage(fetch_pack_usage);
 139                }
 140                dest = arg;
 141                heads = argv + i + 1;
 142                nr_heads = argc - i - 1;
 143                break;
 144        }
 145        if (!dest)
 146                usage(fetch_pack_usage);
 147        pid = git_connect(fd, dest, exec);
 148        if (pid < 0)
 149                return 1;
 150        ret = fetch_pack(fd, nr_heads, heads);
 151        close(fd[0]);
 152        close(fd[1]);
 153        finish_connect(pid);
 154        return ret;
 155}