git-send-pack: documentation
[gitweb.git] / fetch-pack.c
index 151c1ff6b35bc62c2a2f010d3125869e5f3b8edc..65e007639ac744c3f354f71c157a85c5d6477d49 100644 (file)
@@ -1,36 +1,26 @@
 #include "cache.h"
 #include "refs.h"
 #include "pkt-line.h"
+#include <sys/wait.h>
 
-static const char fetch_pack_usage[] = "git-fetch-pack [host:]directory [heads]* < mycommitlist";
+static int quiet;
+static const char fetch_pack_usage[] = "git-fetch-pack [-q] [--exec=upload-pack] [host:]directory [heads]* < mycommitlist";
 static const char *exec = "git-upload-pack";
 
-static int get_ack(int fd, unsigned char *result_sha1)
-{
-       static char line[1000];
-       int len = packet_read_line(fd, line, sizeof(line));
-
-       if (!len)
-               die("git-fetch-pack: expected ACK/NAK, got EOF");
-       if (line[len-1] == '\n')
-               line[--len] = 0;
-       if (!strcmp(line, "NAK"))
-               return 0;
-       if (!strncmp(line, "ACK ", 3)) {
-               if (!get_sha1_hex(line+4, result_sha1))
-                       return 1;
-       }
-       die("git-fetch_pack: expected ACK/NAK, got '%s'", line);
-}
-
 static int find_common(int fd[2], unsigned char *result_sha1, unsigned char *remote)
 {
        static char line[1000];
-       int count = 0, flushes = 0;
+       int count = 0, flushes = 0, retval;
+       FILE *revs;
 
+       revs = popen("git-rev-list $(git-rev-parse --all)", "r");
+       if (!revs)
+               die("unable to run 'git-rev-list'");
        packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
        packet_flush(fd[1]);
-       while (fgets(line, sizeof(line), stdin) != NULL) {
+       flushes = 1;
+       retval = -1;
+       while (fgets(line, sizeof(line), revs) != NULL) {
                unsigned char sha1[20];
                if (get_sha1_hex(line, sha1))
                        die("git-fetch-pack: expected object name, got crud");
@@ -45,103 +35,76 @@ static int find_common(int fd[2], unsigned char *result_sha1, unsigned char *rem
                         */
                        if (count == 32)
                                continue;
-                       if (get_ack(fd[0], result_sha1))
-                               return 0;
+                       if (get_ack(fd[0], result_sha1)) {
+                               flushes = 0;
+                               retval = 0;
+                               break;
+                       }
                        flushes--;
                }
        }
-       flushes++;
-       packet_flush(fd[1]);
+       pclose(revs);
+       packet_write(fd[1], "done\n");
        while (flushes) {
                flushes--;
                if (get_ack(fd[0], result_sha1))
                        return 0;
        }
-       return -1;
-}
-
-static int get_old_sha1(const char *refname, unsigned char *sha1)
-{
-       static char pathname[PATH_MAX];
-       const char *git_dir;
-       int fd, ret;
-
-       git_dir = gitenv(GIT_DIR_ENVIRONMENT) ? : DEFAULT_GIT_DIR_ENVIRONMENT;
-       snprintf(pathname, sizeof(pathname), "%s/%s", git_dir, refname);
-       fd = open(pathname, O_RDONLY);
-       ret = -1;
-       if (fd >= 0) {
-               char buffer[60];
-               if (read(fd, buffer, sizeof(buffer)) >= 40)
-                       ret = get_sha1_hex(buffer, sha1);
-               close(fd);
-       }
-       return ret;
-}
-
-static int check_ref(const char *refname, const unsigned char *sha1)
-{
-       unsigned char mysha1[20];
-       char oldhex[41];
-
-       if (get_old_sha1(refname, mysha1) < 0)
-               memset(mysha1, 0, 20);
-
-       if (!memcmp(sha1, mysha1, 20)) {
-               printf("%s: unchanged\n", refname);
-               return 0;
-       }
-       
-       memcpy(oldhex, sha1_to_hex(mysha1), 41);
-       printf("%s: %s (%s)\n", refname, sha1_to_hex(sha1), oldhex);
-       return 1;
-}
-
-static int get_remote_heads(int fd, int nr_match, char **match, unsigned char *result)
-{
-       int count = 0;
-
-       for (;;) {
-               static char line[1000];
-               unsigned char sha1[20];
-               char *refname;
-               int len;
-
-               len = packet_read_line(fd, line, sizeof(line));
-               if (!len)
-                       break;
-               if (line[len-1] == '\n')
-                       line[--len] = 0;
-               if (len < 42 || get_sha1_hex(line, sha1))
-                       die("git-fetch-pack: protocol error - expected ref descriptor, got '%sä'", line);
-               refname = line+41;
-               if (nr_match && !path_match(refname, nr_match, match))
-                       continue;
-               if (check_ref(refname, sha1)) {
-                       count++;
-                       memcpy(result, sha1, 20);
-               }
-       }
-       return count;
+       return retval;
 }
 
+/*
+ * Eventually we'll want to be able to fetch multiple heads.
+ *
+ * Right now we'll just require a single match.
+ */
 static int fetch_pack(int fd[2], int nr_match, char **match)
 {
-       unsigned char sha1[20], remote[20];
-       int heads;
+       struct ref *ref;
+       unsigned char sha1[20];
+       int status;
+       pid_t pid;
 
-       heads = get_remote_heads(fd[0], nr_match, match, remote);
-       if (heads != 1) {
+       get_remote_heads(fd[0], &ref, nr_match, match);
+       if (!ref) {
+               packet_flush(fd[1]);
+               die("no matching remote head");
+       }
+       if (ref->next) {
                packet_flush(fd[1]);
-               die(heads ? "multiple remote heads" : "no matching remote head");
+               die("multiple remote heads");
        }
-       if (find_common(fd, sha1, remote) < 0)
+       if (find_common(fd, sha1, ref->old_sha1) < 0)
                die("git-fetch-pack: no common commits");
-       close(fd[1]);
-       dup2(fd[0], 0);
+       pid = fork();
+       if (pid < 0)
+               die("git-fetch-pack: unable to fork off git-unpack-objects");
+       if (!pid) {
+               dup2(fd[0], 0);
+               close(fd[0]);
+               close(fd[1]);
+               execlp("git-unpack-objects", "git-unpack-objects",
+                      quiet ? "-q" : NULL, NULL);
+               die("git-unpack-objects exec failed");
+       }
        close(fd[0]);
-       execlp("git-unpack-objects", "git-unpack-objects", NULL);
-       die("git-unpack-objects exec failed");
+       close(fd[1]);
+       while (waitpid(pid, &status, 0) < 0) {
+               if (errno != EINTR)
+                       die("waiting for git-unpack-objects: %s", strerror(errno));
+       }
+       if (WIFEXITED(status)) {
+               int code = WEXITSTATUS(status);
+               if (code)
+                       die("git-unpack-objects died with error code %d", code);
+               puts(sha1_to_hex(ref->old_sha1));
+               return 0;
+       }
+       if (WIFSIGNALED(status)) {
+               int sig = WTERMSIG(status);
+               die("git-unpack-objects died of signal %d", sig);
+       }
+       die("Sherlock Holmes! git-unpack-objects died of unnatural causes %d!", status);
 }
 
 int main(int argc, char **argv)
@@ -157,7 +120,10 @@ int main(int argc, char **argv)
                char *arg = argv[i];
 
                if (*arg == '-') {
-                       /* Arguments go here */
+                       if (!strncmp("--exec=", arg, 7)) {
+                               exec = arg + 7;
+                               continue;
+                       }
                        usage(fetch_pack_usage);
                }
                dest = arg;