git-send-pack: actually send the object pack

This concludes this lesson.  I've actually successfully sent an update
using the git-send-pack command.

Probably tons of work still to do, and nasty debugging, but it's now
actually potentially useful.

diff --git a/send-pack.c b/send-pack.c
index ca3eabb..4519867 100644 (file)
--- a/send-pack.c
+++ b/send-pack.c
@@ -13,7 +13,82 @@ struct ref {
        char name[0];
 };
 
-static struct ref *ref_list = NULL, **last_ref = &ref_list;
+static void exec_pack_objects(void)
+{
+       static char *args[] = {
+               "git-pack-objects",
+               "--stdout",
+               NULL
+       };
+       execvp("git-pack-objects", args);
+       die("git-pack-objects exec failed (%s)", strerror(errno));
+}
+
+static void exec_rev_list(struct ref *refs)
+{
+       static char *args[1000];
+       int i = 0;
+
+       args[i++] = "git-rev-list";     /* 0 */
+       args[i++] = "--objects";        /* 1 */
+       while (refs) {
+               char *buf = malloc(100);
+               if (i > 900)
+                       die("git-rev-list environment overflow");
+               args[i++] = buf;
+               snprintf(buf, 50, "^%s", sha1_to_hex(refs->old_sha1));
+               buf += 50;
+               args[i++] = buf;
+               snprintf(buf, 50, "%s", sha1_to_hex(refs->new_sha1));
+               refs = refs->next;
+       }
+       args[i] = NULL;
+       execvp("git-rev-list", args);
+       die("git-rev-list exec failed (%s)", strerror(errno));
+}
+
+static void rev_list(int fd, struct ref *refs)
+{
+       int pipe_fd[2];
+       pid_t pack_objects_pid;
+
+       if (pipe(pipe_fd) < 0)
+               die("rev-list setup: pipe failed");
+       pack_objects_pid = fork();
+       if (!pack_objects_pid) {
+               dup2(pipe_fd[0], 0);
+               dup2(fd, 1);
+               close(pipe_fd[0]);
+               close(pipe_fd[1]);
+               close(fd);
+               exec_pack_objects();
+               die("pack-objects setup failed");
+       }
+       if (pack_objects_pid < 0)
+               die("pack-objects fork failed");
+       dup2(pipe_fd[1], 1);
+       close(pipe_fd[0]);
+       close(pipe_fd[1]);
+       close(fd);
+       exec_rev_list(refs);
+}
+
+static int pack_objects(int fd, struct ref *refs)
+{
+       pid_t rev_list_pid;
+
+       rev_list_pid = fork();
+       if (!rev_list_pid) {
+               rev_list(fd, refs);
+               die("rev-list setup failed");
+       }
+       if (rev_list_pid < 0)
+               die("rev-list fork failed");
+       /*
+        * We don't wait for the rev-list pipeline in the parent:
+        * we end up waiting for the other end instead
+        */
+}
 
 static int read_ref(const char *ref, unsigned char *sha1)
 {
@@ -35,6 +110,7 @@ static int read_ref(const char *ref, unsigned char *sha1)
 
 static int send_pack(int in, int out)
 {
+       struct ref *ref_list = NULL, **last_ref = &ref_list;
        struct ref *ref;
 
        for (;;) {
@@ -79,17 +155,8 @@ static int send_pack(int in, int out)
        }
        
        packet_flush(out);
-       /*
-        * FIXME! Here we need to now send the pack-file to the "out" fd, using something
-        * like this:
-        *
-        *   fork() +
-        *      dup2(out, 1) +
-        *      execve("/bin/sh git-rev-list --objects ..for-each-ref-list.. | "
-        *              "git-pack-objects --stdout");
-        *
-        * but I'm too tired right now.
-        */
+       if (ref_list)
+               pack_objects(out, ref_list);
        close(out);
        return 0;
 }