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-rw-r--r--clone-pack.c182
1 files changed, 182 insertions, 0 deletions
diff --git a/clone-pack.c b/clone-pack.c
new file mode 100644
index 0000000..e9c20de
--- /dev/null
+++ b/clone-pack.c
@@ -0,0 +1,182 @@
+#include "cache.h"
+#include "refs.h"
+#include "pkt-line.h"
+#include <sys/wait.h>
+
+static int quiet;
+static const char clone_pack_usage[] = "git-clone-pack [-q] [--exec=<git-upload-pack>] [<host>:]<directory> [<heads>]*";
+static const char *exec = "git-upload-pack";
+
+static void clone_handshake(int fd[2], struct ref *ref)
+{
+ unsigned char sha1[20];
+
+ while (ref) {
+ packet_write(fd[1], "want %s\n", sha1_to_hex(ref->old_sha1));
+ ref = ref->next;
+ }
+ packet_flush(fd[1]);
+
+ /* We don't have nuttin' */
+ packet_write(fd[1], "done\n");
+ if (get_ack(fd[0], sha1))
+ error("Huh! git-clone-pack got positive ack for %s", sha1_to_hex(sha1));
+}
+
+static int is_master(struct ref *ref)
+{
+ return !strcmp(ref->name, "refs/heads/master");
+}
+
+static void write_one_ref(struct ref *ref)
+{
+ char *path = git_path(ref->name);
+ int fd;
+ char *hex;
+
+ if (safe_create_leading_directories(path))
+ die("unable to create leading directory for %s", ref->name);
+ fd = open(path, O_CREAT | O_EXCL | O_WRONLY, 0666);
+ if (fd < 0)
+ die("unable to create ref %s", ref->name);
+ hex = sha1_to_hex(ref->old_sha1);
+ hex[40] = '\n';
+ if (write(fd, hex, 41) != 41)
+ die("unable to write ref %s", ref->name);
+ close(fd);
+}
+
+static void write_refs(struct ref *ref)
+{
+ struct ref *head = NULL, *head_ptr, *master_ref;
+ char *head_path;
+
+ if (!strcmp(ref->name, "HEAD")) {
+ head = ref;
+ ref = ref->next;
+ }
+ head_ptr = NULL;
+ master_ref = NULL;
+ while (ref) {
+ if (is_master(ref))
+ master_ref = ref;
+ if (head && !memcmp(ref->old_sha1, head->old_sha1, 20)) {
+ if (!head_ptr || ref == master_ref)
+ head_ptr = ref;
+ }
+ write_one_ref(ref);
+ ref = ref->next;
+ }
+ if (!head)
+ return;
+
+ head_path = git_path("HEAD");
+ if (!head_ptr) {
+ /*
+ * If we had a master ref, and it wasn't HEAD, we need to undo the
+ * symlink, and write a standalone HEAD. Give a warning, because that's
+ * really really wrong.
+ */
+ if (master_ref) {
+ error("HEAD doesn't point to any refs! Making standalone HEAD");
+ unlink(head_path);
+ }
+ write_one_ref(head);
+ return;
+ }
+
+ /* We reset to the master branch if it's available */
+ if (master_ref)
+ return;
+
+ /*
+ * Uhhuh. Other end didn't have master. We start HEAD off with
+ * the first branch with the same value.
+ */
+ unlink(head_path);
+ if (symlink(head_ptr->name, head_path) < 0)
+ die("unable to link HEAD to %s", head_ptr->name);
+}
+
+static int clone_pack(int fd[2], int nr_match, char **match)
+{
+ struct ref *refs;
+ int status;
+ pid_t pid;
+
+ get_remote_heads(fd[0], &refs, nr_match, match);
+ if (!refs) {
+ packet_flush(fd[1]);
+ die("no matching remote head");
+ }
+ clone_handshake(fd, refs);
+ pid = fork();
+ if (pid < 0)
+ die("git-clone-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]);
+ 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);
+ write_refs(refs);
+ 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)
+{
+ int i, ret, nr_heads;
+ char *dest = NULL, **heads;
+ int fd[2];
+ pid_t pid;
+
+ nr_heads = 0;
+ heads = NULL;
+ for (i = 1; i < argc; i++) {
+ char *arg = argv[i];
+
+ if (*arg == '-') {
+ if (!strcmp("-q", arg)) {
+ quiet = 1;
+ continue;
+ }
+ if (!strncmp("--exec=", arg, 7)) {
+ exec = arg + 7;
+ continue;
+ }
+ usage(clone_pack_usage);
+ }
+ dest = arg;
+ heads = argv + i + 1;
+ nr_heads = argc - i - 1;
+ break;
+ }
+ if (!dest)
+ usage(clone_pack_usage);
+ pid = git_connect(fd, dest, exec);
+ if (pid < 0)
+ return 1;
+ ret = clone_pack(fd, nr_heads, heads);
+ close(fd[0]);
+ close(fd[1]);
+ finish_connect(pid);
+ return ret;
+}