1 files changed, 94 insertions, 0 deletions
diff --git a/connected.c b/connected.c
new file mode 100644
index 0000000000..fae8d64c12
--- /dev/null
+++ b/connected.c
@@ -0,0 +1,94 @@
+#include "cache.h"
+#include "run-command.h"
+#include "sigchain.h"
+#include "connected.h"
+#include "transport.h"
+
+int check_everything_connected(sha1_iterate_fn fn, int quiet, void *cb_data)
+{
+	return check_everything_connected_with_transport(fn, quiet, cb_data, NULL);
+}
+/*
+ * If we feed all the commits we want to verify to this command
+ *
+ *  $ git rev-list --objects --stdin --not --all
+ *
+ * and if it does not error out, that means everything reachable from
+ * these commits locally exists and is connected to our existing refs.
+ * Note that this does _not_ validate the individual objects.
+ *
+ * Returns 0 if everything is connected, non-zero otherwise.
+ */
+int check_everything_connected_with_transport(sha1_iterate_fn fn,
+					      int quiet,
+					      void *cb_data,
+					      struct transport *transport)
+{
+	struct child_process rev_list;
+	const char *argv[] = {"rev-list", "--objects",
+			      "--stdin", "--not", "--all", NULL, NULL};
+	char commit[41];
+	unsigned char sha1[20];
+	int err = 0;
+	struct packed_git *new_pack = NULL;
+
+	if (fn(cb_data, sha1))
+		return err;
+
+	if (transport && transport->smart_options &&
+	    transport->smart_options->self_contained_and_connected &&
+	    transport->pack_lockfile &&
+	    !suffixcmp(transport->pack_lockfile, ".keep")) {
+		struct strbuf idx_file = STRBUF_INIT;
+		strbuf_addstr(&idx_file, transport->pack_lockfile);
+		strbuf_setlen(&idx_file, idx_file.len - 5); /* ".keep" */
+		strbuf_addstr(&idx_file, ".idx");
+		new_pack = add_packed_git(idx_file.buf, idx_file.len, 1);
+		strbuf_release(&idx_file);
+	}
+
+	if (quiet)
+		argv[5] = "--quiet";
+
+	memset(&rev_list, 0, sizeof(rev_list));
+	rev_list.argv = argv;
+	rev_list.git_cmd = 1;
+	rev_list.in = -1;
+	rev_list.no_stdout = 1;
+	rev_list.no_stderr = quiet;
+	if (start_command(&rev_list))
+		return error(_("Could not run 'git rev-list'"));
+
+	sigchain_push(SIGPIPE, SIG_IGN);
+
+	commit[40] = '\n';
+	do {
+		/*
+		 * If index-pack already checked that:
+		 * - there are no dangling pointers in the new pack
+		 * - the pack is self contained
+		 * Then if the updated ref is in the new pack, then we
+		 * are sure the ref is good and not sending it to
+		 * rev-list for verification.
+		 */
+		if (new_pack && find_pack_entry_one(sha1, new_pack))
+			continue;
+
+		memcpy(commit, sha1_to_hex(sha1), 40);
+		if (write_in_full(rev_list.in, commit, 41) < 0) {
+			if (errno != EPIPE && errno != EINVAL)
+				error(_("failed write to rev-list: %s"),
+				      strerror(errno));
+			err = -1;
+			break;
+		}
+	} while (!fn(cb_data, sha1));
+
+	if (close(rev_list.in)) {
+		error(_("failed to close rev-list's stdin: %s"), strerror(errno));
+		err = -1;
+	}
+
+	sigchain_pop(SIGPIPE);
+	return finish_command(&rev_list) || err;
+}