Build-in send-pack, with an API for other programs to call.

Also marks some more things as const, as needed.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 468 insertions, 0 deletions

diff --git a/builtin-send-pack.c b/builtin-send-pack.c
new file mode 100644
index 000000000..aedef09ef
--- /dev/null
+++ b/builtin-send-pack.c
@@ -0,0 +1,468 @@
+#include "cache.h"
+#include "commit.h"
+#include "tag.h"
+#include "refs.h"
+#include "pkt-line.h"
+#include "run-command.h"
+#include "remote.h"
+#include "send-pack.h"
+
+static const char send_pack_usage[] =
+"git-send-pack [--all] [--dry-run] [--force] [--receive-pack=<git-receive-pack>] [--verbose] [--thin] [<host>:]<directory> [<ref>...]\n"
+"  --all and explicit <ref> specification are mutually exclusive.";
+
+static struct send_pack_args args = {
+	/* .receivepack = */ "git-receive-pack",
+};
+
+/*
+ * Make a pack stream and spit it out into file descriptor fd
+ */
+static int pack_objects(int fd, struct ref *refs)
+{
+	/*
+	 * The child becomes pack-objects --revs; we feed
+	 * the revision parameters to it via its stdin and
+	 * let its stdout go back to the other end.
+	 */
+	const char *argv[] = {
+		"pack-objects",
+		"--all-progress",
+		"--revs",
+		"--stdout",
+		NULL,
+		NULL,
+	};
+	struct child_process po;
+
+	if (args.use_thin_pack)
+		argv[4] = "--thin";
+	memset(&po, 0, sizeof(po));
+	po.argv = argv;
+	po.in = -1;
+	po.out = fd;
+	po.git_cmd = 1;
+	if (start_command(&po))
+		die("git-pack-objects failed (%s)", strerror(errno));
+
+	/*
+	 * We feed the pack-objects we just spawned with revision
+	 * parameters by writing to the pipe.
+	 */
+	while (refs) {
+		char buf[42];
+
+		if (!is_null_sha1(refs->old_sha1) &&
+		    has_sha1_file(refs->old_sha1)) {
+			memcpy(buf + 1, sha1_to_hex(refs->old_sha1), 40);
+			buf[0] = '^';
+			buf[41] = '\n';
+			if (!write_or_whine(po.in, buf, 42,
+						"send-pack: send refs"))
+				break;
+		}
+		if (!is_null_sha1(refs->new_sha1)) {
+			memcpy(buf, sha1_to_hex(refs->new_sha1), 40);
+			buf[40] = '\n';
+			if (!write_or_whine(po.in, buf, 41,
+						"send-pack: send refs"))
+				break;
+		}
+		refs = refs->next;
+	}
+
+	if (finish_command(&po))
+		return error("pack-objects died with strange error");
+	return 0;
+}
+
+static void unmark_and_free(struct commit_list *list, unsigned int mark)
+{
+	while (list) {
+		struct commit_list *temp = list;
+		temp->item->object.flags &= ~mark;
+		list = temp->next;
+		free(temp);
+	}
+}
+
+static int ref_newer(const unsigned char *new_sha1,
+		     const unsigned char *old_sha1)
+{
+	struct object *o;
+	struct commit *old, *new;
+	struct commit_list *list, *used;
+	int found = 0;
+
+	/* Both new and old must be commit-ish and new is descendant of
+	 * old.  Otherwise we require --force.
+	 */
+	o = deref_tag(parse_object(old_sha1), NULL, 0);
+	if (!o || o->type != OBJ_COMMIT)
+		return 0;
+	old = (struct commit *) o;
+
+	o = deref_tag(parse_object(new_sha1), NULL, 0);
+	if (!o || o->type != OBJ_COMMIT)
+		return 0;
+	new = (struct commit *) o;
+
+	if (parse_commit(new) < 0)
+		return 0;
+
+	used = list = NULL;
+	commit_list_insert(new, &list);
+	while (list) {
+		new = pop_most_recent_commit(&list, 1);
+		commit_list_insert(new, &used);
+		if (new == old) {
+			found = 1;
+			break;
+		}
+	}
+	unmark_and_free(list, 1);
+	unmark_and_free(used, 1);
+	return found;
+}
+
+static struct ref *local_refs, **local_tail;
+static struct ref *remote_refs, **remote_tail;
+
+static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
+{
+	struct ref *ref;
+	int len = strlen(refname) + 1;
+	ref = xcalloc(1, sizeof(*ref) + len);
+	hashcpy(ref->new_sha1, sha1);
+	memcpy(ref->name, refname, len);
+	*local_tail = ref;
+	local_tail = &ref->next;
+	return 0;
+}
+
+static void get_local_heads(void)
+{
+	local_tail = &local_refs;
+	for_each_ref(one_local_ref, NULL);
+}
+
+static int receive_status(int in)
+{
+	char line[1000];
+	int ret = 0;
+	int len = packet_read_line(in, line, sizeof(line));
+	if (len < 10 || memcmp(line, "unpack ", 7)) {
+		fprintf(stderr, "did not receive status back\n");
+		return -1;
+	}
+	if (memcmp(line, "unpack ok\n", 10)) {
+		fputs(line, stderr);
+		ret = -1;
+	}
+	while (1) {
+		len = packet_read_line(in, line, sizeof(line));
+		if (!len)
+			break;
+		if (len < 3 ||
+		    (memcmp(line, "ok", 2) && memcmp(line, "ng", 2))) {
+			fprintf(stderr, "protocol error: %s\n", line);
+			ret = -1;
+			break;
+		}
+		if (!memcmp(line, "ok", 2))
+			continue;
+		fputs(line, stderr);
+		ret = -1;
+	}
+	return ret;
+}
+
+static void update_tracking_ref(struct remote *remote, struct ref *ref)
+{
+	struct refspec rs;
+	int will_delete_ref;
+
+	rs.src = ref->name;
+	rs.dst = NULL;
+
+	if (!ref->peer_ref)
+		return;
+
+	will_delete_ref = is_null_sha1(ref->peer_ref->new_sha1);
+
+	if (!will_delete_ref &&
+			!hashcmp(ref->old_sha1, ref->peer_ref->new_sha1))
+		return;
+
+	if (!remote_find_tracking(remote, &rs)) {
+		fprintf(stderr, "updating local tracking ref '%s'\n", rs.dst);
+		if (is_null_sha1(ref->peer_ref->new_sha1)) {
+			if (delete_ref(rs.dst, NULL))
+				error("Failed to delete");
+		} else
+			update_ref("update by push", rs.dst,
+					ref->new_sha1, NULL, 0, 0);
+		free(rs.dst);
+	}
+}
+
+static int do_send_pack(int in, int out, struct remote *remote, int nr_refspec, const char **refspec)
+{
+	struct ref *ref;
+	int new_refs;
+	int ret = 0;
+	int ask_for_status_report = 0;
+	int allow_deleting_refs = 0;
+	int expect_status_report = 0;
+
+	/* No funny business with the matcher */
+	remote_tail = get_remote_heads(in, &remote_refs, 0, NULL, REF_NORMAL);
+	get_local_heads();
+
+	/* Does the other end support the reporting? */
+	if (server_supports("report-status"))
+		ask_for_status_report = 1;
+	if (server_supports("delete-refs"))
+		allow_deleting_refs = 1;
+
+	/* match them up */
+	if (!remote_tail)
+		remote_tail = &remote_refs;
+	if (match_refs(local_refs, remote_refs, &remote_tail,
+		       nr_refspec, refspec, args.send_all))
+		return -1;
+
+	if (!remote_refs) {
+		fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
+			"Perhaps you should specify a branch such as 'master'.\n");
+		return 0;
+	}
+
+	/*
+	 * Finally, tell the other end!
+	 */
+	new_refs = 0;
+	for (ref = remote_refs; ref; ref = ref->next) {
+		char old_hex[60], *new_hex;
+		int will_delete_ref;
+
+		if (!ref->peer_ref)
+			continue;
+
+
+		will_delete_ref = is_null_sha1(ref->peer_ref->new_sha1);
+		if (will_delete_ref && !allow_deleting_refs) {
+			error("remote does not support deleting refs");
+			ret = -2;
+			continue;
+		}
+		if (!will_delete_ref &&
+		    !hashcmp(ref->old_sha1, ref->peer_ref->new_sha1)) {
+			if (args.verbose)
+				fprintf(stderr, "'%s': up-to-date\n", ref->name);
+			continue;
+		}
+
+		/* This part determines what can overwrite what.
+		 * The rules are:
+		 *
+		 * (0) you can always use --force or +A:B notation to
+		 *     selectively force individual ref pairs.
+		 *
+		 * (1) if the old thing does not exist, it is OK.
+		 *
+		 * (2) if you do not have the old thing, you are not allowed
+		 *     to overwrite it; you would not know what you are losing
+		 *     otherwise.
+		 *
+		 * (3) if both new and old are commit-ish, and new is a
+		 *     descendant of old, it is OK.
+		 *
+		 * (4) regardless of all of the above, removing :B is
+		 *     always allowed.
+		 */
+
+		if (!args.force_update &&
+		    !will_delete_ref &&
+		    !is_null_sha1(ref->old_sha1) &&
+		    !ref->force) {
+			if (!has_sha1_file(ref->old_sha1) ||
+			    !ref_newer(ref->peer_ref->new_sha1,
+				       ref->old_sha1)) {
+				/* We do not have the remote ref, or
+				 * we know that the remote ref is not
+				 * an ancestor of what we are trying to
+				 * push.  Either way this can be losing
+				 * commits at the remote end and likely
+				 * we were not up to date to begin with.
+				 */
+				error("remote '%s' is not a strict "
+				      "subset of local ref '%s'. "
+				      "maybe you are not up-to-date and "
+				      "need to pull first?",
+				      ref->name,
+				      ref->peer_ref->name);
+				ret = -2;
+				continue;
+			}
+		}
+		hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
+		if (!will_delete_ref)
+			new_refs++;
+		strcpy(old_hex, sha1_to_hex(ref->old_sha1));
+		new_hex = sha1_to_hex(ref->new_sha1);
+
+		if (!args.dry_run) {
+			if (ask_for_status_report) {
+				packet_write(out, "%s %s %s%c%s",
+					old_hex, new_hex, ref->name, 0,
+					"report-status");
+				ask_for_status_report = 0;
+				expect_status_report = 1;
+			}
+			else
+				packet_write(out, "%s %s %s",
+					old_hex, new_hex, ref->name);
+		}
+		if (will_delete_ref)
+			fprintf(stderr, "deleting '%s'\n", ref->name);
+		else {
+			fprintf(stderr, "updating '%s'", ref->name);
+			if (strcmp(ref->name, ref->peer_ref->name))
+				fprintf(stderr, " using '%s'",
+					ref->peer_ref->name);
+			fprintf(stderr, "\n  from %s\n  to   %s\n",
+				old_hex, new_hex);
+		}
+	}
+
+	packet_flush(out);
+	if (new_refs && !args.dry_run)
+		ret = pack_objects(out, remote_refs);
+	close(out);
+
+	if (expect_status_report) {
+		if (receive_status(in))
+			ret = -4;
+	}
+
+	if (!args.dry_run && remote && ret == 0) {
+		for (ref = remote_refs; ref; ref = ref->next)
+			update_tracking_ref(remote, ref);
+	}
+
+	if (!new_refs && ret == 0)
+		fprintf(stderr, "Everything up-to-date\n");
+	return ret;
+}
+
+static void verify_remote_names(int nr_heads, const char **heads)
+{
+	int i;
+
+	for (i = 0; i < nr_heads; i++) {
+		const char *remote = strchr(heads[i], ':');
+
+		remote = remote ? (remote + 1) : heads[i];
+		switch (check_ref_format(remote)) {
+		case 0: /* ok */
+		case -2: /* ok but a single level -- that is fine for
+			  * a match pattern.
+			  */
+		case -3: /* ok but ends with a pattern-match character */
+			continue;
+		}
+		die("remote part of refspec is not a valid name in %s",
+		    heads[i]);
+	}
+}
+
+int cmd_send_pack(int argc, const char **argv, const char *prefix)
+{
+	int i, nr_heads = 0;
+	const char **heads = NULL;
+	const char *remote_name = NULL;
+	struct remote *remote = NULL;
+	const char *dest = NULL;
+
+	argv++;
+	for (i = 1; i < argc; i++, argv++) {
+		const char *arg = *argv;
+
+		if (*arg == '-') {
+			if (!prefixcmp(arg, "--receive-pack=")) {
+				args.receivepack = arg + 15;
+				continue;
+			}
+			if (!prefixcmp(arg, "--exec=")) {
+				args.receivepack = arg + 7;
+				continue;
+			}
+			if (!prefixcmp(arg, "--remote=")) {
+				remote_name = arg + 9;
+				continue;
+			}
+			if (!strcmp(arg, "--all")) {
+				args.send_all = 1;
+				continue;
+			}
+			if (!strcmp(arg, "--dry-run")) {
+				args.dry_run = 1;
+				continue;
+			}
+			if (!strcmp(arg, "--force")) {
+				args.force_update = 1;
+				continue;
+			}
+			if (!strcmp(arg, "--verbose")) {
+				args.verbose = 1;
+				continue;
+			}
+			if (!strcmp(arg, "--thin")) {
+				args.use_thin_pack = 1;
+				continue;
+			}
+			usage(send_pack_usage);
+		}
+		if (!dest) {
+			dest = arg;
+			continue;
+		}
+		heads = (const char **) argv;
+		nr_heads = argc - i;
+		break;
+	}
+	if (!dest)
+		usage(send_pack_usage);
+	if (heads && args.send_all)
+		usage(send_pack_usage);
+
+	if (remote_name) {
+		remote = remote_get(remote_name);
+		if (!remote_has_url(remote, dest)) {
+			die("Destination %s is not a uri for %s",
+			    dest, remote_name);
+		}
+	}
+
+	return send_pack(&args, dest, remote, nr_heads, heads);
+}
+
+int send_pack(struct send_pack_args *my_args,
+	      const char *dest, struct remote *remote,
+	      int nr_heads, const char **heads)
+{
+	int fd[2], ret;
+	struct child_process *conn;
+
+	memcpy(&args, my_args, sizeof(args));
+
+	verify_remote_names(nr_heads, heads);
+
+	conn = git_connect(fd, dest, args.receivepack, args.verbose ? CONNECT_VERBOSE : 0);
+	ret = do_send_pack(fd[0], fd[1], remote, nr_heads, heads);
+	close(fd[0]);
+	close(fd[1]);
+	ret |= finish_connect(conn);
+	return !!ret;
+}