Move bundle specific stuff into bundle.[ch]

The transport specific stuff was moved into libgit.a, and the
bundle specific stuff will not be left behind.

This is a big code move, with one exception: the function
unbundle() no longer outputs the list of refs.  You have to call
list_bundle_refs() yourself for that.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 343 insertions, 0 deletions

diff --git a/bundle.c b/bundle.c
new file mode 100644
index 0000000000..0869fcf026
--- /dev/null
+++ b/bundle.c
@@ -0,0 +1,343 @@
+#include "cache.h"
+#include "bundle.h"
+#include "object.h"
+#include "commit.h"
+#include "diff.h"
+#include "revision.h"
+#include "list-objects.h"
+#include "run-command.h"
+
+static const char bundle_signature[] = "# v2 git bundle\n";
+
+static void add_to_ref_list(const unsigned char *sha1, const char *name,
+		struct ref_list *list)
+{
+	if (list->nr + 1 >= list->alloc) {
+		list->alloc = alloc_nr(list->nr + 1);
+		list->list = xrealloc(list->list,
+				list->alloc * sizeof(list->list[0]));
+	}
+	memcpy(list->list[list->nr].sha1, sha1, 20);
+	list->list[list->nr].name = xstrdup(name);
+	list->nr++;
+}
+
+/* returns an fd */
+int read_bundle_header(const char *path, struct bundle_header *header) {
+	char buffer[1024];
+	int fd;
+	long fpos;
+	FILE *ffd = fopen(path, "rb");
+
+	if (!ffd)
+		return error("could not open '%s'", path);
+	if (!fgets(buffer, sizeof(buffer), ffd) ||
+			strcmp(buffer, bundle_signature)) {
+		fclose(ffd);
+		return error("'%s' does not look like a v2 bundle file", path);
+	}
+	while (fgets(buffer, sizeof(buffer), ffd)
+			&& buffer[0] != '\n') {
+		int is_prereq = buffer[0] == '-';
+		int offset = is_prereq ? 1 : 0;
+		int len = strlen(buffer);
+		unsigned char sha1[20];
+		struct ref_list *list = is_prereq ? &header->prerequisites
+			: &header->references;
+		char delim;
+
+		if (buffer[len - 1] == '\n')
+			buffer[len - 1] = '\0';
+		if (get_sha1_hex(buffer + offset, sha1)) {
+			warning("unrecognized header: %s", buffer);
+			continue;
+		}
+		delim = buffer[40 + offset];
+		if (!isspace(delim) && (delim != '\0' || !is_prereq))
+			die ("invalid header: %s", buffer);
+		add_to_ref_list(sha1, isspace(delim) ?
+				buffer + 41 + offset : "", list);
+	}
+	fpos = ftell(ffd);
+	fclose(ffd);
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
+		return error("could not open '%s'", path);
+	lseek(fd, fpos, SEEK_SET);
+	return fd;
+}
+
+static int list_refs(struct ref_list *r, int argc, const char **argv)
+{
+	int i;
+
+	for (i = 0; i < r->nr; i++) {
+		if (argc > 1) {
+			int j;
+			for (j = 1; j < argc; j++)
+				if (!strcmp(r->list[i].name, argv[j]))
+					break;
+			if (j == argc)
+				continue;
+		}
+		printf("%s %s\n", sha1_to_hex(r->list[i].sha1),
+				r->list[i].name);
+	}
+	return 0;
+}
+
+#define PREREQ_MARK (1u<<16)
+
+int verify_bundle(struct bundle_header *header, int verbose)
+{
+	/*
+	 * Do fast check, then if any prereqs are missing then go line by line
+	 * to be verbose about the errors
+	 */
+	struct ref_list *p = &header->prerequisites;
+	struct rev_info revs;
+	const char *argv[] = {NULL, "--all"};
+	struct object_array refs;
+	struct commit *commit;
+	int i, ret = 0, req_nr;
+	const char *message = "Repository lacks these prerequisite commits:";
+
+	init_revisions(&revs, NULL);
+	for (i = 0; i < p->nr; i++) {
+		struct ref_list_entry *e = p->list + i;
+		struct object *o = parse_object(e->sha1);
+		if (o) {
+			o->flags |= PREREQ_MARK;
+			add_pending_object(&revs, o, e->name);
+			continue;
+		}
+		if (++ret == 1)
+			error(message);
+		error("%s %s", sha1_to_hex(e->sha1), e->name);
+	}
+	if (revs.pending.nr != p->nr)
+		return ret;
+	req_nr = revs.pending.nr;
+	setup_revisions(2, argv, &revs, NULL);
+
+	memset(&refs, 0, sizeof(struct object_array));
+	for (i = 0; i < revs.pending.nr; i++) {
+		struct object_array_entry *e = revs.pending.objects + i;
+		add_object_array(e->item, e->name, &refs);
+	}
+
+	prepare_revision_walk(&revs);
+
+	i = req_nr;
+	while (i && (commit = get_revision(&revs)))
+		if (commit->object.flags & PREREQ_MARK)
+			i--;
+
+	for (i = 0; i < req_nr; i++)
+		if (!(refs.objects[i].item->flags & SHOWN)) {
+			if (++ret == 1)
+				error(message);
+			error("%s %s", sha1_to_hex(refs.objects[i].item->sha1),
+				refs.objects[i].name);
+		}
+
+	for (i = 0; i < refs.nr; i++)
+		clear_commit_marks((struct commit *)refs.objects[i].item, -1);
+
+	if (verbose) {
+		struct ref_list *r;
+
+		r = &header->references;
+		printf("The bundle contains %d ref%s\n",
+		       r->nr, (1 < r->nr) ? "s" : "");
+		list_refs(r, 0, NULL);
+		r = &header->prerequisites;
+		printf("The bundle requires these %d ref%s\n",
+		       r->nr, (1 < r->nr) ? "s" : "");
+		list_refs(r, 0, NULL);
+	}
+	return ret;
+}
+
+int list_bundle_refs(struct bundle_header *header, int argc, const char **argv)
+{
+	return list_refs(&header->references, argc, argv);
+}
+
+int create_bundle(struct bundle_header *header, const char *path,
+		int argc, const char **argv)
+{
+	static struct lock_file lock;
+	int bundle_fd = -1;
+	int bundle_to_stdout;
+	const char **argv_boundary = xmalloc((argc + 4) * sizeof(const char *));
+	const char **argv_pack = xmalloc(5 * sizeof(const char *));
+	int i, ref_count = 0;
+	char buffer[1024];
+	struct rev_info revs;
+	struct child_process rls;
+	FILE *rls_fout;
+
+	bundle_to_stdout = !strcmp(path, "-");
+	if (bundle_to_stdout)
+		bundle_fd = 1;
+	else
+		bundle_fd = hold_lock_file_for_update(&lock, path, 1);
+
+	/* write signature */
+	write_or_die(bundle_fd, bundle_signature, strlen(bundle_signature));
+
+	/* init revs to list objects for pack-objects later */
+	save_commit_buffer = 0;
+	init_revisions(&revs, NULL);
+
+	/* write prerequisites */
+	memcpy(argv_boundary + 3, argv + 1, argc * sizeof(const char *));
+	argv_boundary[0] = "rev-list";
+	argv_boundary[1] = "--boundary";
+	argv_boundary[2] = "--pretty=oneline";
+	argv_boundary[argc + 2] = NULL;
+	memset(&rls, 0, sizeof(rls));
+	rls.argv = argv_boundary;
+	rls.out = -1;
+	rls.git_cmd = 1;
+	if (start_command(&rls))
+		return -1;
+	rls_fout = fdopen(rls.out, "r");
+	while (fgets(buffer, sizeof(buffer), rls_fout)) {
+		unsigned char sha1[20];
+		if (buffer[0] == '-') {
+			write_or_die(bundle_fd, buffer, strlen(buffer));
+			if (!get_sha1_hex(buffer + 1, sha1)) {
+				struct object *object = parse_object(sha1);
+				object->flags |= UNINTERESTING;
+				add_pending_object(&revs, object, buffer);
+			}
+		} else if (!get_sha1_hex(buffer, sha1)) {
+			struct object *object = parse_object(sha1);
+			object->flags |= SHOWN;
+		}
+	}
+	fclose(rls_fout);
+	if (finish_command(&rls))
+		return error("rev-list died");
+
+	/* write references */
+	argc = setup_revisions(argc, argv, &revs, NULL);
+	if (argc > 1)
+		return error("unrecognized argument: %s'", argv[1]);
+
+	for (i = 0; i < revs.pending.nr; i++) {
+		struct object_array_entry *e = revs.pending.objects + i;
+		unsigned char sha1[20];
+		char *ref;
+
+		if (e->item->flags & UNINTERESTING)
+			continue;
+		if (dwim_ref(e->name, strlen(e->name), sha1, &ref) != 1)
+			continue;
+		/*
+		 * Make sure the refs we wrote out is correct; --max-count and
+		 * other limiting options could have prevented all the tips
+		 * from getting output.
+		 *
+		 * Non commit objects such as tags and blobs do not have
+		 * this issue as they are not affected by those extra
+		 * constraints.
+		 */
+		if (!(e->item->flags & SHOWN) && e->item->type == OBJ_COMMIT) {
+			warning("ref '%s' is excluded by the rev-list options",
+				e->name);
+			free(ref);
+			continue;
+		}
+		/*
+		 * If you run "git bundle create bndl v1.0..v2.0", the
+		 * name of the positive ref is "v2.0" but that is the
+		 * commit that is referenced by the tag, and not the tag
+		 * itself.
+		 */
+		if (hashcmp(sha1, e->item->sha1)) {
+			/*
+			 * Is this the positive end of a range expressed
+			 * in terms of a tag (e.g. v2.0 from the range
+			 * "v1.0..v2.0")?
+			 */
+			struct commit *one = lookup_commit_reference(sha1);
+			struct object *obj;
+
+			if (e->item == &(one->object)) {
+				/*
+				 * Need to include e->name as an
+				 * independent ref to the pack-objects
+				 * input, so that the tag is included
+				 * in the output; otherwise we would
+				 * end up triggering "empty bundle"
+				 * error.
+				 */
+				obj = parse_object(sha1);
+				obj->flags |= SHOWN;
+				add_pending_object(&revs, obj, e->name);
+			}
+			free(ref);
+			continue;
+		}
+
+		ref_count++;
+		write_or_die(bundle_fd, sha1_to_hex(e->item->sha1), 40);
+		write_or_die(bundle_fd, " ", 1);
+		write_or_die(bundle_fd, ref, strlen(ref));
+		write_or_die(bundle_fd, "\n", 1);
+		free(ref);
+	}
+	if (!ref_count)
+		die ("Refusing to create empty bundle.");
+
+	/* end header */
+	write_or_die(bundle_fd, "\n", 1);
+
+	/* write pack */
+	argv_pack[0] = "pack-objects";
+	argv_pack[1] = "--all-progress";
+	argv_pack[2] = "--stdout";
+	argv_pack[3] = "--thin";
+	argv_pack[4] = NULL;
+	memset(&rls, 0, sizeof(rls));
+	rls.argv = argv_pack;
+	rls.in = -1;
+	rls.out = bundle_fd;
+	rls.git_cmd = 1;
+	if (start_command(&rls))
+		return error("Could not spawn pack-objects");
+	for (i = 0; i < revs.pending.nr; i++) {
+		struct object *object = revs.pending.objects[i].item;
+		if (object->flags & UNINTERESTING)
+			write(rls.in, "^", 1);
+		write(rls.in, sha1_to_hex(object->sha1), 40);
+		write(rls.in, "\n", 1);
+	}
+	if (finish_command(&rls))
+		return error ("pack-objects died");
+	close(bundle_fd);
+	if (!bundle_to_stdout)
+		commit_lock_file(&lock);
+	return 0;
+}
+
+int unbundle(struct bundle_header *header, int bundle_fd)
+{
+	const char *argv_index_pack[] = {"index-pack",
+		"--fix-thin", "--stdin", NULL};
+	struct child_process ip;
+
+	if (verify_bundle(header, 0))
+		return -1;
+	memset(&ip, 0, sizeof(ip));
+	ip.argv = argv_index_pack;
+	ip.in = bundle_fd;
+	ip.no_stdout = 1;
+	ip.git_cmd = 1;
+	if (run_command(&ip))
+		return error("index-pack died");
+	return 0;
+}