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git/bundle.c

646 lines
17 KiB

#include "cache.h"
#include "lockfile.h"
#include "bundle.h"
#include "object-store.h"
#include "repository.h"
#include "object.h"
#include "commit.h"
#include "diff.h"
#include "revision.h"
#include "list-objects.h"
#include "run-command.h"
#include "refs.h"
#include "strvec.h"
#include "list-objects-filter-options.h"
static const char v2_bundle_signature[] = "# v2 git bundle\n";
static const char v3_bundle_signature[] = "# v3 git bundle\n";
static struct {
int version;
const char *signature;
} bundle_sigs[] = {
{ 2, v2_bundle_signature },
{ 3, v3_bundle_signature },
};
void bundle_header_init(struct bundle_header *header)
{
struct bundle_header blank = BUNDLE_HEADER_INIT;
memcpy(header, &blank, sizeof(*header));
}
void bundle_header_release(struct bundle_header *header)
{
string_list_clear(&header->prerequisites, 1);
string_list_clear(&header->references, 1);
list_objects_filter_release(&header->filter);
}
static int parse_capability(struct bundle_header *header, const char *capability)
{
const char *arg;
if (skip_prefix(capability, "object-format=", &arg)) {
int algo = hash_algo_by_name(arg);
if (algo == GIT_HASH_UNKNOWN)
return error(_("unrecognized bundle hash algorithm: %s"), arg);
header->hash_algo = &hash_algos[algo];
return 0;
}
if (skip_prefix(capability, "filter=", &arg)) {
parse_list_objects_filter(&header->filter, arg);
return 0;
}
return error(_("unknown capability '%s'"), capability);
}
static int parse_bundle_signature(struct bundle_header *header, const char *line)
{
int i;
for (i = 0; i < ARRAY_SIZE(bundle_sigs); i++) {
if (!strcmp(line, bundle_sigs[i].signature)) {
header->version = bundle_sigs[i].version;
return 0;
}
}
return -1;
}
int read_bundle_header_fd(int fd, struct bundle_header *header,
const char *report_path)
{
struct strbuf buf = STRBUF_INIT;
int status = 0;
/* The bundle header begins with the signature */
if (strbuf_getwholeline_fd(&buf, fd, '\n') ||
parse_bundle_signature(header, buf.buf)) {
if (report_path)
error(_("'%s' does not look like a v2 or v3 bundle file"),
report_path);
status = -1;
goto abort;
}
header->hash_algo = the_hash_algo;
/* The bundle header ends with an empty line */
while (!strbuf_getwholeline_fd(&buf, fd, '\n') &&
buf.len && buf.buf[0] != '\n') {
struct object_id oid;
int is_prereq = 0;
const char *p;
strbuf_rtrim(&buf);
if (header->version == 3 && *buf.buf == '@') {
if (parse_capability(header, buf.buf + 1)) {
status = -1;
break;
}
continue;
}
if (*buf.buf == '-') {
is_prereq = 1;
strbuf_remove(&buf, 0, 1);
}
/*
* Tip lines have object name, SP, and refname.
* Prerequisites have object name that is optionally
* followed by SP and subject line.
*/
if (parse_oid_hex_algop(buf.buf, &oid, &p, header->hash_algo) ||
(*p && !isspace(*p)) ||
(!is_prereq && !*p)) {
if (report_path)
error(_("unrecognized header: %s%s (%d)"),
(is_prereq ? "-" : ""), buf.buf, (int)buf.len);
status = -1;
break;
} else {
struct object_id *dup = oiddup(&oid);
if (is_prereq)
string_list_append(&header->prerequisites, "")->util = dup;
else
string_list_append(&header->references, p + 1)->util = dup;
}
}
abort:
if (status) {
close(fd);
fd = -1;
}
strbuf_release(&buf);
return fd;
}
int read_bundle_header(const char *path, struct bundle_header *header)
{
int fd = open(path, O_RDONLY);
if (fd < 0)
return error(_("could not open '%s'"), path);
return read_bundle_header_fd(fd, header, path);
}
int is_bundle(const char *path, int quiet)
{
struct bundle_header header = BUNDLE_HEADER_INIT;
int fd = open(path, O_RDONLY);
if (fd < 0)
return 0;
fd = read_bundle_header_fd(fd, &header, quiet ? NULL : path);
if (fd >= 0)
close(fd);
bundle_header_release(&header);
return (fd >= 0);
}
static int list_refs(struct string_list *r, int argc, const char **argv)
{
int i;
for (i = 0; i < r->nr; i++) {
struct object_id *oid;
const char *name;
if (argc > 1) {
int j;
for (j = 1; j < argc; j++)
if (!strcmp(r->items[i].string, argv[j]))
break;
if (j == argc)
continue;
}
oid = r->items[i].util;
name = r->items[i].string;
printf("%s %s\n", oid_to_hex(oid), name);
}
return 0;
}
/* Remember to update object flag allocation in object.h */
#define PREREQ_MARK (1u<<16)
int verify_bundle(struct repository *r,
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 string_list *p = &header->prerequisites;
struct rev_info revs = REV_INFO_INIT;
const char *argv[] = {NULL, "--all", NULL};
struct commit *commit;
int i, ret = 0, req_nr;
const char *message = _("Repository lacks these prerequisite commits:");
if (!r || !r->objects || !r->objects->odb) {
ret = error(_("need a repository to verify a bundle"));
goto cleanup;
}
repo_init_revisions(r, &revs, NULL);
for (i = 0; i < p->nr; i++) {
struct string_list_item *e = p->items + i;
const char *name = e->string;
struct object_id *oid = e->util;
struct object *o = parse_object(r, oid);
if (o) {
o->flags |= PREREQ_MARK;
add_pending_object(&revs, o, name);
continue;
}
if (++ret == 1)
error("%s", message);
error("%s %s", oid_to_hex(oid), name);
}
if (revs.pending.nr != p->nr)
goto cleanup;
req_nr = revs.pending.nr;
setup_revisions(2, argv, &revs, NULL);
list_objects_filter_copy(&revs.filter, &header->filter);
if (prepare_revision_walk(&revs))
die(_("revision walk setup failed"));
i = req_nr;
while (i && (commit = get_revision(&revs)))
if (commit->object.flags & PREREQ_MARK)
i--;
for (i = 0; i < p->nr; i++) {
struct string_list_item *e = p->items + i;
const char *name = e->string;
const struct object_id *oid = e->util;
struct object *o = parse_object(r, oid);
assert(o); /* otherwise we'd have returned early */
if (o->flags & SHOWN)
continue;
if (++ret == 1)
error("%s", message);
error("%s %s", oid_to_hex(oid), name);
}
/* Clean up objects used, as they will be reused. */
for (i = 0; i < p->nr; i++) {
struct string_list_item *e = p->items + i;
struct object_id *oid = e->util;
commit = lookup_commit_reference_gently(r, oid, 1);
if (commit)
clear_commit_marks(commit, ALL_REV_FLAGS);
}
if (verbose) {
struct string_list *r;
r = &header->references;
printf_ln(Q_("The bundle contains this ref:",
"The bundle contains these %"PRIuMAX" refs:",
r->nr),
(uintmax_t)r->nr);
list_refs(r, 0, NULL);
r = &header->prerequisites;
if (!r->nr) {
printf_ln(_("The bundle records a complete history."));
} else {
printf_ln(Q_("The bundle requires this ref:",
"The bundle requires these %"PRIuMAX" refs:",
r->nr),
(uintmax_t)r->nr);
list_refs(r, 0, NULL);
}
printf_ln("The bundle uses this hash algorithm: %s",
header->hash_algo->name);
if (header->filter.choice)
printf_ln("The bundle uses this filter: %s",
list_objects_filter_spec(&header->filter));
}
cleanup:
release_revisions(&revs);
return ret;
}
int list_bundle_refs(struct bundle_header *header, int argc, const char **argv)
{
return list_refs(&header->references, argc, argv);
}
static int is_tag_in_date_range(struct object *tag, struct rev_info *revs)
{
unsigned long size;
enum object_type type;
char *buf = NULL, *line, *lineend;
timestamp_t date;
int result = 1;
if (revs->max_age == -1 && revs->min_age == -1)
goto out;
buf = read_object_file(&tag->oid, &type, &size);
if (!buf)
goto out;
line = memmem(buf, size, "\ntagger ", 8);
if (!line++)
goto out;
lineend = memchr(line, '\n', buf + size - line);
line = memchr(line, '>', lineend ? lineend - line : buf + size - line);
if (!line++)
goto out;
date = parse_timestamp(line, NULL, 10);
result = (revs->max_age == -1 || revs->max_age < date) &&
(revs->min_age == -1 || revs->min_age > date);
out:
free(buf);
return result;
}
bundle: dup() output descriptor closer to point-of-use When writing a bundle to a file, the bundle code actually creates "your.bundle.lock" using our lockfile interface. We feed that output descriptor to a child git-pack-objects via run-command, which has the quirk that it closes the output descriptor in the parent. To avoid confusing the lockfile code (which still thinks the descriptor is valid), we dup() it, and operate on the duplicate. However, this has a confusing side effect: after the dup() but before we call pack-objects, we have _two_ descriptors open to the lockfile. If we call die() during that time, the lockfile code will try to clean up the partially-written file. It knows to close() the file before unlinking, since on some platforms (i.e., Windows) the open file would block the deletion. But it doesn't know about the duplicate descriptor. On Windows, triggering an error at the right part of the code will result in the cleanup failing and the lockfile being left in the filesystem. We can solve this by moving the dup() much closer to start_command(), shrinking the window in which we have the second descriptor open. It's easy to place this in such a way that no die() is possible. We could still die due to a signal in the exact wrong moment, but we already tolerate races there (e.g., a signal could come before we manage to put the file on the cleanup list in the first place). As a bonus, this shields create_bundle() itself from the duplicate-fd trick, and we can simplify its error handling (note that the lock rollback now happens unconditionally, but that's OK; it's a noop if we didn't open the lock in the first place). The included test uses an empty bundle to cause a failure at the right spot in the code, because that's easy to trigger (the other likely errors are write() problems like ENOSPC). Note that it would already pass on non-Windows systems (because they are happy to unlink an already-open file). Based-on-a-patch-by: Gaël Lhez <gael.lhez@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Tested-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
4 years ago
/* Write the pack data to bundle_fd */
static int write_pack_data(int bundle_fd, struct rev_info *revs, struct strvec *pack_options)
{
struct child_process pack_objects = CHILD_PROCESS_INIT;
int i;
strvec_pushl(&pack_objects.args,
"pack-objects",
"--stdout", "--thin", "--delta-base-offset",
NULL);
strvec_pushv(&pack_objects.args, pack_options->v);
if (revs->filter.choice)
strvec_pushf(&pack_objects.args, "--filter=%s",
list_objects_filter_spec(&revs->filter));
pack_objects.in = -1;
pack_objects.out = bundle_fd;
pack_objects.git_cmd = 1;
bundle: dup() output descriptor closer to point-of-use When writing a bundle to a file, the bundle code actually creates "your.bundle.lock" using our lockfile interface. We feed that output descriptor to a child git-pack-objects via run-command, which has the quirk that it closes the output descriptor in the parent. To avoid confusing the lockfile code (which still thinks the descriptor is valid), we dup() it, and operate on the duplicate. However, this has a confusing side effect: after the dup() but before we call pack-objects, we have _two_ descriptors open to the lockfile. If we call die() during that time, the lockfile code will try to clean up the partially-written file. It knows to close() the file before unlinking, since on some platforms (i.e., Windows) the open file would block the deletion. But it doesn't know about the duplicate descriptor. On Windows, triggering an error at the right part of the code will result in the cleanup failing and the lockfile being left in the filesystem. We can solve this by moving the dup() much closer to start_command(), shrinking the window in which we have the second descriptor open. It's easy to place this in such a way that no die() is possible. We could still die due to a signal in the exact wrong moment, but we already tolerate races there (e.g., a signal could come before we manage to put the file on the cleanup list in the first place). As a bonus, this shields create_bundle() itself from the duplicate-fd trick, and we can simplify its error handling (note that the lock rollback now happens unconditionally, but that's OK; it's a noop if we didn't open the lock in the first place). The included test uses an empty bundle to cause a failure at the right spot in the code, because that's easy to trigger (the other likely errors are write() problems like ENOSPC). Note that it would already pass on non-Windows systems (because they are happy to unlink an already-open file). Based-on-a-patch-by: Gaël Lhez <gael.lhez@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Tested-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
4 years ago
/*
* start_command() will close our descriptor if it's >1. Duplicate it
* to avoid surprising the caller.
*/
if (pack_objects.out > 1) {
pack_objects.out = dup(pack_objects.out);
if (pack_objects.out < 0) {
error_errno(_("unable to dup bundle descriptor"));
child_process_clear(&pack_objects);
return -1;
}
}
if (start_command(&pack_objects))
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_or_die(pack_objects.in, "^", 1);
write_or_die(pack_objects.in, oid_to_hex(&object->oid), the_hash_algo->hexsz);
write_or_die(pack_objects.in, "\n", 1);
}
close(pack_objects.in);
if (finish_command(&pack_objects))
return error(_("pack-objects died"));
return 0;
}
/*
* Write out bundle refs based on the tips already
* parsed into revs.pending. As a side effect, may
* manipulate revs.pending to include additional
* necessary objects (like tags).
*
* Returns the number of refs written, or negative
* on error.
*/
static int write_bundle_refs(int bundle_fd, struct rev_info *revs)
{
int i;
int ref_count = 0;
for (i = 0; i < revs->pending.nr; i++) {
struct object_array_entry *e = revs->pending.objects + i;
struct object_id oid;
char *ref;
const char *display_ref;
int flag;
if (e->item->flags & UNINTERESTING)
continue;
if (dwim_ref(e->name, strlen(e->name), &oid, &ref, 0) != 1)
goto skip_write_ref;
if (read_ref_full(e->name, RESOLVE_REF_READING, &oid, &flag))
flag = 0;
display_ref = (flag & REF_ISSYMREF) ? e->name : ref;
if (e->item->type == OBJ_TAG &&
!is_tag_in_date_range(e->item, revs)) {
e->item->flags |= UNINTERESTING;
goto skip_write_ref;
}
/*
* 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);
goto skip_write_ref;
}
/*
* 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 (!oideq(&oid, &e->item->oid)) {
/*
* 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(revs->repo, &oid);
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_or_die(&oid, e->name);
obj->flags |= SHOWN;
add_pending_object(revs, obj, e->name);
}
goto skip_write_ref;
}
ref_count++;
write_or_die(bundle_fd, oid_to_hex(&e->item->oid), the_hash_algo->hexsz);
write_or_die(bundle_fd, " ", 1);
write_or_die(bundle_fd, display_ref, strlen(display_ref));
write_or_die(bundle_fd, "\n", 1);
skip_write_ref:
free(ref);
}
/* end header */
write_or_die(bundle_fd, "\n", 1);