git/bundle.c
Ævar Arnfjörð Bjarmason 89c6e450fe bundle.h: make "fd" version of read_bundle_header() public
Change the parse_bundle_header() function to be non-static, and rename
it to parse_bundle_header_fd(). The parse_bundle_header() function is
already public, and it's a thin wrapper around this function. This
will be used by code that wants to pass a fd to the bundle API.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-16 15:02:10 -07:00

642 lines
17 KiB
C

#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;
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)
return error(_("need a repository to verify a bundle"));
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)
return ret;
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));
}
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;
}
/* 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;
/*
* 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);
return ref_count;
}
struct bundle_prerequisites_info {
struct object_array *pending;
int fd;
};
static void write_bundle_prerequisites(struct commit *commit, void *data)
{
struct bundle_prerequisites_info *bpi = data;
struct object *object;
struct pretty_print_context ctx = { 0 };
struct strbuf buf = STRBUF_INIT;
if (!(commit->object.flags & BOUNDARY))
return;
strbuf_addf(&buf, "-%s ", oid_to_hex(&commit->object.oid));
write_or_die(bpi->fd, buf.buf, buf.len);
ctx.fmt = CMIT_FMT_ONELINE;
ctx.output_encoding = get_log_output_encoding();
strbuf_reset(&buf);
pretty_print_commit(&ctx, commit, &buf);
strbuf_trim(&buf);
object = (struct object *)commit;
object->flags |= UNINTERESTING;
add_object_array_with_path(object, buf.buf, bpi->pending, S_IFINVALID,
NULL);
strbuf_addch(&buf, '\n');
write_or_die(bpi->fd, buf.buf, buf.len);
strbuf_release(&buf);
}
int create_bundle(struct repository *r, const char *path,
int argc, const char **argv, struct strvec *pack_options, int version)
{
struct lock_file lock = LOCK_INIT;
int bundle_fd = -1;
int bundle_to_stdout;
int ref_count = 0;
struct rev_info revs, revs_copy;
int min_version = 2;
struct bundle_prerequisites_info bpi;
int i;
/* init revs to list objects for pack-objects later */
save_commit_buffer = 0;
repo_init_revisions(r, &revs, NULL);
/*
* Pre-initialize the '--objects' flag so we can parse a
* --filter option successfully.
*/
revs.tree_objects = revs.blob_objects = 1;
argc = setup_revisions(argc, argv, &revs, NULL);
/*
* Reasons to require version 3:
*
* 1. @object-format is required because our hash algorithm is not
* SHA1.
* 2. @filter is required because we parsed an object filter.
*/
if (the_hash_algo != &hash_algos[GIT_HASH_SHA1] || revs.filter.choice)
min_version = 3;
if (argc > 1) {
error(_("unrecognized argument: %s"), argv[1]);
goto err;
}
bundle_to_stdout = !strcmp(path, "-");
if (bundle_to_stdout)
bundle_fd = 1;
else
bundle_fd = hold_lock_file_for_update(&lock, path,
LOCK_DIE_ON_ERROR);
if (version == -1)
version = min_version;
if (version < 2 || version > 3) {
die(_("unsupported bundle version %d"), version);
} else if (version < min_version) {
die(_("cannot write bundle version %d with algorithm %s"), version, the_hash_algo->name);
} else if (version == 2) {
write_or_die(bundle_fd, v2_bundle_signature, strlen(v2_bundle_signature));
} else {
const char *capability = "@object-format=";
write_or_die(bundle_fd, v3_bundle_signature, strlen(v3_bundle_signature));
write_or_die(bundle_fd, capability, strlen(capability));
write_or_die(bundle_fd, the_hash_algo->name, strlen(the_hash_algo->name));
write_or_die(bundle_fd, "\n", 1);
if (revs.filter.choice) {
const char *value = expand_list_objects_filter_spec(&revs.filter);
capability = "@filter=";
write_or_die(bundle_fd, capability, strlen(capability));
write_or_die(bundle_fd, value, strlen(value));
write_or_die(bundle_fd, "\n", 1);
}
}
/* save revs.pending in revs_copy for later use */
memcpy(&revs_copy, &revs, sizeof(revs));
revs_copy.pending.nr = 0;
revs_copy.pending.alloc = 0;
revs_copy.pending.objects = NULL;
for (i = 0; i < revs.pending.nr; i++) {
struct object_array_entry *e = revs.pending.objects + i;
if (e)
add_object_array_with_path(e->item, e->name,
&revs_copy.pending,
e->mode, e->path);
}
/* write prerequisites */
revs.boundary = 1;
if (prepare_revision_walk(&revs))
die("revision walk setup failed");
bpi.fd = bundle_fd;
bpi.pending = &revs_copy.pending;
/*
* Remove any object walking here. We only care about commits and
* tags here. The revs_copy has the right instances of these values.
*/
revs.blob_objects = revs.tree_objects = 0;
traverse_commit_list(&revs, write_bundle_prerequisites, NULL, &bpi);
object_array_remove_duplicates(&revs_copy.pending);
/* write bundle refs */
ref_count = write_bundle_refs(bundle_fd, &revs_copy);
if (!ref_count)
die(_("Refusing to create empty bundle."));
else if (ref_count < 0)
goto err;
/* write pack */
if (write_pack_data(bundle_fd, &revs_copy, pack_options))
goto err;
if (!bundle_to_stdout) {
if (commit_lock_file(&lock))
die_errno(_("cannot create '%s'"), path);
}
return 0;
err:
rollback_lock_file(&lock);
return -1;
}
int unbundle(struct repository *r, struct bundle_header *header,
int bundle_fd, struct strvec *extra_index_pack_args)
{
struct child_process ip = CHILD_PROCESS_INIT;
strvec_pushl(&ip.args, "index-pack", "--fix-thin", "--stdin", NULL);
/* If there is a filter, then we need to create the promisor pack. */
if (header->filter.choice)
strvec_push(&ip.args, "--promisor=from-bundle");
if (extra_index_pack_args) {
strvec_pushv(&ip.args, extra_index_pack_args->v);
strvec_clear(extra_index_pack_args);
}
if (verify_bundle(r, header, 0))
return -1;
ip.in = bundle_fd;
ip.no_stdout = 1;
ip.git_cmd = 1;
if (run_command(&ip))
return error(_("index-pack died"));
return 0;
}