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git/fetch-pack.c
Jeff King ae1a7eefff fetch-pack: signal v2 server that we are done making requests 
When fetching with the v0 protocol over ssh (or a local upload-pack with
pipes), the server closes the connection as soon as it is finished
sending the pack. So even though the client may still be operating on
the data via index-pack (e.g., resolving deltas, checking connectivity,
etc), the server has released all resources.

With the v2 protocol, however, the server considers the ssh session only
as a transport, with individual requests coming over it. After sending
the pack, it goes back to its main loop, waiting for another request to
come from the client. As a result, the ssh session hangs around until
the client process ends, which may be much later (because resolving
deltas, etc, may consume a lot of CPU).

This is bad for two reasons:

  - it's consuming resources on the server to leave open a connection
    that won't see any more use

  - if something bad happens to the ssh connection in the meantime (say,
    it gets killed by the network because it's idle, as happened in a
    real-world report), then ssh will exit non-zero, and we'll propagate
    the error up the stack.

The server is correct here not to hang up after serving the pack. The v2
protocol's design is meant to allow multiple requests like this, and
hanging up would be the wrong thing for a hypothetical client which was
planning to make more requests (though in practice, the git.git client
never would, and I doubt any other implementations would either).

The right thing is instead for the client to signal to the server that
it's not interested in making more requests. We can do that by closing
the pipe descriptor we use to write to ssh. This will propagate to the
server upload-pack as an EOF when it tries to read the next request (and
then it will close its half, and the whole connection will go away).

It's important to do this "half duplex" shutdown, because we have to do
it _before_ we actually receive the pack. This is an artifact of the way
fetch-pack and index-pack (or unpack-objects) interact. We hand the
connection off to index-pack (really, a sideband demuxer which feeds
it), and then wait until it returns. And it doesn't do that until it has
resolved all of the deltas in the pack, even though it was done reading
from the server long before.

So just closing the connection fully after index-pack returns would be
too late; we'd have held it open much longer than was necessary. And
teaching index-pack to close the connection is awkward. It's not even
seeing the whole conversation (the sideband demuxer is, but it doesn't
actually know what's in the packets, or when the end comes).

Note that this close() is happening deep within the transport code. It's
possible that a caller would want to perform other operations over the
same ssh transport after receiving the pack. But as of the current code,
none of the callers do, and there haven't been discussions of any plans
to change this. If we need to support that later, we can probably do so
by passing down a flag for "you're the last request on the transport;
it's OK to close" instead of the code just assuming that's true.

The description above all discusses v2 ssh, so it's worth thinking about
how this interacts with other protocols:

  - in v0 protocols, we could do the same half-duplex shutdown (it just
    goes into the v0 do_fetch_pack() instead). This does work, but since
    it doesn't have the same persistence problem in the first place,
    there's little reason to change it at this point.

  - local fetches against git-upload-pack on the same machine will
    behave the same as ssh (they are talking over two pipes, and see EOF
    on their input pipe)

  - fetches against git-daemon will run this same code, and close one of
    the descriptors. In practice, this won't do anything, since there
    our two descriptors are dups of each other, and not part of a
    half-duplex pair. The right thing would probably be to call
    shutdown(SHUT_WR) on it. I didn't bother with that here. It doesn't
    face the same error-code problem (since it's just a TCP connection),
    so it's really only an optimization problem. And git:// is not that
    widely used these days, and has less impact on server resources than
    an ssh termination.

  - v2 http doesn't suffer from this problem in the first place, as our
    pipes terminate at a local git-remote-https, which is passing data
    along as individual requests via curl. Probably curl is keeping the
    TCP/TLS connection open for more requests, and we might be able to
    tell it manually "hey, we are done making requests now". But I think
    that's much less important. It again doesn't suffer from the
    error-code problem, and HTTP keepalive is pretty well understood
    (importantly, the timeouts can be set low, because clients like curl
    know how to reconnect for subsequent requests if necessary). So it's
    probably not worth figuring out how to tell curl that we're done
    (though if we do, this patch is probably the first step anyway;
    fetch-pack closes the pipe back to remote-https, which would be the
    signal that it should tell curl we're done).

The code is pretty straightforward. We close the pipe at the right
moment, and set it to -1 to mark it as invalid. I modified the later
cleanup code to avoid calling close(-1). That's not strictly necessary,
since close(-1) is a noop, but hopefully makes things a bit more obvious
to a reader.

I suspect that trying to call more transport functions after the close()
(e.g., calling transport_fetch_refs() again) would fail, as it's not
smart enough to realize we need to re-open the ssh connection. But
that's already true when v0 is in use. And no current callers want to do
that (and again, the solution is probably a flag in the transport code
to keep things open, which can be added later).

There's no test here, as the situation it covers is inherently racy (the
question is when upload-pack exits, compared to when index-pack finishes
resolving deltas and exits). The rather gross shell snippet below does
recreate the problematic situation; when run on a sufficiently-large
repository (git.git works fine), it kills an "idle" upload-pack while
the client is resolving deltas, leading to a failed clone.

    (
	    git clone --no-local --progress . foo.git 2>&1
	    echo >&2 "clone exit code=$?"
    ) |
    tr '\r' '\n' |
    while read line
    do
	    case "$done,$line" in
	    ,Resolving*)
		    echo "hit resolving deltas; killing upload-pack"
		    killall -9 git-upload-pack
		    done=t
		    ;;
	    esac
    done

Reported-by: Greg Pflaum <greg.pflaum@pnp-hcl.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-20 07:38:40 +09:00

2098 lines
58 KiB
C
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#include "cache.h"
#include "repository.h"
#include "config.h"
#include "lockfile.h"
#include "refs.h"
#include "pkt-line.h"
#include "commit.h"
#include "tag.h"
#include "exec-cmd.h"
#include "pack.h"
#include "sideband.h"
#include "fetch-pack.h"
#include "remote.h"
#include "run-command.h"
#include "connect.h"
#include "transport.h"
#include "version.h"
#include "oid-array.h"
#include "oidset.h"
#include "packfile.h"
#include "object-store.h"
#include "connected.h"
#include "fetch-negotiator.h"
#include "fsck.h"
#include "shallow.h"
#include "commit-reach.h"
#include "commit-graph.h"
static int transfer_unpack_limit = -1;
static int fetch_unpack_limit = -1;
static int unpack_limit = 100;
static int prefer_ofs_delta = 1;
static int no_done;
static int deepen_since_ok;
static int deepen_not_ok;
static int fetch_fsck_objects = -1;
static int transfer_fsck_objects = -1;
static int agent_supported;
static int server_supports_filtering;
static int advertise_sid;
static struct shallow_lock shallow_lock;
static const char *alternate_shallow_file;
static struct fsck_options fsck_options = FSCK_OPTIONS_MISSING_GITMODULES;
static struct strbuf fsck_msg_types = STRBUF_INIT;
static struct string_list uri_protocols = STRING_LIST_INIT_DUP;
/* Remember to update object flag allocation in object.h */
#define COMPLETE (1U << 0)
#define ALTERNATE (1U << 1)
#define COMMON (1U << 6)
#define REACH_SCRATCH (1U << 7)
/*
* After sending this many "have"s if we do not get any new ACK , we
* give up traversing our history.
*/
#define MAX_IN_VAIN 256
static int multi_ack, use_sideband;
/* Allow specifying sha1 if it is a ref tip. */
#define ALLOW_TIP_SHA1 01
/* Allow request of a sha1 if it is reachable from a ref (possibly hidden ref). */
#define ALLOW_REACHABLE_SHA1 02
static unsigned int allow_unadvertised_object_request;
__attribute__((format (printf, 2, 3)))
static inline void print_verbose(const struct fetch_pack_args *args,
const char *fmt, ...)
{
va_list params;
if (!args->verbose)
return;
va_start(params, fmt);
vfprintf(stderr, fmt, params);
va_end(params);
fputc('\n', stderr);
}
struct alternate_object_cache {
struct object **items;
size_t nr, alloc;
};
static void cache_one_alternate(const struct object_id *oid,
void *vcache)
{
struct alternate_object_cache *cache = vcache;
struct object *obj = parse_object(the_repository, oid);
if (!obj || (obj->flags & ALTERNATE))
return;
obj->flags |= ALTERNATE;
ALLOC_GROW(cache->items, cache->nr + 1, cache->alloc);
cache->items[cache->nr++] = obj;
}
static void for_each_cached_alternate(struct fetch_negotiator *negotiator,
void (*cb)(struct fetch_negotiator *,
struct object *))
{
static int initialized;
static struct alternate_object_cache cache;
size_t i;
if (!initialized) {
for_each_alternate_ref(cache_one_alternate, &cache);
initialized = 1;
}
for (i = 0; i < cache.nr; i++)
cb(negotiator, cache.items[i]);
}
static struct commit *deref_without_lazy_fetch(const struct object_id *oid,
int mark_tags_complete)
{
enum object_type type;
struct object_info info = { .typep = &type };
while (1) {
if (oid_object_info_extended(the_repository, oid, &info,
OBJECT_INFO_SKIP_FETCH_OBJECT | OBJECT_INFO_QUICK))
return NULL;
if (type == OBJ_TAG) {
struct tag *tag = (struct tag *)
parse_object(the_repository, oid);
if (!tag->tagged)
return NULL;
if (mark_tags_complete)
tag->object.flags |= COMPLETE;
oid = &tag->tagged->oid;
} else {
break;
}
}
if (type == OBJ_COMMIT)
return (struct commit *) parse_object(the_repository, oid);
return NULL;
}
static int rev_list_insert_ref(struct fetch_negotiator *negotiator,
const struct object_id *oid)
{
struct commit *c = deref_without_lazy_fetch(oid, 0);
if (c)
negotiator->add_tip(negotiator, c);
return 0;
}
static int rev_list_insert_ref_oid(const char *refname, const struct object_id *oid,
int flag, void *cb_data)
{
return rev_list_insert_ref(cb_data, oid);
}
enum ack_type {
NAK = 0,
ACK,
ACK_continue,
ACK_common,
ACK_ready
};
static void consume_shallow_list(struct fetch_pack_args *args,
struct packet_reader *reader)
{
if (args->stateless_rpc && args->deepen) {
/* If we sent a depth we will get back "duplicate"
* shallow and unshallow commands every time there
* is a block of have lines exchanged.
*/
while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
if (starts_with(reader->line, "shallow "))
continue;
if (starts_with(reader->line, "unshallow "))
continue;
die(_("git fetch-pack: expected shallow list"));
}
if (reader->status != PACKET_READ_FLUSH)
die(_("git fetch-pack: expected a flush packet after shallow list"));
}
}
static enum ack_type get_ack(struct packet_reader *reader,
struct object_id *result_oid)
{
int len;
const char *arg;
if (packet_reader_read(reader) != PACKET_READ_NORMAL)
die(_("git fetch-pack: expected ACK/NAK, got a flush packet"));
len = reader->pktlen;
if (!strcmp(reader->line, "NAK"))
return NAK;
if (skip_prefix(reader->line, "ACK ", &arg)) {
const char *p;
if (!parse_oid_hex(arg, result_oid, &p)) {
len -= p - reader->line;
if (len < 1)
return ACK;
if (strstr(p, "continue"))
return ACK_continue;
if (strstr(p, "common"))
return ACK_common;
if (strstr(p, "ready"))
return ACK_ready;
return ACK;
}
}
die(_("git fetch-pack: expected ACK/NAK, got '%s'"), reader->line);
}
static void send_request(struct fetch_pack_args *args,
int fd, struct strbuf *buf)
{
if (args->stateless_rpc) {
send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
packet_flush(fd);
} else {
if (write_in_full(fd, buf->buf, buf->len) < 0)
die_errno(_("unable to write to remote"));
}
}
static void insert_one_alternate_object(struct fetch_negotiator *negotiator,
struct object *obj)
{
rev_list_insert_ref(negotiator, &obj->oid);
}
#define INITIAL_FLUSH 16
#define PIPESAFE_FLUSH 32
#define LARGE_FLUSH 16384
static int next_flush(int stateless_rpc, int count)
{
if (stateless_rpc) {
if (count < LARGE_FLUSH)
count <<= 1;
else
count = count * 11 / 10;
} else {
if (count < PIPESAFE_FLUSH)
count <<= 1;
else
count += PIPESAFE_FLUSH;
}
return count;
}
static void mark_tips(struct fetch_negotiator *negotiator,
const struct oid_array *negotiation_tips)
{
int i;
if (!negotiation_tips) {
for_each_rawref(rev_list_insert_ref_oid, negotiator);
return;
}
for (i = 0; i < negotiation_tips->nr; i++)
rev_list_insert_ref(negotiator, &negotiation_tips->oid[i]);
return;
}
static int find_common(struct fetch_negotiator *negotiator,
struct fetch_pack_args *args,
int fd[2], struct object_id *result_oid,
struct ref *refs)
{
int fetching;
int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
const struct object_id *oid;
unsigned in_vain = 0;
int got_continue = 0;
int got_ready = 0;
struct strbuf req_buf = STRBUF_INIT;
size_t state_len = 0;
struct packet_reader reader;
if (args->stateless_rpc && multi_ack == 1)
die(_("--stateless-rpc requires multi_ack_detailed"));
packet_reader_init(&reader, fd[0], NULL, 0,
PACKET_READ_CHOMP_NEWLINE |
PACKET_READ_DIE_ON_ERR_PACKET);
mark_tips(negotiator, args->negotiation_tips);
for_each_cached_alternate(negotiator, insert_one_alternate_object);
fetching = 0;
for ( ; refs ; refs = refs->next) {
struct object_id *remote = &refs->old_oid;
const char *remote_hex;
struct object *o;
/*
* If that object is complete (i.e. it is an ancestor of a
* local ref), we tell them we have it but do not have to
* tell them about its ancestors, which they already know
* about.
*
* We use lookup_object here because we are only
* interested in the case we *know* the object is
* reachable and we have already scanned it.
*/
if (((o = lookup_object(the_repository, remote)) != NULL) &&
(o->flags & COMPLETE)) {
continue;
}
remote_hex = oid_to_hex(remote);
if (!fetching) {
struct strbuf c = STRBUF_INIT;
if (multi_ack == 2) strbuf_addstr(&c, " multi_ack_detailed");
if (multi_ack == 1) strbuf_addstr(&c, " multi_ack");
if (no_done) strbuf_addstr(&c, " no-done");
if (use_sideband == 2) strbuf_addstr(&c, " side-band-64k");
if (use_sideband == 1) strbuf_addstr(&c, " side-band");
if (args->deepen_relative) strbuf_addstr(&c, " deepen-relative");
if (args->use_thin_pack) strbuf_addstr(&c, " thin-pack");
if (args->no_progress) strbuf_addstr(&c, " no-progress");
if (args->include_tag) strbuf_addstr(&c, " include-tag");
if (prefer_ofs_delta) strbuf_addstr(&c, " ofs-delta");
if (deepen_since_ok) strbuf_addstr(&c, " deepen-since");
if (deepen_not_ok) strbuf_addstr(&c, " deepen-not");
if (agent_supported) strbuf_addf(&c, " agent=%s",
git_user_agent_sanitized());
if (advertise_sid)
strbuf_addf(&c, " session-id=%s", trace2_session_id());
if (args->filter_options.choice)
strbuf_addstr(&c, " filter");
packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
strbuf_release(&c);
} else
packet_buf_write(&req_buf, "want %s\n", remote_hex);
fetching++;
}
if (!fetching) {
strbuf_release(&req_buf);
packet_flush(fd[1]);
return 1;
}
if (is_repository_shallow(the_repository))
write_shallow_commits(&req_buf, 1, NULL);
if (args->depth > 0)
packet_buf_write(&req_buf, "deepen %d", args->depth);
if (args->deepen_since) {
timestamp_t max_age = approxidate(args->deepen_since);
packet_buf_write(&req_buf, "deepen-since %"PRItime, max_age);
}
if (args->deepen_not) {
int i;
for (i = 0; i < args->deepen_not->nr; i++) {
struct string_list_item *s = args->deepen_not->items + i;
packet_buf_write(&req_buf, "deepen-not %s", s->string);
}
}
if (server_supports_filtering && args->filter_options.choice) {
const char *spec =
expand_list_objects_filter_spec(&args->filter_options);
packet_buf_write(&req_buf, "filter %s", spec);
}
packet_buf_flush(&req_buf);
state_len = req_buf.len;
if (args->deepen) {
const char *arg;
struct object_id oid;
send_request(args, fd[1], &req_buf);
while (packet_reader_read(&reader) == PACKET_READ_NORMAL) {
if (skip_prefix(reader.line, "shallow ", &arg)) {
if (get_oid_hex(arg, &oid))
die(_("invalid shallow line: %s"), reader.line);
register_shallow(the_repository, &oid);
continue;
}
if (skip_prefix(reader.line, "unshallow ", &arg)) {
if (get_oid_hex(arg, &oid))
die(_("invalid unshallow line: %s"), reader.line);
if (!lookup_object(the_repository, &oid))
die(_("object not found: %s"), reader.line);
/* make sure that it is parsed as shallow */
if (!parse_object(the_repository, &oid))
die(_("error in object: %s"), reader.line);
if (unregister_shallow(&oid))
die(_("no shallow found: %s"), reader.line);
continue;
}
die(_("expected shallow/unshallow, got %s"), reader.line);
}
} else if (!args->stateless_rpc)
send_request(args, fd[1], &req_buf);
if (!args->stateless_rpc) {
/* If we aren't using the stateless-rpc interface
* we don't need to retain the headers.
*/
strbuf_setlen(&req_buf, 0);
state_len = 0;
}
trace2_region_enter("fetch-pack", "negotiation_v0_v1", the_repository);
flushes = 0;
retval = -1;
while ((oid = negotiator->next(negotiator))) {
packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
print_verbose(args, "have %s", oid_to_hex(oid));
in_vain++;
if (flush_at <= ++count) {
int ack;
packet_buf_flush(&req_buf);
send_request(args, fd[1], &req_buf);
strbuf_setlen(&req_buf, state_len);
flushes++;
flush_at = next_flush(args->stateless_rpc, count);
/*
* We keep one window "ahead" of the other side, and
* will wait for an ACK only on the next one
*/
if (!args->stateless_rpc && count == INITIAL_FLUSH)
continue;
consume_shallow_list(args, &reader);
do {
ack = get_ack(&reader, result_oid);
if (ack)
print_verbose(args, _("got %s %d %s"), "ack",
ack, oid_to_hex(result_oid));
switch (ack) {
case ACK:
flushes = 0;
multi_ack = 0;
retval = 0;
goto done;
case ACK_common:
case ACK_ready:
case ACK_continue: {
struct commit *commit =
lookup_commit(the_repository,
result_oid);
int was_common;
if (!commit)
die(_("invalid commit %s"), oid_to_hex(result_oid));
was_common = negotiator->ack(negotiator, commit);
if (args->stateless_rpc
&& ack == ACK_common
&& !was_common) {
/* We need to replay the have for this object
* on the next RPC request so the peer knows
* it is in common with us.
*/
const char *hex = oid_to_hex(result_oid);
packet_buf_write(&req_buf, "have %s\n", hex);
state_len = req_buf.len;
/*
* Reset in_vain because an ack
* for this commit has not been
* seen.
*/
in_vain = 0;
} else if (!args->stateless_rpc
|| ack != ACK_common)
in_vain = 0;
retval = 0;
got_continue = 1;
if (ack == ACK_ready)
got_ready = 1;
break;
}
}
} while (ack);
flushes--;
if (got_continue && MAX_IN_VAIN < in_vain) {
print_verbose(args, _("giving up"));
break; /* give up */
}
if (got_ready)
break;
}
}
done:
trace2_region_leave("fetch-pack", "negotiation_v0_v1", the_repository);
if (!got_ready || !no_done) {
packet_buf_write(&req_buf, "done\n");
send_request(args, fd[1], &req_buf);
}
print_verbose(args, _("done"));
if (retval != 0) {
multi_ack = 0;
flushes++;
}
strbuf_release(&req_buf);
if (!got_ready || !no_done)
consume_shallow_list(args, &reader);
while (flushes || multi_ack) {
int ack = get_ack(&reader, result_oid);
if (ack) {
print_verbose(args, _("got %s (%d) %s"), "ack",
ack, oid_to_hex(result_oid));
if (ack == ACK)
return 0;
multi_ack = 1;
continue;
}
flushes--;
}
/* it is no error to fetch into a completely empty repo */
return count ? retval : 0;
}
static struct commit_list *complete;
static int mark_complete(const struct object_id *oid)
{
struct commit *commit = deref_without_lazy_fetch(oid, 1);
if (commit && !(commit->object.flags & COMPLETE)) {
commit->object.flags |= COMPLETE;
commit_list_insert(commit, &complete);
}
return 0;
}
static int mark_complete_oid(const char *refname, const struct object_id *oid,
int flag, void *cb_data)
{
return mark_complete(oid);
}
static void mark_recent_complete_commits(struct fetch_pack_args *args,
timestamp_t cutoff)
{
while (complete && cutoff <= complete->item->date) {
print_verbose(args, _("Marking %s as complete"),
oid_to_hex(&complete->item->object.oid));
pop_most_recent_commit(&complete, COMPLETE);
}
}
static void add_refs_to_oidset(struct oidset *oids, struct ref *refs)
{
for (; refs; refs = refs->next)
oidset_insert(oids, &refs->old_oid);
}
static int is_unmatched_ref(const struct ref *ref)
{
struct object_id oid;
const char *p;
return ref->match_status == REF_NOT_MATCHED &&
!parse_oid_hex(ref->name, &oid, &p) &&
*p == '\0' &&
oideq(&oid, &ref->old_oid);
}
static void filter_refs(struct fetch_pack_args *args,
struct ref **refs,
struct ref **sought, int nr_sought)
{
struct ref *newlist = NULL;
struct ref **newtail = &newlist;
struct ref *unmatched = NULL;
struct ref *ref, *next;
struct oidset tip_oids = OIDSET_INIT;
int i;
int strict = !(allow_unadvertised_object_request &
(ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1));
i = 0;
for (ref = *refs; ref; ref = next) {
int keep = 0;
next = ref->next;
if (starts_with(ref->name, "refs/") &&
check_refname_format(ref->name, 0)) {
/*
* trash or a peeled value; do not even add it to
* unmatched list
*/
free_one_ref(ref);
continue;
} else {
while (i < nr_sought) {
int cmp = strcmp(ref->name, sought[i]->name);
if (cmp < 0)
break; /* definitely do not have it */
else if (cmp == 0) {
keep = 1; /* definitely have it */
sought[i]->match_status = REF_MATCHED;
}
i++;
}
if (!keep && args->fetch_all &&
(!args->deepen || !starts_with(ref->name, "refs/tags/")))
keep = 1;
}
if (keep) {
*newtail = ref;
ref->next = NULL;
newtail = &ref->next;
} else {
ref->next = unmatched;
unmatched = ref;
}
}
if (strict) {
for (i = 0; i < nr_sought; i++) {
ref = sought[i];
if (!is_unmatched_ref(ref))
continue;
add_refs_to_oidset(&tip_oids, unmatched);
add_refs_to_oidset(&tip_oids, newlist);
break;
}
}
/* Append unmatched requests to the list */
for (i = 0; i < nr_sought; i++) {
ref = sought[i];
if (!is_unmatched_ref(ref))
continue;
if (!strict || oidset_contains(&tip_oids, &ref->old_oid)) {
ref->match_status = REF_MATCHED;
*newtail = copy_ref(ref);
newtail = &(*newtail)->next;
} else {
ref->match_status = REF_UNADVERTISED_NOT_ALLOWED;
}
}
oidset_clear(&tip_oids);
free_refs(unmatched);
*refs = newlist;
}
static void mark_alternate_complete(struct fetch_negotiator *unused,
struct object *obj)
{
mark_complete(&obj->oid);
}
struct loose_object_iter {
struct oidset *loose_object_set;
struct ref *refs;
};
/*
* Mark recent commits available locally and reachable from a local ref as
* COMPLETE.
*
* The cutoff time for recency is determined by this heuristic: it is the
* earliest commit time of the objects in refs that are commits and that we know
* the commit time of.
*/
static void mark_complete_and_common_ref(struct fetch_negotiator *negotiator,
struct fetch_pack_args *args,
struct ref **refs)
{
struct ref *ref;
int old_save_commit_buffer = save_commit_buffer;
timestamp_t cutoff = 0;
save_commit_buffer = 0;
trace2_region_enter("fetch-pack", "parse_remote_refs_and_find_cutoff", NULL);
for (ref = *refs; ref; ref = ref->next) {
struct object *o;
if (!has_object_file_with_flags(&ref->old_oid,
OBJECT_INFO_QUICK |
OBJECT_INFO_SKIP_FETCH_OBJECT))
continue;
o = parse_object(the_repository, &ref->old_oid);
if (!o)
continue;
/*
* We already have it -- which may mean that we were
* in sync with the other side at some time after
* that (it is OK if we guess wrong here).
*/
if (o->type == OBJ_COMMIT) {
struct commit *commit = (struct commit *)o;
if (!cutoff || cutoff < commit->date)
cutoff = commit->date;
}
}
trace2_region_leave("fetch-pack", "parse_remote_refs_and_find_cutoff", NULL);
/*
* This block marks all local refs as COMPLETE, and then recursively marks all
* parents of those refs as COMPLETE.
*/
trace2_region_enter("fetch-pack", "mark_complete_local_refs", NULL);
if (!args->deepen) {
for_each_rawref(mark_complete_oid, NULL);
for_each_cached_alternate(NULL, mark_alternate_complete);
commit_list_sort_by_date(&complete);
if (cutoff)
mark_recent_complete_commits(args, cutoff);
}
trace2_region_leave("fetch-pack", "mark_complete_local_refs", NULL);
/*
* Mark all complete remote refs as common refs.
* Don't mark them common yet; the server has to be told so first.
*/
trace2_region_enter("fetch-pack", "mark_common_remote_refs", NULL);
for (ref = *refs; ref; ref = ref->next) {
struct commit *c = deref_without_lazy_fetch(&ref->old_oid, 0);
if (!c || !(c->object.flags & COMPLETE))
continue;
negotiator->known_common(negotiator, c);
}
trace2_region_leave("fetch-pack", "mark_common_remote_refs", NULL);
save_commit_buffer = old_save_commit_buffer;
}
/*
* Returns 1 if every object pointed to by the given remote refs is available
* locally and reachable from a local ref, and 0 otherwise.
*/
static int everything_local(struct fetch_pack_args *args,
struct ref **refs)
{
struct ref *ref;
int retval;
for (retval = 1, ref = *refs; ref ; ref = ref->next) {
const struct object_id *remote = &ref->old_oid;
struct object *o;
o = lookup_object(the_repository, remote);
if (!o || !(o->flags & COMPLETE)) {
retval = 0;
print_verbose(args, "want %s (%s)", oid_to_hex(remote),
ref->name);
continue;
}
print_verbose(args, _("already have %s (%s)"), oid_to_hex(remote),
ref->name);
}
return retval;
}
static int sideband_demux(int in, int out, void *data)
{
int *xd = data;
int ret;
ret = recv_sideband("fetch-pack", xd[0], out);
close(out);
return ret;
}
static void create_promisor_file(const char *keep_name,
struct ref **sought, int nr_sought)
{
struct strbuf promisor_name = STRBUF_INIT;
int suffix_stripped;
strbuf_addstr(&promisor_name, keep_name);
suffix_stripped = strbuf_strip_suffix(&promisor_name, ".keep");
if (!suffix_stripped)
BUG("name of pack lockfile should end with .keep (was '%s')",
keep_name);
strbuf_addstr(&promisor_name, ".promisor");
write_promisor_file(promisor_name.buf, sought, nr_sought);
strbuf_release(&promisor_name);
}
static void parse_gitmodules_oids(int fd, struct oidset *gitmodules_oids)
{
int len = the_hash_algo->hexsz + 1; /* hash + NL */
do {
char hex_hash[GIT_MAX_HEXSZ + 1];
int read_len = read_in_full(fd, hex_hash, len);
struct object_id oid;
const char *end;
if (!read_len)
return;
if (read_len != len)
die("invalid length read %d", read_len);
if (parse_oid_hex(hex_hash, &oid, &end) || *end != '\n')
die("invalid hash");
oidset_insert(gitmodules_oids, &oid);
} while (1);
}
/*
* If packfile URIs were provided, pass a non-NULL pointer to index_pack_args.
* The strings to pass as the --index-pack-arg arguments to http-fetch will be
* stored there. (It must be freed by the caller.)
*/
static int get_pack(struct fetch_pack_args *args,
int xd[2], struct string_list *pack_lockfiles,
struct strvec *index_pack_args,
struct ref **sought, int nr_sought,
struct oidset *gitmodules_oids)
{
struct async demux;
int do_keep = args->keep_pack;
const char *cmd_name;
struct pack_header header;
int pass_header = 0;
struct child_process cmd = CHILD_PROCESS_INIT;
int fsck_objects = 0;
int ret;
memset(&demux, 0, sizeof(demux));
if (use_sideband) {
/* xd[] is talking with upload-pack; subprocess reads from
* xd[0], spits out band#2 to stderr, and feeds us band#1
* through demux->out.
*/
demux.proc = sideband_demux;
demux.data = xd;
demux.out = -1;
demux.isolate_sigpipe = 1;
if (start_async(&demux))
die(_("fetch-pack: unable to fork off sideband demultiplexer"));
}
else
demux.out = xd[0];
if (!args->keep_pack && unpack_limit && !index_pack_args) {
if (read_pack_header(demux.out, &header))
die(_("protocol error: bad pack header"));
pass_header = 1;
if (ntohl(header.hdr_entries) < unpack_limit)
do_keep = 0;
else
do_keep = 1;
}
if (alternate_shallow_file) {
strvec_push(&cmd.args, "--shallow-file");
strvec_push(&cmd.args, alternate_shallow_file);
}
if (fetch_fsck_objects >= 0
? fetch_fsck_objects
: transfer_fsck_objects >= 0
? transfer_fsck_objects
: 0)
fsck_objects = 1;
if (do_keep || args->from_promisor || index_pack_args || fsck_objects) {
if (pack_lockfiles || fsck_objects)
cmd.out = -1;
cmd_name = "index-pack";
strvec_push(&cmd.args, cmd_name);
strvec_push(&cmd.args, "--stdin");
if (!args->quiet && !args->no_progress)
strvec_push(&cmd.args, "-v");
if (args->use_thin_pack)
strvec_push(&cmd.args, "--fix-thin");
if ((do_keep || index_pack_args) && (args->lock_pack || unpack_limit)) {
char hostname[HOST_NAME_MAX + 1];
if (xgethostname(hostname, sizeof(hostname)))
xsnprintf(hostname, sizeof(hostname), "localhost");
strvec_pushf(&cmd.args,
"--keep=fetch-pack %"PRIuMAX " on %s",
(uintmax_t)getpid(), hostname);
}
if (!index_pack_args && args->check_self_contained_and_connected)
strvec_push(&cmd.args, "--check-self-contained-and-connected");
else
/*
* We cannot perform any connectivity checks because
* not all packs have been downloaded; let the caller
* have this responsibility.
*/
args->check_self_contained_and_connected = 0;
if (args->from_promisor)
/*
* create_promisor_file() may be called afterwards but
* we still need index-pack to know that this is a
* promisor pack. For example, if transfer.fsckobjects
* is true, index-pack needs to know that .gitmodules
* is a promisor object (so that it won't complain if
* it is missing).
*/
strvec_push(&cmd.args, "--promisor");
}
else {
cmd_name = "unpack-objects";
strvec_push(&cmd.args, cmd_name);
if (args->quiet || args->no_progress)
strvec_push(&cmd.args, "-q");
args->check_self_contained_and_connected = 0;
}
if (pass_header)
strvec_pushf(&cmd.args, "--pack_header=%"PRIu32",%"PRIu32,
ntohl(header.hdr_version),
ntohl(header.hdr_entries));
if (fsck_objects) {
if (args->from_promisor || index_pack_args)
/*
* We cannot use --strict in index-pack because it
* checks both broken objects and links, but we only
* want to check for broken objects.
*/
strvec_push(&cmd.args, "--fsck-objects");
else
strvec_pushf(&cmd.args, "--strict%s",
fsck_msg_types.buf);
}
if (index_pack_args) {
int i;
for (i = 0; i < cmd.args.nr; i++)
strvec_push(index_pack_args, cmd.args.v[i]);
}
cmd.in = demux.out;
cmd.git_cmd = 1;
if (start_command(&cmd))
die(_("fetch-pack: unable to fork off %s"), cmd_name);
if (do_keep && (pack_lockfiles || fsck_objects)) {
int is_well_formed;
char *pack_lockfile = index_pack_lockfile(cmd.out, &is_well_formed);
if (!is_well_formed)
die(_("fetch-pack: invalid index-pack output"));
if (pack_lockfile)
string_list_append_nodup(pack_lockfiles, pack_lockfile);
parse_gitmodules_oids(cmd.out, gitmodules_oids);
close(cmd.out);
}
if (!use_sideband)
/* Closed by start_command() */
xd[0] = -1;
ret = finish_command(&cmd);
if (!ret || (args->check_self_contained_and_connected && ret == 1))
args->self_contained_and_connected =
args->check_self_contained_and_connected &&
ret == 0;
else
die(_("%s failed"), cmd_name);
if (use_sideband && finish_async(&demux))
die(_("error in sideband demultiplexer"));
/*
* Now that index-pack has succeeded, write the promisor file using the
* obtained .keep filename if necessary
*/
if (do_keep && pack_lockfiles && pack_lockfiles->nr && args->from_promisor)
create_promisor_file(pack_lockfiles->items[0].string, sought, nr_sought);
return 0;
}
static int cmp_ref_by_name(const void *a_, const void *b_)
{
const struct ref *a = *((const struct ref **)a_);
const struct ref *b = *((const struct ref **)b_);
return strcmp(a->name, b->name);
}
static struct ref *do_fetch_pack(struct fetch_pack_args *args,
int fd[2],
const struct ref *orig_ref,
struct ref **sought, int nr_sought,
struct shallow_info *si,
struct string_list *pack_lockfiles)
{
struct repository *r = the_repository;
struct ref *ref = copy_ref_list(orig_ref);
struct object_id oid;
const char *agent_feature;
int agent_len;
struct fetch_negotiator negotiator_alloc;
struct fetch_negotiator *negotiator;
negotiator = &negotiator_alloc;
fetch_negotiator_init(r, negotiator);
sort_ref_list(&ref, ref_compare_name);
QSORT(sought, nr_sought, cmp_ref_by_name);
if ((agent_feature = server_feature_value("agent", &agent_len))) {
agent_supported = 1;
if (agent_len)
print_verbose(args, _("Server version is %.*s"),
agent_len, agent_feature);
}
if (!server_supports("session-id"))
advertise_sid = 0;
if (server_supports("shallow"))
print_verbose(args, _("Server supports %s"), "shallow");
else if (args->depth > 0 || is_repository_shallow(r))
die(_("Server does not support shallow clients"));
if (args->depth > 0 || args->deepen_since || args->deepen_not)
args->deepen = 1;
if (server_supports("multi_ack_detailed")) {
print_verbose(args, _("Server supports %s"), "multi_ack_detailed");
multi_ack = 2;
if (server_supports("no-done")) {
print_verbose(args, _("Server supports %s"), "no-done");
if (args->stateless_rpc)
no_done = 1;
}
}
else if (server_supports("multi_ack")) {
print_verbose(args, _("Server supports %s"), "multi_ack");
multi_ack = 1;
}
if (server_supports("side-band-64k")) {
print_verbose(args, _("Server supports %s"), "side-band-64k");
use_sideband = 2;
}
else if (server_supports("side-band")) {
print_verbose(args, _("Server supports %s"), "side-band");
use_sideband = 1;
}
if (server_supports("allow-tip-sha1-in-want")) {
print_verbose(args, _("Server supports %s"), "allow-tip-sha1-in-want");
allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
}
if (server_supports("allow-reachable-sha1-in-want")) {
print_verbose(args, _("Server supports %s"), "allow-reachable-sha1-in-want");
allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
}
if (server_supports("thin-pack"))
print_verbose(args, _("Server supports %s"), "thin-pack");
else
args->use_thin_pack = 0;
if (server_supports("no-progress"))
print_verbose(args, _("Server supports %s"), "no-progress");
else
args->no_progress = 0;
if (server_supports("include-tag"))
print_verbose(args, _("Server supports %s"), "include-tag");
else
args->include_tag = 0;
if (server_supports("ofs-delta"))
print_verbose(args, _("Server supports %s"), "ofs-delta");
else
prefer_ofs_delta = 0;
if (server_supports("filter")) {
server_supports_filtering = 1;
print_verbose(args, _("Server supports %s"), "filter");
} else if (args->filter_options.choice) {
warning("filtering not recognized by server, ignoring");
}
if (server_supports("deepen-since")) {
print_verbose(args, _("Server supports %s"), "deepen-since");
deepen_since_ok = 1;
} else if (args->deepen_since)
die(_("Server does not support --shallow-since"));
if (server_supports("deepen-not")) {
print_verbose(args, _("Server supports %s"), "deepen-not");
deepen_not_ok = 1;
} else if (args->deepen_not)
die(_("Server does not support --shallow-exclude"));
if (server_supports("deepen-relative"))
print_verbose(args, _("Server supports %s"), "deepen-relative");
else if (args->deepen_relative)
die(_("Server does not support --deepen"));
if (!server_supports_hash(the_hash_algo->name, NULL))
die(_("Server does not support this repository's object format"));
mark_complete_and_common_ref(negotiator, args, &ref);
filter_refs(args, &ref, sought, nr_sought);
if (everything_local(args, &ref)) {
packet_flush(fd[1]);
goto all_done;
}
if (find_common(negotiator, args, fd, &oid, ref) < 0)
if (!args->keep_pack)
/* When cloning, it is not unusual to have
* no common commit.
*/
warning(_("no common commits"));
if (args->stateless_rpc)
packet_flush(fd[1]);
if (args->deepen)
setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
NULL);
else if (si->nr_ours || si->nr_theirs) {
if (args->reject_shallow_remote)
die(_("source repository is shallow, reject to clone."));
alternate_shallow_file = setup_temporary_shallow(si->shallow);
} else
alternate_shallow_file = NULL;
if (get_pack(args, fd, pack_lockfiles, NULL, sought, nr_sought,
&fsck_options.gitmodules_found))
die(_("git fetch-pack: fetch failed."));
if (fsck_finish(&fsck_options))
die("fsck failed");
all_done:
if (negotiator)
negotiator->release(negotiator);
return ref;
}
static void add_shallow_requests(struct strbuf *req_buf,
const struct fetch_pack_args *args)
{
if (is_repository_shallow(the_repository))
write_shallow_commits(req_buf, 1, NULL);
if (args->depth > 0)
packet_buf_write(req_buf, "deepen %d", args->depth);
if (args->deepen_since) {
timestamp_t max_age = approxidate(args->deepen_since);
packet_buf_write(req_buf, "deepen-since %"PRItime, max_age);
}
if (args->deepen_not) {
int i;
for (i = 0; i < args->deepen_not->nr; i++) {
struct string_list_item *s = args->deepen_not->items + i;
packet_buf_write(req_buf, "deepen-not %s", s->string);
}
}
if (args->deepen_relative)
packet_buf_write(req_buf, "deepen-relative\n");
}
static void add_wants(const struct ref *wants, struct strbuf *req_buf)
{
int use_ref_in_want = server_supports_feature("fetch", "ref-in-want", 0);
for ( ; wants ; wants = wants->next) {
const struct object_id *remote = &wants->old_oid;
struct object *o;
/*
* If that object is complete (i.e. it is an ancestor of a
* local ref), we tell them we have it but do not have to
* tell them about its ancestors, which they already know
* about.
*
* We use lookup_object here because we are only
* interested in the case we *know* the object is
* reachable and we have already scanned it.
*/
if (((o = lookup_object(the_repository, remote)) != NULL) &&
(o->flags & COMPLETE)) {
continue;
}
if (!use_ref_in_want || wants->exact_oid)
packet_buf_write(req_buf, "want %s\n", oid_to_hex(remote));
else
packet_buf_write(req_buf, "want-ref %s\n", wants->name);
}
}
static void add_common(struct strbuf *req_buf, struct oidset *common)
{
struct oidset_iter iter;
const struct object_id *oid;
oidset_iter_init(common, &iter);
while ((oid = oidset_iter_next(&iter))) {
packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
}
}
static int add_haves(struct fetch_negotiator *negotiator,
struct strbuf *req_buf,
int *haves_to_send)
{
int haves_added = 0;
const struct object_id *oid;
while ((oid = negotiator->next(negotiator))) {
packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
if (++haves_added >= *haves_to_send)
break;
}
/* Increase haves to send on next round */
*haves_to_send = next_flush(1, *haves_to_send);
return haves_added;
}
static void write_fetch_command_and_capabilities(struct strbuf *req_buf,
const struct string_list *server_options)
{
const char *hash_name;
if (server_supports_v2("fetch", 1))
packet_buf_write(req_buf, "command=fetch");
if (server_supports_v2("agent", 0))
packet_buf_write(req_buf, "agent=%s", git_user_agent_sanitized());
if (advertise_sid && server_supports_v2("session-id", 0))
packet_buf_write(req_buf, "session-id=%s", trace2_session_id());
if (server_options && server_options->nr &&
server_supports_v2("server-option", 1)) {
int i;
for (i = 0; i < server_options->nr; i++)
packet_buf_write(req_buf, "server-option=%s",
server_options->items[i].string);
}
if (server_feature_v2("object-format", &hash_name)) {
int hash_algo = hash_algo_by_name(hash_name);
if (hash_algo_by_ptr(the_hash_algo) != hash_algo)
die(_("mismatched algorithms: client %s; server %s"),
the_hash_algo->name, hash_name);
packet_buf_write(req_buf, "object-format=%s", the_hash_algo->name);
} else if (hash_algo_by_ptr(the_hash_algo) != GIT_HASH_SHA1) {
die(_("the server does not support algorithm '%s'"),
the_hash_algo->name);
}
packet_buf_delim(req_buf);
}
static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
struct fetch_pack_args *args,
const struct ref *wants, struct oidset *common,
int *haves_to_send, int *in_vain,
int sideband_all, int seen_ack)
{
int haves_added;
int done_sent = 0;
struct strbuf req_buf = STRBUF_INIT;
write_fetch_command_and_capabilities(&req_buf, args->server_options);
if (args->use_thin_pack)
packet_buf_write(&req_buf, "thin-pack");
if (args->no_progress)
packet_buf_write(&req_buf, "no-progress");
if (args->include_tag)
packet_buf_write(&req_buf, "include-tag");
if (prefer_ofs_delta)
packet_buf_write(&req_buf, "ofs-delta");
if (sideband_all)
packet_buf_write(&req_buf, "sideband-all");
/* Add shallow-info and deepen request */
if (server_supports_feature("fetch", "shallow", 0))
add_shallow_requests(&req_buf, args);
else if (is_repository_shallow(the_repository) || args->deepen)
die(_("Server does not support shallow requests"));
/* Add filter */
if (server_supports_feature("fetch", "filter", 0) &&
args->filter_options.choice) {
const char *spec =
expand_list_objects_filter_spec(&args->filter_options);
print_verbose(args, _("Server supports filter"));
packet_buf_write(&req_buf, "filter %s", spec);
} else if (args->filter_options.choice) {
warning("filtering not recognized by server, ignoring");
}
if (server_supports_feature("fetch", "packfile-uris", 0)) {
int i;
struct strbuf to_send = STRBUF_INIT;
for (i = 0; i < uri_protocols.nr; i++) {
const char *s = uri_protocols.items[i].string;
if (!strcmp(s, "https") || !strcmp(s, "http")) {
if (to_send.len)
strbuf_addch(&to_send, ',');
strbuf_addstr(&to_send, s);
}
}
if (to_send.len) {
packet_buf_write(&req_buf, "packfile-uris %s",
to_send.buf);
strbuf_release(&to_send);
}
}
/* add wants */
add_wants(wants, &req_buf);
/* Add all of the common commits we've found in previous rounds */
add_common(&req_buf, common);
haves_added = add_haves(negotiator, &req_buf, haves_to_send);
*in_vain += haves_added;
if (!haves_added || (seen_ack && *in_vain >= MAX_IN_VAIN)) {
/* Send Done */
packet_buf_write(&req_buf, "done\n");
done_sent = 1;
}
/* Send request */
packet_buf_flush(&req_buf);
if (write_in_full(fd_out, req_buf.buf, req_buf.len) < 0)
die_errno(_("unable to write request to remote"));
strbuf_release(&req_buf);
return done_sent;
}
/*
* Processes a section header in a server's response and checks if it matches
* `section`. If the value of `peek` is 1, the header line will be peeked (and
* not consumed); if 0, the line will be consumed and the function will die if
* the section header doesn't match what was expected.
*/
static int process_section_header(struct packet_reader *reader,
const char *section, int peek)
{
int ret;
if (packet_reader_peek(reader) != PACKET_READ_NORMAL)
die(_("error reading section header '%s'"), section);
ret = !strcmp(reader->line, section);
if (!peek) {
if (!ret)
die(_("expected '%s', received '%s'"),
section, reader->line);
packet_reader_read(reader);
}
return ret;
}
static int process_ack(struct fetch_negotiator *negotiator,
struct packet_reader *reader,
struct object_id *common_oid,
int *received_ready)
{
while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
const char *arg;
if (!strcmp(reader->line, "NAK"))
continue;
if (skip_prefix(reader->line, "ACK ", &arg)) {
if (!get_oid_hex(arg, common_oid)) {
struct commit *commit;
commit = lookup_commit(the_repository, common_oid);
if (negotiator)
negotiator->ack(negotiator, commit);
}
return 1;
}
if (!strcmp(reader->line, "ready")) {
*received_ready = 1;
continue;
}
die(_("unexpected acknowledgment line: '%s'"), reader->line);
}
if (reader->status != PACKET_READ_FLUSH &&
reader->status != PACKET_READ_DELIM)
die(_("error processing acks: %d"), reader->status);
/*
* If an "acknowledgments" section is sent, a packfile is sent if and
* only if "ready" was sent in this section. The other sections
* ("shallow-info" and "wanted-refs") are sent only if a packfile is
* sent. Therefore, a DELIM is expected if "ready" is sent, and a FLUSH
* otherwise.
*/
if (*received_ready && reader->status != PACKET_READ_DELIM)
die(_("expected packfile to be sent after 'ready'"));
if (!*received_ready && reader->status != PACKET_READ_FLUSH)
die(_("expected no other sections to be sent after no 'ready'"));
return 0;
}
static void receive_shallow_info(struct fetch_pack_args *args,
struct packet_reader *reader,
struct oid_array *shallows,
struct shallow_info *si)
{
int unshallow_received = 0;
process_section_header(reader, "shallow-info", 0);
while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
const char *arg;
struct object_id oid;
if (skip_prefix(reader->line, "shallow ", &arg)) {
if (get_oid_hex(arg, &oid))
die(_("invalid shallow line: %s"), reader->line);
oid_array_append(shallows, &oid);
continue;
}
if (skip_prefix(reader->line, "unshallow ", &arg)) {
if (get_oid_hex(arg, &oid))
die(_("invalid unshallow line: %s"), reader->line);
if (!lookup_object(the_repository, &oid))
die(_("object not found: %s"), reader->line);
/* make sure that it is parsed as shallow */
if (!parse_object(the_repository, &oid))
die(_("error in object: %s"), reader->line);
if (unregister_shallow(&oid))
die(_("no shallow found: %s"), reader->line);
unshallow_received = 1;
continue;
}
die(_("expected shallow/unshallow, got %s"), reader->line);
}
if (reader->status != PACKET_READ_FLUSH &&
reader->status != PACKET_READ_DELIM)
die(_("error processing shallow info: %d"), reader->status);
if (args->deepen || unshallow_received) {
/*
* Treat these as shallow lines caused by our depth settings.
* In v0, these lines cannot cause refs to be rejected; do the
* same.
*/
int i;
for (i = 0; i < shallows->nr; i++)
register_shallow(the_repository, &shallows->oid[i]);
setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
NULL);
args->deepen = 1;
} else if (shallows->nr) {
/*
* Treat these as shallow lines caused by the remote being
* shallow. In v0, remote refs that reach these objects are
* rejected (unless --update-shallow is set); do the same.
*/
prepare_shallow_info(si, shallows);
if (si->nr_ours || si->nr_theirs) {
if (args->reject_shallow_remote)
die(_("source repository is shallow, reject to clone."));
alternate_shallow_file =
setup_temporary_shallow(si->shallow);
} else
alternate_shallow_file = NULL;
} else {
alternate_shallow_file = NULL;
}
}
static int cmp_name_ref(const void *name, const void *ref)
{
return strcmp(name, (*(struct ref **)ref)->name);
}
static void receive_wanted_refs(struct packet_reader *reader,
struct ref **sought, int nr_sought)
{
process_section_header(reader, "wanted-refs", 0);
while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
struct object_id oid;
const char *end;
struct ref **found;
if (parse_oid_hex(reader->line, &oid, &end) || *end++ != ' ')
die(_("expected wanted-ref, got '%s'"), reader->line);
found = bsearch(end, sought, nr_sought, sizeof(*sought),
cmp_name_ref);
if (!found)
die(_("unexpected wanted-ref: '%s'"), reader->line);
oidcpy(&(*found)->old_oid, &oid);
}
if (reader->status != PACKET_READ_DELIM)
die(_("error processing wanted refs: %d"), reader->status);
}
static void receive_packfile_uris(struct packet_reader *reader,
struct string_list *uris)
{
process_section_header(reader, "packfile-uris", 0);
while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
if (reader->pktlen < the_hash_algo->hexsz ||
reader->line[the_hash_algo->hexsz] != ' ')
die("expected '<hash> <uri>', got: %s\n", reader->line);
string_list_append(uris, reader->line);
}
if (reader->status != PACKET_READ_DELIM)
die("expected DELIM");
}
enum fetch_state {
FETCH_CHECK_LOCAL = 0,
FETCH_SEND_REQUEST,
FETCH_PROCESS_ACKS,
FETCH_GET_PACK,
FETCH_DONE,
};
static void do_check_stateless_delimiter(int stateless_rpc,
struct packet_reader *reader)
{
check_stateless_delimiter(stateless_rpc, reader,
_("git fetch-pack: expected response end packet"));
}
static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
int fd[2],
const struct ref *orig_ref,
struct ref **sought, int nr_sought,
struct oid_array *shallows,
struct shallow_info *si,
struct string_list *pack_lockfiles)
{
struct repository *r = the_repository;
struct ref *ref = copy_ref_list(orig_ref);
enum fetch_state state = FETCH_CHECK_LOCAL;
struct oidset common = OIDSET_INIT;
struct packet_reader reader;
int in_vain = 0, negotiation_started = 0;
int haves_to_send = INITIAL_FLUSH;
struct fetch_negotiator negotiator_alloc;
struct fetch_negotiator *negotiator;
int seen_ack = 0;
struct object_id common_oid;
int received_ready = 0;
struct string_list packfile_uris = STRING_LIST_INIT_DUP;
int i;
struct strvec index_pack_args = STRVEC_INIT;
negotiator = &negotiator_alloc;
fetch_negotiator_init(r, negotiator);
packet_reader_init(&reader, fd[0], NULL, 0,
PACKET_READ_CHOMP_NEWLINE |
PACKET_READ_DIE_ON_ERR_PACKET);
if (git_env_bool("GIT_TEST_SIDEBAND_ALL", 1) &&
server_supports_feature("fetch", "sideband-all", 0)) {
reader.use_sideband = 1;
reader.me = "fetch-pack";
}
while (state != FETCH_DONE) {
switch (state) {
case FETCH_CHECK_LOCAL:
sort_ref_list(&ref, ref_compare_name);
QSORT(sought, nr_sought, cmp_ref_by_name);
/* v2 supports these by default */
allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
use_sideband = 2;
if (args->depth > 0 || args->deepen_since || args->deepen_not)
args->deepen = 1;
/* Filter 'ref' by 'sought' and those that aren't local */
mark_complete_and_common_ref(negotiator, args, &ref);
filter_refs(args, &ref, sought, nr_sought);
if (everything_local(args, &ref))
state = FETCH_DONE;
else
state = FETCH_SEND_REQUEST;
mark_tips(negotiator, args->negotiation_tips);
for_each_cached_alternate(negotiator,
insert_one_alternate_object);
break;
case FETCH_SEND_REQUEST:
if (!negotiation_started) {
negotiation_started = 1;
trace2_region_enter("fetch-pack",
"negotiation_v2",
the_repository);
}
if (send_fetch_request(negotiator, fd[1], args, ref,
&common,
&haves_to_send, &in_vain,
reader.use_sideband,
seen_ack))
state = FETCH_GET_PACK;
else
state = FETCH_PROCESS_ACKS;
break;
case FETCH_PROCESS_ACKS:
/* Process ACKs/NAKs */
process_section_header(&reader, "acknowledgments", 0);
while (process_ack(negotiator, &reader, &common_oid,
&received_ready)) {
in_vain = 0;
seen_ack = 1;
oidset_insert(&common, &common_oid);
}
if (received_ready) {
/*
* Don't check for response delimiter; get_pack() will
* read the rest of this response.
*/
state = FETCH_GET_PACK;
} else {
do_check_stateless_delimiter(args->stateless_rpc, &reader);
state = FETCH_SEND_REQUEST;
}
break;
case FETCH_GET_PACK:
trace2_region_leave("fetch-pack",
"negotiation_v2",
the_repository);
/* Check for shallow-info section */
if (process_section_header(&reader, "shallow-info", 1))
receive_shallow_info(args, &reader, shallows, si);
if (process_section_header(&reader, "wanted-refs", 1))
receive_wanted_refs(&reader, sought, nr_sought);
/* get the pack(s) */
if (process_section_header(&reader, "packfile-uris", 1))
receive_packfile_uris(&reader, &packfile_uris);
process_section_header(&reader, "packfile", 0);
/*
* this is the final request we'll make of the server;
* do a half-duplex shutdown to indicate that they can
* hang up as soon as the pack is sent.
*/
close(fd[1]);
fd[1] = -1;
if (get_pack(args, fd, pack_lockfiles,
packfile_uris.nr ? &index_pack_args : NULL,
sought, nr_sought, &fsck_options.gitmodules_found))
die(_("git fetch-pack: fetch failed."));
do_check_stateless_delimiter(args->stateless_rpc, &reader);
state = FETCH_DONE;
break;
case FETCH_DONE:
continue;
}
}
for (i = 0; i < packfile_uris.nr; i++) {
int j;
struct child_process cmd = CHILD_PROCESS_INIT;
char packname[GIT_MAX_HEXSZ + 1];
const char *uri = packfile_uris.items[i].string +
the_hash_algo->hexsz + 1;
strvec_push(&cmd.args, "http-fetch");
strvec_pushf(&cmd.args, "--packfile=%.*s",
(int) the_hash_algo->hexsz,
packfile_uris.items[i].string);
for (j = 0; j < index_pack_args.nr; j++)
strvec_pushf(&cmd.args, "--index-pack-arg=%s",
index_pack_args.v[j]);
strvec_push(&cmd.args, uri);
cmd.git_cmd = 1;
cmd.no_stdin = 1;
cmd.out = -1;
if (start_command(&cmd))
die("fetch-pack: unable to spawn http-fetch");
if (read_in_full(cmd.out, packname, 5) < 0 ||
memcmp(packname, "keep\t", 5))
die("fetch-pack: expected keep then TAB at start of http-fetch output");
if (read_in_full(cmd.out, packname,
the_hash_algo->hexsz + 1) < 0 ||
packname[the_hash_algo->hexsz] != '\n')
die("fetch-pack: expected hash then LF at end of http-fetch output");
packname[the_hash_algo->hexsz] = '\0';
parse_gitmodules_oids(cmd.out, &fsck_options.gitmodules_found);
close(cmd.out);
if (finish_command(&cmd))
die("fetch-pack: unable to finish http-fetch");
if (memcmp(packfile_uris.items[i].string, packname,
the_hash_algo->hexsz))
die("fetch-pack: pack downloaded from %s does not match expected hash %.*s",
uri, (int) the_hash_algo->hexsz,
packfile_uris.items[i].string);
string_list_append_nodup(pack_lockfiles,
xstrfmt("%s/pack/pack-%s.keep",
get_object_directory(),
packname));
}
string_list_clear(&packfile_uris, 0);
strvec_clear(&index_pack_args);
if (fsck_finish(&fsck_options))
die("fsck failed");
if (negotiator)
negotiator->release(negotiator);
oidset_clear(&common);
return ref;
}
static int fetch_pack_config_cb(const char *var, const char *value, void *cb)
{
if (strcmp(var, "fetch.fsck.skiplist") == 0) {
const char *path;
if (git_config_pathname(&path, var, value))
return 1;
strbuf_addf(&fsck_msg_types, "%cskiplist=%s",
fsck_msg_types.len ? ',' : '=', path);
free((char *)path);
return 0;
}
if (skip_prefix(var, "fetch.fsck.", &var)) {
if (is_valid_msg_type(var, value))
strbuf_addf(&fsck_msg_types, "%c%s=%s",
fsck_msg_types.len ? ',' : '=', var, value);
else
warning("Skipping unknown msg id '%s'", var);
return 0;
}
return git_default_config(var, value, cb);
}
static void fetch_pack_config(void)
{
git_config_get_int("fetch.unpacklimit", &fetch_unpack_limit);
git_config_get_int("transfer.unpacklimit", &transfer_unpack_limit);
git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
git_config_get_bool("transfer.advertisesid", &advertise_sid);
if (!uri_protocols.nr) {
char *str;
if (!git_config_get_string("fetch.uriprotocols", &str) && str) {
string_list_split(&uri_protocols, str, ',', -1);
free(str);
}
}
git_config(fetch_pack_config_cb, NULL);
}
static void fetch_pack_setup(void)
{
static int did_setup;
if (did_setup)
return;
fetch_pack_config();
if (0 <= transfer_unpack_limit)
unpack_limit = transfer_unpack_limit;
else if (0 <= fetch_unpack_limit)
unpack_limit = fetch_unpack_limit;
did_setup = 1;
}
static int remove_duplicates_in_refs(struct ref **ref, int nr)
{
struct string_list names = STRING_LIST_INIT_NODUP;
int src, dst;
for (src = dst = 0; src < nr; src++) {
struct string_list_item *item;
item = string_list_insert(&names, ref[src]->name);
if (item->util)
continue; /* already have it */
item->util = ref[src];
if (src != dst)
ref[dst] = ref[src];
dst++;
}
for (src = dst; src < nr; src++)
ref[src] = NULL;
string_list_clear(&names, 0);
return dst;
}
static void update_shallow(struct fetch_pack_args *args,
struct ref **sought, int nr_sought,
struct shallow_info *si)
{
struct oid_array ref = OID_ARRAY_INIT;
int *status;
int i;
if (args->deepen && alternate_shallow_file) {
if (*alternate_shallow_file == '\0') { /* --unshallow */
unlink_or_warn(git_path_shallow(the_repository));
rollback_shallow_file(the_repository, &shallow_lock);
} else
commit_shallow_file(the_repository, &shallow_lock);
alternate_shallow_file = NULL;
return;
}
if (!si->shallow || !si->shallow->nr)
return;
if (args->cloning) {
/*
* remote is shallow, but this is a clone, there are
* no objects in repo to worry about. Accept any
* shallow points that exist in the pack (iow in repo
* after get_pack() and reprepare_packed_git())
*/
struct oid_array extra = OID_ARRAY_INIT;
struct object_id *oid = si->shallow->oid;
for (i = 0; i < si->shallow->nr; i++)
if (has_object_file(&oid[i]))
oid_array_append(&extra, &oid[i]);
if (extra.nr) {
setup_alternate_shallow(&shallow_lock,
&alternate_shallow_file,
&extra);
commit_shallow_file(the_repository, &shallow_lock);
alternate_shallow_file = NULL;
}
oid_array_clear(&extra);
return;
}
if (!si->nr_ours && !si->nr_theirs)
return;
remove_nonexistent_theirs_shallow(si);
if (!si->nr_ours && !si->nr_theirs)
return;
for (i = 0; i < nr_sought; i++)
oid_array_append(&ref, &sought[i]->old_oid);
si->ref = &ref;
if (args->update_shallow) {
/*
* remote is also shallow, .git/shallow may be updated
* so all refs can be accepted. Make sure we only add
* shallow roots that are actually reachable from new
* refs.
*/
struct oid_array extra = OID_ARRAY_INIT;
struct object_id *oid = si->shallow->oid;
assign_shallow_commits_to_refs(si, NULL, NULL);
if (!si->nr_ours && !si->nr_theirs) {
oid_array_clear(&ref);
return;
}
for (i = 0; i < si->nr_ours; i++)
oid_array_append(&extra, &oid[si->ours[i]]);
for (i = 0; i < si->nr_theirs; i++)
oid_array_append(&extra, &oid[si->theirs[i]]);
setup_alternate_shallow(&shallow_lock,
&alternate_shallow_file,
&extra);
commit_shallow_file(the_repository, &shallow_lock);
oid_array_clear(&extra);
oid_array_clear(&ref);
alternate_shallow_file = NULL;
return;
}
/*
* remote is also shallow, check what ref is safe to update
* without updating .git/shallow
*/
CALLOC_ARRAY(status, nr_sought);
assign_shallow_commits_to_refs(si, NULL, status);
if (si->nr_ours || si->nr_theirs) {
for (i = 0; i < nr_sought; i++)
if (status[i])
sought[i]->status = REF_STATUS_REJECT_SHALLOW;
}
free(status);
oid_array_clear(&ref);
}
static int iterate_ref_map(void *cb_data, struct object_id *oid)
{
struct ref **rm = cb_data;
struct ref *ref = *rm;
if (!ref)
return -1; /* end of the list */
*rm = ref->next;
oidcpy(oid, &ref->old_oid);
return 0;
}
struct ref *fetch_pack(struct fetch_pack_args *args,
int fd[],
const struct ref *ref,
struct ref **sought, int nr_sought,
struct oid_array *shallow,
struct string_list *pack_lockfiles,
enum protocol_version version)
{
struct ref *ref_cpy;
struct shallow_info si;
struct oid_array shallows_scratch = OID_ARRAY_INIT;
fetch_pack_setup();
if (nr_sought)
nr_sought = remove_duplicates_in_refs(sought, nr_sought);
if (version != protocol_v2 && !ref) {
packet_flush(fd[1]);
die(_("no matching remote head"));
}
if (version == protocol_v2) {
if (shallow->nr)
BUG("Protocol V2 does not provide shallows at this point in the fetch");
memset(&si, 0, sizeof(si));
ref_cpy = do_fetch_pack_v2(args, fd, ref, sought, nr_sought,
&shallows_scratch, &si,
pack_lockfiles);
} else {
prepare_shallow_info(&si, shallow);
ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
&si, pack_lockfiles);
}
reprepare_packed_git(the_repository);
if (!args->cloning && args->deepen) {
struct check_connected_options opt = CHECK_CONNECTED_INIT;
struct ref *iterator = ref_cpy;
opt.shallow_file = alternate_shallow_file;
if (args->deepen)
opt.is_deepening_fetch = 1;
if (check_connected(iterate_ref_map, &iterator, &opt)) {
error(_("remote did not send all necessary objects"));
free_refs(ref_cpy);
ref_cpy = NULL;
rollback_shallow_file(the_repository, &shallow_lock);
goto cleanup;
}
args->connectivity_checked = 1;
}
update_shallow(args, sought, nr_sought, &si);
cleanup:
clear_shallow_info(&si);
oid_array_clear(&shallows_scratch);
return ref_cpy;
}
static int add_to_object_array(const struct object_id *oid, void *data)
{
struct object_array *a = data;
add_object_array(lookup_object(the_repository, oid), "", a);
return 0;
}
static void clear_common_flag(struct oidset *s)
{
struct oidset_iter iter;
const struct object_id *oid;
oidset_iter_init(s, &iter);
while ((oid = oidset_iter_next(&iter))) {
struct object *obj = lookup_object(the_repository, oid);
obj->flags &= ~COMMON;
}
}
void negotiate_using_fetch(const struct oid_array *negotiation_tips,
const struct string_list *server_options,
int stateless_rpc,
int fd[],
struct oidset *acked_commits)
{
struct fetch_negotiator negotiator;
struct packet_reader reader;
struct object_array nt_object_array = OBJECT_ARRAY_INIT;
struct strbuf req_buf = STRBUF_INIT;
int haves_to_send = INITIAL_FLUSH;
int in_vain = 0;
int seen_ack = 0;
int last_iteration = 0;
timestamp_t min_generation = GENERATION_NUMBER_INFINITY;
fetch_negotiator_init(the_repository, &negotiator);
mark_tips(&negotiator, negotiation_tips);
packet_reader_init(&reader, fd[0], NULL, 0,
PACKET_READ_CHOMP_NEWLINE |
PACKET_READ_DIE_ON_ERR_PACKET);
oid_array_for_each((struct oid_array *) negotiation_tips,
add_to_object_array,
&nt_object_array);
while (!last_iteration) {
int haves_added;
struct object_id common_oid;
int received_ready = 0;
strbuf_reset(&req_buf);
write_fetch_command_and_capabilities(&req_buf, server_options);
packet_buf_write(&req_buf, "wait-for-done");
haves_added = add_haves(&negotiator, &req_buf, &haves_to_send);
in_vain += haves_added;
if (!haves_added || (seen_ack && in_vain >= MAX_IN_VAIN))
last_iteration = 1;
/* Send request */
packet_buf_flush(&req_buf);
if (write_in_full(fd[1], req_buf.buf, req_buf.len) < 0)
die_errno(_("unable to write request to remote"));
/* Process ACKs/NAKs */
process_section_header(&reader, "acknowledgments", 0);
while (process_ack(&negotiator, &reader, &common_oid,
&received_ready)) {
struct commit *commit = lookup_commit(the_repository,
&common_oid);
if (commit) {
timestamp_t generation;
parse_commit_or_die(commit);
commit->object.flags |= COMMON;
generation = commit_graph_generation(commit);
if (generation < min_generation)
min_generation = generation;
}
in_vain = 0;
seen_ack = 1;
oidset_insert(acked_commits, &common_oid);
}
if (received_ready)
die(_("unexpected 'ready' from remote"));
else
do_check_stateless_delimiter(stateless_rpc, &reader);
if (can_all_from_reach_with_flag(&nt_object_array, COMMON,
REACH_SCRATCH, 0,
min_generation))
last_iteration = 1;
}
clear_common_flag(acked_commits);
strbuf_release(&req_buf);
}
int report_unmatched_refs(struct ref **sought, int nr_sought)
{
int i, ret = 0;
for (i = 0; i < nr_sought; i++) {
if (!sought[i])
continue;
switch (sought[i]->match_status) {
case REF_MATCHED:
continue;
case REF_NOT_MATCHED:
error(_("no such remote ref %s"), sought[i]->name);
break;
case REF_UNADVERTISED_NOT_ALLOWED:
error(_("Server does not allow request for unadvertised object %s"),
sought[i]->name);
break;
}
ret = 1;
}
return ret;
}
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