git/fetch-pack.h
Jonathan Tan 9c1e657a8f fetch: teach independent negotiation (no packfile)
Currently, the packfile negotiation step within a Git fetch cannot be
done independent of sending the packfile, even though there is at least
one application wherein this is useful. Therefore, make it possible for
this negotiation step to be done independently. A subsequent commit will
use this for one such application - push negotiation.

This feature is for protocol v2 only. (An implementation for protocol v0
would require a separate implementation in the fetch, transport, and
transport helper code.)

In the protocol, the main hindrance towards independent negotiation is
that the server can unilaterally decide to send the packfile. This is
solved by a "wait-for-done" argument: the server will then wait for the
client to say "done". In practice, the client will never say it; instead
it will cease requests once it is satisfied.

In the client, the main change lies in the transport and transport
helper code. fetch_refs_via_pack() performs everything needed - protocol
version and capability checks, and the negotiation itself.

There are 2 code paths that do not go through fetch_refs_via_pack() that
needed to be individually excluded: the bundle transport (excluded
through requiring smart_options, which the bundle transport doesn't
support) and transport helpers that do not support takeover. If or when
we support independent negotiation for protocol v0, we will need to
modify these 2 code paths to support it. But for now, report failure if
independent negotiation is requested in these cases.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-05 10:41:29 +09:00

104 lines
3.1 KiB
C

#ifndef FETCH_PACK_H
#define FETCH_PACK_H
#include "string-list.h"
#include "run-command.h"
#include "protocol.h"
#include "list-objects-filter-options.h"
#include "oidset.h"
struct oid_array;
struct fetch_pack_args {
const char *uploadpack;
int unpacklimit;
int depth;
const char *deepen_since;
const struct string_list *deepen_not;
struct list_objects_filter_options filter_options;
const struct string_list *server_options;
/*
* If not NULL, during packfile negotiation, fetch-pack will send "have"
* lines only with these tips and their ancestors.
*/
const struct oid_array *negotiation_tips;
unsigned deepen_relative:1;
unsigned quiet:1;
unsigned keep_pack:1;
unsigned lock_pack:1;
unsigned use_thin_pack:1;
unsigned fetch_all:1;
unsigned stdin_refs:1;
unsigned diag_url:1;
unsigned verbose:1;
unsigned no_progress:1;
unsigned include_tag:1;
unsigned stateless_rpc:1;
unsigned check_self_contained_and_connected:1;
unsigned self_contained_and_connected:1;
unsigned cloning:1;
unsigned update_shallow:1;
unsigned reject_shallow_remote:1;
unsigned deepen:1;
/*
* Indicate that the remote of this request is a promisor remote. The
* pack received does not need all referred-to objects to be present in
* the local object store, and fetch-pack will store the pack received
* together with a ".promisor" file indicating that the aforementioned
* pack is a promisor pack.
*/
unsigned from_promisor:1;
/*
* Because fetch_pack() overwrites the shallow file upon a
* successful deepening non-clone fetch, if this struct
* specifies such a fetch, fetch_pack() needs to perform a
* connectivity check before deciding if a fetch is successful
* (and overwriting the shallow file). fetch_pack() sets this
* field to 1 if such a connectivity check was performed.
*
* This is different from check_self_contained_and_connected
* in that the former allows existing objects in the
* repository to satisfy connectivity needs, whereas the
* latter doesn't.
*/
unsigned connectivity_checked:1;
};
/*
* sought represents remote references that should be updated from.
* On return, the names that were found on the remote will have been
* marked as such.
*/
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);
/*
* Execute the --negotiate-only mode of "git fetch", adding all known common
* commits to acked_commits.
*
* In the capability advertisement that has happened prior to invoking this
* function, the "wait-for-done" capability must be present.
*/
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);
/*
* Print an appropriate error message for each sought ref that wasn't
* matched. Return 0 if all sought refs were matched, otherwise 1.
*/
int report_unmatched_refs(struct ref **sought, int nr_sought);
#endif