git/transport.h
Jonathan Tan 88e2f9ed8e introduce fetch-object: fetch one promisor object
Introduce fetch-object, providing the ability to fetch one object from a
promisor remote.

This uses fetch-pack. To do this, the transport mechanism has been
updated with 2 flags, "from-promisor" to indicate that the resulting
pack comes from a promisor remote (and thus should be annotated as such
by index-pack), and "no-dependents" to indicate that only the objects
themselves need to be fetched (but fetching additional objects is
nevertheless safe).

Whenever "no-dependents" is used, fetch-pack will refrain from using any
object flags, because it is most likely invoked as part of a dynamic
object fetch by another Git command (which may itself use object flags).
An alternative to this is to leave fetch-pack alone, and instead update
the allocation of flags so that fetch-pack's flags never overlap with
any others, but this will end up shrinking the number of flags available
to nearly every other Git command (that is, every Git command that
accesses objects), so the approach in this commit was used instead.

This will be tested in a subsequent commit.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-12-05 09:46:05 -08:00

272 lines
8.7 KiB
C

#ifndef TRANSPORT_H
#define TRANSPORT_H
#include "cache.h"
#include "run-command.h"
#include "remote.h"
struct string_list;
struct git_transport_options {
unsigned thin : 1;
unsigned keep : 1;
unsigned followtags : 1;
unsigned check_self_contained_and_connected : 1;
unsigned self_contained_and_connected : 1;
unsigned update_shallow : 1;
unsigned deepen_relative : 1;
unsigned from_promisor : 1;
unsigned no_dependents : 1;
int depth;
const char *deepen_since;
const struct string_list *deepen_not;
const char *uploadpack;
const char *receivepack;
struct push_cas_option *cas;
};
enum transport_family {
TRANSPORT_FAMILY_ALL = 0,
TRANSPORT_FAMILY_IPV4,
TRANSPORT_FAMILY_IPV6
};
struct transport {
struct remote *remote;
const char *url;
void *data;
const struct ref *remote_refs;
/**
* Indicates whether we already called get_refs_list(); set by
* transport.c::transport_get_remote_refs().
*/
unsigned got_remote_refs : 1;
/*
* Transports that call take-over destroys the data specific to
* the transport type while doing so, and cannot be reused.
*/
unsigned cannot_reuse : 1;
/*
* A hint from caller that it will be performing a clone, not
* normal fetch. IOW the repository is guaranteed empty.
*/
unsigned cloning : 1;
/*
* These strings will be passed to the {pre, post}-receive hook,
* on the remote side, if both sides support the push options capability.
*/
const struct string_list *push_options;
/**
* Returns 0 if successful, positive if the option is not
* recognized or is inapplicable, and negative if the option
* is applicable but the value is invalid.
**/
int (*set_option)(struct transport *connection, const char *name,
const char *value);
/**
* Returns a list of the remote side's refs. In order to allow
* the transport to try to share connections, for_push is a
* hint as to whether the ultimate operation is a push or a fetch.
*
* If the transport is able to determine the remote hash for
* the ref without a huge amount of effort, it should store it
* in the ref's old_sha1 field; otherwise it should be all 0.
**/
struct ref *(*get_refs_list)(struct transport *transport, int for_push);
/**
* Fetch the objects for the given refs. Note that this gets
* an array, and should ignore the list structure.
*
* If the transport did not get hashes for refs in
* get_refs_list(), it should set the old_sha1 fields in the
* provided refs now.
**/
int (*fetch)(struct transport *transport, int refs_nr, struct ref **refs);
/**
* Push the objects and refs. Send the necessary objects, and
* then, for any refs where peer_ref is set and
* peer_ref->new_oid is different from old_oid, tell the
* remote side to update each ref in the list from old_oid to
* peer_ref->new_oid.
*
* Where possible, set the status for each ref appropriately.
*
* The transport must modify new_sha1 in the ref to the new
* value if the remote accepted the change. Note that this
* could be a different value from peer_ref->new_oid if the
* process involved generating new commits.
**/
int (*push_refs)(struct transport *transport, struct ref *refs, int flags);
int (*push)(struct transport *connection, int refspec_nr, const char **refspec, int flags);
int (*connect)(struct transport *connection, const char *name,
const char *executable, int fd[2]);
/** get_refs_list(), fetch(), and push_refs() can keep
* resources (such as a connection) reserved for further
* use. disconnect() releases these resources.
**/
int (*disconnect)(struct transport *connection);
char *pack_lockfile;
signed verbose : 3;
/**
* Transports should not set this directly, and should use this
* value without having to check isatty(2), -q/--quiet
* (transport->verbose < 0), etc. - checking has already been done
* in transport_set_verbosity().
**/
unsigned progress : 1;
/*
* If transport is at least potentially smart, this points to
* git_transport_options structure to use in case transport
* actually turns out to be smart.
*/
struct git_transport_options *smart_options;
enum transport_family family;
};
#define TRANSPORT_PUSH_ALL (1<<0)
#define TRANSPORT_PUSH_FORCE (1<<1)
#define TRANSPORT_PUSH_DRY_RUN (1<<2)
#define TRANSPORT_PUSH_MIRROR (1<<3)
#define TRANSPORT_PUSH_PORCELAIN (1<<4)
#define TRANSPORT_PUSH_SET_UPSTREAM (1<<5)
#define TRANSPORT_RECURSE_SUBMODULES_CHECK (1<<6)
#define TRANSPORT_PUSH_PRUNE (1<<7)
#define TRANSPORT_RECURSE_SUBMODULES_ON_DEMAND (1<<8)
#define TRANSPORT_PUSH_NO_HOOK (1<<9)
#define TRANSPORT_PUSH_FOLLOW_TAGS (1<<10)
#define TRANSPORT_PUSH_CERT_ALWAYS (1<<11)
#define TRANSPORT_PUSH_CERT_IF_ASKED (1<<12)
#define TRANSPORT_PUSH_ATOMIC (1<<13)
#define TRANSPORT_PUSH_OPTIONS (1<<14)
#define TRANSPORT_RECURSE_SUBMODULES_ONLY (1<<15)
extern int transport_summary_width(const struct ref *refs);
/* Returns a transport suitable for the url */
struct transport *transport_get(struct remote *, const char *);
/*
* Check whether a transport is allowed by the environment.
*
* Type should generally be the URL scheme, as described in
* Documentation/git.txt
*
* from_user specifies if the transport was given by the user. If unknown pass
* a -1 to read from the environment to determine if the transport was given by
* the user.
*
*/
int is_transport_allowed(const char *type, int from_user);
/*
* Check whether a transport is allowed by the environment,
* and die otherwise.
*/
void transport_check_allowed(const char *type);
/* Transport options which apply to git:// and scp-style URLs */
/* The program to use on the remote side to send a pack */
#define TRANS_OPT_UPLOADPACK "uploadpack"
/* The program to use on the remote side to receive a pack */
#define TRANS_OPT_RECEIVEPACK "receivepack"
/* Transfer the data as a thin pack if not null */
#define TRANS_OPT_THIN "thin"
/* Check the current value of the remote ref */
#define TRANS_OPT_CAS "cas"
/* Keep the pack that was transferred if not null */
#define TRANS_OPT_KEEP "keep"
/* Limit the depth of the fetch if not null */
#define TRANS_OPT_DEPTH "depth"
/* Limit the depth of the fetch based on time if not null */
#define TRANS_OPT_DEEPEN_SINCE "deepen-since"
/* Limit the depth of the fetch based on revs if not null */
#define TRANS_OPT_DEEPEN_NOT "deepen-not"
/* Limit the deepen of the fetch if not null */
#define TRANS_OPT_DEEPEN_RELATIVE "deepen-relative"
/* Aggressively fetch annotated tags if possible */
#define TRANS_OPT_FOLLOWTAGS "followtags"
/* Accept refs that may update .git/shallow without --depth */
#define TRANS_OPT_UPDATE_SHALLOW "updateshallow"
/* Send push certificates */
#define TRANS_OPT_PUSH_CERT "pushcert"
/* Indicate that these objects are being fetched by a promisor */
#define TRANS_OPT_FROM_PROMISOR "from-promisor"
/*
* Indicate that only the objects wanted need to be fetched, not their
* dependents
*/
#define TRANS_OPT_NO_DEPENDENTS "no-dependents"
/**
* Returns 0 if the option was used, non-zero otherwise. Prints a
* message to stderr if the option is not used.
**/
int transport_set_option(struct transport *transport, const char *name,
const char *value);
void transport_set_verbosity(struct transport *transport, int verbosity,
int force_progress);
#define REJECT_NON_FF_HEAD 0x01
#define REJECT_NON_FF_OTHER 0x02
#define REJECT_ALREADY_EXISTS 0x04
#define REJECT_FETCH_FIRST 0x08
#define REJECT_NEEDS_FORCE 0x10
int transport_push(struct transport *connection,
int refspec_nr, const char **refspec, int flags,
unsigned int * reject_reasons);
const struct ref *transport_get_remote_refs(struct transport *transport);
int transport_fetch_refs(struct transport *transport, struct ref *refs);
void transport_unlock_pack(struct transport *transport);
int transport_disconnect(struct transport *transport);
char *transport_anonymize_url(const char *url);
void transport_take_over(struct transport *transport,
struct child_process *child);
int transport_connect(struct transport *transport, const char *name,
const char *exec, int fd[2]);
/* Transport methods defined outside transport.c */
int transport_helper_init(struct transport *transport, const char *name);
int bidirectional_transfer_loop(int input, int output);
/* common methods used by transport.c and builtin/send-pack.c */
void transport_verify_remote_names(int nr_heads, const char **heads);
void transport_update_tracking_ref(struct remote *remote, struct ref *ref, int verbose);
int transport_refs_pushed(struct ref *ref);
void transport_print_push_status(const char *dest, struct ref *refs,
int verbose, int porcelain, unsigned int *reject_reasons);
typedef void alternate_ref_fn(const char *refname, const struct object_id *oid, void *);
extern void for_each_alternate_ref(alternate_ref_fn, void *);
#endif