git/transport-internal.h
Jonathan Tan e967ca3847 transport: make transport vtable more private
Move the definition of the transport-specific functions provided by
transports, whether declared in transport.c or transport-helper.c, into
an internal header. This means that transport-using code (as opposed to
transport-declaring code) can no longer access these functions (without
importing the internal header themselves), making it clear that they
should use the transport_*() functions instead, and also allowing the
interface between the transport mechanism and an individual transport to
independently evolve.

This is superficially a reversal of commit 824d5776c3 ("Refactor
struct transport_ops inlined into struct transport", 2007-09-19).
However, the scope of the involved variables was neither affected nor
discussed in that commit, and I think that the advantages in making
those functions more private outweigh the advantages described in that
commit's commit message. A minor additional point is that the code has
gotten more complicated since then, in that the function-pointer
variables are potentially mutated twice (once initially and once if
transport_take_over() is invoked), increasing the value of corralling
them into their own struct.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-12-14 14:28:04 -08:00

62 lines
2.1 KiB
C

#ifndef TRANSPORT_INTERNAL_H
#define TRANSPORT_INTERNAL_H
struct ref;
struct transport;
struct transport_vtable {
/**
* 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 (*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);
};
#endif