transport-internal.hon commit t4008: abstract away SHA-1-specific constants (75fe818)
   1#ifndef TRANSPORT_INTERNAL_H
   2#define TRANSPORT_INTERNAL_H
   3
   4struct ref;
   5struct transport;
   6struct argv_array;
   7
   8struct transport_vtable {
   9        /**
  10         * Returns 0 if successful, positive if the option is not
  11         * recognized or is inapplicable, and negative if the option
  12         * is applicable but the value is invalid.
  13         **/
  14        int (*set_option)(struct transport *connection, const char *name,
  15                          const char *value);
  16        /**
  17         * Returns a list of the remote side's refs. In order to allow
  18         * the transport to try to share connections, for_push is a
  19         * hint as to whether the ultimate operation is a push or a fetch.
  20         *
  21         * If communicating using protocol v2 a list of prefixes can be
  22         * provided to be sent to the server to enable it to limit the ref
  23         * advertisement.  Since ref filtering is done on the server's end, and
  24         * only when using protocol v2, this list will be ignored when not
  25         * using protocol v2 meaning this function can return refs which don't
  26         * match the provided ref_prefixes.
  27         *
  28         * If the transport is able to determine the remote hash for
  29         * the ref without a huge amount of effort, it should store it
  30         * in the ref's old_sha1 field; otherwise it should be all 0.
  31         **/
  32        struct ref *(*get_refs_list)(struct transport *transport, int for_push,
  33                                     const struct argv_array *ref_prefixes);
  34
  35        /**
  36         * Fetch the objects for the given refs. Note that this gets
  37         * an array, and should ignore the list structure.
  38         *
  39         * If the transport did not get hashes for refs in
  40         * get_refs_list(), it should set the old_sha1 fields in the
  41         * provided refs now.
  42         **/
  43        int (*fetch)(struct transport *transport, int refs_nr, struct ref **refs);
  44
  45        /**
  46         * Push the objects and refs. Send the necessary objects, and
  47         * then, for any refs where peer_ref is set and
  48         * peer_ref->new_oid is different from old_oid, tell the
  49         * remote side to update each ref in the list from old_oid to
  50         * peer_ref->new_oid.
  51         *
  52         * Where possible, set the status for each ref appropriately.
  53         *
  54         * The transport must modify new_sha1 in the ref to the new
  55         * value if the remote accepted the change. Note that this
  56         * could be a different value from peer_ref->new_oid if the
  57         * process involved generating new commits.
  58         **/
  59        int (*push_refs)(struct transport *transport, struct ref *refs, int flags);
  60        int (*connect)(struct transport *connection, const char *name,
  61                       const char *executable, int fd[2]);
  62
  63        /** get_refs_list(), fetch(), and push_refs() can keep
  64         * resources (such as a connection) reserved for further
  65         * use. disconnect() releases these resources.
  66         **/
  67        int (*disconnect)(struct transport *connection);
  68};
  69
  70#endif