packfile: replace lseek+read with pread
[git.git] / transport-internal.h
blob004bee5e368f24963d925af997aec051189e1acf
1 #ifndef TRANSPORT_INTERNAL_H
2 #define TRANSPORT_INTERNAL_H
4 struct ref;
5 struct transport;
6 struct argv_array;
8 struct transport_vtable {
9 /**
10 * This transport supports the fetch() function being called
11 * without get_refs_list() first being called.
13 unsigned fetch_without_list : 1;
15 /**
16 * Returns 0 if successful, positive if the option is not
17 * recognized or is inapplicable, and negative if the option
18 * is applicable but the value is invalid.
19 **/
20 int (*set_option)(struct transport *connection, const char *name,
21 const char *value);
22 /**
23 * Returns a list of the remote side's refs. In order to allow
24 * the transport to try to share connections, for_push is a
25 * hint as to whether the ultimate operation is a push or a fetch.
27 * If communicating using protocol v2 a list of prefixes can be
28 * provided to be sent to the server to enable it to limit the ref
29 * advertisement. Since ref filtering is done on the server's end, and
30 * only when using protocol v2, this list will be ignored when not
31 * using protocol v2 meaning this function can return refs which don't
32 * match the provided ref_prefixes.
34 * If the transport is able to determine the remote hash for
35 * the ref without a huge amount of effort, it should store it
36 * in the ref's old_sha1 field; otherwise it should be all 0.
37 **/
38 struct ref *(*get_refs_list)(struct transport *transport, int for_push,
39 const struct argv_array *ref_prefixes);
41 /**
42 * Fetch the objects for the given refs. Note that this gets
43 * an array, and should ignore the list structure.
45 * If the transport did not get hashes for refs in
46 * get_refs_list(), it should set the old_sha1 fields in the
47 * provided refs now.
48 **/
49 int (*fetch)(struct transport *transport, int refs_nr, struct ref **refs);
51 /**
52 * Push the objects and refs. Send the necessary objects, and
53 * then, for any refs where peer_ref is set and
54 * peer_ref->new_oid is different from old_oid, tell the
55 * remote side to update each ref in the list from old_oid to
56 * peer_ref->new_oid.
58 * Where possible, set the status for each ref appropriately.
60 * The transport must modify new_sha1 in the ref to the new
61 * value if the remote accepted the change. Note that this
62 * could be a different value from peer_ref->new_oid if the
63 * process involved generating new commits.
64 **/
65 int (*push_refs)(struct transport *transport, struct ref *refs, int flags);
66 int (*connect)(struct transport *connection, const char *name,
67 const char *executable, int fd[2]);
69 /** get_refs_list(), fetch(), and push_refs() can keep
70 * resources (such as a connection) reserved for further
71 * use. disconnect() releases these resources.
72 **/
73 int (*disconnect)(struct transport *connection);
76 #endif