libgit2.sys.mempack source code

1 /*
2  * Copyright (C) the libgit2 contributors. All rights reserved.
3  *
4  * This file is part of libgit2, distributed under the GNU GPL v2 with
5  * a Linking Exception. For full terms see the included COPYING file.
6  */
7 /**
8  * License: GPL-2.0(Linking Exception)
9  */
10 module libgit2.sys.mempack;
11 
12 
13 private static import libgit2.buffer;
14 private static import libgit2.types;
15 private import libgit2.common: GIT_EXTERN;
16 
17 /*
18  * @file git2/sys/mempack.h
19  * @brief Custom ODB backend that permits packing objects in-memory
20  * @defgroup git_backend Git custom backend APIs
21  * @ingroup Git
22  * @{
23  */
24 extern (C):
25 nothrow @nogc:
26 
27 /**
28  * Instantiate a new mempack backend.
29  *
30  * The backend must be added to an existing ODB with the highest
31  * priority.
32  *
33  *     git_mempack_new(&mempacker);
34  *     git_repository_odb(&odb, repository);
35  *     git_odb_add_backend(odb, mempacker, 999);
36  *
37  * Once the backend has been loaded, all writes to the ODB will
38  * instead be queued in memory, and can be finalized with
39  * `git_mempack_dump`.
40  *
41  * Subsequent reads will also be served from the in-memory store
42  * to ensure consistency, until the memory store is dumped.
43  *
44  * Params:
45  *      out_ = Pointer where to store the ODB backend
46  *
47  * Returns: 0 on success; error code otherwise
48  */
49 @GIT_EXTERN
50 int git_mempack_new(libgit2.types.git_odb_backend** out_);
51 
52 /**
53  * Dump all the queued in-memory writes to a packfile.
54  *
55  * The contents of the packfile will be stored in the given buffer.
56  * It is the caller's responsibility to ensure that the generated
57  * packfile is available to the repository (e.g. by writing it
58  * to disk, or doing something crazy like distributing it across
59  * several copies of the repository over a network).
60  *
61  * Once the generated packfile is available to the repository,
62  * call `git_mempack_reset` to cleanup the memory store.
63  *
64  * Calling `git_mempack_reset` before the packfile has been
65  * written to disk will result in an inconsistent repository
66  * (the objects in the memory store won't be accessible).
67  *
68  * Params:
69  *      pack = Buffer where to store the raw packfile
70  *      repo = The active repository where the backend is loaded
71  *      backend = The mempack backend
72  *
73  * Returns: 0 on success; error code otherwise
74  */
75 @GIT_EXTERN
76 int git_mempack_dump(libgit2.buffer.git_buf* pack, libgit2.types.git_repository* repo, libgit2.types.git_odb_backend* backend);
77 
78 /**
79  * Reset the memory packer by clearing all the queued objects.
80  *
81  * This assumes that `git_mempack_dump` has been called before to
82  * store all the queued objects into a single packfile.
83  *
84  * Alternatively, call `reset` without a previous dump to "undo"
85  * all the recently written objects, giving transaction-like
86  * semantics to the Git repository.
87  *
88  * Params:
89  *      backend = The mempack backend
90  *
91  * Returns: 0 on success; error code otherwise
92  */
93 @GIT_EXTERN
94 int git_mempack_reset(libgit2.types.git_odb_backend* backend);