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Diffstat (limited to 'include/git2/sys/mempack.h')
-rw-r--r-- | include/git2/sys/mempack.h | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/include/git2/sys/mempack.h b/include/git2/sys/mempack.h new file mode 100644 index 000000000..d3bc87b4d --- /dev/null +++ b/include/git2/sys/mempack.h @@ -0,0 +1,85 @@ +/* + * Copyright (C) the libgit2 contributors. All rights reserved. + * + * This file is part of libgit2, distributed under the GNU GPL v2 with + * a Linking Exception. For full terms see the included COPYING file. + */ +#ifndef INCLUDE_sys_git_odb_mempack_h__ +#define INCLUDE_sys_git_odb_mempack_h__ + +#include "git2/common.h" +#include "git2/types.h" +#include "git2/oid.h" +#include "git2/odb.h" + +/** + * @file git2/sys/mempack.h + * @brief Custom ODB backend that permits packing objects in-memory + * @defgroup git_backend Git custom backend APIs + * @ingroup Git + * @{ + */ +GIT_BEGIN_DECL + +/** + * Instantiate a new mempack backend. + * + * The backend must be added to an existing ODB with the highest + * priority. + * + * git_mempack_new(&mempacker); + * git_repository_odb(&odb, repository); + * git_odb_add_backend(odb, mempacker, 999); + * + * Once the backend has been loaded, all writes to the ODB will + * instead be queued in memory, and can be finalized with + * `git_mempack_dump`. + * + * Subsequent reads will also be served from the in-memory store + * to ensure consistency, until the memory store is dumped. + * + * @param out Poiter where to store the ODB backend + * @return 0 on success; error code otherwise + */ +int git_mempack_new(git_odb_backend **out); + +/** + * Dump all the queued in-memory writes to a packfile. + * + * The contents of the packfile will be stored in the given buffer. + * It is the caller's responsability to ensure that the generated + * packfile is available to the repository (e.g. by writing it + * to disk, or doing something crazy like distributing it across + * several copies of the repository over a network). + * + * Once the generated packfile is available to the repository, + * call `git_mempack_reset` to cleanup the memory store. + * + * Calling `git_mempack_reset` before the packfile has been + * written to disk will result in an inconsistent repository + * (the objects in the memory store won't be accessible). + * + * @param pack Buffer where to store the raw packfile + * @param repo The active repository where the backend is loaded + * @param backend The mempack backend + * @return 0 on success; error code otherwise + */ +int git_mempack_dump(git_buf *pack, git_repository *repo, git_odb_backend *backend); + +/** + * Reset the memory packer by clearing all the queued objects. + * + * This assumes that `git_mempack_dump` has been called before to + * store all the queued objects into a single packfile. + * + * Alternatively, call `reset` without a previous dump to "undo" + * all the recently written objects, giving transaction-like + * semantics to the Git repository. + * + * @param backend The mempack backend + */ +void git_mempack_reset(git_odb_backend *backend); + +GIT_END_DECL + +#endif |