libgit2/include/git2/sys/odb_backend.h
Carlos Martín Nieto 7a3764bee9 odb: document git_odb_stream
Clarify the role of each function and in particular mention that there
is no need for the backend or stream to worry about the object's id,
as it will be given when `finalize_write` is called.
2013-08-17 02:02:28 +02:00

87 lines
2.2 KiB
C

/*
* 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_backend_h__
#define INCLUDE_sys_git_odb_backend_h__
#include "git2/common.h"
#include "git2/types.h"
#include "git2/oid.h"
#include "git2/odb.h"
/**
* @file git2/sys/backend.h
* @brief Git custom backend implementors functions
* @defgroup git_backend Git custom backend APIs
* @ingroup Git
* @{
*/
GIT_BEGIN_DECL
/**
* An instance for a custom backend
*/
struct git_odb_backend {
unsigned int version;
git_odb *odb;
/* read and read_prefix each return to libgit2 a buffer which
* will be freed later. The buffer should be allocated using
* the function git_odb_backend_malloc to ensure that it can
* be safely freed later. */
int (* read)(
void **, size_t *, git_otype *, git_odb_backend *, const git_oid *);
/* To find a unique object given a prefix
* of its oid.
* The oid given must be so that the
* remaining (GIT_OID_HEXSZ - len)*4 bits
* are 0s.
*/
int (* read_prefix)(
git_oid *, void **, size_t *, git_otype *,
git_odb_backend *, const git_oid *, size_t);
int (* read_header)(
size_t *, git_otype *, git_odb_backend *, const git_oid *);
/**
* Write an object into the backend. The id of the object has
* already been calculated and is passed in.
*/
int (* write)(
git_odb_backend *, const git_oid *, const void *, size_t, git_otype);
int (* writestream)(
git_odb_stream **, git_odb_backend *, size_t, git_otype);
int (* readstream)(
git_odb_stream **, git_odb_backend *, const git_oid *);
int (* exists)(
git_odb_backend *, const git_oid *);
int (* refresh)(git_odb_backend *);
int (* foreach)(
git_odb_backend *, git_odb_foreach_cb cb, void *payload);
int (* writepack)(
git_odb_writepack **, git_odb_backend *,
git_transfer_progress_callback progress_cb, void *progress_payload);
void (* free)(git_odb_backend *);
};
#define GIT_ODB_BACKEND_VERSION 1
#define GIT_ODB_BACKEND_INIT {GIT_ODB_BACKEND_VERSION}
GIT_EXTERN(void *) git_odb_backend_malloc(git_odb_backend *backend, size_t len);
GIT_END_DECL
#endif