/*
* 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_git_odb_backend_h__
#define INCLUDE_git_odb_backend_h__
#include "common.h"
#include "types.h"
#include "oid.h"
#include "indexer.h"
/**
* @file git2/backend.h
* @brief Git custom backend functions
* @defgroup git_backend Git custom backend API
* @ingroup Git
* @{
*/
GIT_BEGIN_DECL
struct git_odb_stream;
struct git_odb_writepack;
/**
* Function type for callbacks from git_odb_foreach.
*/
typedef int (*git_odb_foreach_cb)(const git_oid *id, void *payload);
/**
* 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 *,
struct 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 *,
struct git_odb_backend *,
const git_oid *,
size_t);
int (* read_header)(
size_t *, git_otype *,
struct git_odb_backend *,
const git_oid *);
/* The writer may assume that the object
* has already been hashed and is passed
* in the first parameter.
*/
int (* write)(
git_oid *,
struct git_odb_backend *,
const void *,
size_t,
git_otype);
int (* writestream)(
struct git_odb_stream **,
struct git_odb_backend *,
size_t,
git_otype);
int (* readstream)(
struct git_odb_stream **,
struct git_odb_backend *,
const git_oid *);
int (* exists)(
struct git_odb_backend *,
const git_oid *);
int (* foreach)(
struct git_odb_backend *,
git_odb_foreach_cb cb,
void *payload);
int (* writepack)(
struct git_odb_writepack **,
struct git_odb_backend *,
git_transfer_progress_callback progress_cb,
void *progress_payload);
void (* free)(struct git_odb_backend *);
};
#define GIT_ODB_BACKEND_VERSION 1
#define GIT_ODB_BACKEND_INIT {GIT_ODB_BACKEND_VERSION}
/** Streaming mode */
enum {
GIT_STREAM_RDONLY = (1 << 1),
GIT_STREAM_WRONLY = (1 << 2),
GIT_STREAM_RW = (GIT_STREAM_RDONLY | GIT_STREAM_WRONLY),
};
/** A stream to read/write from a backend */
struct git_odb_stream {
struct git_odb_backend *backend;
unsigned int mode;
int (*read)(struct git_odb_stream *stream, char *buffer, size_t len);
int (*write)(struct git_odb_stream *stream, const char *buffer, size_t len);
int (*finalize_write)(git_oid *oid_p, struct git_odb_stream *stream);
void (*free)(struct git_odb_stream *stream);
};
/** A stream to write a pack file to the ODB */
struct git_odb_writepack {
struct git_odb_backend *backend;
int (*add)(struct git_odb_writepack *writepack, const void *data, size_t size, git_transfer_progress *stats);
int (*commit)(struct git_odb_writepack *writepack, git_transfer_progress *stats);
void (*free)(struct git_odb_writepack *writepack);
};
GIT_EXTERN(void *) git_odb_backend_malloc(git_odb_backend *backend, size_t len);
/**
* Constructors for in-box ODB backends.
*/
GIT_EXTERN(int) git_odb_backend_pack(git_odb_backend **out, const char *objects_dir);
GIT_EXTERN(int) git_odb_backend_loose(git_odb_backend **out, const char *objects_dir, int compression_level, int do_fsync);
GIT_EXTERN(int) git_odb_backend_one_pack(git_odb_backend **out, const char *index_file);
GIT_END_DECL
#endif
