6 files changed, 462 insertions, 0 deletions

diff --git a/include/git2/sys/commit.h b/include/git2/sys/commit.h
new file mode 100644
index 000000000..096e028c5
--- /dev/null
+++ b/include/git2/sys/commit.h
@@ -0,0 +1,45 @@
+/*
+ * 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_commit_h__
+#define INCLUDE_sys_git_commit_h__
+
+#include "git2/common.h"
+#include "git2/types.h"
+#include "git2/oid.h"
+
+/**
+ * @file git2/sys/commit.h
+ * @brief Low-level Git commit creation
+ * @defgroup git_backend Git custom backend APIs
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Create new commit in the repository from a list of `git_oid` values
+ *
+ * See documentation for `git_commit_create()` for information about the
+ * parameters, as the meaning is identical excepting that `tree` and
+ * `parents` now take `git_oid`.  This is a dangerous API in that the
+ * `parents` list of `git_oid`s in not checked for validity.
+ */
+GIT_EXTERN(int) git_commit_create_from_oids(
+	git_oid *oid,
+	git_repository *repo,
+	const char *update_ref,
+	const git_signature *author,
+	const git_signature *committer,
+	const char *message_encoding,
+	const char *message,
+	const git_oid *tree,
+	int parent_count,
+	const git_oid *parents[]);
+
+/** @} */
+GIT_END_DECL
+#endif
diff --git a/include/git2/sys/config.h b/include/git2/sys/config.h
new file mode 100644
index 000000000..1c9deba7c
--- /dev/null
+++ b/include/git2/sys/config.h
@@ -0,0 +1,71 @@
+/*
+ * 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_config_backend_h__
+#define INCLUDE_sys_git_config_backend_h__
+
+#include "git2/common.h"
+#include "git2/types.h"
+#include "git2/config.h"
+
+/**
+ * @file git2/sys/config.h
+ * @brief Git config backend routines
+ * @defgroup git_backend Git custom backend APIs
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Generic backend that implements the interface to
+ * access a configuration file
+ */
+struct git_config_backend {
+	unsigned int version;
+	struct git_config *cfg;
+
+	/* Open means open the file/database and parse if necessary */
+	int (*open)(struct git_config_backend *, unsigned int level);
+	int (*get)(const struct git_config_backend *, const char *key, const git_config_entry **entry);
+	int (*get_multivar)(struct git_config_backend *, const char *key, const char *regexp, git_config_foreach_cb callback, void *payload);
+	int (*set)(struct git_config_backend *, const char *key, const char *value);
+	int (*set_multivar)(git_config_backend *cfg, const char *name, const char *regexp, const char *value);
+	int (*del)(struct git_config_backend *, const char *key);
+	int (*foreach)(struct git_config_backend *, const char *, git_config_foreach_cb callback, void *payload);
+	int (*refresh)(struct git_config_backend *);
+	void (*free)(struct git_config_backend *);
+};
+#define GIT_CONFIG_BACKEND_VERSION 1
+#define GIT_CONFIG_BACKEND_INIT {GIT_CONFIG_BACKEND_VERSION}
+
+/**
+ * Add a generic config file instance to an existing config
+ *
+ * Note that the configuration object will free the file
+ * automatically.
+ *
+ * Further queries on this config object will access each
+ * of the config file instances in order (instances with
+ * a higher priority level will be accessed first).
+ *
+ * @param cfg the configuration to add the file to
+ * @param file the configuration file (backend) to add
+ * @param level the priority level of the backend
+ * @param force if a config file already exists for the given
+ *  priority level, replace it
+ * @return 0 on success, GIT_EEXISTS when adding more than one file
+ *  for a given priority level (and force_replace set to 0), or error code
+ */
+GIT_EXTERN(int) git_config_add_backend(
+	git_config *cfg,
+	git_config_backend *file,
+	unsigned int level,
+	int force);
+
+/** @} */
+GIT_END_DECL
+#endif
diff --git a/include/git2/sys/odb_backend.h b/include/git2/sys/odb_backend.h
new file mode 100644
index 000000000..3cd2734c0
--- /dev/null
+++ b/include/git2/sys/odb_backend.h
@@ -0,0 +1,86 @@
+/*
+ * 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 *);
+
+	/* The writer may assume that the object
+	 * has already been hashed and is passed
+	 * in the first parameter.
+	 */
+	int (* write)(
+		git_oid *, git_odb_backend *, 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
diff --git a/include/git2/sys/refdb_backend.h b/include/git2/sys/refdb_backend.h
new file mode 100644
index 000000000..d5f599fec
--- /dev/null
+++ b/include/git2/sys/refdb_backend.h
@@ -0,0 +1,130 @@
+/*
+ * 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_refdb_backend_h__
+#define INCLUDE_sys_git_refdb_backend_h__
+
+#include "git2/common.h"
+#include "git2/types.h"
+#include "git2/oid.h"
+
+/**
+ * @file git2/refdb_backend.h
+ * @brief Git custom refs backend functions
+ * @defgroup git_refdb_backend Git custom refs backend API
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/** An instance for a custom backend */
+struct git_refdb_backend {
+    unsigned int version;
+
+	/**
+	 * Queries the refdb backend to determine if the given ref_name
+	 * exists.  A refdb implementation must provide this function.
+	 */
+	int (*exists)(
+		int *exists,
+		git_refdb_backend *backend,
+		const char *ref_name);
+
+	/**
+	 * Queries the refdb backend for a given reference.  A refdb
+	 * implementation must provide this function.
+	 */
+	int (*lookup)(
+		git_reference **out,
+		git_refdb_backend *backend,
+		const char *ref_name);
+
+	/**
+	 * Enumerates each reference in the refdb.  A refdb implementation must
+	 * provide this function.
+	 */
+	int (*foreach)(
+		git_refdb_backend *backend,
+		unsigned int list_flags,
+		git_reference_foreach_cb callback,
+		void *payload);
+
+	/**
+	 * Enumerates each reference in the refdb that matches the given
+	 * glob string.  A refdb implementation may provide this function;
+	 * if it is not provided, foreach will be used and the results filtered
+	 * against the glob.
+	 */
+	int (*foreach_glob)(
+		git_refdb_backend *backend,
+		const char *glob,
+		unsigned int list_flags,
+		git_reference_foreach_cb callback,
+		void *payload);
+
+	/**
+	 * Writes the given reference to the refdb.  A refdb implementation
+	 * must provide this function.
+	 */
+	int (*write)(git_refdb_backend *backend, const git_reference *ref);
+
+	/**
+	 * Deletes the given reference from the refdb.  A refdb implementation
+	 * must provide this function.
+	 */
+	int (*delete)(git_refdb_backend *backend, const git_reference *ref);
+
+	/**
+	 * Suggests that the given refdb compress or optimize its references.
+	 * This mechanism is implementation specific.  (For on-disk reference
+	 * databases, this may pack all loose references.)    A refdb
+	 * implementation may provide this function; if it is not provided,
+	 * nothing will be done.
+	 */
+	int (*compress)(git_refdb_backend *backend);
+
+	/**
+	 * Frees any resources held by the refdb.  A refdb implementation may
+	 * provide this function; if it is not provided, nothing will be done.
+	 */
+	void (*free)(git_refdb_backend *backend);
+};
+
+#define GIT_ODB_BACKEND_VERSION 1
+#define GIT_ODB_BACKEND_INIT {GIT_ODB_BACKEND_VERSION}
+
+/**
+ * Constructors for default filesystem-based refdb backend
+ *
+ * Under normal usage, this is called for you when the repository is
+ * opened / created, but you can use this to explicitly construct a
+ * filesystem refdb backend for a repository.
+ *
+ * @param backend_out Output pointer to the git_refdb_backend object
+ * @param repo Git repository to access
+ * @return 0 on success, <0 error code on failure
+ */
+GIT_EXTERN(int) git_refdb_backend_fs(
+	git_refdb_backend **backend_out,
+	git_repository *repo);
+
+/**
+ * Sets the custom backend to an existing reference DB
+ *
+ * The `git_refdb` will take ownership of the `git_refdb_backend` so you
+ * should NOT free it after calling this function.
+ *
+ * @param refdb database to add the backend to
+ * @param backend pointer to a git_refdb_backend instance
+ * @return 0 on success; error code otherwise
+ */
+GIT_EXTERN(int) git_refdb_set_backend(
+	git_refdb *refdb,
+	git_refdb_backend *backend);
+
+GIT_END_DECL
+
+#endif
diff --git a/include/git2/sys/refs.h b/include/git2/sys/refs.h
new file mode 100644
index 000000000..85963258c
--- /dev/null
+++ b/include/git2/sys/refs.h
@@ -0,0 +1,38 @@
+/*
+ * 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_refdb_h__
+#define INCLUDE_sys_git_refdb_h__
+
+#include "git2/common.h"
+#include "git2/types.h"
+#include "git2/oid.h"
+
+/**
+ * Create a new direct reference from an OID.
+ *
+ * @param name the reference name
+ * @param oid the object id for a direct reference
+ * @param symbolic the target for a symbolic reference
+ * @return the created git_reference or NULL on error
+ */
+GIT_EXTERN(git_reference *) git_reference__alloc(
+	const char *name,
+	const git_oid *oid,
+	const git_oid *peel);
+
+/**
+ * Create a new symbolic reference.
+ *
+ * @param name the reference name
+ * @param symbolic the target for a symbolic reference
+ * @return the created git_reference or NULL on error
+ */
+GIT_EXTERN(git_reference *) git_reference__alloc_symbolic(
+	const char *name,
+	const char *target);
+
+#endif
diff --git a/include/git2/sys/repository.h b/include/git2/sys/repository.h
new file mode 100644
index 000000000..34bc17516
--- /dev/null
+++ b/include/git2/sys/repository.h
@@ -0,0 +1,92 @@
+/*
+ * 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_repository_h__
+#define INCLUDE_sys_git_repository_h__
+
+/**
+ * @file git2/sys/repository.h
+ * @brief Git repository custom implementation routines
+ * @defgroup git_backend Git custom backend APIs
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+/**
+ * Create a new repository with neither backends nor config object
+ *
+ * Note that this is only useful if you wish to associate the repository
+ * with a non-filesystem-backed object database and config store.
+ *
+ * @param out The blank repository
+ * @return 0 on success, or an error code
+ */
+GIT_EXTERN(int) git_repository_new(git_repository **out);
+
+/**
+ * Set the configuration file for this repository
+ *
+ * This configuration file will be used for all configuration
+ * queries involving this repository.
+ *
+ * The repository will keep a reference to the config file;
+ * the user must still free the config after setting it
+ * to the repository, or it will leak.
+ *
+ * @param repo A repository object
+ * @param config A Config object
+ */
+GIT_EXTERN(void) git_repository_set_config(git_repository *repo, git_config *config);
+
+/**
+ * Set the Object Database for this repository
+ *
+ * The ODB will be used for all object-related operations
+ * involving this repository.
+ *
+ * The repository will keep a reference to the ODB; the user
+ * must still free the ODB object after setting it to the
+ * repository, or it will leak.
+ *
+ * @param repo A repository object
+ * @param odb An ODB object
+ */
+GIT_EXTERN(void) git_repository_set_odb(git_repository *repo, git_odb *odb);
+
+/**
+ * Set the Reference Database Backend for this repository
+ *
+ * The refdb will be used for all reference related operations
+ * involving this repository.
+ *
+ * The repository will keep a reference to the refdb; the user
+ * must still free the refdb object after setting it to the
+ * repository, or it will leak.
+ *
+ * @param repo A repository object
+ * @param refdb An refdb object
+ */
+GIT_EXTERN(void) git_repository_set_refdb(git_repository *repo, git_refdb *refdb);
+
+/**
+ * Set the index file for this repository
+ *
+ * This index will be used for all index-related operations
+ * involving this repository.
+ *
+ * The repository will keep a reference to the index file;
+ * the user must still free the index after setting it
+ * to the repository, or it will leak.
+ *
+ * @param repo A repository object
+ * @param index An index object
+ */
+GIT_EXTERN(void) git_repository_set_index(git_repository *repo, git_index *index);
+
+/** @} */
+GIT_END_DECL
+#endif