[libgit2.git] / include / git2 / repository.h

/*
 * Copyright (C) 2009-2012 the libgit2 contributors
 *
 * 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_repository_h__
#define INCLUDE_git_repository_h__

#include "common.h"
#include "types.h"
#include "oid.h"

/**
 * @file git2/repository.h
 * @brief Git repository management routines
 * @defgroup git_repository Git repository management routines
 * @ingroup Git
 * @{
 */
GIT_BEGIN_DECL

/**
 * Open a git repository.
 *
 * The 'path' argument must point to either a git repository
 * folder, or an existing work dir.
 *
 * The method will automatically detect if 'path' is a normal
 * or bare repository or fail is 'path' is neither.
 *
 * @param repository pointer to the repo which will be opened
 * @param path the path to the repository
 * @return 0 or an error code
 */
GIT_EXTERN(int) git_repository_open(git_repository **repository, const char *path);

/**
 * Create a "fake" repository to wrap an object database
 *
 * Create a repository object to wrap an object database to be used
 * with the API when all you have is an object database. This doesn't
 * have any paths associated with it, so use with care.
 *
 * @param repository pointer to the repo
 * @param odb the object database to wrap
 * @return 0 or an error code
 */
GIT_EXTERN(int) git_repository_wrap_odb(git_repository **repository, git_odb *odb);

/**
 * Look for a git repository and copy its path in the given buffer.
 * The lookup start from base_path and walk across parent directories
 * if nothing has been found. The lookup ends when the first repository
 * is found, or when reaching a directory referenced in ceiling_dirs
 * or when the filesystem changes (in case across_fs is true).
 *
 * The method will automatically detect if the repository is bare
 * (if there is a repository).
 *
 * @param repository_path The user allocated buffer which will
 * contain the found path.
 *
 * @param size repository_path size
 *
 * @param start_path The base path where the lookup starts.
 *
 * @param across_fs If true, then the lookup will not stop when a
 * filesystem device change is detected while exploring parent directories.
 *
 * @param ceiling_dirs A GIT_PATH_LIST_SEPARATOR separated list of
 * absolute symbolic link free paths. The lookup will stop when any
 * of this paths is reached. Note that the lookup always performs on
 * start_path no matter start_path appears in ceiling_dirs ceiling_dirs
 * might be NULL (which is equivalent to an empty string)
 *
 * @return 0 or an error code
 */
GIT_EXTERN(int) git_repository_discover(
                char *repository_path,
                size_t size,
                const char *start_path,
                int across_fs,
                const char *ceiling_dirs);

/**
 * Option flags for `git_repository_open_ext`.
 *
 * * GIT_REPOSITORY_OPEN_NO_SEARCH - Only open the repository if it can be
 *   immediately found in the start_path.  Do not walk up from the
 *   start_path looking at parent directories.
 * * GIT_REPOSITORY_OPEN_CROSS_FS - Unless this flag is set, open will not
 *   continue searching across filesystem boundaries (i.e. when `st_dev`
 *   changes from the `stat` system call).  (E.g. Searching in a user's home
 *   directory "/home/user/source/" will not return "/.git/" as the found
 *   repo if "/" is a different filesystem than "/home".)
 */
enum {
        GIT_REPOSITORY_OPEN_NO_SEARCH = (1 << 0),
        GIT_REPOSITORY_OPEN_CROSS_FS  = (1 << 1),
};

/**
 * Find and open a repository with extended controls.
 *
 * @param repo_out Pointer to the repo which will be opened.  This can
 *        actually be NULL if you only want to use the error code to
 *        see if a repo at this path could be opened.
 * @param start_path Path to open as git repository.  If the flags
 *        permit "searching", then this can be a path to a subdirectory
 *        inside the working directory of the repository.
 * @param flags A combination of the GIT_REPOSITORY_OPEN flags above.
 * @param ceiling_dirs A GIT_PATH_LIST_SEPARATOR delimited list of path
 *        prefixes at which the search for a containing repository should
 *        terminate.
 * @return 0 on success, GIT_ENOTFOUND if no repository could be found,
 *        or -1 if there was a repository but open failed for some reason
 *        (such as repo corruption or system errors).
 */
GIT_EXTERN(int) git_repository_open_ext(
        git_repository **repo,
        const char *start_path,
        uint32_t flags,
        const char *ceiling_dirs);

/**
 * Free a previously allocated repository
 *
 * Note that after a repository is free'd, all the objects it has spawned
 * will still exist until they are manually closed by the user
 * with `git_object_free`, but accessing any of the attributes of
 * an object without a backing repository will result in undefined
 * behavior
 *
 * @param repo repository handle to close. If NULL nothing occurs.
 */
GIT_EXTERN(void) git_repository_free(git_repository *repo);

/**
 * Creates a new Git repository in the given folder.
 *
 * TODO:
 *      - Reinit the repository
 *
 * @param repo_out pointer to the repo which will be created or reinitialized
 * @param path the path to the repository
 * @param is_bare if true, a Git repository without a working directory is
 *              created at the pointed path. If false, provided path will be
 *              considered as the working directory into which the .git directory
 *              will be created.
 *
 * @return 0 or an error code
 */
GIT_EXTERN(int) git_repository_init(
        git_repository **repo_out,
        const char *path,
        unsigned is_bare);

/**
 * Option flags for `git_repository_init_ext`.
 *
 * These flags configure extra behaviors to `git_repository_init_ext`.
 * In every case, the default behavior is the zero value (i.e. flag is
 * not set).  Just OR the flag values together for the `flags` parameter
 * when initializing a new repo.  Details of individual values are:
 *
 * * BARE   - Create a bare repository with no working directory.
 * * NO_REINIT - Return an EEXISTS error if the repo_path appears to
 *        already be an git repository.
 * * NO_DOTGIT_DIR - Normally a "/.git/" will be appended to the repo
 *        path for non-bare repos (if it is not already there), but
 *        passing this flag prevents that behavior.
 * * MKDIR  - Make the repo_path (and workdir_path) as needed.  Init is
 *        always willing to create the ".git" directory even without this
 *        flag.  This flag tells init to create the trailing component of
 *        the repo and workdir paths as needed.
 * * MKPATH - Recursively make all components of the repo and workdir
 *        paths as necessary.
 * * EXTERNAL_TEMPLATE - libgit2 normally uses internal templates to
 *        initialize a new repo.  This flags enables external templates,
 *        looking the "template_path" from the options if set, or the
 *        `init.templatedir` global config if not, or falling back on
 *        "/usr/share/git-core/templates" if it exists.
 */
enum {
        GIT_REPOSITORY_INIT_BARE              = (1u << 0),
        GIT_REPOSITORY_INIT_NO_REINIT         = (1u << 1),
        GIT_REPOSITORY_INIT_NO_DOTGIT_DIR     = (1u << 2),
        GIT_REPOSITORY_INIT_MKDIR             = (1u << 3),
        GIT_REPOSITORY_INIT_MKPATH            = (1u << 4),
        GIT_REPOSITORY_INIT_EXTERNAL_TEMPLATE = (1u << 5),
};

/**
 * Mode options for `git_repository_init_ext`.
 *
 * Set the mode field of the `git_repository_init_options` structure
 * either to the custom mode that you would like, or to one of the
 * following modes:
 *
 * * SHARED_UMASK - Use permissions configured by umask - the default.
 * * SHARED_GROUP - Use "--shared=group" behavior, chmod'ing the new repo
 *        to be group writable and "g+sx" for sticky group assignment.
 * * SHARED_ALL - Use "--shared=all" behavior, adding world readability.
 * * Anything else - Set to custom value.
 */
enum {
        GIT_REPOSITORY_INIT_SHARED_UMASK = 0,
        GIT_REPOSITORY_INIT_SHARED_GROUP = 0002775,
        GIT_REPOSITORY_INIT_SHARED_ALL   = 0002777,
};

/**
 * Extended options structure for `git_repository_init_ext`.
 *
 * This contains extra options for `git_repository_init_ext` that enable
 * additional initialization features.  The fields are:
 *
 * * flags - Combination of GIT_REPOSITORY_INIT flags above.
 * * mode  - Set to one of the standard GIT_REPOSITORY_INIT_SHARED_...
 *        constants above, or to a custom value that you would like.
 * * workdir_path - The path to the working dir or NULL for default (i.e.
 *        repo_path parent on non-bare repos).  IF THIS IS RELATIVE PATH,
 *        IT WILL BE EVALUATED RELATIVE TO THE REPO_PATH.  If this is not
 *        the "natural" working directory, a .git gitlink file will be
 *        created here linking to the repo_path.
 * * description - If set, this will be used to initialize the "description"
 *        file in the repository, instead of using the template content.
 * * template_path - When GIT_REPOSITORY_INIT_EXTERNAL_TEMPLATE is set,
 *        this contains the path to use for the template directory.  If
 *        this is NULL, the config or default directory options will be
 *        used instead.
 * * initial_head - The name of the head to point HEAD at.  If NULL, then
 *        this will be treated as "master" and the HEAD ref will be set
 *        to "refs/heads/master".  If this begins with "refs/" it will be
 *        used verbatim; otherwise "refs/heads/" will be prefixed.
 * * origin_url - If this is non-NULL, then after the rest of the
 *        repository initialization is completed, an "origin" remote
 *        will be added pointing to this URL.
 */
typedef struct {
        uint32_t    flags;
        uint32_t    mode;
        const char *workdir_path;
        const char *description;
        const char *template_path;
        const char *initial_head;
        const char *origin_url;
} git_repository_init_options;

/**
 * Create a new Git repository in the given folder with extended controls.
 *
 * This will initialize a new git repository (creating the repo_path
 * if requested by flags) and working directory as needed.  It will
 * auto-detect the case sensitivity of the file system and if the
 * file system supports file mode bits correctly.
 *
 * @param repo_out Pointer to the repo which will be created or reinitialized.
 * @param repo_path The path to the repository.
 * @param opts Pointer to git_repository_init_options struct.
 * @return 0 or an error code on failure.
 */
GIT_EXTERN(int) git_repository_init_ext(
        git_repository **repo_out,
        const char *repo_path,
        git_repository_init_options *opts);

/**
 * Retrieve and resolve the reference pointed at by HEAD.
 *
 * @param head_out pointer to the reference which will be retrieved
 * @param repo a repository object
 *
 * @return 0 on success; error code otherwise
 */
GIT_EXTERN(int) git_repository_head(git_reference **head_out, git_repository *repo);

/**
 * Check if a repository's HEAD is detached
 *
 * A repository's HEAD is detached when it points directly to a commit
 * instead of a branch.
 *
 * @param repo Repo to test
 * @return 1 if HEAD is detached, 0 if it's not; error code if there
 * was an error.
 */
GIT_EXTERN(int) git_repository_head_detached(git_repository *repo);

/**
 * Check if the current branch is an orphan
 *
 * An orphan branch is one named from HEAD but which doesn't exist in
 * the refs namespace, because it doesn't have any commit to point to.
 *
 * @param repo Repo to test
 * @return 1 if the current branch is an orphan, 0 if it's not; error
 * code if there was an error
 */
GIT_EXTERN(int) git_repository_head_orphan(git_repository *repo);

/**
 * Check if a repository is empty
 *
 * An empty repository has just been initialized and contains
 * no commits.
 *
 * @param repo Repo to test
 * @return 1 if the repository is empty, 0 if it isn't, error code
 * if the repository is corrupted
 */
GIT_EXTERN(int) git_repository_is_empty(git_repository *repo);

/**
 * Get the path of this repository
 *
 * This is the path of the `.git` folder for normal repositories,
 * or of the repository itself for bare repositories.
 *
 * @param repo A repository object
 * @return the path to the repository
 */
GIT_EXTERN(const char *) git_repository_path(git_repository *repo);

/**
 * Get the path of the working directory for this repository
 *
 * If the repository is bare, this function will always return
 * NULL.
 *
 * @param repo A repository object
 * @return the path to the working dir, if it exists
 */
GIT_EXTERN(const char *) git_repository_workdir(git_repository *repo);

/**
 * Set the path to the working directory for this repository
 *
 * The working directory doesn't need to be the same one
 * that contains the `.git` folder for this repository.
 *
 * If this repository is bare, setting its working directory
 * will turn it into a normal repository, capable of performing
 * all the common workdir operations (checkout, status, index
 * manipulation, etc).
 *
 * @param repo A repository object
 * @param workdir The path to a working directory
 * @param update_gitlink Create/update gitlink in workdir and set config
 *        "core.worktree" (if workdir is not the parent of the .git directory)
 * @return 0, or an error code
 */
GIT_EXTERN(int) git_repository_set_workdir(
        git_repository *repo, const char *workdir, int update_gitlink);

/**
 * Check if a repository is bare
 *
 * @param repo Repo to test
 * @return 1 if the repository is bare, 0 otherwise.
 */
GIT_EXTERN(int) git_repository_is_bare(git_repository *repo);

/**
 * Get the configuration file for this repository.
 *
 * If a configuration file has not been set, the default
 * config set for the repository will be returned, including
 * global and system configurations (if they are available).
 *
 * The configuration file must be freed once it's no longer
 * being used by the user.
 *
 * @param out Pointer to store the loaded config file
 * @param repo A repository object
 * @return 0, or an error code
 */
GIT_EXTERN(int) git_repository_config(git_config **out, git_repository *repo);

/**
 * 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);

/**
 * Get the Object Database for this repository.
 *
 * If a custom ODB has not been set, the default
 * database for the repository will be returned (the one
 * located in `.git/objects`).
 *
 * The ODB must be freed once it's no longer being used by
 * the user.
 *
 * @param out Pointer to store the loaded ODB
 * @param repo A repository object
 * @return 0, or an error code
 */
GIT_EXTERN(int) git_repository_odb(git_odb **out, git_repository *repo);

/**
 * 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);

/**
 * Get the Index file for this repository.
 *
 * If a custom index has not been set, the default
 * index for the repository will be returned (the one
 * located in `.git/index`).
 *
 * The index must be freed once it's no longer being used by
 * the user.
 *
 * @param out Pointer to store the loaded index
 * @param repo A repository object
 * @return 0, or an error code
 */
GIT_EXTERN(int) git_repository_index(git_index **out, git_repository *repo);

/**
 * 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);

/**
 * Retrieve git's prepared message
 *
 * Operations such as git revert/cherry-pick/merge with the -n option
 * stop just short of creating a commit with the changes and save
 * their prepared message in .git/MERGE_MSG so the next git-commit
 * execution can present it to the user for them to amend if they
 * wish.
 *
 * Use this function to get the contents of this file. Don't forget to
 * remove the file after you create the commit.
 *
 * @param buffer Buffer to write data into or NULL to just read required size
 * @param len Length of buffer in bytes
 * @param repo Repository to read prepared message from
 * @return Bytes written to buffer, GIT_ENOTFOUND if no message, or -1 on error
 */
GIT_EXTERN(int) git_repository_message(char *buffer, size_t len, git_repository *repo);

/**
 * Remove git's prepared message.
 *
 * Remove the message that `git_repository_message` retrieves.
 */
GIT_EXTERN(int) git_repository_message_remove(git_repository *repo);

/**
 * Calculate hash of file using repository filtering rules.
 *
 * If you simply want to calculate the hash of a file on disk with no filters,
 * you can just use the `git_odb_hashfile()` API.  However, if you want to
 * hash a file in the repository and you want to apply filtering rules (e.g.
 * crlf filters) before generating the SHA, then use this function.
 *
 * @param out Output value of calculated SHA
 * @param repo Repository pointer
 * @param path Path to file on disk whose contents should be hashed. If the
 *             repository is not NULL, this can be a relative path.
 * @param type The object type to hash as (e.g. GIT_OBJ_BLOB)
 * @param as_path The path to use to look up filtering rules. If this is
 *             NULL, then the `path` parameter will be used instead. If
 *             this is passed as the empty string, then no filters will be
 *             applied when calculating the hash.
 */
GIT_EXTERN(int) git_repository_hashfile(
    git_oid *out,
    git_repository *repo,
    const char *path,
    git_otype type,
    const char *as_path);

/**
 * Make the repository HEAD directly point to the Commit.
 *
 * If the provided committish cannot be found in the repository, the HEAD
 * is unaltered and GIT_ENOTFOUND is returned.
 *
 * If the provided commitish cannot be peeled into a commit, the HEAD
 * is unaltered and -1 is returned.
 *
 * Otherwise, the HEAD will eventually be detached and will directly point to
 * the peeled Commit.
 *
 * @param repo Repository pointer
 * @param commitish Object id of the Commit the HEAD should point to
 * @return 0 on success, or an error code
 */
GIT_EXTERN(int) git_repository_set_head_detached(
        git_repository* repo,
        const git_oid* commitish);

/**
 * Detach the HEAD.
 *
 * If the HEAD is already detached and points to a Commit, 0 is returned.
 *
 * If the HEAD is already detached and points to a Tag, the HEAD is
 * updated into making it point to the peeled Commit, and 0 is returned.
 *
 * If the HEAD is already detached and points to a non commitish, the HEAD is 
 * unaletered, and -1 is returned.
 *
 * Otherwise, the HEAD will be detached and point to the peeled Commit.
 *
 * @param repo Repository pointer
 * @return 0 on success, or an error code
 */
GIT_EXTERN(int) git_repository_detach_head(
        git_repository* repo);

/** @} */
GIT_END_DECL
#endif