libgit2/src/repository.c

/*
 * Copyright (C) 2009-2011 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.
 */
#include <stdarg.h>

#include "git2/object.h"

#include "common.h"
#include "repository.h"
#include "commit.h"
#include "tag.h"
#include "blob.h"
#include "fileops.h"
#include "config.h"
#include "refs.h"

#define GIT_OBJECTS_INFO_DIR GIT_OBJECTS_DIR "info/"
#define GIT_OBJECTS_PACK_DIR GIT_OBJECTS_DIR "pack/"

#define GIT_FILE_CONTENT_PREFIX "gitdir: "

#define GIT_BRANCH_MASTER "master"


static void drop_odb(git_repository *repo)
{
	if (repo->_odb != NULL) {
		GIT_REFCOUNT_OWN(repo->_odb, NULL);
		git_odb_free(repo->_odb);
		repo->_odb = NULL;
	}
}

static void drop_config(git_repository *repo)
{
	if (repo->_config != NULL) {
		GIT_REFCOUNT_OWN(repo->_config, NULL);
		git_config_free(repo->_config);
		repo->_config = NULL;
	}
}

static void drop_index(git_repository *repo)
{
	if (repo->_index != NULL) {
		GIT_REFCOUNT_OWN(repo->_index, NULL);
		git_index_free(repo->_index);
		repo->_index = NULL;
	}
}

void git_repository_free(git_repository *repo)
{
	if (repo == NULL)
		return;

	git_cache_free(&repo->objects);
	git_repository__refcache_free(&repo->references);

	git__free(repo->path_repository);
	git__free(repo->workdir);

	drop_config(repo);
	drop_index(repo);
	drop_odb(repo);

	git__free(repo);
}

/*
 * Git repository open methods
 *
 * Open a repository object from its path
 */
static int quickcheck_repository_dir(const char *repository_path)
{
	char path_aux[GIT_PATH_MAX];

	/* Ensure HEAD file exists */
	git_path_join(path_aux, repository_path, GIT_HEAD_FILE);
	if (git_futils_isfile(path_aux) < 0)
		return GIT_ERROR;

	git_path_join(path_aux, repository_path, GIT_OBJECTS_DIR);
	if (git_futils_isdir(path_aux) < 0)
		return GIT_ERROR;

	git_path_join(path_aux, repository_path, GIT_REFS_DIR);
	if (git_futils_isdir(path_aux) < 0)
		return GIT_ERROR;

	return GIT_SUCCESS;
}


static git_repository *repository_alloc(void)
{
	int error;

	git_repository *repo = git__malloc(sizeof(git_repository));
	if (!repo)
		return NULL;

	memset(repo, 0x0, sizeof(git_repository));

	error = git_cache_init(&repo->objects, GIT_DEFAULT_CACHE_SIZE, &git_object__free);
	if (error < GIT_SUCCESS) {
		git__free(repo);
		return NULL;
	}

	return repo;
}

static int load_config_data(git_repository *repo)
{
	int error, is_bare;
	git_config *config;

	error = git_repository_config__weakptr(&config, repo);
	if (error < GIT_SUCCESS)
		return error;

	error = git_config_get_bool(config, "core.bare", &is_bare);
	if (error == GIT_SUCCESS)
		repo->is_bare = is_bare;

	/* TODO: what else can we load/cache here? */

	return GIT_SUCCESS;
}

static int load_workdir(git_repository *repo)
{
	if (!repo->is_bare) {
		char workdir_buf[GIT_PATH_MAX];

		if (git_path_dirname_r(workdir_buf, sizeof(workdir_buf), repo->path_repository) < 0)
			return git__throw(GIT_EOSERR,
				"Failed to resolved working directory");

		git_path_join(workdir_buf, workdir_buf, "");

		repo->workdir = git__strdup(workdir_buf);
		if (repo->workdir == NULL)
			return GIT_ENOMEM;
	}

	return GIT_SUCCESS;
}

int git_repository_open(git_repository **repo_out, const char *path)
{
	int error = GIT_SUCCESS;
	char path_buf[GIT_PATH_MAX];
	size_t path_len;
	git_repository *repo = NULL;

	error = git_path_prettify_dir(path_buf, path, NULL);
	if (error < GIT_SUCCESS)
		return git__rethrow(error, "Failed to open repository");

	path_len = strlen(path_buf);

	/**
	 * Check if the path we've been given is actually the path
	 * of the working dir, by testing if it contains a `.git`
	 * folder inside of it.
	 */
	git_path_join(path_buf, path_buf, DOT_GIT);
	if (git_futils_isdir(path_buf) < GIT_SUCCESS) {
		path_buf[path_len] = 0;
	}

	if (quickcheck_repository_dir(path_buf) < GIT_SUCCESS)
		return git__throw(GIT_ENOTAREPO,
			"The given path is not a valid Git repository");

	repo = repository_alloc();
	if (repo == NULL)
		return GIT_ENOMEM;

	repo->path_repository = git__strdup(path_buf);
	if (repo->path_repository == NULL) {
		git_repository_free(repo);
		return GIT_ENOMEM;
	}

	error = load_config_data(repo);
	if (error < GIT_SUCCESS) {
		git_repository_free(repo);
		return error;
	}

	error = load_workdir(repo);
	if (error < GIT_SUCCESS) {
		git_repository_free(repo);
		return error;
	}

	*repo_out = repo;
	return GIT_SUCCESS;
}

static int load_config(
		git_config **out,
		git_repository *repo,
		const char *global_config_path,
		const char *system_config_path)
{
	char config_path[GIT_PATH_MAX];
	int error;
	git_config *cfg = NULL;

	assert(repo && out);

	error = git_config_new(&cfg);
	if (error < GIT_SUCCESS)
		return error;

	git_path_join(config_path, repo->path_repository, GIT_CONFIG_FILENAME_INREPO);
	error = git_config_add_file_ondisk(cfg, config_path, 3);
	if (error < GIT_SUCCESS)
		goto cleanup;

	if (global_config_path != NULL) {
		error = git_config_add_file_ondisk(cfg, global_config_path, 2);
		if (error < GIT_SUCCESS)
			goto cleanup;
	}

	if (system_config_path != NULL) {
		error = git_config_add_file_ondisk(cfg, system_config_path, 1);
		if (error < GIT_SUCCESS)
			goto cleanup;
	}

	*out = cfg;
	return GIT_SUCCESS;

cleanup:
	git_config_free(cfg);
	*out = NULL;
	return error;
}

int git_repository_config__weakptr(git_config **out, git_repository *repo)
{
	if (repo->_config == NULL) {
		int error;

		char buf_global[GIT_PATH_MAX], buf_system[GIT_PATH_MAX];

		const char *global_config_path = NULL;
		const char *system_config_path = NULL;

		if (git_config_find_global(buf_global) == GIT_SUCCESS)
			global_config_path = buf_global;

		if (git_config_find_system(buf_system) == GIT_SUCCESS)
			system_config_path = buf_system;

		error = load_config(&repo->_config, repo, global_config_path, system_config_path);
		if (error < GIT_SUCCESS)
			return error;

		GIT_REFCOUNT_OWN(repo->_config, repo);
	}

	*out = repo->_config;
	return GIT_SUCCESS;
}

int git_repository_config(git_config **out, git_repository *repo)
{
	int error = git_repository_config__weakptr(out, repo);

	if (error == GIT_SUCCESS) {
		GIT_REFCOUNT_INC(*out);
	}

	return error;
}

void git_repository_set_config(git_repository *repo, git_config *config)
{
	assert(repo && config);

	drop_config(repo);

	repo->_config = config;
	GIT_REFCOUNT_OWN(repo->_config, repo);
}

int git_repository_odb__weakptr(git_odb **out, git_repository *repo)
{
	assert(repo && out);

	if (repo->_odb == NULL) {
		int error;
		char odb_path[GIT_PATH_MAX];

		git_path_join(odb_path, repo->path_repository, GIT_OBJECTS_DIR);

		error = git_odb_open(&repo->_odb, odb_path);
		if (error < GIT_SUCCESS)
			return error;

		GIT_REFCOUNT_OWN(repo->_odb, repo);
	}

	GIT_REFCOUNT_INC(repo->_odb);
	*out = repo->_odb;
	return GIT_SUCCESS;
}

int git_repository_odb(git_odb **out, git_repository *repo)
{
	int error = git_repository_odb__weakptr(out, repo);

	if (error == GIT_SUCCESS) {
		GIT_REFCOUNT_INC(*out);
	}

	return error;
}

void git_repository_set_odb(git_repository *repo, git_odb *odb)
{
	assert(repo && odb);

	drop_odb(repo);

	repo->_odb = odb;
	GIT_REFCOUNT_OWN(repo->_odb, repo);
}

int git_repository_index__weakptr(git_index **out, git_repository *repo)
{
	assert(out && repo);

	if (repo->is_bare)
		return git__throw(GIT_EBAREINDEX, "Cannot open index in bare repository");

	if (repo->_index == NULL) {
		int error;
		char index_path[GIT_PATH_MAX];

		git_path_join(index_path, repo->path_repository, GIT_INDEX_FILE);

		error = git_index_open(&repo->_index, index_path);
		if (error < GIT_SUCCESS)
			return error;

		GIT_REFCOUNT_OWN(repo->_index, repo);
	}

	GIT_REFCOUNT_INC(repo->_index);
	*out = repo->_index;
	return GIT_SUCCESS;
}

int git_repository_index(git_index **out, git_repository *repo)
{
	int error = git_repository_index__weakptr(out, repo);

	if (error == GIT_SUCCESS) {
		GIT_REFCOUNT_INC(*out);
	}

	return error;
}

void git_repository_set_index(git_repository *repo, git_index *index)
{
	assert(repo && index);

	drop_index(repo);

	repo->_index = index;
	GIT_REFCOUNT_OWN(repo->_index, repo);
}


static int retrieve_device(dev_t *device_out, const char *path)
{
	struct stat path_info;

	assert(device_out);

	if (p_lstat(path, &path_info))
		return git__throw(GIT_EOSERR, "Failed to get file informations: %s", path);

	*device_out = path_info.st_dev;

	return GIT_SUCCESS;
}

static int retrieve_ceiling_directories_offset(const char *path, const char *ceiling_directories)
{
	char buf[GIT_PATH_MAX + 1];
	char buf2[GIT_PATH_MAX + 1];
	const char *ceil, *sep;
	int len, max_len = -1;
	int min_len;

	assert(path);

	min_len = git_path_root(path) + 1;

	if (ceiling_directories == NULL || min_len == 0)
		return min_len;

	for (sep = ceil = ceiling_directories; *sep; ceil = sep + 1) {
		for (sep = ceil; *sep && *sep != GIT_PATH_LIST_SEPARATOR; sep++);
		len = sep - ceil;

		if (len == 0 || len > GIT_PATH_MAX || git_path_root(ceil) == -1)
			continue;

		strncpy(buf, ceil, len);
		buf[len] = '\0';

		if (p_realpath(buf, buf2) == NULL)
			continue;

		len = strlen(buf2);
		if (len > 0 && buf2[len-1] == '/')
			buf[--len] = '\0';

		if (!strncmp(path, buf2, len) &&
			path[len] == '/' &&
			len > max_len)
		{
			max_len = len;
		}
	}

	return max_len <= min_len ? min_len : max_len;
}

static int read_gitfile(char *path_out, const char *file_path, const char *base_path)
{
	git_fbuffer file;
	int error;
	size_t end_offset;
	char *data;

	assert(path_out && file_path && base_path);

	error = git_futils_readbuffer(&file, file_path);

	if (error < GIT_SUCCESS)
		return error;

	data = (char*)(file.data);

	if (git__prefixcmp(data, GIT_FILE_CONTENT_PREFIX)) {
		git_futils_freebuffer(&file);
		return git__throw(GIT_ENOTFOUND, "Invalid gitfile format `%s`", file_path);
	}

	end_offset = strlen(data) - 1;

	for (;data[end_offset] == '\r' || data[end_offset] == '\n'; --end_offset);
	data[end_offset + 1] = '\0';

	if (strlen(GIT_FILE_CONTENT_PREFIX) == end_offset + 1) {
		git_futils_freebuffer(&file);
		return git__throw(GIT_ENOTFOUND, "No path in git file `%s`", file_path);
	}

	data = data + strlen(GIT_FILE_CONTENT_PREFIX);
	error = git_path_prettify_dir(path_out, data, base_path);
	git_futils_freebuffer(&file);

	if (error == 0 && git_futils_exists(path_out) == 0)
		return GIT_SUCCESS;

	return git__throw(GIT_EOBJCORRUPTED, "The `.git` file points to an inexisting path");
}

int git_repository_discover(
	char *repository_path,
	size_t size,
	const char *start_path,
	int across_fs,
	const char *ceiling_dirs)
{
	int error, ceiling_offset;
	char bare_path[GIT_PATH_MAX];
	char normal_path[GIT_PATH_MAX];
	char *found_path;
	dev_t current_device = 0;

	assert(start_path && repository_path);

	error = git_path_prettify_dir(bare_path, start_path, NULL);
	if (error < GIT_SUCCESS)
		return error;

	if (!across_fs) {
		error = retrieve_device(&current_device, bare_path);
		if (error < GIT_SUCCESS)
			return error;
	}

	ceiling_offset = retrieve_ceiling_directories_offset(bare_path, ceiling_dirs);
	git_path_join(normal_path, bare_path, DOT_GIT);

	while(1) {
		/**
		 * If the `.git` file is regular instead of
		 * a directory, it should contain the path of the actual git repository
		 */
		if (git_futils_isfile(normal_path) == GIT_SUCCESS) {
			error = read_gitfile(repository_path, normal_path, bare_path);

			if (error < GIT_SUCCESS)
				return git__rethrow(error,
					"Unable to read git file `%s`", normal_path);

			error = quickcheck_repository_dir(repository_path);
			if (error < GIT_SUCCESS)
				return git__throw(GIT_ENOTFOUND,
					"The `.git` file found at '%s' points"
					"to an inexisting Git folder", normal_path);

			return GIT_SUCCESS;
		}

		/**
		 * If the `.git` file is a folder, we check inside of it
		 */
		if (git_futils_isdir(normal_path) == GIT_SUCCESS) {
			error = quickcheck_repository_dir(normal_path);
			if (error == GIT_SUCCESS) {
				found_path = normal_path;
				break;
			}
		}

		/**
		 * Otherwise, the repository may be bare, let's check
		 * the root anyway
		 */
		error = quickcheck_repository_dir(bare_path);
		if (error == GIT_SUCCESS) {
			found_path = bare_path;
			break;
		}

		if (git_path_dirname_r(normal_path, sizeof(normal_path), bare_path) < GIT_SUCCESS)
			return git__throw(GIT_EOSERR, "Failed to dirname '%s'", bare_path);

		if (!across_fs) {
			dev_t new_device;
			error = retrieve_device(&new_device, normal_path);

			if (error < GIT_SUCCESS || current_device != new_device) {
				return git__throw(GIT_ENOTAREPO,
					"Not a git repository (or any parent up to mount parent %s)\n"
					"Stopping at filesystem boundary.", bare_path);
			}
			current_device = new_device;
		}

		strcpy(bare_path, normal_path);
		git_path_join(normal_path, bare_path, DOT_GIT);

		// nothing has been found, lets try the parent directory
		if (bare_path[ceiling_offset] == '\0') {
			return git__throw(GIT_ENOTAREPO,
				"Not a git repository (or any of the parent directories): %s", start_path);
		}
	}

	if (size < strlen(found_path) + 2) {
		return git__throw(GIT_ESHORTBUFFER,
			"The repository buffer is not long enough to handle the repository path `%s`", found_path);
	}

	git_path_join(repository_path, found_path, "");
	return GIT_SUCCESS;
}

static int repo_init_reinit(const char *repository_path, int is_bare)
{
	/* TODO: reinit the repository */
	return git__throw(GIT_ENOTIMPLEMENTED,
		"Failed to reinitialize the %srepository at '%s'. "
		"This feature is not yet implemented",
		is_bare ? "bare " : "", repository_path);
}

static int repo_init_createhead(const char *git_dir)
{
	char ref_path[GIT_PATH_MAX];
	git_filebuf ref = GIT_FILEBUF_INIT;

	git_path_join(ref_path, git_dir, GIT_HEAD_FILE);

	git_filebuf_open(&ref, ref_path, 0);
	git_filebuf_printf(&ref, "ref: refs/heads/master\n");

	return git_filebuf_commit(&ref, GIT_REFS_FILE_MODE);
}

static int repo_init_config(const char *git_dir, int is_bare)
{
	char cfg_path[GIT_PATH_MAX];
	git_config *config;
	int error = GIT_SUCCESS;

#define SET_REPO_CONFIG(type, name, val) {\
	error = git_config_set_##type(config, name, val);\
	if (error < GIT_SUCCESS)\
		goto cleanup;\
}

	git_path_join(cfg_path, git_dir, GIT_CONFIG_FILENAME_INREPO);

	error = git_config_open_ondisk(&config, cfg_path);
	if (error < GIT_SUCCESS)
		return error;

	SET_REPO_CONFIG(bool, "core.bare", is_bare);
	SET_REPO_CONFIG(int32, "core.repositoryformatversion", 0);
	/* TODO: what other defaults? */

cleanup:
	git_config_free(config);
	return error;
}

static int repo_init_structure(const char *git_dir, int is_bare)
{
	int error;

	char temp_path[GIT_PATH_MAX];

	if (git_futils_mkdir_r(git_dir, is_bare ? GIT_BARE_DIR_MODE : GIT_DIR_MODE))
		return git__throw(GIT_ERROR, "Failed to initialize repository structure. Could not mkdir");

	/* Hides the ".git" directory */
	if (!is_bare) {
#ifdef GIT_WIN32
		error = p_hide_directory__w32(git_dir);
		if (error < GIT_SUCCESS)
			return git__rethrow(error, "Failed to initialize repository structure");
#endif
	}

	/* Creates the '/objects/info/' directory */
	git_path_join(temp_path, git_dir, GIT_OBJECTS_INFO_DIR);
	error = git_futils_mkdir_r(temp_path, GIT_OBJECT_DIR_MODE);
	if (error < GIT_SUCCESS)
		return git__rethrow(error, "Failed to initialize repository structure");

	/* Creates the '/objects/pack/' directory */
	git_path_join(temp_path, git_dir, GIT_OBJECTS_PACK_DIR);
	error = p_mkdir(temp_path, GIT_OBJECT_DIR_MODE);
	if (error < GIT_SUCCESS)
		return git__throw(error, "Unable to create `%s` folder", temp_path);

	/* Creates the '/refs/heads/' directory */
	git_path_join(temp_path, git_dir, GIT_REFS_HEADS_DIR);
	error = git_futils_mkdir_r(temp_path, GIT_REFS_DIR_MODE);
	if (error < GIT_SUCCESS)
		return git__rethrow(error, "Failed to initialize repository structure");

	/* Creates the '/refs/tags/' directory */
	git_path_join(temp_path, git_dir, GIT_REFS_TAGS_DIR);
	error = p_mkdir(temp_path, GIT_REFS_DIR_MODE);
	if (error < GIT_SUCCESS)
		return git__throw(error, "Unable to create `%s` folder", temp_path);

	/* TODO: what's left? templates? */

	return GIT_SUCCESS;
}

int git_repository_init(git_repository **repo_out, const char *path, unsigned is_bare)
{
	int error = GIT_SUCCESS;
	git_repository *repo = NULL;
	char repository_path[GIT_PATH_MAX];

	assert(repo_out && path);

	git_path_join(repository_path, path, is_bare ? "" : GIT_DIR);

	if (git_futils_isdir(repository_path)) {
		if (quickcheck_repository_dir(repository_path) == GIT_SUCCESS)
			return repo_init_reinit(repository_path, is_bare);
	}

	error = repo_init_structure(repository_path, is_bare);
	if (error < GIT_SUCCESS)
		goto cleanup;

	error = repo_init_config(repository_path, is_bare);
	if (error < GIT_SUCCESS)
		goto cleanup;

	error = repo_init_createhead(repository_path);
	if (error < GIT_SUCCESS)
		goto cleanup;

	return git_repository_open(repo_out, repository_path);

cleanup:
	git_repository_free(repo);
	return git__rethrow(error, "Failed to (re)init the repository `%s`", path);
}

int git_repository_head_detached(git_repository *repo)
{
	git_reference *ref;
	int error;
	size_t _size;
	git_otype type;
	git_odb *odb = NULL;

	error = git_repository_odb__weakptr(&odb, repo);
	if (error < GIT_SUCCESS)
		return error;

	error = git_reference_lookup(&ref, repo, GIT_HEAD_FILE);
	if (error < GIT_SUCCESS)
		return error;

	if (git_reference_type(ref) == GIT_REF_SYMBOLIC) {
		git_reference_free(ref);
		return 0;
	}

	error = git_odb_read_header(&_size, &type, odb, git_reference_oid(ref));

	git_reference_free(ref);

	if (error < GIT_SUCCESS)
		return error;

	if (type != GIT_OBJ_COMMIT)
		return git__throw(GIT_EOBJCORRUPTED, "HEAD is not a commit");

	return 1;
}

int git_repository_head(git_reference **head_out, git_repository *repo)
{
	git_reference *ref, *resolved_ref;
	int error;

	*head_out = NULL;

	error = git_reference_lookup(&ref, repo, GIT_HEAD_FILE);
	if (error < GIT_SUCCESS)
		return git__rethrow(GIT_ENOTAREPO, "Failed to locate the HEAD");

	error = git_reference_resolve(&resolved_ref, ref);
	if (error < GIT_SUCCESS) {
		git_reference_free(ref);
		return git__rethrow(error, "Failed to resolve the HEAD");
	}

	git_reference_free(ref);

	*head_out = resolved_ref;
	return GIT_SUCCESS;
}

int git_repository_head_orphan(git_repository *repo)
{
	git_reference *ref;
	int error;

	error = git_repository_head(&ref, repo);

	if (error == GIT_SUCCESS)
		git_reference_free(ref);

	return error == GIT_ENOTFOUND ? 1 : error;
}

int git_repository_is_empty(git_repository *repo)
{
	git_reference *head = NULL, *branch = NULL;
	int error;

	error = git_reference_lookup(&head, repo, "HEAD");
	if (error < GIT_SUCCESS)
		return git__throw(error, "Corrupted repository. HEAD does not exist");

	if (git_reference_type(head) != GIT_REF_SYMBOLIC) {
		git_reference_free(head);
		return 0;
	}

	if (strcmp(git_reference_target(head), "refs/heads/master") != 0) {
		git_reference_free(head);
		return 0;
	}

	error = git_reference_resolve(&branch, head);

	git_reference_free(head);
	git_reference_free(branch);

	return error == GIT_ENOTFOUND ? 1 : error;
}

const char *git_repository_path(git_repository *repo)
{
	assert(repo);
	return repo->path_repository;
}

const char *git_repository_workdir(git_repository *repo)
{
	assert(repo);

	if (repo->is_bare)
		return NULL;

	return repo->workdir;
}

int git_repository_set_workdir(git_repository *repo, const char *workdir)
{
	assert(repo && workdir);

	free(repo->workdir);

	repo->workdir = git__strdup(workdir);
	if (repo->workdir == NULL)
		return GIT_ENOMEM;

	repo->is_bare = 0;
	return GIT_SUCCESS;
}

int git_repository_is_bare(git_repository *repo)
{
	assert(repo);
	return repo->is_bare;
}