text: /*
   * 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.
   */
  #include "common.h"
  #include "fileops.h"
  #include <ctype.h>
  #if GIT_WIN32
  #include "win32/findfile.h"
  #endif
  
  int git_futils_mkpath2file(const char *file_path, const mode_t mode)
  {
  	return git_futils_mkdir(
  		file_path, NULL, mode,
  		GIT_MKDIR_PATH | GIT_MKDIR_SKIP_LAST | GIT_MKDIR_VERIFY_DIR);
  }
  
  int git_futils_mktmp(git_buf *path_out, const char *filename)
  {
  	int fd;
  
  	git_buf_sets(path_out, filename);
  	git_buf_puts(path_out, "_git2_XXXXXX");
  
  	if (git_buf_oom(path_out))
  		return -1;
  
  	if ((fd = p_mkstemp(path_out->ptr)) < 0) {
  		giterr_set(GITERR_OS,
  			"Failed to create temporary file '%s'", path_out->ptr);
  		return -1;
  	}
  
  	return fd;
  }
  
  int git_futils_creat_withpath(const char *path, const mode_t dirmode, const mode_t mode)
  {
  	int fd;
  
  	if (git_futils_mkpath2file(path, dirmode) < 0)
  		return -1;
  
  	fd = p_creat(path, mode);
  	if (fd < 0) {
  		giterr_set(GITERR_OS, "Failed to create file '%s'", path);
  		return -1;
  	}
  
  	return fd;
  }
  
  int git_futils_creat_locked(const char *path, const mode_t mode)
  {
  	int fd;
  
  #ifdef GIT_WIN32
  	wchar_t buf[GIT_WIN_PATH];
  
  	git__utf8_to_16(buf, GIT_WIN_PATH, path);
  	fd = _wopen(buf, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_EXCL, mode);
  #else
  	fd = open(path, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_EXCL, mode);
  #endif
  
  	if (fd < 0) {
  		giterr_set(GITERR_OS, "Failed to create locked file '%s'", path);
  		return -1;
  	}
  
  	return fd;
  }
  
  int git_futils_creat_locked_withpath(const char *path, const mode_t dirmode, const mode_t mode)
  {
  	if (git_futils_mkpath2file(path, dirmode) < 0)
  		return -1;
  
  	return git_futils_creat_locked(path, mode);
  }
  
  int git_futils_open_ro(const char *path)
  {
  	int fd = p_open(path, O_RDONLY);
  	if (fd < 0) {
  		if (errno == ENOENT || errno == ENOTDIR)
  			fd = GIT_ENOTFOUND;
  		giterr_set(GITERR_OS, "Failed to open '%s'", path);
  	}
  	return fd;
  }
  
  git_off_t git_futils_filesize(git_file fd)
  {
  	struct stat sb;
  
  	if (p_fstat(fd, &sb)) {
  		giterr_set(GITERR_OS, "Failed to stat file descriptor");
  		return -1;
  	}
  
  	return sb.st_size;
  }
  
  mode_t git_futils_canonical_mode(mode_t raw_mode)
  {
  	if (S_ISREG(raw_mode))
  		return S_IFREG | GIT_CANONICAL_PERMS(raw_mode);
  	else if (S_ISLNK(raw_mode))
  		return S_IFLNK;
  	else if (S_ISGITLINK(raw_mode))
  		return S_IFGITLINK;
  	else if (S_ISDIR(raw_mode))
  		return S_IFDIR;
  	else
  		return 0;
  }
  
  int git_futils_readbuffer_fd(git_buf *buf, git_file fd, size_t len)
  {
  	ssize_t read_size = 0;
  
  	git_buf_clear(buf);
  
  	if (git_buf_grow(buf, len + 1) < 0)
  		return -1;
  
  	/* p_read loops internally to read len bytes */
  	read_size = p_read(fd, buf->ptr, len);
  
  	if (read_size != (ssize_t)len) {
  		giterr_set(GITERR_OS, "Failed to read descriptor");
  		return -1;
  	}
  
  	buf->ptr[read_size] = '\0';
  	buf->size = read_size;
  
  	return 0;
  }
  
  int git_futils_readbuffer_updated(
  	git_buf *buf, const char *path, time_t *mtime, size_t *size, int *updated)
  {
  	git_file fd;
  	struct stat st;
  	bool changed = false;
  
  	assert(buf && path && *path);
  
  	if (updated != NULL)
  		*updated = 0;
  
  	if ((fd = git_futils_open_ro(path)) < 0)
  		return fd;
  
  	if (p_fstat(fd, &st) < 0 || S_ISDIR(st.st_mode) || !git__is_sizet(st.st_size+1)) {
  		p_close(fd);
  		giterr_set(GITERR_OS, "Invalid regular file stat for '%s'", path);
  		return -1;
  	}
  
  	/*
  	 * If we were given a time and/or a size, we only want to read the file
  	 * if it has been modified.
  	 */
  	if (size && *size != (size_t)st.st_size)
  		changed = true;
  	if (mtime && *mtime != st.st_mtime)
  		changed = true;
  	if (!size && !mtime)
  		changed = true;
  
  	if (!changed) {
  		p_close(fd);
  		return 0;
  	}
  
  	if (mtime != NULL)
  		*mtime = st.st_mtime;
  	if (size != NULL)
  		*size = (size_t)st.st_size;
  
  	if (git_futils_readbuffer_fd(buf, fd, (size_t)st.st_size) < 0) {
  		p_close(fd);
  		return -1;
  	}
  
  	p_close(fd);
  
  	if (updated != NULL)
  		*updated = 1;
  
  	return 0;
  }
  
  int git_futils_readbuffer(git_buf *buf, const char *path)
  {
  	return git_futils_readbuffer_updated(buf, path, NULL, NULL, NULL);
  }
  
  int git_futils_mv_withpath(const char *from, const char *to, const mode_t dirmode)
  {
  	if (git_futils_mkpath2file(to, dirmode) < 0)
  		return -1;
  
  	if (p_rename(from, to) < 0) {
  		giterr_set(GITERR_OS, "Failed to rename '%s' to '%s'", from, to);
  		return -1;
  	}
  
  	return 0;
  }
  
  int git_futils_mmap_ro(git_map *out, git_file fd, git_off_t begin, size_t len)
  {
  	return p_mmap(out, len, GIT_PROT_READ, GIT_MAP_SHARED, fd, begin);
  }
  
  int git_futils_mmap_ro_file(git_map *out, const char *path)
  {
  	git_file fd = git_futils_open_ro(path);
  	git_off_t len;
  	int result;
  
  	if (fd < 0)
  		return fd;
  
  	len = git_futils_filesize(fd);
  	if (!git__is_sizet(len)) {
  		giterr_set(GITERR_OS, "File `%s` too large to mmap", path);
  		return -1;
  	}
  
  	result = git_futils_mmap_ro(out, fd, 0, (size_t)len);
  	p_close(fd);
  	return result;
  }
  
  void git_futils_mmap_free(git_map *out)
  {
  	p_munmap(out);
  }
  
  int git_futils_mkdir(
  	const char *path,
  	const char *base,
  	mode_t mode,
  	uint32_t flags)
  {
  	int error = -1;
  	git_buf make_path = GIT_BUF_INIT;
  	ssize_t root = 0;
  	char lastch, *tail;
  
  	/* build path and find "root" where we should start calling mkdir */
  	if (git_path_join_unrooted(&make_path, path, base, &root) < 0)
  		return -1;
  
  	if (make_path.size == 0) {
  		giterr_set(GITERR_OS, "Attempt to create empty path");
  		goto fail;
  	}
  
  	/* remove trailing slashes on path */
  	while (make_path.ptr[make_path.size - 1] == '/') {
  		make_path.size--;
  		make_path.ptr[make_path.size] = '\0';
  	}
  
  	/* if we are not supposed to made the last element, truncate it */
  	if ((flags & GIT_MKDIR_SKIP_LAST) != 0)
  		git_buf_rtruncate_at_char(&make_path, '/');
  
  	/* if we are not supposed to make the whole path, reset root */
  	if ((flags & GIT_MKDIR_PATH) == 0)
  		root = git_buf_rfind(&make_path, '/');
  
  	/* clip root to make_path length */
  	if (root >= (ssize_t)make_path.size)
  		root = (ssize_t)make_path.size - 1;
  	if (root < 0)
  		root = 0;
  
  	tail = & make_path.ptr[root];
  
  	while (*tail) {
  		/* advance tail to include next path component */
  		while (*tail == '/')
  			tail++;
  		while (*tail && *tail != '/')
  			tail++;
  
  		/* truncate path at next component */
  		lastch = *tail;
  		*tail = '\0';
  
  		/* make directory */
  		if (p_mkdir(make_path.ptr, mode) < 0) {
  			int already_exists = 0;
  
  			switch (errno) {
  				case EEXIST:
  					if (!lastch && (flags & GIT_MKDIR_VERIFY_DIR) != 0 &&
  						!git_path_isdir(make_path.ptr)) {
  						giterr_set(
  							GITERR_OS, "Existing path is not a directory '%s'",
  							make_path.ptr);
  						error = GIT_ENOTFOUND;
  						goto fail;
  					}
  
  					already_exists = 1;
  					break;
  				case ENOSYS:
  					/* Solaris can generate this error if you try to mkdir
  					 * a path which is already a mount point. In that case,
  					 * the path does already exist; but it's not implied by
  					 * the definition of the error, so let's recheck */
  					if (git_path_isdir(make_path.ptr)) {
  						already_exists = 1;
  						break;
  					}
  
  					/* Fall through */
  					errno = ENOSYS;
  				default:
  					giterr_set(GITERR_OS, "Failed to make directory '%s'",
  						make_path.ptr);
  					goto fail;
  			}
  
  			if (already_exists && (flags & GIT_MKDIR_EXCL) != 0) {
  				giterr_set(GITERR_OS, "Directory already exists '%s'",
  					make_path.ptr);
  				error = GIT_EEXISTS;
  				goto fail;
  			}
  		}
  
  		/* chmod if requested */
  		if ((flags & GIT_MKDIR_CHMOD_PATH) != 0 ||
  			((flags & GIT_MKDIR_CHMOD) != 0 && lastch == '\0'))
  		{
  			if (p_chmod(make_path.ptr, mode) < 0) {
  				giterr_set(GITERR_OS, "Failed to set permissions on '%s'",
  					make_path.ptr);
  				goto fail;
  			}
  		}
  
  		*tail = lastch;
  	}
  
  	git_buf_free(&make_path);
  	return 0;
  
  fail:
  	git_buf_free(&make_path);
  	return error;
  }
  
  int git_futils_mkdir_r(const char *path, const char *base, const mode_t mode)
  {
  	return git_futils_mkdir(path, base, mode, GIT_MKDIR_PATH);
  }
  
  typedef struct {
  	const char *base;
  	size_t baselen;
  	uint32_t flags;
  	int error;
  } futils__rmdir_data;
  
  static int futils__error_cannot_rmdir(const char *path, const char *filemsg)
  {
  	if (filemsg)
  		giterr_set(GITERR_OS, "Could not remove directory. File '%s' %s",
  				   path, filemsg);
  	else
  		giterr_set(GITERR_OS, "Could not remove directory '%s'", path);
  
  	return -1;
  }
  
  static int futils__rm_first_parent(git_buf *path, const char *ceiling)
  {
  	int error = GIT_ENOTFOUND;
  	struct stat st;
  
  	while (error == GIT_ENOTFOUND) {
  		git_buf_rtruncate_at_char(path, '/');
  
  		if (!path->size || git__prefixcmp(path->ptr, ceiling) != 0)
  			error = 0;
  		else if (p_lstat_posixly(path->ptr, &st) == 0) {
  			if (S_ISREG(st.st_mode) || S_ISLNK(st.st_mode))
  				error = p_unlink(path->ptr);
  			else if (!S_ISDIR(st.st_mode))
  				error = -1; /* fail to remove non-regular file */
  		} else if (errno != ENOTDIR)
  			error = -1;
  	}
  
  	if (error)
  		futils__error_cannot_rmdir(path->ptr, "cannot remove parent");
  
  	return error;
  }
  
  static int futils__rmdir_recurs_foreach(void *opaque, git_buf *path)
  {
  	struct stat st;
  	futils__rmdir_data *data = opaque;
  
  	if ((data->error = p_lstat_posixly(path->ptr, &st)) < 0) {
  		if (errno == ENOENT)
  			data->error = 0;
  		else if (errno == ENOTDIR) {
  			/* asked to remove a/b/c/d/e and a/b is a normal file */
  			if ((data->flags & GIT_RMDIR_REMOVE_BLOCKERS) != 0)
  				data->error = futils__rm_first_parent(path, data->base);
  			else
  				futils__error_cannot_rmdir(
  					path->ptr, "parent is not directory");
  		}
  		else
  			futils__error_cannot_rmdir(path->ptr, "cannot access");
  	}
  
  	else if (S_ISDIR(st.st_mode)) {
  		int error = git_path_direach(path, futils__rmdir_recurs_foreach, data);
  		if (error < 0)
  			return (error == GIT_EUSER) ? data->error : error;
  
  		data->error = p_rmdir(path->ptr);
  
  		if (data->error < 0) {
  			if ((data->flags & GIT_RMDIR_SKIP_NONEMPTY) != 0 &&
  				(errno == ENOTEMPTY || errno == EEXIST))
  				data->error = 0;
  			else
  				futils__error_cannot_rmdir(path->ptr, NULL);
  		}
  	}
  
  	else if ((data->flags & GIT_RMDIR_REMOVE_FILES) != 0) {
  		data->error = p_unlink(path->ptr);
  
  		if (data->error < 0)
  			futils__error_cannot_rmdir(path->ptr, "cannot be removed");
  	}
  
  	else if ((data->flags & GIT_RMDIR_SKIP_NONEMPTY) == 0)
  		data->error = futils__error_cannot_rmdir(path->ptr, "still present");
  
  	return data->error;
  }
  
  static int futils__rmdir_empty_parent(void *opaque, git_buf *path)
  {
  	futils__rmdir_data *data = opaque;
  	int error;
  
  	if (git_buf_len(path) <= data->baselen)
  		return GIT_ITEROVER;
  
  	error = p_rmdir(git_buf_cstr(path));
  
  	if (error) {
  		int en = errno;
  
  		if (en == ENOENT || en == ENOTDIR) {
  			giterr_clear();
  			error = 0;
  		} else if (en == ENOTEMPTY || en == EEXIST) {
  			giterr_clear();
  			error = GIT_ITEROVER;
  		} else {
  			futils__error_cannot_rmdir(git_buf_cstr(path), NULL);
  		}
  	}
  
  	return error;
  }
  
  int git_futils_rmdir_r(
  	const char *path, const char *base, uint32_t flags)
  {
  	int error;
  	git_buf fullpath = GIT_BUF_INIT;
  	futils__rmdir_data data;
  
  	/* build path and find "root" where we should start calling mkdir */
  	if (git_path_join_unrooted(&fullpath, path, base, NULL) < 0)
  		return -1;
  
  	data.base    = base ? base : "";
  	data.baselen = base ? strlen(base) : 0;
  	data.flags   = flags;
  	data.error   = 0;
  
  	error = futils__rmdir_recurs_foreach(&data, &fullpath);
  
  	/* remove now-empty parents if requested */
  	if (!error && (flags & GIT_RMDIR_EMPTY_PARENTS) != 0) {
  		error = git_path_walk_up(
  			&fullpath, base, futils__rmdir_empty_parent, &data);
  
  		if (error == GIT_ITEROVER)
  			error = 0;
  	}
  
  	git_buf_free(&fullpath);
  
  	return error;
  }
  
  int git_futils_find_system_file(git_buf *path, const char *filename)
  {
  #ifdef GIT_WIN32
  	// try to find git.exe/git.cmd on path
  	if (!win32_find_system_file_using_path(path, filename))
  		return 0;
  
  	// try to find msysgit installation path using registry
  	if (!win32_find_system_file_using_registry(path, filename))
  		return 0;
  #else
  	if (git_buf_joinpath(path, "/etc", filename) < 0)
  		return -1;
  
  	if (git_path_exists(path->ptr) == true)
  		return 0;
  #endif
  
  	git_buf_clear(path);
  	giterr_set(GITERR_OS, "The system file '%s' doesn't exist", filename);
  	return GIT_ENOTFOUND;
  }
  
  int git_futils_find_global_file(git_buf *path, const char *filename)
  {
  #ifdef GIT_WIN32
  	struct win32_path root;
  	static const wchar_t *tmpls[4] = {
  		L"%HOME%\\",
  		L"%HOMEDRIVE%%HOMEPATH%\\",
  		L"%USERPROFILE%\\",
  		NULL,
  	};
  	const wchar_t **tmpl;
  
  	for (tmpl = tmpls; *tmpl != NULL; tmpl++) {
  		/* try to expand environment variable, skipping if not set */
  		if (win32_expand_path(&root, *tmpl) != 0 || root.path[0] == L'%')
  			continue;
  
  		/* try to look up file under path */
  		if (!win32_find_file(path, &root, filename))
  			return 0;
  	}
  
  	giterr_set(GITERR_OS, "The global file '%s' doesn't exist", filename);
  	git_buf_clear(path);
  
  	return GIT_ENOTFOUND;
  #else
  	const char *home = getenv("HOME");
  
  	if (home == NULL) {
  		giterr_set(GITERR_OS, "Global file lookup failed. "
  			"Cannot locate the user's home directory");
  		return GIT_ENOTFOUND;
  	}
  
  	if (git_buf_joinpath(path, home, filename) < 0)
  		return -1;
  
  	if (git_path_exists(path->ptr) == false) {
  		giterr_set(GITERR_OS, "The global file '%s' doesn't exist", filename);
  		git_buf_clear(path);
  		return GIT_ENOTFOUND;
  	}
  
  	return 0;
  #endif
  }
  
  int git_futils_fake_symlink(const char *old, const char *new)
  {
  	int retcode = GIT_ERROR;
  	int fd = git_futils_creat_withpath(new, 0755, 0644);
  	if (fd >= 0) {
  		retcode = p_write(fd, old, strlen(old));
  		p_close(fd);
  	}
  	return retcode;
  }
  
  static int cp_by_fd(int ifd, int ofd, bool close_fd_when_done)
  {
  	int error = 0;
  	char buffer[4096];
  	ssize_t len = 0;
  
  	while (!error && (len = p_read(ifd, buffer, sizeof(buffer))) > 0)
  		/* p_write() does not have the same semantics as write().  It loops
  		 * internally and will return 0 when it has completed writing.
  		 */
  		error = p_write(ofd, buffer, len);
  
  	if (len < 0) {
  		giterr_set(GITERR_OS, "Read error while copying file");
  		error = (int)len;
  	}
  
  	if (close_fd_when_done) {
  		p_close(ifd);
  		p_close(ofd);
  	}
  
  	return error;
  }
  
  int git_futils_cp(const char *from, const char *to, mode_t filemode)
  {
  	int ifd, ofd;
  
  	if ((ifd = git_futils_open_ro(from)) < 0)
  		return ifd;
  
  	if ((ofd = p_open(to, O_WRONLY | O_CREAT | O_EXCL, filemode)) < 0) {
  		if (errno == ENOENT || errno == ENOTDIR)
  			ofd = GIT_ENOTFOUND;
  		giterr_set(GITERR_OS, "Failed to open '%s' for writing", to);
  		p_close(ifd);
  		return ofd;
  	}
  
  	return cp_by_fd(ifd, ofd, true);
  }
  
  static int cp_link(const char *from, const char *to, size_t link_size)
  {
  	int error = 0;
  	ssize_t read_len;
  	char *link_data = git__malloc(link_size + 1);
  	GITERR_CHECK_ALLOC(link_data);
  
  	read_len = p_readlink(from, link_data, link_size);
  	if (read_len != (ssize_t)link_size) {
  		giterr_set(GITERR_OS, "Failed to read symlink data for '%s'", from);
  		error = -1;
  	}
  	else {
  		link_data[read_len] = '\0';
  
  		if (p_symlink(link_data, to) < 0) {
  			giterr_set(GITERR_OS, "Could not symlink '%s' as '%s'",
  				link_data, to);
  			error = -1;
  		}
  	}
  
  	git__free(link_data);
  	return error;
  }
  
  typedef struct {
  	const char *to_root;
  	git_buf to;
  	ssize_t from_prefix;
  	uint32_t flags;
  	uint32_t mkdir_flags;
  	mode_t dirmode;
  } cp_r_info;
  
  static int _cp_r_callback(void *ref, git_buf *from)
  {
  	cp_r_info *info = ref;
  	struct stat from_st, to_st;
  	bool exists = false;
  
  	if ((info->flags & GIT_CPDIR_COPY_DOTFILES) == 0 &&
  		from->ptr[git_path_basename_offset(from)] == '.')
  		return 0;
  
  	if (git_buf_joinpath(
  			&info->to, info->to_root, from->ptr + info->from_prefix) < 0)
  		return -1;
  
  	if (p_lstat(info->to.ptr, &to_st) < 0) {
  		if (errno != ENOENT && errno != ENOTDIR) {
  			giterr_set(GITERR_OS,
  				"Could not access %s while copying files", info->to.ptr);
  			return -1;
  		}
  	} else
  		exists = true;
  
  	if (git_path_lstat(from->ptr, &from_st) < 0)
  		return -1;
  
  	if (S_ISDIR(from_st.st_mode)) {
  		int error = 0;
  		mode_t oldmode = info->dirmode;
  
  		/* if we are not chmod'ing, then overwrite dirmode */
  		if ((info->flags & GIT_CPDIR_CHMOD) == 0)
  			info->dirmode = from_st.st_mode;
  
  		/* make directory now if CREATE_EMPTY_DIRS is requested and needed */
  		if (!exists && (info->flags & GIT_CPDIR_CREATE_EMPTY_DIRS) != 0)
  			error = git_futils_mkdir(
  				info->to.ptr, NULL, info->dirmode, info->mkdir_flags);
  
  		/* recurse onto target directory */
  		if (!exists || S_ISDIR(to_st.st_mode))
  			error = git_path_direach(from, _cp_r_callback, info);
  
  		if (oldmode != 0)
  			info->dirmode = oldmode;
  
  		return error;
  	}
  
  	if (exists) {
  		if ((info->flags & GIT_CPDIR_OVERWRITE) == 0)
  			return 0;
  
  		if (p_unlink(info->to.ptr) < 0) {
  			giterr_set(GITERR_OS, "Cannot overwrite existing file '%s'",
  				info->to.ptr);
  			return -1;
  		}
  	}
  
  	/* Done if this isn't a regular file or a symlink */
  	if (!S_ISREG(from_st.st_mode) &&
  		(!S_ISLNK(from_st.st_mode) ||
  		 (info->flags & GIT_CPDIR_COPY_SYMLINKS) == 0))
  		return 0;
  
  	/* Make container directory on demand if needed */
  	if ((info->flags & GIT_CPDIR_CREATE_EMPTY_DIRS) == 0 &&
  		git_futils_mkdir(
  			info->to.ptr, NULL, info->dirmode, info->mkdir_flags) < 0)
  		return -1;
  
  	/* make symlink or regular file */
  	if (S_ISLNK(from_st.st_mode))
  		return cp_link(from->ptr, info->to.ptr, (size_t)from_st.st_size);
  	else
  		return git_futils_cp(from->ptr, info->to.ptr, from_st.st_mode);
  }
  
  int git_futils_cp_r(
  	const char *from,
  	const char *to,
  	uint32_t flags,
  	mode_t dirmode)
  {
  	int error;
  	git_buf path = GIT_BUF_INIT;
  	cp_r_info info;
  
  	if (git_buf_sets(&path, from) < 0)
  		return -1;
  
  	info.to_root = to;
  	info.flags   = flags;
  	info.dirmode = dirmode;
  	info.from_prefix = path.size;
  	git_buf_init(&info.to, 0);
  
  	/* precalculate mkdir flags */
  	if ((flags & GIT_CPDIR_CREATE_EMPTY_DIRS) == 0) {
  		info.mkdir_flags = GIT_MKDIR_PATH | GIT_MKDIR_SKIP_LAST;
  		if ((flags & GIT_CPDIR_CHMOD) != 0)
  			info.mkdir_flags |= GIT_MKDIR_CHMOD_PATH;
  	} else {
  		info.mkdir_flags =
  			((flags & GIT_CPDIR_CHMOD) != 0) ? GIT_MKDIR_CHMOD : 0;
  	}
  
  	error = _cp_r_callback(&info, &path);
  
  	git_buf_free(&path);
  	git_buf_free(&info.to);
  
  	return error;
  }
  
  int git_futils_filestamp_check(
  	git_futils_filestamp *stamp, const char *path)
  {
  	struct stat st;
  
  	/* if the stamp is NULL, then always reload */
  	if (stamp == NULL)
  		return 1;
  
  	if (p_stat(path, &st) < 0)
  		return GIT_ENOTFOUND;
  
  	if (stamp->mtime == (git_time_t)st.st_mtime &&
  		stamp->size  == (git_off_t)st.st_size   &&
  		stamp->ino   == (unsigned int)st.st_ino)
  		return 0;
  
  	stamp->mtime = (git_time_t)st.st_mtime;
  	stamp->size  = (git_off_t)st.st_size;
  	stamp->ino   = (unsigned int)st.st_ino;
  
  	return 1;
  }
  
  void git_futils_filestamp_set(
  	git_futils_filestamp *target, const git_futils_filestamp *source)
  {
  	assert(target);
  
  	if (source)
  		memcpy(target, source, sizeof(*target));
  	else
  		memset(target, 0, sizeof(*target));
  }
  