Function updateFile [src]

Check the file size, mtime, and mode of source_path and dest_path. If they are equal, does nothing. Otherwise, atomically copies source_path to dest_path. The destination file gains the mtime, atime, and mode of the source file so that the next call to updateFile will not need a copy. Returns the previous status of the file before updating. If any of the directories do not exist for dest_path, they are created. On Windows, both paths should be encoded as WTF-8. On WASI, both paths should be encoded as valid UTF-8. On other platforms, both paths are an opaque sequence of bytes with no particular encoding.

Prototype

 pub fn updateFile( source_dir: Dir, source_path: []const u8, dest_dir: Dir, dest_path: []const u8, options: CopyFileOptions, ) !PrevStatus

Parameters

source_dir: Dirsource_path: []const u8dest_dir: Dirdest_path: []const u8options: CopyFileOptions

Source

  pub fn updateFile(
    source_dir: Dir,
    source_path: []const u8,
    dest_dir: Dir,
    dest_path: []const u8,
    options: CopyFileOptions,
) !PrevStatus {
    var src_file = try source_dir.openFile(source_path, .{});
    defer src_file.close();

    const src_stat = try src_file.stat();
    const actual_mode = options.override_mode orelse src_stat.mode;
    check_dest_stat: {
        const dest_stat = blk: {
            var dest_file = dest_dir.openFile(dest_path, .{}) catch |err| switch (err) {
                error.FileNotFound => break :check_dest_stat,
                else => |e| return e,
            };
            defer dest_file.close();

            break :blk try dest_file.stat();
        };

        if (src_stat.size == dest_stat.size and
            src_stat.mtime == dest_stat.mtime and
            actual_mode == dest_stat.mode)
        {
            return PrevStatus.fresh;
        }
    }

    if (fs.path.dirname(dest_path)) |dirname| {
        try dest_dir.makePath(dirname);
    }

    var buffer: [1000]u8 = undefined; // Used only when direct fd-to-fd is not available.
    var atomic_file = try dest_dir.atomicFile(dest_path, .{
        .mode = actual_mode,
        .write_buffer = &buffer,
    });
    defer atomic_file.deinit();

    var src_reader: File.Reader = .initSize(src_file, &.{}, src_stat.size);
    const dest_writer = &atomic_file.file_writer.interface;

    _ = dest_writer.sendFileAll(&src_reader, .unlimited) catch |err| switch (err) {
        error.ReadFailed => return src_reader.err.?,
        error.WriteFailed => return atomic_file.file_writer.err.?,
    };
    try atomic_file.flush();
    try atomic_file.file_writer.file.updateTimes(src_stat.atime, src_stat.mtime);
    try atomic_file.renameIntoPlace();
    return .stale;
}  