next

    pub fn next(self: *Iterator) !?File {
        if (self.unread_file_bytes > 0) {
            // If file content was not consumed by caller
            try self.reader.discardAll64(self.unread_file_bytes);
            self.unread_file_bytes = 0;
        }
        var file: File = self.newFile();

        while (try self.readHeader()) |header| {
            const kind = header.kind();
            const size: u64 = try header.size();
            self.padding = blockPadding(size);

            switch (kind) {
                // File types to return upstream
                .directory, .normal, .symbolic_link => {
                    file.kind = switch (kind) {
                        .directory => .directory,
                        .normal => .file,
                        .symbolic_link => .sym_link,
                        else => unreachable,
                    };
                    file.mode = try header.mode();

                    // set file attributes if not already set by prefix/extended headers
                    if (file.size == 0) {
                        file.size = size;
                    }
                    if (file.link_name.len == 0) {
                        file.link_name = try header.linkName(self.link_name_buffer);
                    }
                    if (file.name.len == 0) {
                        file.name = try header.fullName(self.file_name_buffer);
                    }

                    self.padding = blockPadding(file.size);
                    self.unread_file_bytes = file.size;
                    return file;
                },
                // Prefix header types
                .gnu_long_name => {
                    file.name = try self.readString(@intCast(size), self.file_name_buffer);
                },
                .gnu_long_link => {
                    file.link_name = try self.readString(@intCast(size), self.link_name_buffer);
                },
                .extended_header => {
                    // Use just attributes from last extended header.
                    file = self.newFile();

                    var rdr: PaxIterator = .{
                        .reader = self.reader,
                        .size = @intCast(size),
                    };
                    while (try rdr.next()) |attr| {
                        switch (attr.kind) {
                            .path => {
                                file.name = try attr.value(self.file_name_buffer);
                            },
                            .linkpath => {
                                file.link_name = try attr.value(self.link_name_buffer);
                            },
                            .size => {
                                var buf: [pax_max_size_attr_len]u8 = undefined;
                                file.size = try std.fmt.parseInt(u64, try attr.value(&buf), 10);
                            },
                        }
                    }
                },
                // Ignored header type
                .global_extended_header => {
                    self.reader.discardAll64(size) catch return error.TarHeadersTooBig;
                },
                // All other are unsupported header types
                else => {
                    const d = self.diagnostics orelse return error.TarUnsupportedHeader;
                    try d.errors.append(d.allocator, .{ .unsupported_file_type = .{
                        .file_name = try d.allocator.dupe(u8, header.name()),
                        .file_type = kind,
                    } });
                    if (kind == .gnu_sparse) {
                        try self.skipGnuSparseExtendedHeaders(header);
                    }
                    self.reader.discardAll64(size) catch return error.TarHeadersTooBig;
                },
            }
        }
        return null;
    }