helloMessage

fn helloMessage(msg_bytes: []align(4) u8) Allocator.Error!void

File

Code

fn helloMessage(msg_bytes: []align(4) u8) Allocator.Error!void {
    if (msg_bytes.len < @sizeOf(abi.Hello)) @panic("malformed Hello message");
    const hdr: *const abi.Hello = @ptrCast(msg_bytes[0..@sizeOf(abi.Hello)]);
    const trailing = msg_bytes[@sizeOf(abi.Hello)..];

    client_base_timestamp = js.timestamp();
    server_base_timestamp = hdr.timestamp;

    const steps = try gpa.alloc(Step, hdr.steps_len);
    errdefer gpa.free(steps);

    const step_name_lens: []align(1) const u32 = @ptrCast(trailing[0 .. steps.len * 4]);

    const step_name_data_len: usize = len: {
        var sum: usize = 0;
        for (step_name_lens) |n| sum += n;
        break :len sum;
    };
    const step_name_data: []const u8 = trailing[steps.len * 4 ..][0..step_name_data_len];
    const step_status_bits: []const u8 = trailing[steps.len * 4 + step_name_data_len ..];

    const duped_step_name_data = try gpa.dupe(u8, step_name_data);
    errdefer gpa.free(duped_step_name_data);

    var name_off: usize = 0;
    for (steps, step_name_lens, 0..) |*step_out, name_len, step_idx| {
        step_out.* = .{
            .name = duped_step_name_data[name_off..][0..name_len],
            .status = @fromBackingInt(@intCast(@as(u2, @truncate(step_status_bits[step_idx / 4] >> @intCast((step_idx % 4) * 2))))),
        };
        name_off += name_len;
    }

    gpa.free(step_list);
    gpa.free(step_list_data);
    step_list = steps;
    step_list_data = duped_step_name_data;

    js.hello(step_list.len, hdr.status, hdr.flags.time_report);
}