init

pub fn init(opts: Options) WebServer {
    // The upcoming `std.Io` interface should allow us to use `Io.async` and `Io.concurrent`
    // instead of threads, so that the web server can function in single-threaded builds.
    comptime assert(!builtin.single_threaded);

    const all_steps = opts.all_steps;

    const step_names_trailing = opts.gpa.alloc(u8, len: {
        var name_bytes: usize = 0;
        for (all_steps) |step| name_bytes += step.name.len;
        break :len name_bytes + all_steps.len * 4;
    }) catch @panic("out of memory");
    {
        const step_name_lens: []align(1) u32 = @ptrCast(step_names_trailing[0 .. all_steps.len * 4]);
        var idx: usize = all_steps.len * 4;
        for (all_steps, step_name_lens) |step, *name_len| {
            name_len.* = @intCast(step.name.len);
            @memcpy(step_names_trailing[idx..][0..step.name.len], step.name);
            idx += step.name.len;
        }
        assert(idx == step_names_trailing.len);
    }

    const step_status_bits = opts.gpa.alloc(
        u8,
        std.math.divCeil(usize, all_steps.len, 4) catch unreachable,
    ) catch @panic("out of memory");
    @memset(step_status_bits, 0);

    const time_reports_len: usize = if (opts.graph.time_report) all_steps.len else 0;
    const time_report_msgs = opts.gpa.alloc([]u8, time_reports_len) catch @panic("out of memory");
    const time_report_update_times = opts.gpa.alloc(i64, time_reports_len) catch @panic("out of memory");
    @memset(time_report_msgs, &.{});
    @memset(time_report_update_times, std.math.minInt(i64));

    return .{
        .gpa = opts.gpa,
        .thread_pool = opts.thread_pool,
        .graph = opts.graph,
        .all_steps = all_steps,
        .listen_address = opts.listen_address,
        .ttyconf = opts.ttyconf,
        .root_prog_node = opts.root_prog_node,
        .watch = opts.watch,

        .tcp_server = null,
        .serve_thread = null,

        .base_timestamp = std.time.nanoTimestamp(),
        .step_names_trailing = step_names_trailing,

        .step_status_bits = step_status_bits,

        .fuzz = null,
        .time_report_mutex = .{},
        .time_report_msgs = time_report_msgs,
        .time_report_update_times = time_report_update_times,

        .build_status = .init(.idle),
        .update_id = .init(0),

        .runner_request_mutex = .{},
        .runner_request_ready_cond = .{},
        .runner_request_empty_cond = .{},
        .runner_request = null,
    };
}