Daku v1.0.0-alpha.2

Daku 是一个类似 WASI 的系统接口 API，但有不同的目标。

由于目前处于 alpha 阶段，一些事情可能会改变，但变化的可能性不大。alpha、beta 和预发布阶段不会持续很长时间（一旦有实现，它将完全稳定）。

目标

• 异步优先
• 立即稳定
• 简单
• 减少系统调用
• 基于通道
• 通过门户实现安全
• 反 POSIX
• 全面的多媒体支持

API

大库 API 导出单个函数 ar()

(import "daku" "ar" (func $event
    (param $cmd_size i32)   ;; List[Command].size
    (param $cmd_data i32)   ;; List[Command].reference
    (result i32)            ;; List[Uint32].size 
))

该函数将多个异步任务排队，作为列表传递（前两个参数）。当任何异步任务完成时，它会被推送到就绪列表，函数返回已完成任务的数量。每次调用 ar() 都会清除就绪列表。

命令

#[repr(C, packed)]
struct Command {
    /// Ready index for when command completes
    ready: u32,
    /// Channel id to use
    channel: u32,
    /// Data buffer size
    size: u32,
    /// Data buffer reference
    data: *const (),
}

通道

通道 0 是特殊的，允许您连接到门户。

#[repr(C, packed)]
struct Connect {
    /// The capacity of the ready list
    ready_capacity: u32,
    /// Reference to uninitialized ready list
    ready_data: *mut u32,
    /// The number of new portals
    portals_size: u32,
    /// in: List of new portal IDs - out: List of new portal channel IDs
    portals_data: *mut u32,
}

有关门户命令 API，请参阅 门户。

类型

时间戳

#[repr(transparent)]
struct Timestamp {
    /// The number of TAI microseconds since Jan 1 00:00:00.000_000, year 0 in
    /// [ISO 8601:2004](https://en.wikipedia.org/wiki/ISO_8601)
    ///
    /// This gives about a range of ±292_470 years since year 0.
    ///
    /// This differs from Unix time in 3 ways:
    ///  - Epoch is 0000-01-01T00:00:00.000_000 TAI instead of
    ///    1970-01-01T00:00:00.000_000 UTC
    ///  - Precision is microseconds instead of seconds
    ///  - TAI not UTC, meaning that a leap second gets representation, rather
    ///    than being represented as repeat of previous second as it would be in
    ///    unix time.
    micros: i64,
}

时间

#[repr(C, packed)]
struct Time {
    /// Range: 0 ~ 23 (always UTC, localized only for display)
    hour: u8,
    /// Range: 0 ~ 59
    minute: u8,
    /// Range: 0 ~ 60_999 (can represent leap seconds)
    millis: u16,
}

日期

#[repr(C, packed)]
struct Date {
    /// Range: 0 ~ 65_535
    year: u16,
    /// Range: 1 ~ 12
    month: u8,
    /// Range: (of week: 1 ~ 7) << 5 | (of month: 1 ~ 31)
    day: u8,
}

日期时间

#[repr(C, packed)]
struct DateTime {
    date: Date,
    time: Time,
}

列表

#[repr(C, packed)]
struct List<T> {
    size: u32,
    data: *mut T,
}

文本

#[repr(C, packed)]
struct Text {
    /// Number of bytes
    size: usize,
    /// UTF-8 String
    data: *mut u8,
}

时区

#[repr(C, u32)]
enum TimeDesignation {
    Utc = 0,
}

#[repr(C, packed)]
struct TimeAdjustment {
    /// Time to replace
    when: DateTime,
    /// New time
    new: DateTime,
}

#[repr(C, packed)]
struct LeapSecond {
    /// Which year
    year: i16,
    /// Always the last day of the month
    month: u8,
    /// Direction: Either -1 or +1
    delta: i8,
}

#[repr(C, packed)]
struct TimeZone {
    /// Name of TimeZone (abbreviated, null terminated unless size 6)
    designation: TimeDesignation,
    /// List of adjustments made in this timezone
    deltas: List<TimeAdjustment>,
    /// Replace UTC jan 1 00:00:00:000 year 0 with Local time adjustments
    /// 
    /// This must be equivalent to all of the adjustments in `deltas` plus
    /// any daylight savings time modifications.
    offset: DateTime,
    /// List of leap seconds
    leap_seconds: List<LeapSecond>,
    /// Sum of leap seconds
    leap: i16,
    /// Is daylight savings time?
    is_dst: bool,
    /// Reserved for future use
    reserved: u8,
}

语言

#[repr(C, u32)]
enum Language {
    /// English United States
    EnUS = u32::from_ne_bytes(*b"enUS"),
    /// English Great Britain
    EnGB = u32::from_ne_bytes(*b"enGB"),
    /// Esperanto
    EoXX = u32::from_ne_bytes(*b"eoXX"),
}

#[repr(C, packed)]
struct Lang {
    /// List of languages in order of user preference (0 is most preferred)
    list: List<Language>,
}