Proposed WIT for tracing portion of wasi-observe

.github/workflows/main.yml

@@ -11,4 +11,4 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v3
-    - uses: WebAssembly/wit-abi-up-to-date@v17
+    - uses: WebAssembly/wit-abi-up-to-date@v22

justfile

@@ -13,7 +13,7 @@ _prepare:
   fi
 
   if ! &>/dev/null which wit-bindgen; then
-    cargo install wit-bindgen-cli@0.16.0
+    cargo install wit-bindgen-cli@0.30.0
   fi
 
 build:

wit/deps.lock

@@ -1,3 +1,13 @@
+[clocks]
+url = "https://github.com/WebAssembly/wasi-clocks/archive/main.tar.gz"
+sha256 = "ea9d69ee803bc176e23e5268f5e24a2ac485dd1f62a0ab4c748e9d3f901f576f"
+sha512 = "5efc22927c46cd56c41e5549ec775561c7fac2ea0d365abc0b55396d9475a7c9f984077a81f84a44a726f1c008fd2fadbffffa4fa53ecd5fbfd05afd379ab428"
+deps = ["io"]
+
+[io]
+sha256 = "2a74bd811adc46b5a0f19827ddbde89870e52b17615f4d0873f06fd977250caf"
+sha512 = "94624f00c66e66203592cee820f80b1ba91ecdb71f682c154f25eaf71f8d8954197dcb64503bc21e72ed5e812af7eae876df47b7eb727b02db3a74a7ce0aefca"
+
 [logging]
 url = "https://github.com/WebAssembly/wasi-logging/archive/main.tar.gz"
 sha256 = "9676b482485bb0fd2751a390374c1108865a096b7037f4b5dbe524f066bfb06e"

wit/deps.toml

@@ -1 +1,2 @@
 logging = "https://github.com/WebAssembly/wasi-logging/archive/main.tar.gz"
+clocks = "https://github.com/WebAssembly/wasi-clocks/archive/main.tar.gz"

wit/deps/clocks/monotonic-clock.wit

@@ -0,0 +1,50 @@
+package wasi:[email protected];
+/// WASI Monotonic Clock is a clock API intended to let users measure elapsed
+/// time.
+///
+/// It is intended to be portable at least between Unix-family platforms and
+/// Windows.
+///
+/// A monotonic clock is a clock which has an unspecified initial value, and
+/// successive reads of the clock will produce non-decreasing values.
+@since(version = 0.2.0)
+interface monotonic-clock {
+    @since(version = 0.2.0)
+    use wasi:io/[email protected].{pollable};
+
+    /// An instant in time, in nanoseconds. An instant is relative to an
+    /// unspecified initial value, and can only be compared to instances from
+    /// the same monotonic-clock.
+    @since(version = 0.2.0)
+    type instant = u64;
+
+    /// A duration of time, in nanoseconds.
+    @since(version = 0.2.0)
+    type duration = u64;
+
+    /// Read the current value of the clock.
+    ///
+    /// The clock is monotonic, therefore calling this function repeatedly will
+    /// produce a sequence of non-decreasing values.
+    @since(version = 0.2.0)
+    now: func() -> instant;
+
+    /// Query the resolution of the clock. Returns the duration of time
+    /// corresponding to a clock tick.
+    @since(version = 0.2.0)
+    resolution: func() -> duration;
+
+    /// Create a `pollable` which will resolve once the specified instant
+    /// has occurred.
+    @since(version = 0.2.0)
+    subscribe-instant: func(
+        when: instant,
+    ) -> pollable;
+
+    /// Create a `pollable` that will resolve after the specified duration has
+    /// elapsed from the time this function is invoked.
+    @since(version = 0.2.0)
+    subscribe-duration: func(
+        when: duration,
+    ) -> pollable;
+}

wit/deps/clocks/timezone.wit

@@ -0,0 +1,55 @@
+package wasi:[email protected];
+
+@unstable(feature = clocks-timezone)
+interface timezone {
+    @unstable(feature = clocks-timezone)
+    use wall-clock.{datetime};
+
+    /// Return information needed to display the given `datetime`. This includes
+    /// the UTC offset, the time zone name, and a flag indicating whether
+    /// daylight saving time is active.
+    ///
+    /// If the timezone cannot be determined for the given `datetime`, return a
+    /// `timezone-display` for `UTC` with a `utc-offset` of 0 and no daylight
+    /// saving time.
+    @unstable(feature = clocks-timezone)
+    display: func(when: datetime) -> timezone-display;
+
+    /// The same as `display`, but only return the UTC offset.
+    @unstable(feature = clocks-timezone)
+    utc-offset: func(when: datetime) -> s32;
+
+    /// Information useful for displaying the timezone of a specific `datetime`.
+    ///
+    /// This information may vary within a single `timezone` to reflect daylight
+    /// saving time adjustments.
+    @unstable(feature = clocks-timezone)
+    record timezone-display {
+        /// The number of seconds difference between UTC time and the local
+        /// time of the timezone.
+        ///
+        /// The returned value will always be less than 86400 which is the
+        /// number of seconds in a day (24*60*60).
+        ///
+        /// In implementations that do not expose an actual time zone, this
+        /// should return 0.
+        utc-offset: s32,
+
+        /// The abbreviated name of the timezone to display to a user. The name
+        /// `UTC` indicates Coordinated Universal Time. Otherwise, this should
+        /// reference local standards for the name of the time zone.
+        ///
+        /// In implementations that do not expose an actual time zone, this
+        /// should be the string `UTC`.
+        ///
+        /// In time zones that do not have an applicable name, a formatted
+        /// representation of the UTC offset may be returned, such as `-04:00`.
+        name: string,
+
+        /// Whether daylight saving time is active.
+        ///
+        /// In implementations that do not expose an actual time zone, this
+        /// should return false.
+        in-daylight-saving-time: bool,
+    }
+}

wit/deps/clocks/wall-clock.wit

@@ -0,0 +1,46 @@
+package wasi:[email protected];
+/// WASI Wall Clock is a clock API intended to let users query the current
+/// time. The name "wall" makes an analogy to a "clock on the wall", which
+/// is not necessarily monotonic as it may be reset.
+///
+/// It is intended to be portable at least between Unix-family platforms and
+/// Windows.
+///
+/// A wall clock is a clock which measures the date and time according to
+/// some external reference.
+///
+/// External references may be reset, so this clock is not necessarily
+/// monotonic, making it unsuitable for measuring elapsed time.
+///
+/// It is intended for reporting the current date and time for humans.
+@since(version = 0.2.0)
+interface wall-clock {
+    /// A time and date in seconds plus nanoseconds.
+    @since(version = 0.2.0)
+    record datetime {
+        seconds: u64,
+        nanoseconds: u32,
+    }
+
+    /// Read the current value of the clock.
+    ///
+    /// This clock is not monotonic, therefore calling this function repeatedly
+    /// will not necessarily produce a sequence of non-decreasing values.
+    ///
+    /// The returned timestamps represent the number of seconds since
+    /// 1970-01-01T00:00:00Z, also known as [POSIX's Seconds Since the Epoch],
+    /// also known as [Unix Time].
+    ///
+    /// The nanoseconds field of the output is always less than 1000000000.
+    ///
+    /// [POSIX's Seconds Since the Epoch]: https://pubs.opengroup.org/onlinepubs/9699919799/xrat/V4_xbd_chap04.html#tag_21_04_16
+    /// [Unix Time]: https://en.wikipedia.org/wiki/Unix_time
+    @since(version = 0.2.0)
+    now: func() -> datetime;
+
+    /// Query the resolution of the clock.
+    ///
+    /// The nanoseconds field of the output is always less than 1000000000.
+    @since(version = 0.2.0)
+    resolution: func() -> datetime;
+}

wit/deps/clocks/world.wit

@@ -0,0 +1,11 @@
+package wasi:[email protected];
+
+@since(version = 0.2.0)
+world imports {
+    @since(version = 0.2.0)
+    import monotonic-clock;
+    @since(version = 0.2.0)
+    import wall-clock;
+    @unstable(feature = clocks-timezone)
+    import timezone;
+}

wit/deps/io/error.wit

@@ -0,0 +1,34 @@
+package wasi:[email protected];
+
+@since(version = 0.2.0)
+interface error {
+    /// A resource which represents some error information.
+    ///
+    /// The only method provided by this resource is `to-debug-string`,
+    /// which provides some human-readable information about the error.
+    ///
+    /// In the `wasi:io` package, this resource is returned through the
+    /// `wasi:io/streams/stream-error` type.
+    ///
+    /// To provide more specific error information, other interfaces may
+    /// offer functions to "downcast" this error into more specific types. For example,
+    /// errors returned from streams derived from filesystem types can be described using
+    /// the filesystem's own error-code type. This is done using the function
+    /// `wasi:filesystem/types/filesystem-error-code`, which takes a `borrow<error>`
+    /// parameter and returns an `option<wasi:filesystem/types/error-code>`.
+    ///
+    /// The set of functions which can "downcast" an `error` into a more
+    /// concrete type is open.
+    @since(version = 0.2.0)
+    resource error {
+        /// Returns a string that is suitable to assist humans in debugging
+        /// this error.
+        ///
+        /// WARNING: The returned string should not be consumed mechanically!
+        /// It may change across platforms, hosts, or other implementation
+        /// details. Parsing this string is a major platform-compatibility
+        /// hazard.
+        @since(version = 0.2.0)
+        to-debug-string: func() -> string;
+    }
+}

wit/deps/io/poll.wit

@@ -0,0 +1,47 @@
+package wasi:[email protected];
+
+/// A poll API intended to let users wait for I/O events on multiple handles
+/// at once.
+@since(version = 0.2.0)
+interface poll {
+    /// `pollable` represents a single I/O event which may be ready, or not.
+    @since(version = 0.2.0)
+    resource pollable {
+
+      /// Return the readiness of a pollable. This function never blocks.
+      ///
+      /// Returns `true` when the pollable is ready, and `false` otherwise.
+      @since(version = 0.2.0)
+      ready: func() -> bool;
+
+      /// `block` returns immediately if the pollable is ready, and otherwise
+      /// blocks until ready.
+      ///
+      /// This function is equivalent to calling `poll.poll` on a list
+      /// containing only this pollable.
+      @since(version = 0.2.0)
+      block: func();
+    }
+
+    /// Poll for completion on a set of pollables.
+    ///
+    /// This function takes a list of pollables, which identify I/O sources of
+    /// interest, and waits until one or more of the events is ready for I/O.
+    ///
+    /// The result `list<u32>` contains one or more indices of handles in the
+    /// argument list that is ready for I/O.
+    ///
+    /// This function traps if either:
+    /// - the list is empty, or:
+    /// - the list contains more elements than can be indexed with a `u32` value.
+    ///
+    /// A timeout can be implemented by adding a pollable from the
+    /// wasi-clocks API to the list.
+    ///
+    /// This function does not return a `result`; polling in itself does not
+    /// do any I/O so it doesn't fail. If any of the I/O sources identified by
+    /// the pollables has an error, it is indicated by marking the source as
+    /// being ready for I/O.
+    @since(version = 0.2.0)
+    poll: func(in: list<borrow<pollable>>) -> list<u32>;
+}