Merge pull request #303 from emmatebibyte/unix-time

Add UNIX time API

kindling/host/src/time.rs

@@ -28,6 +28,9 @@ lazy_static::lazy_static! {
 
     static ref STOPWATCH_FACTORY: RequestResponse<(), ()> =
         RequestResponse::expect_service("hearth.StopwatchFactory");
+
+    static ref UNIX_TIME: RequestResponse<(), u128> =
+        RequestResponse::expect_service("hearth.UnixTime");
 }
 
 /// Sleeps for the given time in seconds.
@@ -41,6 +44,12 @@ pub fn sleep(duration: f32) {
     let _ = reply.recv_raw();
 }
 
+/// Gets the time since the UNIX epoch in nanoseconds as a unsigned 128-bit
+/// integer.
+pub fn get_unix_time() -> u128 {
+    UNIX_TIME.request((), &[]).0
+}
+
 pub struct Timer(RequestResponse<f32, ()>);
 
 impl Default for Timer {

plugins/time/src/lib.rs

@@ -16,6 +16,8 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with Hearth. If not, see <https://www.gnu.org/licenses/>.
 
+use std::time::SystemTime;
+
 use hearth_runtime::{
     async_trait,
     flue::Table,
@@ -34,7 +36,11 @@ use hearth_runtime::{
 
 /// A plugin that provides timing services to guests.
 ///
-/// Adds the [SleepService], [TimerFactory], and [StopwatchFactory] services.
+/// Adds the following services:
+/// - [SleepService]
+/// - [TimerFactory]
+/// - [StopwatchFactory]
+/// - [UnixTimeService]
 #[derive(Default)]
 pub struct TimePlugin;
 
@@ -43,7 +49,8 @@ impl Plugin for TimePlugin {
         builder
             .add_plugin(SleepService)
             .add_plugin(TimerFactory)
-            .add_plugin(StopwatchFactory);
+            .add_plugin(StopwatchFactory)
+            .add_plugin(UnixTimeService);
     }
 }
 
@@ -203,3 +210,32 @@ impl RequestResponseProcess for Stopwatch {
         }
     }
 }
+
+/// Native service that returns time since the UNIX epoch in nanoseconds as an
+/// unsigned 128-bit integer.
+#[derive(GetProcessMetadata)]
+pub struct UnixTimeService;
+
+#[async_trait]
+impl RequestResponseProcess for UnixTimeService {
+    type Request = ();
+    type Response = u128;
+
+    async fn on_request<'a>(
+        &'a mut self,
+        _request: &mut RequestInfo<'a, Self::Request>,
+    ) -> ResponseInfo<'a, Self::Response> {
+        let time_since_epoch = SystemTime::now()
+            .duration_since(SystemTime::UNIX_EPOCH)
+            .expect("system time before UNIX epoch");
+
+        ResponseInfo {
+            data: time_since_epoch.as_nanos(),
+            caps: vec![],
+        }
+    }
+}
+
+impl ServiceRunner for UnixTimeService {
+    const NAME: &'static str = "hearth.UnixTime";
+}