harmos-runtime 0.1.7

/* ***
 *
 * Harmos
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * ***
 */

/* === Modules === */

/* === Re-Exports === */

/* === Imports === */

// Standard Library Imports
use std::sync::{
    Arc,
    atomic::{AtomicUsize, Ordering},
};

use std::time::Duration;

// Third Party Imports

// Local Imports
use super::{Lanes, app::App};
use harmos_runtime::operations::RetryPolicy;
use harmos_runtime::{Runtime, state::Position};

/* === Constants === */

/* === Macros === */

/* === Type Aliases === */

/* === Structs === */

struct Bench {
    device: String,
    reads: AtomicUsize,
}

/* === Enums === */

#[harmos_runtime::operation(resources = [Bench, harmos_runtime::operations::HostContext], operations = [ReadContractDeclaration], response = Reading,
        id = "resources.read",
        policy = harmos_runtime::OperationPolicy {
            timeout: Duration::from_secs(2),
            attempt_timeout: Duration::from_secs(1),
            retries: RetryPolicy::Never,
        },
    )]
struct ReadContractDeclaration {
    nested: bool,
}

// The Device A Read Saw And How Many Reads Preceded It.
#[harmos_runtime::message]
struct Reading {
    device: String,
    seen: u64,
}

#[harmos_runtime::catalog]
enum Operations {
    ReadContractDeclaration(ReadContractDeclaration),
}

/* === Traits === */

/* === Implementations === */

impl harmos_runtime::Operation for ReadContractDeclaration {
    type Error = harmos_runtime::operations::InvocationError;

    async fn run(self, ctx: harmos_runtime::Context<'_, Self>) -> Result<harmos_runtime::Response<Reading>, Self::Error> {
        let resources = ctx.resource::<Bench>();
        let host = ctx.resource::<harmos_runtime::operations::HostContext>();
        assert!(Arc::ptr_eq(&resources, host.borrow().scope().resources::<App<Arc<Bench>>>()));
        let seen = u64::try_from(resources.reads.fetch_add(1, Ordering::SeqCst)).expect("read counts fit in u64");
        if self.nested {
            let child = ctx.operation(ReadContractDeclaration { nested: false }).await?;
            assert_eq!(child.device, resources.device);
            assert_eq!(child.seen, seen + 1);
        }
        Ok(Reading { device: resources.device.clone(), seen }.into())
    }
}

/* === Public Functions === */

/* === Private Functions === */

/* === Tests === */

#[tokio::test]
async fn needs_lacks_registration() {
    let runtime = Runtime::<App>::builder((), ()).runtime().await.unwrap();
    assert_eq!(runtime.stop().await.unwrap(), Position::ORIGIN);
}

#[tokio::test]
async fn child_own_resources() {
    let resources = Arc::new(Bench {
        device: "sim://rig-a".to_owned(),
        reads: AtomicUsize::new(0),
    });
    let runtime = Runtime::<App<Arc<Bench>>>::builder((), resources.clone()).register(Lanes::catalog()).runtime().await.unwrap();
    runtime
        .operations
        .register(harmos_runtime::RegistrationExt::lane(
            harmos_runtime::RegistrationBatch::new({
                let mut dependencies = harmos_runtime::Dependencies::new();
                dependencies.insert(resources.clone()).unwrap();
                dependencies
            })
            .operation::<ReadContractDeclaration>(),
            Lanes::Open,
        ))
        .await
        .unwrap();

    let parent = runtime.operation(ReadContractDeclaration { nested: true }).start().await.unwrap().await.unwrap();
    assert_eq!(parent.device, "sim://rig-a");
    assert_eq!(parent.seen, 0);
    let following = runtime.operation(ReadContractDeclaration { nested: false }).start().await.unwrap().await.unwrap();
    assert_eq!(following.seen, 2, "parent, child and following attempt share one value");
    runtime.stop().await.unwrap();
}