Add support for passing custom context via a JobRegistry

.github/workflows/toolchain.yml

@@ -52,6 +52,8 @@ jobs:
   test:
     name: Test
     runs-on: ubuntu-latest
+    env:
+      RUST_BACKTRACE: "1"
     steps:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
@@ -67,10 +69,13 @@ jobs:
       - uses: actions-rs/cargo@v1
         with:
           command: test
+          args: -- --nocapture
 
   test_nightly:
     name: Test (Nightly)
     runs-on: ubuntu-latest
+    env:
+      RUST_BACKTRACE: "1"
     steps:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
@@ -86,3 +91,4 @@ jobs:
       - uses: actions-rs/cargo@v1
         with:
           command: test
+          args: -- --nocapture

.vscode/settings.json

@@ -0,0 +1,4 @@
+{
+    "rust-analyzer.checkOnSave.allFeatures": false,
+    "rust-analyzer.cargo.allFeatures": false
+}

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "sqlxmq"
-version = "0.1.2"
+version = "0.2.0"
 authors = ["Diggory Blake <diggsey@googlemail.com>"]
 edition = "2018"
 license = "MIT OR Apache-2.0"
@@ -16,14 +16,15 @@ members = ["sqlxmq_macros", "sqlxmq_stress"]
 
 [dependencies]
 sqlx = { version = "0.5.2", features = ["postgres", "chrono", "uuid"] }
-tokio = { version = "1.4.0", features = ["full"] }
+tokio = { version = "=1.8.0", features = ["full"] }
 dotenv = "0.15.0"
 chrono = "0.4.19"
 uuid = { version = "0.8.2", features = ["v4"] }
 log = "0.4.14"
 serde_json = "1.0.64"
 serde = "1.0.124"
-sqlxmq_macros = { version = "0.1", path = "sqlxmq_macros" }
+sqlxmq_macros = { version = "0.2.0", path = "sqlxmq_macros" }
+anymap2 = "0.13.0"
 
 [features]
 default = ["runtime-tokio-native-tls"]

README.md

@@ -127,13 +127,17 @@ use sqlxmq::{job, CurrentJob};
 // Arguments to the `#[job]` attribute allow setting default job options.
 #[job(channel_name = "foo")]
 async fn example_job(
+    // The first argument should always be the current job.
     mut current_job: CurrentJob,
+    // Additional arguments are optional, but can be used to access context
+    // provided via `JobRegistry::set_context`.
+    message: &'static str,
 ) -> sqlx::Result<()> {
     // Decode a JSON payload
     let who: Option<String> = current_job.json()?;
 
     // Do some work
-    println!("Hello, {}!", who.as_deref().unwrap_or("world"));
+    println!("{}, {}!", message, who.as_deref().unwrap_or("world"));
 
     // Mark the job as complete
     current_job.complete().await?;
@@ -160,6 +164,9 @@ async fn main() -> Result<(), Box<dyn Error>> {
     // Here is where you can configure the registry
     // registry.set_error_handler(...)
 
+    // And add context
+    registry.set_context("Hello");
+
     let runner = registry
         // Create a job runner using the connection pool.
         .runner(&pool)

sqlxmq_macros/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "sqlxmq_macros"
-version = "0.1.2"
+version = "0.2.0"
 authors = ["Diggory Blake <diggsey@googlemail.com>"]
 edition = "2018"
 license = "MIT OR Apache-2.0"

sqlxmq_macros/src/lib.rs

@@ -92,8 +92,12 @@ fn interpret_job_arg(options: &mut JobOptions, arg: NestedMeta) -> Result<()> {
 
 /// Marks a function as being a background job.
 ///
-/// The function must take a single `CurrentJob` argument, and should
-/// be async or return a future.
+/// The first argument to the function must have type `CurrentJob`.
+/// Additional arguments can be used to access context from the job
+/// registry. Context is accessed based on the type of the argument.
+/// Context arguments must be `Send + Sync + Clone + 'static`.
+///
+/// The function should be async or return a future.
 ///
 /// The async result must be a `Result<(), E>` type, where `E` is convertible
 /// to a `Box<dyn Error + Send + Sync + 'static>`, which is the case for most
@@ -103,7 +107,7 @@ fn interpret_job_arg(options: &mut JobOptions, arg: NestedMeta) -> Result<()> {
 ///
 /// # Name
 ///
-/// ```
+/// ```ignore
 /// #[job("example")]
 /// #[job(name="example")]
 /// ```
@@ -115,7 +119,7 @@ fn interpret_job_arg(options: &mut JobOptions, arg: NestedMeta) -> Result<()> {
 ///
 /// # Channel name
 ///
-/// ```
+/// ```ignore
 /// #[job(channel_name="foo")]
 /// ```
 ///
@@ -123,7 +127,7 @@ fn interpret_job_arg(options: &mut JobOptions, arg: NestedMeta) -> Result<()> {
 ///
 /// # Retries
 ///
-/// ```
+/// ```ignore
 /// #[job(retries = 3)]
 /// ```
 ///
@@ -131,7 +135,7 @@ fn interpret_job_arg(options: &mut JobOptions, arg: NestedMeta) -> Result<()> {
 ///
 /// # Retry backoff
 ///
-/// ```
+/// ```ignore
 /// #[job(backoff_secs=1.5)]
 /// #[job(backoff_secs=2)]
 /// ```
@@ -140,7 +144,7 @@ fn interpret_job_arg(options: &mut JobOptions, arg: NestedMeta) -> Result<()> {
 ///
 /// # Ordered
 ///
-/// ```
+/// ```ignore
 /// #[job(ordered)]
 /// #[job(ordered=true)]
 /// #[job(ordered=false)]
@@ -150,7 +154,7 @@ fn interpret_job_arg(options: &mut JobOptions, arg: NestedMeta) -> Result<()> {
 ///
 /// # Prototype
 ///
-/// ```
+/// ```ignore
 /// fn my_proto<'a, 'b>(
 ///     builder: &'a mut JobBuilder<'b>
 /// ) -> &'a mut JobBuilder<'b> {
@@ -170,7 +174,7 @@ fn interpret_job_arg(options: &mut JobOptions, arg: NestedMeta) -> Result<()> {
 /// prototype will always be applied first so that explicit options can override it.
 /// Each option can only be provided once in the attribute.
 ///
-/// ```
+/// ```ignore
 /// #[job("my_job", proto(my_proto), retries=0, ordered)]
 /// ```
 ///
@@ -223,6 +227,18 @@ pub fn job(attr: TokenStream, item: TokenStream) -> TokenStream {
         });
     }
 
+    let extract_ctx: Vec<_> = inner_fn
+        .sig
+        .inputs
+        .iter()
+        .skip(1)
+        .map(|_| {
+            quote! {
+                registry.context()
+            }
+        })
+        .collect();
+
     let expanded = quote! {
         #(#errors)*
         #[allow(non_upper_case_globals)]
@@ -234,7 +250,7 @@ pub fn job(attr: TokenStream, item: TokenStream) -> TokenStream {
                     builder #(#chain)*
                 }),
                 sqlxmq::hidden::RunFn(|registry, current_job| {
-                    registry.spawn_internal(#fq_name, inner(current_job));
+                    registry.spawn_internal(#fq_name, inner(current_job #(, #extract_ctx)*));
                 }),
             )
         };

src/lib.rs

@@ -126,13 +126,17 @@
 //! // Arguments to the `#[job]` attribute allow setting default job options.
 //! #[job(channel_name = "foo")]
 //! async fn example_job(
+//!     // The first argument should always be the current job.
 //!     mut current_job: CurrentJob,
+//!     // Additional arguments are optional, but can be used to access context
+//!     // provided via [`JobRegistry::set_context`].
+//!     message: &'static str,
 //! ) -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
 //!     // Decode a JSON payload
 //!     let who: Option<String> = current_job.json()?;
 //!
 //!     // Do some work
-//!     println!("Hello, {}!", who.as_deref().unwrap_or("world"));
+//!     println!("{}, {}!", message, who.as_deref().unwrap_or("world"));
 //!
 //!     // Mark the job as complete
 //!     current_job.complete().await?;
@@ -172,6 +176,9 @@
 //!     // Here is where you can configure the registry
 //!     // registry.set_error_handler(...)
 //!
+//!     // And add context
+//!     registry.set_context("Hello");
+//!
 //!     let runner = registry
 //!         // Create a job runner using the connection pool.
 //!         .runner(&pool)
@@ -321,12 +328,22 @@ mod tests {
         Ok(())
     }
 
+    #[job]
+    async fn example_job_with_ctx(
+        mut current_job: CurrentJob,
+        ctx1: i32,
+        ctx2: &'static str,
+    ) -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
+        assert_eq!(ctx1, 42);
+        assert_eq!(ctx2, "Hello, world!");
+        current_job.complete().await?;
+        Ok(())
+    }
+
     async fn named_job_runner(pool: &Pool<Postgres>) -> OwnedHandle {
-        JobRegistry::new(&[example_job1, example_job2])
-            .runner(pool)
-            .run()
-            .await
-            .unwrap()
+        let mut registry = JobRegistry::new(&[example_job1, example_job2, example_job_with_ctx]);
+        registry.set_context(42).set_context("Hello, world!");
+        registry.runner(pool).run().await.unwrap()
     }
 
     async fn pause() {
@@ -339,6 +356,7 @@ mod tests {
 
     #[tokio::test]
     async fn it_can_spawn_job() {
+        {
             let pool = &*test_pool().await;
             let (_runner, counter) =
                 test_job_runner(&pool, |mut job| async move { job.complete().await }).await;
@@ -348,9 +366,12 @@ mod tests {
             pause().await;
             assert_eq!(counter.load(Ordering::SeqCst), 1);
         }
+        pause().await;
+    }
 
     #[tokio::test]
     async fn it_runs_jobs_in_order() {
+        {
             let pool = &*test_pool().await;
             let (tx, mut rx) = mpsc::unbounded();
 
@@ -383,9 +404,12 @@ mod tests {
             pause().await;
             assert_eq!(counter.load(Ordering::SeqCst), 2);
         }
+        pause().await;
+    }
 
     #[tokio::test]
     async fn it_runs_jobs_in_parallel() {
+        {
             let pool = &*test_pool().await;
             let (tx, mut rx) = mpsc::unbounded();
 
@@ -409,9 +433,12 @@ mod tests {
                 job.complete().await.unwrap();
             }
         }
+        pause().await;
+    }
 
     #[tokio::test]
     async fn it_retries_failed_jobs() {
+        {
             let pool = &*test_pool().await;
             let (_runner, counter) = test_job_runner(&pool, move |_| async {}).await;
 
@@ -443,9 +470,12 @@ mod tests {
             pause_ms(backoff * 5).await;
             assert_eq!(counter.load(Ordering::SeqCst), 3);
         }
+        pause().await;
+    }
 
     #[tokio::test]
     async fn it_can_checkpoint_jobs() {
+        {
             let pool = &*test_pool().await;
             let (_runner, counter) = test_job_runner(&pool, move |mut current_job| async move {
                 let state: bool = current_job.json().unwrap().unwrap();
@@ -485,14 +515,20 @@ mod tests {
             pause_ms(backoff * 3).await;
             assert_eq!(counter.load(Ordering::SeqCst), 2);
         }
+        pause().await;
+    }
 
     #[tokio::test]
     async fn it_can_use_registry() {
+        {
             let pool = &*test_pool().await;
             let _runner = named_job_runner(pool).await;
 
             example_job1.builder().spawn(pool).await.unwrap();
             example_job2.builder().spawn(pool).await.unwrap();
+            example_job_with_ctx.builder().spawn(pool).await.unwrap();
+            pause().await;
+        }
         pause().await;
     }
 }

src/registry.rs

@@ -1,9 +1,12 @@
+use std::any::type_name;
 use std::collections::HashMap;
 use std::error::Error;
 use std::fmt::Display;
 use std::future::Future;
 use std::sync::Arc;
 
+use anymap2::any::CloneAnySendSync;
+use anymap2::Map;
 use sqlx::{Pool, Postgres};
 use uuid::Uuid;
 
@@ -16,6 +19,7 @@ use crate::{JobBuilder, JobRunnerOptions};
 pub struct JobRegistry {
     error_handler: Arc<dyn Fn(&str, Box<dyn Error + Send + 'static>) + Send + Sync>,
     job_map: HashMap<&'static str, &'static NamedJob>,
+    context: Map<dyn CloneAnySendSync + Send + Sync>,
 }
 
 /// Error returned when a job is received whose name is not in the registry.
@@ -41,6 +45,7 @@ impl JobRegistry {
         Self {
             error_handler: Arc::new(Self::default_error_handler),
             job_map,
+            context: Map::new(),
         }
     }
 
@@ -53,6 +58,24 @@ impl JobRegistry {
         self
     }
 
+    /// Provide context for the jobs.
+    pub fn set_context<C: Clone + Send + Sync + 'static>(&mut self, context: C) -> &mut Self {
+        self.context.insert(context);
+        self
+    }
+
+    /// Access job context. Will panic if context with this type has not been provided.
+    pub fn context<C: Clone + Send + Sync + 'static>(&self) -> C {
+        if let Some(c) = self.context.get::<C>() {
+            c.clone()
+        } else {
+            panic!(
+                "No context of type `{}` has been provided.",
+                type_name::<C>()
+            );
+        }
+    }
+
     /// Look-up a job by name.
     pub fn resolve_job(&self, name: &str) -> Option<&'static NamedJob> {
         self.job_map.get(name).copied()

src/runner.rs

@@ -123,6 +123,13 @@ impl CurrentJob {
             .await?;
         Ok(())
     }
+
+    async fn stop_keep_alive(&mut self) {
+        if let Some(keep_alive) = self.keep_alive.take() {
+            keep_alive.stop().await;
+        }
+    }
+
     /// Complete this job and commit the provided transaction at the same time.
     /// If the transaction cannot be committed, the job will not be completed.
     pub async fn complete_with_transaction(
@@ -131,13 +138,13 @@ impl CurrentJob {
     ) -> Result<(), sqlx::Error> {
         self.delete(&mut tx).await?;
         tx.commit().await?;
-        self.keep_alive = None;
+        self.stop_keep_alive().await;
         Ok(())
     }
     /// Complete this job.
     pub async fn complete(&mut self) -> Result<(), sqlx::Error> {
         self.delete(self.pool()).await?;
-        self.keep_alive = None;
+        self.stop_keep_alive().await;
         Ok(())
     }
     /// Checkpoint this job and commit the provided transaction at the same time.
@@ -254,7 +261,7 @@ impl JobRunnerOptions {
             notify: Notify::new(),
         });
         let listener_task = start_listener(job_runner.clone()).await?;
-        Ok(OwnedHandle(task::spawn(main_loop(
+        Ok(OwnedHandle::new(task::spawn(main_loop(
             job_runner,
             listener_task,
         ))))
@@ -271,7 +278,7 @@ async fn start_listener(job_runner: Arc<JobRunner>) -> Result<OwnedHandle, sqlx:
     } else {
         listener.listen("mq").await?;
     }
-    Ok(OwnedHandle(task::spawn(async move {
+    Ok(OwnedHandle::new(task::spawn(async move {
         let mut num_errors = 0;
         loop {
             if num_errors > 0 || listener.recv().await.is_ok() {
@@ -356,7 +363,7 @@ async fn poll_and_dispatch(
         {
             let retry_backoff = to_duration(retry_backoff);
             let keep_alive = if options.keep_alive {
-                Some(OwnedHandle(task::spawn(keep_job_alive(
+                Some(OwnedHandle::new(task::spawn(keep_job_alive(
                     id,
                     options.pool.clone(),
                     retry_backoff,

src/utils.rs

@@ -31,10 +31,29 @@ impl<T: Any> DerefMut for Opaque<T> {
 /// the handle is dropped. Extract the inner join handle to prevent this
 /// behaviour.
 #[derive(Debug)]
-pub struct OwnedHandle(pub JoinHandle<()>);
+pub struct OwnedHandle(Option<JoinHandle<()>>);
+
+impl OwnedHandle {
+    /// Construct a new `OwnedHandle` from the provided `JoinHandle`
+    pub fn new(inner: JoinHandle<()>) -> Self {
+        Self(Some(inner))
+    }
+    /// Get back the original `JoinHandle`
+    pub fn into_inner(mut self) -> JoinHandle<()> {
+        self.0.take().expect("Only consumed once")
+    }
+    /// Stop the task and wait for it to finish.
+    pub async fn stop(self) {
+        let handle = self.into_inner();
+        handle.abort();
+        let _ = handle.await;
+    }
+}
 
 impl Drop for OwnedHandle {
     fn drop(&mut self) {
-        self.0.abort();
+        if let Some(handle) = self.0.take() {
+            handle.abort();
+        }
     }
 }