Bring back checkdb for polling newly available tasks

jobs-actix/src/server.rs

@@ -2,6 +2,7 @@ use crate::{
     storage::{ActixStorage, StorageWrapper},
     worker::Worker,
 };
+use actix::clock::{interval_at, Duration, Instant};
 use anyhow::Error;
 use background_jobs_core::{NewJobInfo, ReturnJobInfo, Stats, Storage};
 use log::{error, trace};
@@ -32,10 +33,42 @@ impl Server {
     where
         S: Storage + Sync + 'static,
     {
-        Server {
+        let server = Server {
             storage: Arc::new(StorageWrapper(storage)),
             cache: ServerCache::new(),
+        };
+
+        let server2 = server.clone();
+        actix::spawn(async move {
+            let mut interval = interval_at(Instant::now(), Duration::from_secs(1));
+
+            loop {
+                interval.tick().await;
+                if let Err(e) = server.check_db().await {
+                    error!("Error while checking database for new jobs, {}", e);
+                }
+            }
+        });
+
+        server2
+    }
+
+    async fn check_db(&self) -> Result<(), Error> {
+        for queue in self.cache.keys().await {
+            'worker_loop: while let Some(worker) = self.cache.pop(queue.clone()).await {
+                if let Ok(Some(job)) = self.storage.request_job(&queue, worker.id()).await {
+                    if let Err(job) = worker.process_job(job).await {
+                        error!("Worker has hung up");
+                        self.storage.return_job(job.unexecuted()).await?
+                    }
+                } else {
+                    self.cache.push(queue.clone(), worker).await;
+                    break 'worker_loop;
+                }
+            }
         }
+
+        Ok(())
     }
 
     pub(crate) async fn new_job(&self, job: NewJobInfo) -> Result<(), Error> {
@@ -100,6 +133,12 @@ impl ServerCache {
         }
     }
 
+    async fn keys(&self) -> Vec<String> {
+        let cache = self.cache.lock().await;
+
+        cache.keys().cloned().collect()
+    }
+
     async fn push(&self, queue: String, worker: Box<dyn Worker + Send>) {
         let mut cache = self.cache.lock().await;