Add next tick for job in job scheduler

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "tokio-cron-scheduler"
-version = "0.8.0"
+version = "0.8.1"
 authors = ["Michael van Niekerk <[email protected]>"]
 edition = "2018"
 

README.md

@@ -59,8 +59,13 @@ async fn main() {
         println!("I run every 10 seconds");
     }).await.unwrap());
 
-    sched.add(Job::new_async("1/7 * * * * *", |uuid, l| Box::pin( async {
+    sched.add(Job::new_async("1/7 * * * * *", |uuid, mut l| Box::pin( async {
         println!("I run async every 7 seconds");
+        let next_tick = l.next_tick_for_job(uuid).await;
+        match next_tick {
+          Ok(Some(ts)) => info!("Next time for 7s is {:?}", ts),
+          _ => warn!("Could not get next tick for 7s job"),
+        }
     })).await.unwrap());
 
     sched.add(Job::new("1/30 * * * * *", |uuid, l| {

examples/lib.rs

@@ -1,7 +1,7 @@
 use anyhow::Result;
 use std::time::Duration;
 use tokio_cron_scheduler::{Job, JobScheduler};
-use tracing::{error, info};
+use tracing::{error, info, warn};
 
 pub async fn run_example(mut sched: JobScheduler) -> Result<()> {
     #[cfg(feature = "signal")]
@@ -40,9 +40,15 @@ pub async fn run_example(mut sched: JobScheduler) -> Result<()> {
     let five_s_job_guid = five_s_job.guid();
     sched.add(five_s_job).await?;
 
-    let mut four_s_job_async = Job::new_async("1/4 * * * * *", |uuid, _l| {
+    let mut four_s_job_async = Job::new_async("1/4 * * * * *", |uuid, l| {
+        let mut l = l.clone();
         Box::pin(async move {
             info!("I run async every 4 seconds id {:?}", uuid);
+            let next_tick = l.next_tick_for_job(uuid).await;
+            match next_tick {
+                Ok(Some(ts)) => info!("Next time for 4s is {:?}", ts),
+                _ => warn!("Could not get next tick for 4s job"),
+            }
         })
     })
     .unwrap();

src/job_scheduler.rs

@@ -8,6 +8,7 @@ use crate::simple::{
     SimpleJobCode, SimpleMetadataStore, SimpleNotificationCode, SimpleNotificationStore,
 };
 use crate::store::{MetaDataStorage, NotificationStore};
+use chrono::{DateTime, NaiveDateTime, Utc};
 use std::future::Future;
 use std::pin::Pin;
 use std::sync::Arc;
@@ -382,6 +383,28 @@ impl JobsSchedulerLocked {
         }
     }
 
+    /// `next_tick_for_job` returns the date/time for when the next tick will
+    /// be for a job
+    pub async fn next_tick_for_job(
+        &mut self,
+        job_id: Uuid,
+    ) -> Result<Option<DateTime<Utc>>, JobSchedulerError> {
+        if !self.inited().await {
+            let mut s = self.clone();
+            s.init().await?;
+        }
+        let next_tick = {
+            let mut r = self.context.metadata_storage.write().await;
+            r.get(job_id).await.map(|v| {
+                v.map(|vv| vv.next_tick)
+                    .filter(|t| *t != 0)
+                    .map(|ts| NaiveDateTime::from_timestamp(ts as i64, 0))
+                    .map(|ts| DateTime::from_utc(ts, Utc))
+            })
+        };
+        next_tick
+    }
+
     ///
     /// Shut the scheduler down
     pub async fn shutdown(&mut self) -> Result<(), JobSchedulerError> {