feat: support for running immediately

cron.go

@@ -11,19 +11,20 @@ import (
 // specified by the schedule. It may be started, stopped, and the entries may
 // be inspected while running.
 type Cron struct {
-	entries   []*Entry
-	chain     Chain
-	stop      chan struct{}
-	add       chan *Entry
-	remove    chan EntryID
-	snapshot  chan chan []Entry
-	running   bool
-	logger    Logger
-	runningMu sync.Mutex
-	location  *time.Location
-	parser    ScheduleParser
-	nextID    EntryID
-	jobWaiter sync.WaitGroup
+	entries        []*Entry
+	chain          Chain
+	stop           chan struct{}
+	add            chan *Entry
+	remove         chan EntryID
+	snapshot       chan chan []Entry
+	immediatelyRun chan *Entry
+	running        bool
+	logger         Logger
+	runningMu      sync.Mutex
+	location       *time.Location
+	parser         ScheduleParser
+	nextID         EntryID
+	jobWaiter      sync.WaitGroup
 }
 
 // ScheduleParser is an interface for schedule spec parsers that return a Schedule
@@ -112,17 +113,18 @@ func (s byTime) Less(i, j int) bool {
 // See "cron.With*" to modify the default behavior.
 func New(opts ...Option) *Cron {
 	c := &Cron{
-		entries:   nil,
-		chain:     NewChain(),
-		add:       make(chan *Entry),
-		stop:      make(chan struct{}),
-		snapshot:  make(chan chan []Entry),
-		remove:    make(chan EntryID),
-		running:   false,
-		runningMu: sync.Mutex{},
-		logger:    DefaultLogger,
-		location:  time.Local,
-		parser:    standardParser,
+		entries:        nil,
+		chain:          NewChain(),
+		add:            make(chan *Entry),
+		stop:           make(chan struct{}),
+		snapshot:       make(chan chan []Entry),
+		remove:         make(chan EntryID),
+		immediatelyRun: make(chan *Entry),
+		running:        false,
+		runningMu:      sync.Mutex{},
+		logger:         DefaultLogger,
+		location:       time.Local,
+		parser:         standardParser,
 	}
 	for _, opt := range opts {
 		opt(c)
@@ -234,6 +236,12 @@ func (c *Cron) Run() {
 	c.run()
 }
 
+// ImmediatelyRun schedule the job immediately
+func (c *Cron) ImmediatelyRun(id EntryID) {
+	entry := c.Entry(id)
+	c.immediatelyRun <- &entry
+}
+
 // run the scheduler.. this is private just due to the need to synchronize
 // access to the 'running' state variable.
 func (c *Cron) run() {
@@ -297,6 +305,14 @@ func (c *Cron) run() {
 				now = c.now()
 				c.removeEntry(id)
 				c.logger.Info("removed", "entry", id)
+
+			case entry := <-c.immediatelyRun:
+				timer.Stop()
+				now = c.now()
+				c.startJob(entry.WrappedJob)
+				entry.Prev = now
+				entry.Next = now
+				c.logger.Info("run immediately", "now", now, "entry", entry.ID, "next", entry.Next)
 			}
 
 			break