Refactored the scheduler and source interfaces to accommondate both polling (e.g., HTTP) sources and streaming (e.g., message queue) sources.

scheduler/scheduler.go

@@ -17,15 +17,27 @@ import (
 // one function everywhere without type mismatch friction.
 type Logger = logging.Logf
 
+// Job describes one scheduler task.
+//
+// A Job may be backed by either:
+//   - a polling source (sources.Source): uses Every + jitter and calls Poll()
+//   - a stream source (sources.StreamSource): ignores Every and calls Run()
+//
+// Jitter behavior:
+//   - For polling sources: Jitter is applied at startup and before each poll tick.
+//   - For stream sources: Jitter is applied once at startup only (optional; useful to avoid
+//     reconnect storms when many instances start together).
 type Job struct {
-	Source sources.Source
+	Source sources.Input
 	Every  time.Duration
 
 	// Jitter is the maximum additional delay added before each poll.
 	// Example: if Every=15m and Jitter=30s, each poll will occur at:
 	//   tick time + random(0..30s)
 	//
-	// If Jitter == 0, we compute a default jitter based on Every.
+	// If Jitter == 0 for polling sources, we compute a default jitter based on Every.
+	//
+	// For stream sources, Jitter is treated as *startup jitter only*.
 	Jitter time.Duration
 }
 
@@ -35,8 +47,9 @@ type Scheduler struct {
 	Logf Logger
 }
 
-// Run starts one polling goroutine per job.
-// Each job runs on its own interval and emits 0..N events per poll.
+// Run starts one goroutine per job.
+// Poll jobs run on their own interval and emit 0..N events per poll.
+// Stream jobs run continuously and emit events as they arrive.
 func (s *Scheduler) Run(ctx context.Context) error {
 	if s.Out == nil {
 		return fmt.Errorf("scheduler.Run: Out channel is nil")
@@ -59,17 +72,48 @@ func (s *Scheduler) runJob(ctx context.Context, job Job) {
 		s.logf("scheduler: job has nil source")
 		return
 	}
-	if job.Every <= 0 {
-		s.logf("scheduler: job %s has invalid interval", job.Source.Name())
+
+	// Stream sources: event-driven.
+	if ss, ok := job.Source.(sources.StreamSource); ok {
+		s.runStream(ctx, job, ss)
 		return
 	}
 
+	// Poll sources: time-based.
+	ps, ok := job.Source.(sources.Source)
+	if !ok {
+		s.logf("scheduler: source %T (%s) implements neither Poll() nor Run()", job.Source, job.Source.Name())
+		return
+	}
+	if job.Every <= 0 {
+		s.logf("scheduler: polling job %q missing/invalid interval (sources[].every)", ps.Name())
+		return
+	}
+
+	s.runPoller(ctx, job, ps)
+}
+
+func (s *Scheduler) runStream(ctx context.Context, job Job, src sources.StreamSource) {
+	// Optional startup jitter: helps avoid reconnect storms if many daemons start at once.
+	if job.Jitter > 0 {
+		rng := seededRNG(src.Name())
+		if !sleepJitter(ctx, rng, job.Jitter) {
+			return
+		}
+	}
+
+	// Stream sources should block until ctx cancel or fatal error.
+	if err := src.Run(ctx, s.Out); err != nil && ctx.Err() == nil {
+		s.logf("scheduler: stream source %q exited with error: %v", src.Name(), err)
+	}
+}
+
+func (s *Scheduler) runPoller(ctx context.Context, job Job, src sources.Source) {
 	// Compute jitter: either configured per job, or a sensible default.
 	jitter := effectiveJitter(job.Every, job.Jitter)
 
 	// Each worker gets its own RNG (safe + no lock contention).
-	seed := time.Now().UnixNano() ^ int64(hashStringFNV32a(job.Source.Name()))
-	rng := rand.New(rand.NewSource(seed))
+	rng := seededRNG(src.Name())
 
 	// Optional startup jitter: avoids all jobs firing at the exact moment the daemon starts.
 	if !sleepJitter(ctx, rng, jitter) {
@@ -77,7 +121,7 @@ func (s *Scheduler) runJob(ctx context.Context, job Job) {
 	}
 
 	// Immediate poll at startup (after startup jitter).
-	s.pollOnce(ctx, job)
+	s.pollOnce(ctx, src)
 
 	t := time.NewTicker(job.Every)
 	defer t.Stop()
@@ -89,7 +133,7 @@ func (s *Scheduler) runJob(ctx context.Context, job Job) {
 			if !sleepJitter(ctx, rng, jitter) {
 				return
 			}
-			s.pollOnce(ctx, job)
+			s.pollOnce(ctx, src)
 
 		case <-ctx.Done():
 			return
@@ -97,10 +141,10 @@ func (s *Scheduler) runJob(ctx context.Context, job Job) {
 	}
 }
 
-func (s *Scheduler) pollOnce(ctx context.Context, job Job) {
-	events, err := job.Source.Poll(ctx)
+func (s *Scheduler) pollOnce(ctx context.Context, src sources.Source) {
+	events, err := src.Poll(ctx)
 	if err != nil {
-		s.logf("scheduler: poll failed (%s): %v", job.Source.Name(), err)
+		s.logf("scheduler: poll failed (%s): %v", src.Name(), err)
 		return
 	}
 
@@ -120,6 +164,13 @@ func (s *Scheduler) logf(format string, args ...any) {
 	s.Logf(format, args...)
 }
 
+// ---- helpers ----
+
+func seededRNG(name string) *rand.Rand {
+	seed := time.Now().UnixNano() ^ int64(hashStringFNV32a(name))
+	return rand.New(rand.NewSource(seed))
+}
+
 // effectiveJitter chooses a jitter value.
 // - If configuredMax > 0, use it (but clamp).
 // - Else default to min(every/10, 30s).