Initial cloud-services repo - gateway service + pkg modules

pkg/scheduler/bucket.go

@@ -0,0 +1,52 @@
+package scheduler
+
+import (
+	"sync"
+)
+
+// Assign elements to a bucket and perform an action 12 cycles later. This can be
+// used in conjunction with a cron job to perform cleanup tasks at a constant point
+// in the future.
+type Bucket[T any] struct {
+	elements [12][]T
+	bucket   int
+	mutex    sync.Mutex
+}
+
+type BucketInterface[T any] interface {
+	Process(handler func(element Bucket[T]))
+	Schedule(element T) error
+	clear()
+	lapse()
+}
+
+// Run a callback on each element in next bucket, then clear
+func (e *Bucket[T]) Process(handler func(element T)) {
+	e.mutex.Lock()
+	defer e.mutex.Unlock()
+	e.lapse()
+	if len(e.elements[e.bucket]) > 0 {
+		for _, element := range e.elements[e.bucket] {
+			handler(element)
+		}
+		e.clear()
+	}
+}
+
+// Add element to a bucket to be deleted later
+func (e *Bucket[T]) Schedule(element T) {
+	e.mutex.Lock()
+	defer e.mutex.Unlock()
+	e.elements[e.bucket] = append(e.elements[e.bucket], element)
+}
+
+// Remove all elements from current bucket
+func (e *Bucket[T]) clear() {
+	e.elements[e.bucket] = []T{}
+}
+
+// Increment the active bucket
+func (e *Bucket[T]) lapse() {
+	e.bucket += 1
+	e.bucket %= len(e.elements)
+}