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)
+}

pkg/scheduler/bucket_test.go

@@ -0,0 +1,63 @@
+package scheduler
+
+import (
+	"testing"
+
+	"fiskerinc.com/modules/testhelper"
+)
+
+func TestBucketProcess(t *testing.T) {
+	bucket := Bucket[int]{}
+	actual := []int{}
+
+	bucket.elements[1] = []int{1, 2, 3}
+
+	double := func(element int) {
+		actual = append(actual, element*2)
+	}
+
+	bucket.Process(double)
+
+	if len(bucket.elements[1]) != 0 {
+		t.Errorf("Expected bucket to be clearsd after processing, but it wasn't")
+	}
+
+	if bucket.bucket != 1 {
+		t.Errorf("Expected active bucket to be incremented, but it wasn't")
+	}
+
+	expected := []int{2, 4, 6}
+	for i := 0; i < len(expected); i++ {
+		if actual[i] != expected[i] {
+			t.Errorf(testhelper.TestErrorTemplate, "Bucket.Process()", expected, actual)
+		}
+	}
+}
+
+func TestBucketLoop(t *testing.T) {
+	bucket := Bucket[int]{}
+
+	stub := func(element int) {}
+
+	bucket.Process(stub)
+	bucket.Process(stub)
+	bucket.Process(stub)
+	bucket.Process(stub)
+	bucket.Process(stub)
+	bucket.Process(stub)
+	bucket.Process(stub)
+	bucket.Process(stub)
+	bucket.Process(stub)
+	bucket.Process(stub)
+	bucket.Process(stub)
+
+	if bucket.bucket != 11 {
+		t.Errorf("Expected active bucket to be 11, got %d", bucket.bucket)
+	}
+
+	bucket.Process(stub)
+
+	if bucket.bucket != 0 {
+		t.Errorf("Expected active bucket to be 0, got %d", bucket.bucket)
+	}
+}