diff --git a/trace/evictedqueue.go b/trace/evictedqueue.go index ffc264f23..05156520f 100644 --- a/trace/evictedqueue.go +++ b/trace/evictedqueue.go @@ -15,24 +15,45 @@ package trace type evictedQueue struct { - queue []interface{} + ringQueue []interface{} capacity int droppedCount int + writeIdx int + readIdx int + startRead bool } func newEvictedQueue(capacity int) *evictedQueue { eq := &evictedQueue{ - capacity: capacity, - queue: make([]interface{}, 0), + capacity: capacity, + ringQueue: make([]interface{}, 0), } return eq } func (eq *evictedQueue) add(value interface{}) { - if len(eq.queue) == eq.capacity { - eq.queue = eq.queue[1:] - eq.droppedCount++ + if len(eq.ringQueue) < eq.capacity { + eq.ringQueue = append(eq.ringQueue, value) + return } - eq.queue = append(eq.queue, value) + + eq.ringQueue[eq.writeIdx] = value + eq.droppedCount++ + eq.writeIdx++ + eq.writeIdx %= eq.capacity + eq.readIdx = eq.writeIdx +} + +// Do not add more item after use readNext +func (eq *evictedQueue) readNext() interface{} { + if eq.startRead && eq.readIdx == eq.writeIdx { + return nil + } + + eq.startRead = true + res := eq.ringQueue[eq.readIdx] + eq.readIdx++ + eq.readIdx %= eq.capacity + return res } diff --git a/trace/evictedqueue_test.go b/trace/evictedqueue_test.go index 0e10fa5db..2dd6de297 100644 --- a/trace/evictedqueue_test.go +++ b/trace/evictedqueue_test.go @@ -22,44 +22,48 @@ import ( func init() { } -func TestAdd(t *testing.T) { - q := newEvictedQueue(3) - q.add("value1") - q.add("value2") - if wantLen, gotLen := 2, len(q.queue); wantLen != gotLen { - t.Errorf("got queue length %d want %d", gotLen, wantLen) - } -} +func TestAddAndReadNext(t *testing.T) { + t.Run("len(ringQueue) < capacity", func(t *testing.T) { + values := []string{"value1", "value2"} + capacity := 3 + q := newEvictedQueue(capacity) -func (eq *evictedQueue) queueToArray() []string { - arr := make([]string, 0) - for _, value := range eq.queue { - arr = append(arr, value.(string)) - } - return arr -} + for _, value := range values { + q.add(value) + } + + gotValues := make([]string, len(q.ringQueue)) + for i := 0; i < len(gotValues); i++ { + gotValues[i] = q.readNext().(string) + } + + if !reflect.DeepEqual(values, gotValues) { + t.Errorf("got array = %#v; want %#v", gotValues, values) + } + }) + t.Run("dropped count", func(t *testing.T) { + values := []string{"value1", "value2", "value3", "value1", "value4", "value1", "value3", "value1", "value4"} + wantValues := []string{"value3", "value1", "value4"} + capacity := 3 + wantDroppedCount := len(values) - capacity + + q := newEvictedQueue(capacity) + + for _, value := range values { + q.add(value) + } -func TestDropCount(t *testing.T) { - q := newEvictedQueue(3) - q.add("value1") - q.add("value2") - q.add("value3") - q.add("value1") - q.add("value4") - if wantLen, gotLen := 3, len(q.queue); wantLen != gotLen { - t.Errorf("got queue length %d want %d", gotLen, wantLen) - } - if wantDropCount, gotDropCount := 2, q.droppedCount; wantDropCount != gotDropCount { - t.Errorf("got drop count %d want %d", gotDropCount, wantDropCount) - } - wantArr := []string{"value3", "value1", "value4"} - gotArr := q.queueToArray() + gotValues := make([]string, len(wantValues)) + for i := 0; i < len(gotValues); i++ { + gotValues[i] = q.readNext().(string) + } - if wantLen, gotLen := len(wantArr), len(gotArr); gotLen != wantLen { - t.Errorf("got array len %d want %d", gotLen, wantLen) - } + if !reflect.DeepEqual(wantValues, gotValues) { + t.Errorf("got array = %#v; want %#v", gotValues, wantValues) + } - if !reflect.DeepEqual(gotArr, wantArr) { - t.Errorf("got array = %#v; want %#v", gotArr, wantArr) - } + if wantDroppedCount != q.droppedCount { + t.Errorf("got dropped count %d want %d", q.droppedCount, wantDroppedCount) + } + }) } diff --git a/trace/trace.go b/trace/trace.go index 125e2cd90..ab287e259 100644 --- a/trace/trace.go +++ b/trace/trace.go @@ -300,15 +300,15 @@ func (s *Span) makeSpanData() *SpanData { sd.Attributes = s.lruAttributesToAttributeMap() sd.DroppedAttributeCount = s.lruAttributes.droppedCount } - if len(s.annotations.queue) > 0 { + if len(s.annotations.ringQueue) > 0 { sd.Annotations = s.interfaceArrayToAnnotationArray() sd.DroppedAnnotationCount = s.annotations.droppedCount } - if len(s.messageEvents.queue) > 0 { + if len(s.messageEvents.ringQueue) > 0 { sd.MessageEvents = s.interfaceArrayToMessageEventArray() sd.DroppedMessageEventCount = s.messageEvents.droppedCount } - if len(s.links.queue) > 0 { + if len(s.links.ringQueue) > 0 { sd.Links = s.interfaceArrayToLinksArray() sd.DroppedLinkCount = s.links.droppedCount } @@ -345,25 +345,25 @@ func (s *Span) SetStatus(status Status) { } func (s *Span) interfaceArrayToLinksArray() []Link { - linksArr := make([]Link, 0, len(s.links.queue)) - for _, value := range s.links.queue { - linksArr = append(linksArr, value.(Link)) + linksArr := make([]Link, len(s.links.ringQueue)) + for i := 0; i < len(linksArr); i++ { + linksArr[i] = s.links.readNext().(Link) } return linksArr } func (s *Span) interfaceArrayToMessageEventArray() []MessageEvent { - messageEventArr := make([]MessageEvent, 0, len(s.messageEvents.queue)) - for _, value := range s.messageEvents.queue { - messageEventArr = append(messageEventArr, value.(MessageEvent)) + messageEventArr := make([]MessageEvent, len(s.messageEvents.ringQueue)) + for i := 0; i < len(messageEventArr); i++ { + messageEventArr[i] = s.messageEvents.readNext().(MessageEvent) } return messageEventArr } func (s *Span) interfaceArrayToAnnotationArray() []Annotation { - annotationArr := make([]Annotation, 0, len(s.annotations.queue)) - for _, value := range s.annotations.queue { - annotationArr = append(annotationArr, value.(Annotation)) + annotationArr := make([]Annotation, len(s.annotations.ringQueue)) + for i := 0; i < len(annotationArr); i++ { + annotationArr[i] = s.annotations.readNext().(Annotation) } return annotationArr }