InsertEventIntoDescendingList() helper.

utils.go

@@ -75,3 +75,57 @@ func escapeString(dst []byte, s string) []byte {
 	dst = append(dst, '"')
 	return dst
 }
+
+func InsertEventIntoDescendingList(sortedArray []*Event, event *Event) []*Event {
+	size := len(sortedArray)
+	start := 0
+	end := size - 1
+	var mid int
+	position := start
+
+	if end < 0 {
+		return []*Event{event}
+	} else if event.CreatedAt < sortedArray[end].CreatedAt {
+		return append(sortedArray, event)
+	} else if event.CreatedAt > sortedArray[start].CreatedAt {
+		newArr := make([]*Event, size+1)
+		newArr[0] = event
+		copy(newArr[1:], sortedArray)
+		return newArr
+	} else if event.CreatedAt == sortedArray[start].CreatedAt {
+		position = start
+	} else {
+		for {
+			if end <= start+1 {
+				position = end
+				break
+			}
+			mid = int(start + (end-start)/2)
+			if sortedArray[mid].CreatedAt > event.CreatedAt {
+				start = mid
+			} else if sortedArray[mid].CreatedAt < event.CreatedAt {
+				end = mid
+			} else {
+				position = mid
+				break
+			}
+		}
+	}
+
+	if sortedArray[position].ID != event.ID {
+		if cap(sortedArray) > size {
+			newArr := sortedArray[0 : size+1]
+			copy(newArr[position+1:], sortedArray[position:])
+			newArr[position] = event
+			return newArr
+		} else {
+			newArr := make([]*Event, size+1, size+5)
+			copy(newArr[:position], sortedArray[:position])
+			copy(newArr[position+1:], sortedArray[position:])
+			newArr[position] = event
+			return newArr
+		}
+	}
+
+	return sortedArray
+}