refactor(wau & mau): change calculate method according to comment

change the GetPeriodInfoFromPOs method. add basic tests.
SJTU-jCourse · Nov 20, 2024 · 92dbb36 · 92dbb36
1 parent 32d3bc4
commit 92dbb36
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Showing 2 changed files with 89 additions and 28 deletions.
diff --git a/model/converter/statistic.go b/model/converter/statistic.go
@@ -24,45 +24,49 @@ func ConvertDailyInfoFromPO(po po.StatisticPO) model.DailyInfo {
 	}
 }
 
-// GetPeriodInfoFromPOs 从统计数据中获取指定的周期信息, 调用者保证pos中的数据是按时间增序排列的
+// GetPeriodInfoFromPOs 从统计数据中获取指定的周期信息, 调用者保证pos中的数据是按时间增序排列的, 保证返回的数据是按时间增序排列的
 func GetPeriodInfoFromPOs(pos []po.StatisticPO, keys []model.PeriodInfoKey) (map[model.PeriodInfoKey][]model.PeriodInfo, error) {
 	const week = 7
 	const month = 30
 	periodInfoMap := make(map[model.PeriodInfoKey][]model.PeriodInfo)
+	total := len(pos)
 	for _, key := range keys {
+		periodInfoMap[key] = make([]model.PeriodInfo, 0)
 		switch key {
 		case model.PeriodInfoKeyMAU:
-			for i := range pos {
-				if i >= month-1 {
-					monthWindow := make([]int64, month)
-					for j := i - month + 1; j <= i; j++ {
-						monthWindow[j] = pos[j].UVCount
-					}
-					newInfo := model.PeriodInfo{
-						StartTime: pos[i-month+1].Date.Unix(),
-						EndTime:   pos[i].Date.Unix(),
-						Value:     mathutil.Average(monthWindow...),
-						Key:       key,
-					}
-					periodInfoMap[key] = append(periodInfoMap[key], newInfo)
+			months := total / month
+			// 这里反向遍历, 保证返回的数据是按时间增序排列的
+			for i := months - 1; i >= 0; i-- {
+				end := total - 1 - i*month
+				start := end - month + 1
+				monthWindow := make([]int64, month)
+				for j := start; j <= end; j++ {
+					monthWindow[j-start] = pos[j].UVCount
 				}
+				newInfo := model.PeriodInfo{
+					StartTime: pos[start].Date.Unix(),
+					EndTime:   pos[end].Date.Unix(),
+					Value:     mathutil.Average(monthWindow...),
+					Key:       key,
+				}
+				periodInfoMap[key] = append(periodInfoMap[key], newInfo)
 			}
 		case model.PeriodInfoKeyWAU:
-			periodInfoMap[key] = make([]model.PeriodInfo, 0)
-			for i := range pos {
-				if i >= week-1 {
-					weekWindow := make([]int64, week)
-					for j := i - week + 1; j <= i; j++ {
-						weekWindow[j] = pos[j].UVCount
-					}
-					newInfo := model.PeriodInfo{
-						StartTime: pos[i-week+1].Date.Unix(),
-						EndTime:   pos[i].Date.Unix(),
-						Value:     mathutil.Average(weekWindow...),
-						Key:       key,
-					}
-					periodInfoMap[key] = append(periodInfoMap[key], newInfo)
+			weeks := total / week
+			for i := weeks - 1; i >= 0; i-- {
+				end := total - 1 - i*week
+				start := end - week + 1
+				weekWindow := make([]int64, week)
+				for j := start; j <= end; j++ {
+					weekWindow[j-start] = pos[j].UVCount
+				}
+				newInfo := model.PeriodInfo{
+					StartTime: pos[start].Date.Unix(),
+					EndTime:   pos[end].Date.Unix(),
+					Value:     mathutil.Average(weekWindow...),
+					Key:       key,
 				}
+				periodInfoMap[key] = append(periodInfoMap[key], newInfo)
 			}
 		default:
 			return nil, fmt.Errorf(model.ErrInvalidPeriodInfoKey, key)

diff --git a/model/converter/statistic_test.go b/model/converter/statistic_test.go
@@ -1,8 +1,10 @@
 package converter
 
 import (
+	"jcourse_go/model/model"
 	"jcourse_go/model/po"
 	"jcourse_go/util"
+	"math/rand"
 	"testing"
 	"time"
 
@@ -37,3 +39,58 @@ func TestConvertStatisticDataFromPO(t *testing.T) {
 		assert.True(t, statisticData.UVData.Contains(10086))
 	})
 }
+
+func TestGetPeriodInfoFromPOs(t *testing.T) {
+	// Helper function to create a StatisticPO with a given date and UVCount
+	createStatisticPO := func(daysAgo int) po.StatisticPO {
+		return po.StatisticPO{
+			Date:         util.GetMidTime(time.Now()).AddDate(0, 0, -daysAgo),
+			UVCount:      int64(rand.Uint64() % 1000),
+			PVCount:      int64(rand.Uint64() % 1000),
+			TotalReviews: 10000 - int64(daysAgo)*100,
+			TotalUsers:   1000 - int64(daysAgo)*10,
+			NewReviews:   100,
+			NewUsers:     10,
+		}
+	}
+
+	// Test data
+	pos := make([]po.StatisticPO, 40)
+	for i := 0; i < 40; i++ {
+		pos[i] = createStatisticPO(i)
+	}
+
+	keys := []model.PeriodInfoKey{model.PeriodInfoKeyMAU, model.PeriodInfoKeyWAU}
+
+	// Call the function
+	periodInfoMap, err := GetPeriodInfoFromPOs(pos, keys)
+	assert.Nil(t, err)
+
+	// Verify the results for MAU
+	mauInfo := periodInfoMap[model.PeriodInfoKeyMAU]
+	assert.Equal(t, 1, len(mauInfo))
+	assert.Equal(t, pos[10].Date.Unix(), mauInfo[0].StartTime)
+	assert.Equal(t, pos[39].Date.Unix(), mauInfo[0].EndTime)
+	mau := int64(0)
+	for i := 10; i < 40; i++ {
+		mau += pos[i].UVCount
+	}
+	mau /= 30
+	assert.Equal(t, mau, mauInfo[0].Value) // Average of UVCounts from 0 to 29
+
+	// Verify the results for WAU
+	wauInfo := periodInfoMap[model.PeriodInfoKeyWAU]
+	assert.Equal(t, 5, len(wauInfo))
+	for i, info := range wauInfo {
+		start := 7*i + 5 // 6, 13, 20, 27, 34
+		end := start + 6
+		expectedValue := int64(0)
+		for j := start; j <= end; j++ {
+			expectedValue += pos[j].UVCount
+		}
+		expectedValue /= 7
+		assert.Equal(t, pos[start].Date.Unix(), info.StartTime)
+		assert.Equal(t, pos[end].Date.Unix(), info.EndTime)
+		assert.Equal(t, expectedValue, info.Value)
+	}
+}