Track top metrics

pkg/stats/redis.go

@@ -12,24 +12,63 @@ type RedisStats struct {
 }
 
 func (r RedisStats) Inc(metric, hashID string) (int64, error) {
-	key := r.makeKey(hashID)
-	return r.client.HIncrBy(key, metric, 1).Result()
+	now := time.Now().UTC()
+
+	key := r.makeKey(now, hashID)
+	top := r.makeTop(now, metric)
+
+	var cmd *redis.IntCmd
+	_, err := r.client.TxPipelined(func(p redis.Pipeliner) error {
+		cmd = p.HIncrBy(key, metric, 1)
+		p.ZIncrBy(top, 1, hashID)
+		return nil
+	})
+
+	if err != nil {
+		return 0, err
+	}
+
+	return cmd.Result()
 }
 
 func (r RedisStats) Get(metric, hashID string) (int64, error) {
-	key := r.makeKey(hashID)
+	now := time.Now().UTC()
+	key := r.makeKey(now, hashID)
 	return r.client.HGet(key, metric).Int64()
 }
 
+func (r RedisStats) Top(metric string) (map[string]int64, error) {
+	now := time.Now().UTC()
+	top := r.makeTop(now, metric)
+
+	zrange, err := r.client.ZRevRangeWithScores(top, 0, 10).Result()
+	if err != nil {
+		return nil, err
+	}
+
+	ret := make(map[string]int64)
+	for _, x := range zrange {
+		key := x.Member.(string)
+		val := int64(x.Score)
+
+		ret[key] = val
+	}
+
+	return ret, nil
+}
+
+func (r RedisStats) makeKey(now time.Time, hashID string) string {
+	return fmt.Sprintf("stats/%d/%d/%s", now.Year(), now.Month(), hashID)
+}
+
+func (r RedisStats) makeTop(now time.Time, metric string) string {
+	return fmt.Sprintf("stats/top/%d/%d/%s", now.Year(), now.Month(), metric)
+}
+
 func (r RedisStats) Close() error {
 	return r.client.Close()
 }
 
-func (r RedisStats) makeKey(hashID string) string {
-	now := time.Now().UTC()
-	return fmt.Sprintf("stats/%d/%d/%s", now.Year(), now.Month(), hashID)
-}
-
 func NewRedisStats(redisUrl string) (*RedisStats, error) {
 	opts, err := redis.ParseURL(redisUrl)
 	if err != nil {

pkg/stats/redis_test.go

@@ -27,6 +27,43 @@ func TestRedisStats_IncAndGet(t *testing.T) {
 	require.Equal(t, int64(2), v)
 }
 
+func TestRedisStats_Top(t *testing.T) {
+	t.Skip("run redis tests manually")
+
+	s := createRedisClient(t)
+
+	// 3
+	s.Inc(metric, "123")
+	s.Inc(metric, "123")
+	s.Inc(metric, "123")
+
+	// 2
+	s.Inc(metric, "321")
+	s.Inc(metric, "321")
+
+	// 1
+	s.Inc(metric, "213")
+
+	top, err := s.Top(metric)
+	require.NoError(t, err)
+	require.Len(t, top, 3)
+
+	// 3
+	h3, ok := top["123"]
+	require.True(t, ok)
+	require.Equal(t, int64(3), h3)
+
+	// 2
+	h2, ok := top["321"]
+	require.True(t, ok)
+	require.Equal(t, int64(2), h2)
+
+	// 1
+	h1, ok := top["213"]
+	require.True(t, ok)
+	require.Equal(t, int64(1), h1)
+}
+
 func createRedisClient(t *testing.T) *RedisStats {
 	client, err := NewRedisStats("redis://localhost")
 	require.NoError(t, err)