getLivestreamStatisticsHandler n+1

[cureseven]

#16

ROUTINE ======================== main.getLivestreamStatisticsHandler in /home/isucon/isucon13-onaka-no-owari/webapp/go/stats_handler.go
         0    103.03s (flat, cum)  3.14% of Total
         .          .    231:   if err != nil {
         .          .    232:           return echo.NewHTTPError(http.StatusBadRequest, "livestream_id in path must be integer")
         .          .    233:   }
         .          .    234:   livestreamID := int64(id)
         .          .    235:
         .    20.20ms    236:   tx, err := dbConn.BeginTxx(ctx, nil)
         .          .    237:   if err != nil {
         .          .    238:           return echo.NewHTTPError(http.StatusInternalServerError, "failed to begin transaction: "+err.Error())
         .          .    239:   }
         .          .    240:   defer tx.Rollback()
         .          .    241:
         .          .    242:   var livestream LivestreamModel
         .          .    243:   if err := tx.GetContext(ctx, &livestream, "SELECT * FROM livestreams WHERE id = ?", livestreamID); err != nil {
         .          .    244:           if errors.Is(err, sql.ErrNoRows) {
         .          .    245:                   return echo.NewHTTPError(http.StatusBadRequest, "cannot get stats of not found livestream")
         .          .    246:           } else {
         .          .    247:                   return echo.NewHTTPError(http.StatusInternalServerError, "failed to get livestream: "+err.Error())
         .          .    248:           }
         .          .    249:   }
         .          .    250:
         .          .    251:   var livestreams []*LivestreamModel
         .   343.43ms    252:   if err := tx.SelectContext(ctx, &livestreams, "SELECT * FROM livestreams"); err != nil && !errors.Is(err, sql.ErrNoRows) {
         .          .    253:           return echo.NewHTTPError(http.StatusInternalServerError, "failed to get livestreams: "+err.Error())
         .          .    254:   }
         .          .    255:
         .          .    256:   // ランク算出
         .          .    257:   var ranking LivestreamRanking
         .          .    258:   for _, livestream := range livestreams {
         .          .    259:           var reactions int64
         .     64.15s    260:           if err := tx.GetContext(ctx, &reactions, "SELECT COUNT(*) FROM livestreams l INNER JOIN reactions r ON l.id = r.livestream_id WHERE l.id = ?", livestream.ID); err != nil && !errors.Is(err, sql.ErrNoRows) {
         .          .    261:                   return echo.NewHTTPError(http.StatusInternalServerError, "failed to count reactions: "+err.Error())
         .          .    262:           }
         .          .    263:
         .    20.20ms    264:           var totalTips int64
         .     38.48s    265:           if err := tx.GetContext(ctx, &totalTips, "SELECT IFNULL(SUM(l2.tip), 0) FROM livestreams l INNER JOIN livecomments l2 ON l.id = l2.livestream_id WHERE l.id = ?", livestream.ID); err != nil && !errors.Is(err, sql.ErrNoRows) {
         .          .    266:                   return echo.NewHTTPError(http.StatusInternalServerError, "failed to count tips: "+err.Error())
         .          .    267:           }
         .          .    268:
         .          .    269:           score := reactions + totalTips
         .          .    270:           ranking = append(ranking, LivestreamRankingEntry{
         .          .    271:                   LivestreamID: livestream.ID,
         .          .    272:                   Score:        score,
         .          .    273:           })
         .          .    274:   }
         .          .    275:   sort.Sort(ranking)
         .          .    276:
         .          .    277:   var rank int64 = 1
         .          .    278:   for i := len(ranking) - 1; i >= 0; i-- {
         .          .    279:           entry := ranking[i]
         .          .    280:           if entry.LivestreamID == livestreamID {
         .          .    281:                   break
         .          .    282:           }
         .          .    283:           rank++
         .          .    284:   }
         .          .    285:
         .          .    286:   // 視聴者数算出
         .          .    287:   var viewersCount int64
         .          .    288:   if err := tx.GetContext(ctx, &viewersCount, `SELECT COUNT(*) FROM livestreams l INNER JOIN livestream_viewers_history h ON h.livestream_id = l.id WHERE l.id = ?`, livestreamID); err != nil && !errors.Is(err, sql.ErrNoRows) {
         .          .    289:           return echo.NewHTTPError(http.StatusInternalServerError, "failed to count livestream viewers: "+err.Error())
         .          .    290:   }
         .          .    291:
         .          .    292:   // 最大チップ額
         .          .    293:   var maxTip int64
         .          .    294:   if err := tx.GetContext(ctx, &maxTip, `SELECT IFNULL(MAX(tip), 0) FROM livestreams l INNER JOIN livecomments l2 ON l2.livestream_id = l.id WHERE l.id = ?`, livestreamID); err != nil && !errors.Is(err, sql.ErrNoRows) {
         .          .    295:           return echo.NewHTTPError(http.StatusInternalServerError, "failed to find maximum tip livecomment: "+err.Error())
         .          .    296:   }
         .          .    297:
         .          .    298:   // リアクション数
         .          .    299:   var totalReactions int64
         .          .    300:   if err := tx.GetContext(ctx, &totalReactions, "SELECT COUNT(*) FROM livestreams l INNER JOIN reactions r ON r.livestream_id = l.id WHERE l.id = ?", livestreamID); err != nil && !errors.Is(err, sql.ErrNoRows) {
         .          .    301:           return echo.NewHTTPError(http.StatusInternalServerError, "failed to count total reactions: "+err.Error())
         .          .    302:   }
         .          .    303:
         .          .    304:   // スパム報告数
         .          .    305:   var totalReports int64
         .    10.10ms    306:   if err := tx.GetContext(ctx, &totalReports, `SELECT COUNT(*) FROM livestreams l INNER JOIN livecomment_reports r ON r.livestream_id = l.id WHERE l.id = ?`, livestreamID); err != nil && !errors.Is(err, sql.ErrNoRows) {
         .          .    307:           return echo.NewHTTPError(http.StatusInternalServerError, "failed to count total spam reports: "+err.Error())
         .          .    308:   }
         .          .    309:
         .          .    310:   if err := tx.Commit(); err != nil {
         .          .    311:           return echo.NewHTTPError(http.StatusInternalServerError, "failed to commit: "+err.Error())