From c9a6e1bef206ca726633f11df5c0eb8d75688bbb Mon Sep 17 00:00:00 2001
From: yedf2 <120050102@qq.com>
Date: Sat, 1 Jul 2023 17:44:04 +0800
Subject: [PATCH] fix scan return more records

---
 dtmsvr/storage/redis/redis.go | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/dtmsvr/storage/redis/redis.go b/dtmsvr/storage/redis/redis.go
index 6f4d732..624f6a0 100644
--- a/dtmsvr/storage/redis/redis.go
+++ b/dtmsvr/storage/redis/redis.go
@@ -70,6 +70,7 @@ func (s *Store) ScanTransGlobalStores(position *string, limit int64, condition s
 	globals := []storage.TransGlobalStore{}
 	redis := redisGet()
 	for {
+		limit -= int64(len(globals))
 		keys, nextCursor, err := redis.Scan(ctx, lid, conf.Store.RedisPrefix+"_g_*", limit).Result()
 		logger.Debugf("calling redis scan: SCAN %d MATCH %s COUNT %d ,scan result: nextCursor:%d keys_len:%d", lid, conf.Store.RedisPrefix+"_g_*", limit, nextCursor, len(keys))
 
@@ -87,14 +88,15 @@ func (s *Store) ScanTransGlobalStores(position *string, limit int64, condition s
 					(condition.CreateTimeEnd.IsZero() || global.CreateTime.Before(condition.CreateTimeEnd)) {
 					globals = append(globals, global)
 				}
-				if len(globals) == int(limit) {
+				// redis.Scan may return more records than limit
+				if len(globals) >= int(limit) {
 					break
 				}
 			}
 		}
 
 		lid = nextCursor
-		if len(globals) == int(limit) || nextCursor == 0 {
+		if len(globals) >= int(limit) || nextCursor == 0 {
 			break
 		}
 	}
@@ -374,12 +376,14 @@ func (s *Store) ScanKV(cat string, position *string, limit int64) []storage.KVSt
 	kvs := []storage.KVStore{}
 	redis := redisGet()
 	for {
+		limit -= int64(len(kvs))
 		keys, nextCursor, err := redis.Scan(ctx, lid, conf.Store.RedisPrefix+"_kv_"+cat+"_*", limit).Result()
 		logger.Debugf("calling redis scan: SCAN %d MATCH %s COUNT %d ,scan result: nextCursor:%d keys_len:%d", lid, conf.Store.RedisPrefix+"_kv_"+cat+"_*", limit, nextCursor, len(keys))
 		dtmimp.E2P(err)
 		if len(keys) > 0 {
 			values, err := redis.MGet(ctx, keys...).Result()
 			dtmimp.E2P(err)
+			logger.Debugf("keys: %s values: %s", dtmimp.MustMarshalString(keys), dtmimp.MustMarshalString(values))
 			for _, v := range values {
 				if v == nil {
 					continue
@@ -391,7 +395,8 @@ func (s *Store) ScanKV(cat string, position *string, limit int64) []storage.KVSt
 		}
 
 		lid = nextCursor
-		if len(kvs) == int(limit) || nextCursor == 0 {
+		// for redis, `count` in `scan` command is only a hint, may return more than `count` items
+		if len(kvs) >= int(limit) || nextCursor == 0 {
 			break
 		}
 	}