First try at paging with ZSETS

cmd/server/fetch.go

@@ -359,6 +359,7 @@ func (b *memoryBackend) channelAddItem(channel string, item microsub.Item) {
 
 	// send to redis
 	channelKey := fmt.Sprintf("channel:%s:posts", channel)
+	zchannelKey := fmt.Sprintf("zchannel:%s:posts", channel)
 
 	data, err := json.Marshal(item)
 	if err != nil {
@@ -385,6 +386,18 @@ func (b *memoryBackend) channelAddItem(channel string, item microsub.Item) {
 		log.Printf("error while adding item %s to channel %s for redis: %v\n", itemKey, channelKey, err)
 		return
 	}
+
+	score, err := time.Parse(time.RFC3339, item.Published)
+	if err != nil {
+		log.Printf("error can't parse %s as time\n", item.Published)
+	}
+
+	added, err = redis.Int64(conn.Do("ZADD", zchannelKey, score.Unix()*1.0, itemKey))
+	if err != nil {
+		log.Printf("error while zadding item %s to channel %s for redis: %v\n", itemKey, channelKey, err)
+		return
+	}
+
 	if added > 0 {
 		log.Printf("Adding item to channel %s\n", channel)
 		log.Println(item)

cmd/server/memory.go

@@ -362,9 +362,40 @@ func (b *memoryBackend) TimelineGet(after, before, channel string) microsub.Time
 
 	items := []microsub.Item{}
 
-	channelKey := fmt.Sprintf("channel:%s:posts", channel)
+	zchannelKey := fmt.Sprintf("zchannel:%s:posts", channel)
+	//channelKey := fmt.Sprintf("channel:%s:posts", channel)
+
+	//itemJsons, err := redis.ByteSlices(conn.Do("SORT", channelKey, "BY", "*->Published", "GET", "*->Data", "ASC", "ALPHA"))
+	// if err != nil {
+	// 	log.Println(err)
+	// 	return microsub.Timeline{
+	// 		Paging: microsub.Pagination{},
+	// 		Items:  items,
+	// 	}
+	// }
+
+	if len(after) == 0 {
+		after = "-inf"
+	}
+	if len(before) == 0 {
+		before = "+inf"
+	}
+
+	itemJSONs := [][]byte{}
+
+	itemScores, err := redis.Strings(
+		conn.Do(
+			"ZRANGEBYSCORE",
+			zchannelKey,
+			after,
+			before,
+			"LIMIT",
+			0,
+			20,
+			"WITHSCORES",
+		),
+	)
 
-	itemJsons, err := redis.ByteSlices(conn.Do("SORT", channelKey, "BY", "*->Published", "GET", "*->Data", "ASC", "ALPHA"))
 	if err != nil {
 		log.Println(err)
 		return microsub.Timeline{
@@ -373,18 +404,41 @@ func (b *memoryBackend) TimelineGet(after, before, channel string) microsub.Time
 		}
 	}
 
-	for _, obj := range itemJsons {
+	if len(itemScores) >= 2 {
-		item := microsub.Item{}
+		before = itemScores[1]
-		json.Unmarshal(obj, &item)
+		after = itemScores[len(itemScores)-1]
-		item.Read = b.checkRead(channel, item.ID)
+	} else {
-		if item.Read {
+		before = ""
+		after = ""
+	}
+
+	for i := 0; i < len(itemScores); i += 2 {
+		itemID := itemScores[i]
+		itemJSON, err := redis.Bytes(conn.Do("HGET", itemID, "Data"))
+		if err != nil {
+			log.Println(err)
 			continue
 		}
+		itemJSONs = append(itemJSONs, itemJSON)
+	}
+
+	for _, obj := range itemJSONs {
+		item := microsub.Item{}
+		err := json.Unmarshal(obj, &item)
+		if err != nil {
+			log.Println(err)
+			continue
+		}
+		item.Read = b.checkRead(channel, item.ID)
 		items = append(items, item)
 	}
+	paging := microsub.Pagination{
+		After:  after,
+		Before: before,
+	}
 
 	return microsub.Timeline{
-		Paging: microsub.Pagination{},
+		Paging: paging,
 		Items:  items,
 	}
 }