Commit 26e1b5f9 authored by Fernando Takagi's avatar Fernando Takagi
Browse files

Refactor cacheable cursor create time

parent f0ead1c5

server/core_channel.go

+16 −6
Original line number Diff line number Diff line
@@ -138,7 +138,6 @@ WHERE stream_mode = $1 AND stream_subject = $2::UUID AND stream_descriptor = $3: 
		userIDOne := stream.Subject.String()

		userIDTwo := stream.Subcontext.String()

		messages := make([]*api.ChannelMessage, 0, limit)

		createTimeNano := make(map[string]int64)

		var nextCursor, prevCursor *channelMessageListCursor



		var dbID string
@@ -148,19 +147,23 @@ WHERE stream_mode = $1 AND stream_subject = $2::UUID AND stream_descriptor = $3: 
		var dbContent string

		var dbCreateTime pgtype.Timestamptz

		var dbUpdateTime pgtype.Timestamptz

		var dbFirstCreateTimeNano int64

		var dbLastCreateTimeNano int64

		for rows.Next() {

			if len(messages) >= limit {

				dbLastCreateTimeNano = dbCreateTime.Time.UnixNano()

				nextCursor = &channelMessageListCursor{

					StreamMode:       stream.Mode,

					StreamSubject:    stream.Subject.String(),

					StreamSubcontext: stream.Subcontext.String(),

					StreamLabel:      stream.Label,

					CreateTime:       dbCreateTime.Time.UnixNano(),

					CreateTime:       dbLastCreateTimeNano,

					Id:               dbID,

					Forward:          forward,

					IsNext:           true,

				}

				break



			}



			err = rows.Scan(&dbID, &dbCode, &dbSenderID, &dbUsername, &dbContent, &dbCreateTime, &dbUpdateTime)
@@ -181,7 +184,6 @@ WHERE stream_mode = $1 AND stream_subject = $2::UUID AND stream_descriptor = $3: 
				UpdateTime: &timestamppb.Timestamp{Seconds: dbUpdateTime.Time.Unix()},

				Persistent: &wrapperspb.BoolValue{Value: true},

			}

			createTimeNano[dbID] = dbCreateTime.Time.UnixNano()

			switch stream.Mode {

			case StreamModeChannel:

				message.RoomName = stream.Label
@@ -194,6 +196,9 @@ WHERE stream_mode = $1 AND stream_subject = $2::UUID AND stream_descriptor = $3: 


			messages = append(messages, message)



			if dbFirstCreateTimeNano == 0 {

				dbFirstCreateTimeNano = dbCreateTime.Time.UnixNano()

			}

			// There can only be a previous page if this is a paginated listing.

			if incomingCursor != nil && prevCursor == nil {

				prevCursor = &channelMessageListCursor{
@@ -201,7 +206,7 @@ WHERE stream_mode = $1 AND stream_subject = $2::UUID AND stream_descriptor = $3: 
					StreamSubject:    stream.Subject.String(),

					StreamSubcontext: stream.Subcontext.String(),

					StreamLabel:      stream.Label,

					CreateTime:       dbCreateTime.Time.UnixNano(),

					CreateTime:       dbFirstCreateTimeNano,

					Id:               dbID,

					Forward:          forward,

					IsNext:           false,
@@ -210,6 +215,7 @@ WHERE stream_mode = $1 AND stream_subject = $2::UUID AND stream_descriptor = $3: 
		}

		_ = rows.Close()



		flipped := false

		if incomingCursor != nil && !incomingCursor.IsNext {

			// If this was a previous page listing, flip the results to their normal order and swap the cursors.

			nextCursor, prevCursor = prevCursor, nextCursor
@@ -223,17 +229,22 @@ WHERE stream_mode = $1 AND stream_subject = $2::UUID AND stream_descriptor = $3: 
			for i, j := 0, len(messages)-1; i < j; i, j = i+1, j-1 {

				messages[i], messages[j] = messages[j], messages[i]

			}

			flipped = true

		}



		var cacheableCursor *channelMessageListCursor

		if l := len(messages); l > 0 {

			createTime := dbLastCreateTimeNano

			if flipped {

				createTime = dbFirstCreateTimeNano

			}

			// There is at least 1 message returned by the listing, so use it as the foundation of a new cacheable cursor.

			cacheableCursor = &channelMessageListCursor{

				StreamMode:       stream.Mode,

				StreamSubject:    stream.Subject.String(),

				StreamSubcontext: stream.Subcontext.String(),

				StreamLabel:      stream.Label,

				CreateTime:       createTimeNano[messages[l-1].MessageId],

				CreateTime:       createTime,

				Id:               messages[l-1].MessageId,

				Forward:          true,

				IsNext:           true,
@@ -348,7 +359,6 @@ WHERE stream_mode = $1 AND stream_subject = $2::UUID AND stream_descriptor = $3: 
	if start > 0 {

		// Check if there might be a prev cursor

		setPrevCursor = true

		firstRecords = firstRecords[:len(firstRecords)-1]

	}



	records = records[start:end]