Method handleProposeChanges

db/blip_handler.go:817–906

Handles a "proposeChanges" request, similar to "changes" but in no-conflicts mode

(rq *blip.Message)

// Handles a "proposeChanges" request, similar to "changes" but in no-conflicts mode
func (bh *blipHandler) handleProposeChanges(rq *blip.Message) error {

	// we don't know whether this batch of changes has completed because they look like unsolicited revs to us,
	// but we can stop clients swarming us with these causing CheckProposedRev work
	bh.inFlightChangesThrottle <- struct{}{}
	defer func() { <-bh.inFlightChangesThrottle }()

	includeConflictRev := false
	if val := rq.Properties[ProposeChangesConflictsIncludeRev]; val != "" {
		includeConflictRev = val == trueProperty
	}

	var changeList [][]interface{}
	if err := rq.ReadJSONBody(&changeList); err != nil {
		return err
	}
	bh.logEndpointEntry(rq.Profile(), fmt.Sprintf("#Changes: %d", len(changeList)))
	if len(changeList) == 0 {
		return nil
	}
	output := bytes.NewBuffer(make([]byte, 0, 5*len(changeList)))
	output.Write([]byte("["))
	nWritten := 0

	// proposeChanges stats
	startTime := time.Now()
	bh.replicationStats.HandleChangesCount.Add(int64(len(changeList)))
	defer func() {
		bh.replicationStats.HandleChangesTime.Add(time.Since(startTime).Nanoseconds())
	}()
	versionVectorProtocol := bh.useHLV()

	for i, change := range changeList {
		docID := change[0].(string)
		rev := change[1].(string) // rev can represent a RevTree ID or HLV current version
		parentRevID := ""
		if len(change) > 2 {
			parentRevID = change[2].(string)
		}
		var status ProposedRevStatus
		var currentRev string

		changeIsVector := false
		if versionVectorProtocol {
			// TODO: CBG-4812 Use base.IsRevTreeID
			changeIsVector = strings.Contains(rev, "@")
		}
		if versionVectorProtocol && changeIsVector {
			proposedVersionStr := ExtractCVFromProposeChangesRev(rev)
			status, currentRev = bh.collection.CheckProposedVersion(bh.loggingCtx, docID, proposedVersionStr, parentRevID, rev)
		} else {
			status, currentRev = bh.collection.CheckProposedRev(bh.loggingCtx, docID, rev, parentRevID)
		}
		if status == ProposedRev_OK_IsNew {
			// Remember that the doc doesn't exist locally, in order to optimize the upcoming Put:
			bh.collectionCtx.notePendingInsertion(docID)
		} else if status != ProposedRev_OK {
			// Reject the proposed change.