Method updateAndReturnDoc

db/crud.go:2692–3010

Calling updateAndReturnDoc directly allows callers to: 1. Receive the updated document body in the response 2. Specify the existing document body/xattr/cas, to avoid initial retrieval of the doc in cases that the current contents are already known (e.g. import). On cas failure, the document will sti

(ctx context.Context, docid string, allowImport bool, expiry *uint32, opts *sgbucket.MutateInOptions, docUpdateEvent DocUpdateType, existingDoc *sgbucket.BucketDocument, isImport bool, updateRevCache bool, callback updateAndReturnDocCallback)

//  3. If isImport=true, document body will not be updated - only metadata xattr(s)

func (db *DatabaseCollectionWithUser) updateAndReturnDoc(ctx context.Context, docid string, allowImport bool, expiry *uint32, opts *sgbucket.MutateInOptions, docUpdateEvent DocUpdateType, existingDoc *sgbucket.BucketDocument, isImport bool, updateRevCache bool, callback updateAndReturnDocCallback) (doc *Document, newRevID string, err error) {
	key := realDocID(docid)
	if key == "" {
		return nil, "", base.HTTPErrorf(400, "Invalid doc ID")
	}

	var prevCurrentRev string
	var storedDoc *Document
	var changedAccessPrincipals, changedRoleAccessUsers []string // Returned by documentUpdateFunc
	var docSequence uint64                                       // Must be scoped outside callback, used over multiple iterations
	var unusedSequences []uint64                                 // Must be scoped outside callback, used over multiple iterations
	var oldBodyJSON string                                       // Stores previous revision body for use by DocumentChangeEvent
	var createNewRevIDSkipped bool
	var previousAttachments map[string][]string

	// Update the document
	inConflict := false
	upgradeInProgress := false
	docBytes := 0   // Track size of document written, for write stats
	xattrBytes := 0 // Track size of xattr written, for write stats
	skipObsoleteAttachmentsRemoval := false
	isNewDocCreation := false

	// Don't remove obsolete attachments if using ECCV - the other cluster may still need them!
	if db.dbCtx.CachedCCVEnabled.Load() {
		skipObsoleteAttachmentsRemoval = true
	}

	if db.UseXattrs() || upgradeInProgress {
		var casOut uint64
		// Update the document, storing metadata in extended attribute
		if opts == nil {
			opts = &sgbucket.MutateInOptions{}
		}
		opts.MacroExpansion = macroExpandSpec(base.SyncXattrName)
		var initialExpiry uint32
		if expiry != nil {
			initialExpiry = *expiry
		}
		casOut, err = db.dataStore.WriteUpdateWithXattrs(ctx, key, db.syncGlobalSyncMouRevSeqNoAndUserXattrKeys(), initialExpiry, existingDoc, opts, func(currentValue []byte, currentXattrs map[string][]byte, cas uint64) (updatedDoc sgbucket.UpdatedDoc, err error) {
			// Be careful: this block can be invoked multiple times if there are races!
			if doc, err = db.unmarshalDocumentWithXattrs(ctx, docid, currentValue, currentXattrs, cas, DocUnmarshalAll); err != nil {
				return
			}

			prevCurrentRev = doc.GetRevTreeID()

			// Check whether Sync Data originated in body
			currentSyncXattr := currentXattrs[base.SyncXattrName]
			if currentSyncXattr == nil && doc.Sequence > 0 {
				doc.inlineSyncData = true
			}

			previousAttachments, err = getAttachmentIDsForLeafRevisions(ctx, db, doc, newRevID)
			if err != nil {
				skipObsoleteAttachmentsRemoval = true
				base.ErrorfCtx(ctx, "Error retrieving previous leaf attachments of doc: %s, Error: %v", base.UD(docid), err)
			}