CBG-3503 Update HLV on import (#6572)

db/crud.go

@@ -855,19 +855,37 @@ func (db *DatabaseCollectionWithUser) updateHLV(d *Document, docUpdateEvent DocU
 	case ExistingVersion:
 		// preserve any other logic on the HLV that has been done by the client, only update to cvCAS will be needed
 		d.HLV.CurrentVersionCAS = hlvExpandMacroCASValue
+		d.HLV.ImportCAS = 0 // remove importCAS for non-imports to save space
 	case Import:
-		// work to be done to decide if the VV needs updating here, pending CBG-3503
+		if d.HLV.CurrentVersionCAS == d.Cas {
+			// if cvCAS = document CAS, the HLV has already been updated for this mutation by another HLV-aware peer.
+			// Set ImportCAS to the previous document CAS, but don't otherwise modify HLV
+			d.HLV.ImportCAS = d.Cas
+		} else {
+			// Otherwise this is an SDK mutation made by the local cluster that should be added to HLV.
+			newVVEntry := SourceAndVersion{}
+			newVVEntry.SourceID = db.dbCtx.BucketUUID
+			newVVEntry.Version = hlvExpandMacroCASValue
+			err := d.SyncData.HLV.AddVersion(newVVEntry)
+			if err != nil {
+				return nil, err
+			}
+			d.HLV.CurrentVersionCAS = hlvExpandMacroCASValue
+			d.HLV.ImportCAS = d.Cas
+		}
+
 	case NewVersion, ExistingVersionWithUpdateToHLV:
 		// add a new entry to the version vector
-		newVVEntry := CurrentVersionVector{}
+		newVVEntry := SourceAndVersion{}
 		newVVEntry.SourceID = db.dbCtx.BucketUUID
-		newVVEntry.VersionCAS = hlvExpandMacroCASValue
+		newVVEntry.Version = hlvExpandMacroCASValue
 		err := d.SyncData.HLV.AddVersion(newVVEntry)
 		if err != nil {
 			return nil, err
 		}
 		// update the cvCAS on the SGWrite event too
 		d.HLV.CurrentVersionCAS = hlvExpandMacroCASValue
+		d.HLV.ImportCAS = 0 // remove importCAS for non-imports to save space
 	}
 	return d, nil
 }
@@ -2206,7 +2224,7 @@ func (db *DatabaseCollectionWithUser) updateAndReturnDoc(ctx context.Context, do
 			Attachments: doc.Attachments,
 			Expiry:      doc.Expiry,
 			Deleted:     doc.History[newRevID].Deleted,
-			CV:          &CurrentVersionVector{VersionCAS: doc.HLV.Version, SourceID: doc.HLV.SourceID},
+			CV:          &SourceAndVersion{Version: doc.HLV.Version, SourceID: doc.HLV.SourceID},
 		}
 
 		if createNewRevIDSkipped {

db/document.go

@@ -1212,14 +1212,14 @@ func computeMetadataOnlyUpdate(currentCas uint64, currentMou *MetadataOnlyUpdate
 }
 
 // HasCurrentVersion Compares the specified CV with the fetched documents CV, returns error on mismatch between the two
-func (d *Document) HasCurrentVersion(cv CurrentVersionVector) error {
+func (d *Document) HasCurrentVersion(cv SourceAndVersion) error {
 	if d.HLV == nil {
 		return base.RedactErrorf("no HLV present in fetched doc %s", base.UD(d.ID))
 	}
 
 	// fetch the current version for the loaded doc and compare against the CV specified in the IDandCV key
 	fetchedDocSource, fetchedDocVersion := d.HLV.GetCurrentVersion()
-	if fetchedDocSource != cv.SourceID || fetchedDocVersion != cv.VersionCAS {
+	if fetchedDocSource != cv.SourceID || fetchedDocVersion != cv.Version {
 		return base.RedactErrorf("mismatch between specified current version and fetched document current version for doc %s", base.UD(d.ID))
 	}
 	return nil

db/hybrid_logical_vector.go

@@ -21,22 +21,31 @@ const hlvExpandMacroCASValue = math.MaxUint64
 
 type HybridLogicalVector struct {
 	CurrentVersionCAS uint64            // current version cas (or cvCAS) stores the current CAS at the time of replication
+	ImportCAS         uint64            // Set when an import modifies the document CAS but preserves the HLV (import of a version replicated by XDCR)
 	SourceID          string            // source bucket uuid of where this entry originated from
 	Version           uint64            // current cas of the current version on the version vector
 	MergeVersions     map[string]uint64 // map of merge versions for fast efficient lookup
 	PreviousVersions  map[string]uint64 // map of previous versions for fast efficient lookup
 }
 
-// CurrentVersionVector is a structure used to add a new sourceID:CAS entry to a HLV
-type CurrentVersionVector struct {
-	VersionCAS uint64
-	SourceID   string
+// SourceAndVersion is a structure used to add a new entry to a HLV
+type SourceAndVersion struct {
+	SourceID string
+	Version  uint64
+}
+
+func CreateVersion(source string, version uint64) SourceAndVersion {
+	return SourceAndVersion{
+		SourceID: source,
+		Version:  version,
+	}
 }
 
 type PersistedHybridLogicalVector struct {
 	CurrentVersionCAS string            `json:"cvCas,omitempty"`
-	SourceID          string            `json:"src,omitempty"`
-	Version           string            `json:"vrs,omitempty"`
+	ImportCAS         string            `json:"importCAS,omitempty"`
+	SourceID          string            `json:"src"`
+	Version           string            `json:"vrs"`
 	MergeVersions     map[string]string `json:"mv,omitempty"`
 	PreviousVersions  map[string]string `json:"pv,omitempty"`
 }
@@ -66,27 +75,27 @@ func (hlv *HybridLogicalVector) IsInConflict(otherVector HybridLogicalVector) bo
 
 // AddVersion adds a version vector to the in memory representation of a HLV and moves current version vector to
 // previous versions on the HLV if needed
-func (hlv *HybridLogicalVector) AddVersion(newVersion CurrentVersionVector) error {
-	if newVersion.VersionCAS < hlv.Version {
-		return fmt.Errorf("attempting to add new version vector entry with a CAS that is less than the current version CAS value. Current cas: %d new cas %d", hlv.Version, newVersion.VersionCAS)
+func (hlv *HybridLogicalVector) AddVersion(newVersion SourceAndVersion) error {
+	if newVersion.Version < hlv.Version {
+		return fmt.Errorf("attempting to add new version vector entry with a CAS that is less than the current version CAS value. Current cas: %d new cas %d", hlv.Version, newVersion.Version)
 	}
 	// check if this is the first time we're adding a source - version pair
 	if hlv.SourceID == "" {
-		hlv.Version = newVersion.VersionCAS
+		hlv.Version = newVersion.Version
 		hlv.SourceID = newVersion.SourceID
 		return nil
 	}
 	// if new entry has the same source we simple just update the version
 	if newVersion.SourceID == hlv.SourceID {
-		hlv.Version = newVersion.VersionCAS
+		hlv.Version = newVersion.Version
 		return nil
 	}
 	// if we get here this is a new version from a different sourceID thus need to move current sourceID to previous versions and update current version
 	if hlv.PreviousVersions == nil {
 		hlv.PreviousVersions = make(map[string]uint64)
 	}
 	hlv.PreviousVersions[hlv.SourceID] = hlv.Version
-	hlv.Version = newVersion.VersionCAS
+	hlv.Version = newVersion.Version
 	hlv.SourceID = newVersion.SourceID
 	return nil
 }
@@ -204,10 +213,14 @@ func (hlv *HybridLogicalVector) UnmarshalJSON(inputjson []byte) error {
 func (hlv *HybridLogicalVector) convertHLVToPersistedFormat() (*PersistedHybridLogicalVector, error) {
 	persistedHLV := PersistedHybridLogicalVector{}
 	var cvCasByteArray []byte
+	var importCASBytes []byte
 	var vrsCasByteArray []byte
 	if hlv.CurrentVersionCAS != 0 {
 		cvCasByteArray = base.Uint64CASToLittleEndianHex(hlv.CurrentVersionCAS)
 	}
+	if hlv.ImportCAS != 0 {
+		importCASBytes = base.Uint64CASToLittleEndianHex(hlv.ImportCAS)
+	}
 	if hlv.Version != 0 {
 		vrsCasByteArray = base.Uint64CASToLittleEndianHex(hlv.Version)
 	}
@@ -222,6 +235,7 @@ func (hlv *HybridLogicalVector) convertHLVToPersistedFormat() (*PersistedHybridL
 	}
 
 	persistedHLV.CurrentVersionCAS = string(cvCasByteArray)
+	persistedHLV.ImportCAS = string(importCASBytes)
 	persistedHLV.SourceID = hlv.SourceID
 	persistedHLV.Version = string(vrsCasByteArray)
 	persistedHLV.PreviousVersions = pvPersistedFormat
@@ -231,6 +245,9 @@ func (hlv *HybridLogicalVector) convertHLVToPersistedFormat() (*PersistedHybridL
 
 func (hlv *HybridLogicalVector) convertPersistedHLVToInMemoryHLV(persistedJSON PersistedHybridLogicalVector) {
 	hlv.CurrentVersionCAS = base.HexCasToUint64(persistedJSON.CurrentVersionCAS)
+	if persistedJSON.ImportCAS != "" {
+		hlv.ImportCAS = base.HexCasToUint64(persistedJSON.ImportCAS)
+	}
 	hlv.SourceID = persistedJSON.SourceID
 	// convert the hex cas to uint64 cas
 	hlv.Version = base.HexCasToUint64(persistedJSON.Version)

db/hybrid_logical_vector_test.go

@@ -9,11 +9,14 @@
 package db
 
 import (
+	"context"
 	"reflect"
 	"strconv"
 	"strings"
 	"testing"
 
+	sgbucket "github.com/couchbase/sg-bucket"
+	"github.com/couchbase/sync_gateway/base"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -34,14 +37,14 @@ func TestInternalHLVFunctions(t *testing.T) {
 	const newSource = "s_testsource"
 
 	// create a new version vector entry that will error method AddVersion
-	badNewVector := CurrentVersionVector{
-		VersionCAS: 123345,
-		SourceID:   currSourceId,
+	badNewVector := SourceAndVersion{
+		Version:  123345,
+		SourceID: currSourceId,
 	}
 	// create a new version vector entry that should be added to HLV successfully
-	newVersionVector := CurrentVersionVector{
-		VersionCAS: newCAS,
-		SourceID:   currSourceId,
+	newVersionVector := SourceAndVersion{
+		Version:  newCAS,
+		SourceID: currSourceId,
 	}
 
 	// Get current version vector, sourceID and CAS pair
@@ -229,3 +232,93 @@ func TestHybridLogicalVectorPersistence(t *testing.T) {
 	assert.Equal(t, inMemoryHLV.PreviousVersions, hlvFromPersistance.PreviousVersions)
 	assert.Equal(t, inMemoryHLV.MergeVersions, hlvFromPersistance.MergeVersions)
 }
+
+// Tests import of server-side mutations made by HLV-aware and non-HLV-aware peers
+func TestHLVImport(t *testing.T) {
+
+	base.SetUpTestLogging(t, base.LevelInfo, base.KeyMigrate, base.KeyImport)
+
+	db, ctx := setupTestDB(t)
+	defer db.Close(ctx)
+
+	collection := GetSingleDatabaseCollectionWithUser(t, db)
+	localSource := collection.dbCtx.BucketUUID
+
+	// 1. Test standard import of an SDK write
+	standardImportKey := "standardImport_" + t.Name()
+	standardImportBody := []byte(`{"prop":"value"}`)
+	cas, err := collection.dataStore.WriteCas(standardImportKey, 0, 0, 0, standardImportBody, sgbucket.Raw)
+	require.NoError(t, err, "write error")
+	_, err = collection.ImportDocRaw(ctx, standardImportKey, standardImportBody, nil, nil, false, cas, nil, ImportFromFeed)
+	require.NoError(t, err, "import error")
+
+	importedDoc, _, err := collection.GetDocWithXattr(ctx, standardImportKey, DocUnmarshalAll)
+	require.NoError(t, err)
+	importedHLV := importedDoc.HLV
+	require.Equal(t, cas, importedHLV.ImportCAS)
+	require.Equal(t, importedDoc.Cas, importedHLV.CurrentVersionCAS)
+	require.Equal(t, importedDoc.Cas, importedHLV.Version)
+	require.Equal(t, localSource, importedHLV.SourceID)
+
+	// 2. Test import of write by HLV-aware peer (HLV is already updated, sync metadata is not).
+	otherSource := "otherSource"
+	hlvHelper := NewHLVAgent(t, collection.dataStore, otherSource, "_sync")
+	existingHLVKey := "existingHLV_" + t.Name()
+	_ = hlvHelper.insertWithHLV(ctx, existingHLVKey)
+
+	var existingBody, existingXattr []byte
+	cas, err = collection.dataStore.GetWithXattr(ctx, existingHLVKey, "_sync", "", &existingBody, &existingXattr, nil)
+	require.NoError(t, err)
+
+	_, err = collection.ImportDocRaw(ctx, existingHLVKey, existingBody, existingXattr, nil, false, cas, nil, ImportFromFeed)
+	require.NoError(t, err, "import error")
+
+	importedDoc, _, err = collection.GetDocWithXattr(ctx, existingHLVKey, DocUnmarshalAll)
+	require.NoError(t, err)
+	importedHLV = importedDoc.HLV
+	// cas in the HLV's current version and cvCAS should not have changed, and should match importCAS
+	require.Equal(t, cas, importedHLV.ImportCAS)
+	require.Equal(t, cas, importedHLV.CurrentVersionCAS)
+	require.Equal(t, cas, importedHLV.Version)
+	require.Equal(t, otherSource, importedHLV.SourceID)
+}
+
+// HLVAgent performs HLV updates directly (not via SG) for simulating/testing interaction with non-SG HLV agents
+type HLVAgent struct {
+	t         *testing.T
+	datastore base.DataStore
+	source    string // All writes by the HLVHelper are done as this source
+	xattrName string // xattr name to store the HLV
+}
+
+var defaultHelperBody = map[string]interface{}{"version": 1}
+
+func NewHLVAgent(t *testing.T, datastore base.DataStore, source string, xattrName string) *HLVAgent {
+	return &HLVAgent{
+		t:         t,
+		datastore: datastore,
+		source:    source, // all writes by the HLVHelper are done as this source
+		xattrName: xattrName,
+	}
+}
+
+// insertWithHLV inserts a new document into the bucket with a populated HLV (matching a write from
+// a different HLV-aware peer)
+func (h *HLVAgent) insertWithHLV(ctx context.Context, key string) (casOut uint64) {
+	hlv := &HybridLogicalVector{}
+	err := hlv.AddVersion(CreateVersion(h.source, hlvExpandMacroCASValue))
+	require.NoError(h.t, err)
+	hlv.CurrentVersionCAS = hlvExpandMacroCASValue
+
+	syncData := &SyncData{HLV: hlv}
+	syncDataBytes, err := base.JSONMarshal(syncData)
+	require.NoError(h.t, err)
+
+	mutateInOpts := &sgbucket.MutateInOptions{
+		MacroExpansion: hlv.computeMacroExpansions(),
+	}
+
+	cas, err := h.datastore.WriteCasWithXattr(ctx, key, h.xattrName, 0, 0, defaultHelperBody, syncDataBytes, mutateInOpts)
+	require.NoError(h.t, err)
+	return cas
+}

db/revision_cache_bypass.go

@@ -51,7 +51,7 @@ func (rc *BypassRevisionCache) GetWithRev(ctx context.Context, docID, revID stri
 }
 
 // GetWithCV fetches the Current Version for the given docID and CV immediately from the bucket.
-func (rc *BypassRevisionCache) GetWithCV(ctx context.Context, docID string, cv *CurrentVersionVector, collectionID uint32, includeDelta bool) (docRev DocumentRevision, err error) {
+func (rc *BypassRevisionCache) GetWithCV(ctx context.Context, docID string, cv *SourceAndVersion, collectionID uint32, includeDelta bool) (docRev DocumentRevision, err error) {
 
 	docRev = DocumentRevision{
 		CV: cv,
@@ -113,7 +113,7 @@ func (rc *BypassRevisionCache) RemoveWithRev(docID, revID string, collectionID u
 	// no-op
 }
 
-func (rc *BypassRevisionCache) RemoveWithCV(docID string, cv *CurrentVersionVector, collectionID uint32) {
+func (rc *BypassRevisionCache) RemoveWithCV(docID string, cv *SourceAndVersion, collectionID uint32) {
 	// no-op
 }