From 6fbfb87d90a05e2870b78bdea004696cee071dab Mon Sep 17 00:00:00 2001
From: Jozef Kralik <jozef.kralik@kistler.com>
Date: Wed, 17 Feb 2021 08:33:19 +0000
Subject: [PATCH] eventstore: fix using of hints in mongo

---
 .../cqrs/eventstore/mongodb/eventstore.go     | 39 +++++++++----------
 1 file changed, 18 insertions(+), 21 deletions(-)

diff --git a/resource-aggregate/cqrs/eventstore/mongodb/eventstore.go b/resource-aggregate/cqrs/eventstore/mongodb/eventstore.go
index c35600bc2..4cd899f19 100644
--- a/resource-aggregate/cqrs/eventstore/mongodb/eventstore.go
+++ b/resource-aggregate/cqrs/eventstore/mongodb/eventstore.go
@@ -36,8 +36,8 @@ var snapshotsQueryIndex = bson.D{
 }
 
 var eventsQueryIndex = bson.D{
-	{versionKey, 1},
 	{aggregateIDKey, 1},
+	{versionKey, 1},
 }
 
 type signOperator string
@@ -279,21 +279,21 @@ func (s *EventStore) Save(ctx context.Context, collectionID, aggregateID string,
 		return false, errors.New("cannot save events without AggregateId")
 	}
 
+	col := s.client.Database(s.DBName()).Collection(getEventCollectionName(collectionID))
 	if events[0].Version() == 0 {
-		concurrencyException, err = s.SaveSnapshotQuery(ctx, collectionID, aggregateID, 0)
+		err = s.ensureIndex(ctx, col, eventsQueryIndex)
 		if err != nil {
-			return false, fmt.Errorf("cannot save events without snapshot query for version 0: %w", err)
-		}
-		if concurrencyException {
-			return concurrencyException, nil
+			return false, fmt.Errorf("cannot save events: %w", err)
 		}
 	}
 
-	col := s.client.Database(s.DBName()).Collection(getEventCollectionName(collectionID))
 	if events[0].Version() == 0 {
-		err = s.ensureIndex(ctx, col, eventsQueryIndex)
+		concurrencyException, err = s.SaveSnapshotQuery(ctx, collectionID, aggregateID, 0)
 		if err != nil {
-			return false, fmt.Errorf("cannot save events: %w", err)
+			return false, fmt.Errorf("cannot save events without snapshot query for version 0: %w", err)
+		}
+		if concurrencyException {
+			return concurrencyException, nil
 		}
 	}
 
@@ -349,8 +349,7 @@ func (i *iterator) Err() error {
 }
 
 func versionQueriesToMgoQuery(queries []eventstore.VersionQuery, op signOperator) (bson.M, error) {
-	orQueries := make([]bson.M, 0, 32)
-
+	orQueries := make([]bson.D, 0, 32)
 	if len(queries) == 0 {
 		return bson.M{}, fmt.Errorf("empty []eventstore.VersionQuery")
 	}
@@ -368,10 +367,10 @@ func versionQueriesToMgoQuery(queries []eventstore.VersionQuery, op signOperator
 	return bson.M{"$or": orQueries}, nil
 }
 
-func versionQueryToMgoQuery(query eventstore.VersionQuery, op signOperator) bson.M {
-	return bson.M{
-		versionKey:     bson.M{string(op): query.Version},
-		aggregateIDKey: aggregateID2Hash(query.AggregateID),
+func versionQueryToMgoQuery(query eventstore.VersionQuery, op signOperator) bson.D {
+	return bson.D{
+		{Key: aggregateIDKey, Value: aggregateID2Hash(query.AggregateID)},
+		{Key: versionKey, Value: bson.M{string(op): query.Version}},
 	}
 }
 
@@ -682,26 +681,24 @@ func getSnapshotID(aggregateID string) string {
 	return aggregateID + ".s"
 }
 
-func snapshotQueriesToMgoQuery(queries []eventstore.SnapshotQuery) (bson.M, *options.FindOptions) {
+func snapshotQueriesToMgoQuery(queries []eventstore.SnapshotQuery) (interface{}, *options.FindOptions) {
 	if len(queries) == 0 {
 		opts := options.FindOptions{}
 		opts.SetHint(eventsQueryIndex)
-		return bson.M{aggregateIDKey: aggregateID2Hash("snapshot"), versionKey: -1}, &opts
+		return bson.D{{Key: aggregateIDKey, Value: aggregateID2Hash("snapshot")}, {Key: versionKey, Value: -1}}, &opts
 	}
 
 	if len(queries) == 1 {
 		opts := options.FindOptions{}
 		opts.SetHint(snapshotsQueryIndex)
-		return bson.M{idKey: getSnapshotID(queries[0].AggregateID)}, &opts
+		return bson.D{{Key: idKey, Value: getSnapshotID(queries[0].AggregateID)}}, &opts
 	}
 
 	orQueries := make([]bson.M, 0, 32)
 	for _, q := range queries {
-		andQueries := make([]bson.M, 0, 4)
 		if q.AggregateID != "" {
-			andQueries = append(andQueries, bson.M{idKey: getSnapshotID(q.AggregateID)})
+			orQueries = append(orQueries, bson.M{idKey: getSnapshotID(q.AggregateID)})
 		}
-		orQueries = append(orQueries, bson.M{"$and": andQueries})
 	}
 	opts := options.FindOptions{}
 	opts.SetHint(snapshotsQueryIndex)