rebuild rank caches on restore

api.go

@@ -2283,7 +2283,11 @@ func (api *API) RestoreShard(ctx context.Context, indexName string, shard uint64
 				return err
 			}
 		}
-		_, err = view.CreateFragmentIfNotExists(shard)
+		frag, err := view.CreateFragmentIfNotExists(shard)
+		if err != nil {
+			return err
+		}
+		err = frag.RebuildRankCache(ctx)
 		if err != nil {
 			return err
 		}

fragment.go

@@ -2890,6 +2890,31 @@ func (f *fragment) FlushCache() error {
 	defer f.mu.Unlock()
 	return f.flushCache()
 }
+func (f *fragment) RebuildRankCache(ctx context.Context) error {
+	if f.CacheType != CacheTypeRanked {
+		return nil //only rebuild ranked caches
+	}
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	tx, err := f.holder.BeginTx(false, f.idx, f.shard)
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+	rows, err := f.unprotectedRows(ctx, tx, uint64(0))
+	if err != nil {
+		return err
+	}
+	for _, id := range rows {
+		n, err := tx.CountRange(f.index(), f.field(), f.view(), f.shard, id*ShardWidth, (id+1)*ShardWidth)
+		if err != nil {
+			return errors.Wrap(err, "CountRange")
+		}
+		f.cache.BulkAdd(id, n)
+	}
+	f.cache.Invalidate()
+	return nil
+}
 
 func (f *fragment) flushCache() error {
 	if f.cache == nil {