Merge pull request #790 from mschoch/use-vellum-reset

update to use new vellum Reset API

index/scorch/segment/zap/build.go

@@ -471,16 +471,11 @@ func persistDictionary(memSegment *mem.Segment, w *CountHashWriter, postingsLocs
 	varintBuf := make([]byte, binary.MaxVarintLen64)
 
 	var buffer bytes.Buffer
+	builder, err := vellum.New(&buffer, nil)
+	if err != nil {
+		return nil, err
+	}
 	for fieldID, fieldTerms := range memSegment.DictKeys {
-		if fieldID != 0 {
-			buffer.Reset()
-		}
-
-		// start a new vellum for this field
-		builder, err := vellum.New(&buffer, nil)
-		if err != nil {
-			return nil, err
-		}
 
 		dict := memSegment.Dicts[fieldID]
 		// now walk the dictionary in order of fieldTerms (already sorted)
@@ -514,6 +509,13 @@ func persistDictionary(memSegment *mem.Segment, w *CountHashWriter, postingsLocs
 		if err != nil {
 			return nil, err
 		}
+
+		// reset buffer and vellum builder
+		buffer.Reset()
+		err = builder.Reset(&buffer)
+		if err != nil {
+			return nil, err
+		}
 	}
 
 	return rv, nil

index/scorch/segment/zap/merge.go

@@ -180,16 +180,13 @@ func persistMergedRest(segments []*SegmentBase, dropsIn []*roaring.Bitmap,
 	var docTermMap [][]byte
 
 	var vellumBuf bytes.Buffer
+	newVellum, err := vellum.New(&vellumBuf, nil)
+	if err != nil {
+		return nil, 0, err
+	}
 
 	// for each field
 	for fieldID, fieldName := range fieldsInv {
-		if fieldID != 0 {
-			vellumBuf.Reset()
-		}
-		newVellum, err := vellum.New(&vellumBuf, nil)
-		if err != nil {
-			return nil, 0, err
-		}
 
 		// collect FST iterators from all active segments for this field
 		var newDocNums [][]uint64
@@ -423,6 +420,13 @@ func persistMergedRest(segments []*SegmentBase, dropsIn []*roaring.Bitmap,
 		if err != nil {
 			return nil, 0, err
 		}
+
+		// reset vellum buffer and vellum builder
+		vellumBuf.Reset()
+		err = newVellum.Reset(&vellumBuf)
+		if err != nil {
+			return nil, 0, err
+		}
 	}
 
 	fieldDvLocsOffset := uint64(w.Count())