feat: implement if_seq_no and if_primary_term parameters in bulk inde…

…xer (#783) (#784)

Co-authored-by: ben <ben@wese.io>

esutil/bulk_indexer.go

@@ -107,6 +107,8 @@ type BulkIndexerItem struct {
 	VersionType     string
 	Body            io.ReadSeeker
 	RetryOnConflict *int
+	IfSeqNo         *int64
+	IfPrimaryTerm   *int64
 	meta            bytes.Buffer // Item metadata header
 	payloadLength   int          // Item payload total length metadata+newline+body length
 
@@ -177,6 +179,15 @@ func (item *BulkIndexerItem) marshallMeta() {
 		aux = aux[:0]
 	}
 
+	if item.DocumentID != "" && item.IfSeqNo != nil && item.IfPrimaryTerm != nil {
+		item.meta.WriteRune(',')
+		item.meta.WriteString(`"if_seq_no":`)
+		item.meta.WriteString(strconv.FormatInt(*item.IfSeqNo, 10))
+		item.meta.WriteRune(',')
+		item.meta.WriteString(`"if_primary_term":`)
+		item.meta.WriteString(strconv.FormatInt(*item.IfPrimaryTerm, 10))
+	}
+
 	item.meta.WriteRune('}')
 	item.meta.WriteRune('}')
 	item.meta.WriteRune('\n')

esutil/bulk_indexer_internal_test.go

@@ -598,6 +598,8 @@ func TestBulkIndexer(t *testing.T) {
 	})
 	t.Run("Worker.writeMeta()", func(t *testing.T) {
 		v := int64(23)
+		ifSeqNo := int64(45)
+		ifPrimaryTerm := int64(67)
 		type args struct {
 			item BulkIndexerItem
 		}
@@ -706,6 +708,16 @@ func TestBulkIndexer(t *testing.T) {
 				}},
 				`{"update":{"_id":"1","retry_on_conflict":3}}` + "\n",
 			},
+			{
+				"with if_seq_no and if_primary_term",
+				args{BulkIndexerItem{
+					Action:        "index",
+					DocumentID:    "1",
+					IfSeqNo:       &ifSeqNo,
+					IfPrimaryTerm: &ifPrimaryTerm,
+				}},
+				`{"index":{"_id":"1","if_seq_no":45,"if_primary_term":67}}` + "\n",
+			},
 		}
 		for _, tt := range tests {
 			tt := tt