From 3e28f462d88c9eb9cc84a26b6228fd278170fdb3 Mon Sep 17 00:00:00 2001
From: Shlomi Noach <shlomi-noach@github.com>
Date: Tue, 3 Jan 2017 13:44:52 +0200
Subject: [PATCH] Initial support for batching multiple DMLs when writing to
 ghost table

---
 go/logic/applier.go | 45 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/go/logic/applier.go b/go/logic/applier.go
index afff578..8fb940a 100644
--- a/go/logic/applier.go
+++ b/go/logic/applier.go
@@ -950,3 +950,48 @@ func (this *Applier) ApplyDMLEventQuery(dmlEvent *binlog.BinlogDMLEvent) error {
 	}
 	return nil
 }
+
+// ApplyDMLEventQueries applies multiple DML queries onto the _ghost_ table
+func (this *Applier) ApplyDMLEventQueries(dmlEvents [](*binlog.BinlogDMLEvent)) error {
+
+	var totalDelta int64
+
+	err := func() error {
+		tx, err := this.db.Begin()
+		if err != nil {
+			return err
+		}
+		sessionQuery := `SET
+			SESSION time_zone = '+00:00',
+			sql_mode = CONCAT(@@session.sql_mode, ',STRICT_ALL_TABLES')
+			`
+		if _, err := tx.Exec(sessionQuery); err != nil {
+			return err
+		}
+		for _, dmlEvent := range dmlEvents {
+			query, args, rowDelta, err := this.buildDMLEventQuery(dmlEvent)
+			if err != nil {
+				return err
+			}
+			if _, err := tx.Exec(query, args...); err != nil {
+				err = fmt.Errorf("%s; query=%s; args=%+v", err.Error(), query, args)
+				return err
+			}
+			totalDelta += rowDelta
+		}
+		if err := tx.Commit(); err != nil {
+			return err
+		}
+		return nil
+	}()
+
+	if err != nil {
+		return log.Errore(err)
+	}
+	// no error
+	atomic.AddInt64(&this.migrationContext.TotalDMLEventsApplied, int64(len(dmlEvents)))
+	if this.migrationContext.CountTableRows {
+		atomic.AddInt64(&this.migrationContext.RowsDeltaEstimate, totalDelta)
+	}
+	return nil
+}