Merge pull request #683 from cloudwan/CW-736-workaround-mysql

Workaround for go-sql-driver/mysql#731

Author: Daisuke Morita

db/sql/sql.go

@@ -367,7 +367,7 @@ func (db *DB) BeginTx(options ...transaction.Option) (tx transaction.Transaction
 		return nil, err
 	}
 
-	rawTx, err := db.DB.BeginTxx(params.Context, sqlOptions)
+	rawTx, err := db.DB.BeginTxx(safeMysqlContext(params.Context), sqlOptions)
 	if err != nil {
 		db.updateCounter(1, "begin.failed")
 		return nil, err
@@ -583,7 +583,7 @@ func (tx *Transaction) Exec(ctx context.Context, sql string, args ...interface{}
 
 func (tx *Transaction) exec(ctx context.Context, sql string, args ...interface{}) error {
 	tx.logQuery(sql, args...)
-	_, err := tx.transaction.ExecContext(ctx, sql, args...)
+	_, err := tx.transaction.ExecContext(safeMysqlContext(ctx), sql, args...)
 	return err
 }
 
@@ -856,7 +856,7 @@ func buildSelect(sc *selectContext) (string, []interface{}, error) {
 
 func (tx *Transaction) executeSelect(ctx context.Context, sc *selectContext, sql string, args []interface{}) (list []*schema.Resource, total uint64, err error) {
 	tx.logQuery(sql, args...)
-	rows, err := tx.transaction.QueryxContext(ctx, sql, args...)
+	rows, err := tx.transaction.QueryxContext(safeMysqlContext(ctx), sql, args...)
 	if err != nil {
 		return
 	}
@@ -955,7 +955,7 @@ func (tx *Transaction) Query(ctx context.Context, s *schema.Schema, query string
 	defer tx.measureTime(time.Now(), s.ID, "query")
 
 	tx.logQuery(query, arguments...)
-	rows, err := tx.transaction.QueryxContext(ctx, query, arguments...)
+	rows, err := tx.transaction.QueryxContext(safeMysqlContext(ctx), query, arguments...)
 	if err != nil {
 		return nil, fmt.Errorf("Failed to run query: %s", query)
 	}
@@ -1022,7 +1022,7 @@ func (tx *Transaction) Count(ctx context.Context, s *schema.Schema, filter trans
 		return
 	}
 	result := map[string]interface{}{}
-	err = tx.transaction.QueryRowxContext(ctx, sql, args...).MapScan(result)
+	err = tx.transaction.QueryRowxContext(safeMysqlContext(ctx), sql, args...).MapScan(result)
 	if err != nil {
 		return
 	}
@@ -1089,7 +1089,7 @@ func (tx *Transaction) StateFetch(ctx context.Context, s *schema.Schema, filter
 		return
 	}
 	tx.logQuery(sql, args...)
-	rows, err := tx.transaction.QueryxContext(ctx, sql, args...)
+	rows, err := tx.transaction.QueryxContext(safeMysqlContext(ctx), sql, args...)
 	if err != nil {
 		return
 	}
@@ -1265,3 +1265,10 @@ func (db *DB) SetMaxOpenConns(maxIdleConns int) {
 	// db.DB.SetMaxOpenConns(maxIdleConns)
 	// db.DB.SetMaxIdleConns(maxIdleConns)
 }
+
+// Mysql driver does not support graceful cancellation via context.Cancel()
+// This function (and its usages) should be removed when (if) this defect got fixed:
+// https://github.com/go-sql-driver/mysql/issues/731
+func safeMysqlContext(_ context.Context) context.Context {
+	return context.Background()
+}