Refactor Conn.exec

conn.go

@@ -430,108 +430,67 @@ optionLoop:
 	}
 
 	if simpleProtocol {
+		return c.execSimpleProtocol(ctx, sql, arguments)
+	}
+
+	if ps, ok := c.preparedStatements[sql]; ok {
+		return c.execPrepared(ctx, ps, arguments)
+	}
+
+	if len(arguments) == 0 {
+		return c.execSimpleProtocol(ctx, sql, arguments)
+	}
+
+	ps, err := c.Prepare(ctx, "", sql)
+	if err != nil {
+		return nil, err
+	}
+	return c.execPrepared(ctx, ps, arguments)
+}
+
+func (c *Conn) execSimpleProtocol(ctx context.Context, sql string, arguments []interface{}) (commandTag pgconn.CommandTag, err error) {
+	if len(arguments) > 0 {
 		sql, err = c.sanitizeForSimpleQuery(sql, arguments...)
 		if err != nil {
 			return nil, err
 		}
-
-		mrr := c.pgConn.Exec(ctx, sql)
-		if mrr.NextResult() {
-			result := mrr.ResultReader().Read()
-			err = mrr.Close()
-			return result.CommandTag, err
-		} else {
-			err = mrr.Close()
-			return nil, err
-		}
 	}
 
+	mrr := c.pgConn.Exec(ctx, sql)
+	for mrr.NextResult() {
+		commandTag, err = mrr.ResultReader().Close()
+	}
+	err = mrr.Close()
+	return commandTag, err
+}
+
+func (c *Conn) execPrepared(ctx context.Context, ps *PreparedStatement, arguments []interface{}) (commandTag pgconn.CommandTag, err error) {
 	c.eqb.Reset()
 
-	if ps, ok := c.preparedStatements[sql]; ok {
-		args, err := convertDriverValuers(arguments)
-		if err != nil {
-			return nil, err
-		}
-
-		for i := range args {
-			err = c.eqb.AppendParam(c.ConnInfo, ps.ParameterOIDs[i], args[i])
-			if err != nil {
-				return nil, err
-			}
-		}
-
-		for i := range ps.FieldDescriptions {
-			if dt, ok := c.ConnInfo.DataTypeForOID(pgtype.OID(ps.FieldDescriptions[i].DataTypeOID)); ok {
-				if _, ok := dt.Value.(pgtype.BinaryDecoder); ok {
-					c.eqb.AppendResultFormat(BinaryFormatCode)
-				} else {
-					c.eqb.AppendResultFormat(TextFormatCode)
-				}
-			}
-		}
-
-		result := c.pgConn.ExecPrepared(ctx, ps.Name, c.eqb.paramValues, c.eqb.paramFormats, c.eqb.resultFormats).Read()
-		return result.CommandTag, result.Err
+	args, err := convertDriverValuers(arguments)
+	if err != nil {
+		return nil, err
 	}
 
-	if len(arguments) == 0 {
-		results, err := c.pgConn.Exec(ctx, sql).ReadAll()
+	for i := range args {
+		err = c.eqb.AppendParam(c.ConnInfo, ps.ParameterOIDs[i], args[i])
 		if err != nil {
 			return nil, err
 		}
-		if len(results) == 0 {
-			return nil, nil
-		}
-
-		return results[len(results)-1].CommandTag, nil
-	} else {
-		psd, err := c.pgConn.Prepare(ctx, "", sql, nil)
-		if err != nil {
-			return nil, err
-		}
-
-		if len(psd.ParamOIDs) != len(arguments) {
-			return nil, errors.Errorf("expected %d arguments, got %d", len(psd.ParamOIDs), len(arguments))
-		}
-
-		ps := &PreparedStatement{
-			Name:              psd.Name,
-			SQL:               psd.SQL,
-			ParameterOIDs:     make([]pgtype.OID, len(psd.ParamOIDs)),
-			FieldDescriptions: psd.Fields,
-		}
-
-		for i := range ps.ParameterOIDs {
-			ps.ParameterOIDs[i] = pgtype.OID(psd.ParamOIDs[i])
-		}
-
-		arguments, err = convertDriverValuers(arguments)
-		if err != nil {
-			return nil, err
-		}
-
-		for i := range arguments {
-			err = c.eqb.AppendParam(c.ConnInfo, ps.ParameterOIDs[i], arguments[i])
-			if err != nil {
-				return nil, err
-			}
-		}
-
-		for i := range ps.FieldDescriptions {
-			if dt, ok := c.ConnInfo.DataTypeForOID(pgtype.OID(ps.FieldDescriptions[i].DataTypeOID)); ok {
-				if _, ok := dt.Value.(pgtype.BinaryDecoder); ok {
-					c.eqb.AppendResultFormat(BinaryFormatCode)
-				} else {
-					c.eqb.AppendResultFormat(TextFormatCode)
-				}
-			}
-		}
-
-		result := c.pgConn.ExecPrepared(ctx, psd.Name, c.eqb.paramValues, c.eqb.paramFormats, c.eqb.resultFormats).Read()
-		return result.CommandTag, result.Err
 	}
 
+	for i := range ps.FieldDescriptions {
+		if dt, ok := c.ConnInfo.DataTypeForOID(pgtype.OID(ps.FieldDescriptions[i].DataTypeOID)); ok {
+			if _, ok := dt.Value.(pgtype.BinaryDecoder); ok {
+				c.eqb.AppendResultFormat(BinaryFormatCode)
+			} else {
+				c.eqb.AppendResultFormat(TextFormatCode)
+			}
+		}
+	}
+
+	result := c.pgConn.ExecPrepared(ctx, ps.Name, c.eqb.paramValues, c.eqb.paramFormats, c.eqb.resultFormats).Read()
+	return result.CommandTag, result.Err
 }
 
 func (c *Conn) getRows(ctx context.Context, sql string, args []interface{}) *connRows {