tidb datum_eval 代码
文件路径：/types/datum_eval.go
/ Copyright 2016 PingCAP, Inc.
/
/ Licensed under the Apache License, Version 2.0 (the "License");
/ you may not use this file except in compliance with the License.
/ You may obtain a copy of the License at
/
/ http://www.apache.org/licenses/LICENSE-2.0
/
/ Unless required by applicable law or agreed to in writing, software
/ distributed under the License is distributed on an "AS IS" BASIS,
/ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/ See the License for the specific language governing permissions and
/ limitations under the License.
package types
import (
"github.com/pingcap/errors"
"github.com/pingcap/tidb/parser/opcode"
"github.com/pingcap/tidb/util/mathutil"
)
/ ComputePlus computes the result of a+b.
func ComputePlus(a, b Datum) (d Datum, err error) {
switch a.Kind() {
case KindInt64:
switch b.Kind() {
case KindInt64:
r, err1 := AddInt64(a.GetInt64(), b.GetInt64())
d.SetInt64(r)
return d, errors.Trace(err1)
case KindUint64:
r, err1 := AddInteger(b.GetUint64(), a.GetInt64())
d.SetUint64(r)
return d, errors.Trace(err1)
}
case KindUint64:
switch b.Kind() {
case KindInt64:
r, err1 := AddInteger(a.GetUint64(), b.GetInt64())
d.SetUint64(r)
return d, errors.Trace(err1)
case KindUint64:
r, err1 := AddUint64(a.GetUint64(), b.GetUint64())
d.SetUint64(r)
return d, errors.Trace(err1)
}
case KindFloat64:
if b.Kind() == KindFloat64 {
r := a.GetFloat64() + b.GetFloat64()
d.SetFloat64(r)
return d, nil
}
case KindMysqlDecimal:
if b.Kind() == KindMysqlDecimal {
r := new(MyDecimal)
err = DecimalAdd(a.GetMysqlDecimal(), b.GetMysqlDecimal(), r)
d.SetMysqlDecimal(r)
d.SetFrac(mathutil.Max(a.Frac(), b.Frac()))
return d, err
}
}
_, err = InvOp2(a.GetValue(), b.GetValue(), opcode.Plus)
return d, err
}