forked from pingcap/tidb
/
final.go
80 lines (71 loc) · 2.33 KB
/
final.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
// Copyright 2015 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,
// See the License for the specific language governing permissions and
// limitations under the License.
package plans
import (
"github.com/pingcap/tidb/context"
"github.com/pingcap/tidb/expression"
"github.com/pingcap/tidb/field"
"github.com/pingcap/tidb/plan"
"github.com/pingcap/tidb/util/format"
)
var (
_ plan.Plan = (*SelectFinalPlan)(nil)
)
// SelectFinalPlan sets info field for resuilt.
type SelectFinalPlan struct {
*SelectList
Src plan.Plan
infered bool // If result field info is already infered
}
// Do implements the plan.Plan Do interface, and sets result info field.
func (r *SelectFinalPlan) Do(ctx context.Context, f plan.RowIterFunc) error {
// Reset infered. For prepared statements, this plan may run many times.
r.infered = false
return r.Src.Do(ctx, func(rid interface{}, in []interface{}) (bool, error) {
// we should not output hidden fields to client
out := in[0:r.HiddenFieldOffset]
for i, o := range out {
switch v := o.(type) {
case bool:
// Convert bool field to int
if v {
out[i] = uint8(1)
} else {
out[i] = uint8(0)
}
}
}
if !r.infered {
setResultFieldInfo(r.ResultFields[0:r.HiddenFieldOffset], out)
r.infered = true
}
return f(rid, out)
})
}
// Explain implements the plan.Plan Explain interface.
func (r *SelectFinalPlan) Explain(w format.Formatter) {
r.Src.Explain(w)
if r.HiddenFieldOffset == len(r.Src.GetFields()) {
// we have no hidden fields, can return.
return
}
w.Format("┌Evaluate\n└Output field names %v\n", field.RFQNames(r.ResultFields[0:r.HiddenFieldOffset]))
}
// GetFields implements the plan.Plan GetFields interface.
func (r *SelectFinalPlan) GetFields() []*field.ResultField {
return r.ResultFields[0:r.HiddenFieldOffset]
}
// Filter implements the plan.Plan Filter interface.
func (r *SelectFinalPlan) Filter(ctx context.Context, expr expression.Expression) (p plan.Plan, filtered bool, err error) {
return r, false, nil
}