Files
tidb/plan/stringer.go
2016-08-20 16:00:20 +08:00

127 lines
3.2 KiB
Go

// 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 plan
import (
"fmt"
"strings"
)
// ToString explains a Plan, returns description string.
func ToString(p Plan) string {
strs, _ := toString(p, []string{}, []int{})
return strings.Join(strs, "->")
}
func toString(in Plan, strs []string, idxs []int) ([]string, []int) {
switch in.(type) {
case *Join, *NewUnion, *PhysicalHashJoin, *PhysicalHashSemiJoin:
idxs = append(idxs, len(strs))
}
for _, c := range in.GetChildren() {
strs, idxs = toString(c, strs, idxs)
}
var str string
switch x := in.(type) {
case *CheckTable:
str = "CheckTable"
case *PhysicalIndexScan:
str = fmt.Sprintf("Index(%s.%s)%v", x.Table.Name.L, x.Index.Name.L, x.Ranges)
case *PhysicalTableScan:
str = fmt.Sprintf("Table(%s)", x.Table.Name.L)
case *PhysicalDummyScan:
str = "Dummy"
case *PhysicalHashJoin:
last := len(idxs) - 1
idx := idxs[last]
children := strs[idx:]
strs = strs[:idx]
idxs = idxs[:last]
if x.SmallTable == 0 {
str = "RightHashJoin{" + strings.Join(children, "->") + "}"
} else {
str = "LeftHashJoin{" + strings.Join(children, "->") + "}"
}
for _, eq := range x.EqualConditions {
l := eq.Args[0].ToString()
r := eq.Args[1].ToString()
str += fmt.Sprintf("(%s,%s)", l, r)
}
case *PhysicalHashSemiJoin:
last := len(idxs) - 1
idx := idxs[last]
children := strs[idx:]
strs = strs[:idx]
idxs = idxs[:last]
if x.WithAux {
str = "SemiJoinWithAux{" + strings.Join(children, "->") + "}"
} else {
str = "SemiJoin{" + strings.Join(children, "->") + "}"
}
case *Apply:
str = fmt.Sprintf("Apply(%s)", ToString(x.InnerPlan))
case *PhysicalApply:
str = fmt.Sprintf("Apply(%s)", ToString(x.InnerPlan))
case *Exists:
str = "Exists"
case *MaxOneRow:
str = "MaxOneRow"
case *Limit:
str = "Limit"
case *SelectLock:
str = "Lock"
case *ShowDDL:
str = "ShowDDL"
case *Filter:
str = "Filter"
case *NewSort:
str = "Sort"
if x.ExecLimit != nil {
str += fmt.Sprintf(" + Limit(%v) + Offset(%v)", x.ExecLimit.Count, x.ExecLimit.Offset)
}
case *Join:
last := len(idxs) - 1
idx := idxs[last]
children := strs[idx:]
strs = strs[:idx]
str = "Join{" + strings.Join(children, "->") + "}"
idxs = idxs[:last]
case *NewUnion:
last := len(idxs) - 1
idx := idxs[last]
children := strs[idx:]
strs = strs[:idx]
str = "UnionAll{" + strings.Join(children, "->") + "}"
idxs = idxs[:last]
case *DataSource:
str = fmt.Sprintf("DataScan(%v)", x.Table.Name.L)
case *Selection:
str = "Selection"
case *Projection:
str = "Projection"
case *Aggregation:
str = "Aggr"
case *Distinct:
str = "Distinct"
case *Trim:
str = "Trim"
default:
str = fmt.Sprintf("%T", in)
}
strs = append(strs, str)
return strs, idxs
}