Files
tidb/pkg/planner/core/task_base.go

107 lines
2.8 KiB
Go

// Copyright 2024 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 core
import (
"github.com/pingcap/tidb/pkg/util/size"
)
var (
_ Task = &RootTask{}
)
// Task is a new version of `PhysicalPlanInfo`. It stores cost information for a task.
// A task may be CopTask, RootTask, MPPTaskMeta or a ParallelTask.
type Task interface {
// Count returns current task's row count.
Count() float64
// Copy return a shallow copy of current task with the same pointer to p.
Copy() Task
// Plan returns current task's plan.
Plan() PhysicalPlan
// Invalid returns whether current task is invalid.
Invalid() bool
// ConvertToRootTask will convert current task as root type.
ConvertToRootTask(ctx PlanContext) *RootTask
// MemoryUsage returns the memory usage of current task.
MemoryUsage() int64
}
// RootTask is the final sink node of a plan graph. It should be a single goroutine on tidb.
type RootTask struct {
p PhysicalPlan
isEmpty bool // isEmpty indicates if this task contains a dual table and returns empty data.
// TODO: The flag 'isEmpty' is only checked by Projection and UnionAll. We should support more cases in the future.
}
// GetPlan returns the root task's plan.
func (t *RootTask) GetPlan() PhysicalPlan {
return t.p
}
// SetPlan sets the root task' plan.
func (t *RootTask) SetPlan(p PhysicalPlan) {
t.p = p
}
// IsEmpty indicates whether root task is empty.
func (t *RootTask) IsEmpty() bool {
return t.isEmpty
}
// SetEmpty set the root task as empty.
func (t *RootTask) SetEmpty(x bool) {
t.isEmpty = x
}
// Copy implements Task interface.
func (t *RootTask) Copy() Task {
return &RootTask{
p: t.p,
}
}
// ConvertToRootTask implements Task interface.
func (t *RootTask) ConvertToRootTask(_ PlanContext) *RootTask {
return t.Copy().(*RootTask)
}
// Invalid implements Task interface.
func (t *RootTask) Invalid() bool {
return t.p == nil
}
// Count implements Task interface.
func (t *RootTask) Count() float64 {
return t.p.StatsInfo().RowCount
}
// Plan implements Task interface.
func (t *RootTask) Plan() PhysicalPlan {
return t.p
}
// MemoryUsage return the memory usage of rootTask
func (t *RootTask) MemoryUsage() (sum int64) {
if t == nil {
return
}
sum = size.SizeOfInterface + size.SizeOfBool
if t.p != nil {
sum += t.p.MemoryUsage()
}
return sum
}