Files
tidb/pkg/disttask/framework/taskexecutor/execute/interface.go

101 lines
3.3 KiB
Go

// Copyright 2023 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 execute
import (
"context"
"reflect"
"github.com/pingcap/tidb/pkg/disttask/framework/proto"
)
// StepExecutor defines the executor for subtasks of a task step.
// the calling sequence is:
//
// Init
// for every subtask of this step:
// if RunSubtask failed then break
// else OnFinished
// Cleanup
type StepExecutor interface {
StepExecFrameworkInfo
// Init is used to initialize the environment.
// if failed, task executor will retry later.
Init(context.Context) error
// RunSubtask is used to run the subtask.
RunSubtask(ctx context.Context, subtask *proto.Subtask) error
// RealtimeSummary returns the realtime summary of the running subtask by this executor.
RealtimeSummary() *SubtaskSummary
// OnFinished is used to handle the subtask when it is finished.
// The subtask meta can be updated in place.
OnFinished(ctx context.Context, subtask *proto.Subtask) error
// Cleanup is used to clean up the environment.
Cleanup(context.Context) error
}
// SubtaskSummary contains the summary of a subtask.
type SubtaskSummary struct {
RowCount int64
}
// StepExecFrameworkInfo is an interface that should be embedded into the
// implementation of StepExecutor. It's set by the framework automatically and
// the implementation can use it to access necessary information. The framework
// will init it before `StepExecutor.Init`, before that you cannot call methods
// in this interface.
type StepExecFrameworkInfo interface {
// restricted is a private method to prevent other package mistakenly implements
// StepExecFrameworkInfo. So when StepExecFrameworkInfo is composed with other
// interfaces, the implementation of other interface must embed
// StepExecFrameworkInfo.
restricted()
// GetResource returns the expected resource of this step executor.
GetResource() *proto.StepResource
}
var stepExecFrameworkInfoName = reflect.TypeOf((*StepExecFrameworkInfo)(nil)).Elem().Name()
type frameworkInfo struct {
resource *proto.StepResource
}
func (*frameworkInfo) restricted() {}
func (f *frameworkInfo) GetResource() *proto.StepResource {
return f.resource
}
// SetFrameworkInfo sets the framework info for the StepExecutor.
func SetFrameworkInfo(exec StepExecutor, resource *proto.StepResource) {
if exec == nil {
return
}
toInject := &frameworkInfo{resource: resource}
// use reflection to set the framework info
e := reflect.ValueOf(exec)
if e.Kind() == reflect.Ptr || e.Kind() == reflect.Interface {
e = e.Elem()
}
info := e.FieldByName(stepExecFrameworkInfoName)
// if `exec` embeds StepExecutor rather than StepExecFrameworkInfo, the field
// will not be found. This is happened in mock generated code.
if info.IsValid() && info.CanSet() {
info.Set(reflect.ValueOf(toInject))
}
}