Files
orbit/sdk/go/examples/cancellation/main.go

134 lines
3.8 KiB
Go

// cancellation 演示运行中取消、处理器确认停止、结果查询和有界排空。
package main
import (
"context"
"encoding/json"
"errors"
"fmt"
"os"
"time"
orbit "git.yuntuo.hk/k2safe/orbit/sdk/go"
)
func main() {
if err := run(); err != nil {
fmt.Fprintln(os.Stderr, err)
os.Exit(1)
}
}
func run() error {
token, queue := os.Getenv("ORBIT_TOKEN"), os.Getenv("ORBIT_QUEUE_ID")
if path := os.Getenv("ORBIT_CREDENTIALS_FILE"); path != "" {
raw, err := os.ReadFile(path)
if err != nil {
return fmt.Errorf("read private credentials: %w", err)
}
var c struct {
Token string `json:"token"`
QueueID string `json:"queue_id"`
}
if json.Unmarshal(raw, &c) != nil {
return errors.New("invalid credentials file")
}
if token == "" {
token = c.Token
}
if queue == "" {
queue = c.QueueID
}
}
client, err := orbit.NewClient(os.Getenv("ORBIT_URL"), orbit.Options{Token: token})
if err != nil {
return err
}
operation, err := orbit.NewWorkerMessageID()
if err != nil {
return err
}
name := "object.cancel." + operation
ctx, cancel := context.WithTimeout(context.Background(), 25*time.Second)
defer cancel()
entered := make(chan struct{})
w, err := orbit.NewWorker(client, orbit.WorkerOptions{QueueID: queue, Capacity: 1, ShutdownTimeout: 5 * time.Second, Handlers: []orbit.WorkerHandler{{Capability: orbit.WorkerCapability{Handler: name, HandlerVersion: "v1", PayloadVersion: "v1"}, Handle: func(work context.Context, e orbit.WorkerExecution) (json.RawMessage, error) {
close(entered)
<-work.Done()
if !errors.Is(context.Cause(work), orbit.ErrTaskCancellationRequested) {
return nil, work.Err()
}
// 此示例没有外部副作用,因此可以确认安全停止;真实接入需完成自己的核实。
return nil, &orbit.WorkerCancellationConfirmed{Details: json.RawMessage(`{"evidence_ref":"objects/no-external-work"}`)}
}}}})
if err != nil {
return err
}
task, err := client.SubmitTask(ctx, "submit-"+operation, orbit.SubmitTaskRequest{QueueID: queue, Handler: name, HandlerVersion: "v1", PayloadVersion: "v1", Payload: json.RawMessage(`{"object_ref":"objects/example"}`), TaskTimeoutMS: 20000, Retry: orbit.RetryPolicy{MaxAttempts: 1, AttemptTimeoutMS: 15000}})
if err != nil {
return err
}
run, stop := context.WithCancel(ctx)
done := make(chan error, 1)
go func() { done <- w.Run(run) }()
waited := false
defer func() {
stop()
if !waited {
<-done
}
}()
select {
case <-entered:
case err := <-done:
waited = true
return fmt.Errorf("Worker stopped before handler: %v", err)
case <-ctx.Done():
return ctx.Err()
}
for {
current, err := client.GetTask(ctx, task.Task.ID)
if err != nil {
return err
}
key, err := orbit.NewWorkerMessageID()
if err != nil {
return err
}
out, err := client.CancelTask(ctx, current.ID, key, orbit.CancelTaskRequest{ExpectedRevision: current.Revision, Reason: "finish cancellation example"})
if err == nil {
fmt.Printf("task=%s cancel_requested=%t accepted_state=%s\n", out.Task.ID, out.Task.CancelRequestedAt != nil, out.Task.State)
break
}
var api *orbit.APIError
if !errors.As(err, &api) || api.Code != "STATE_CONFLICT" {
return err
}
}
for {
current, err := client.GetTask(ctx, task.Task.ID)
if err != nil {
return err
}
if current.State == orbit.TaskCancelled {
fmt.Printf("final_state=%s attempts=%d\n", current.State, current.AttemptCount)
break
}
if current.State == orbit.TaskNeedsReview || current.State == orbit.TaskFailed || current.State == orbit.TaskSucceeded {
return fmt.Errorf("unexpected result: %s", current.State)
}
select {
case <-ctx.Done():
return ctx.Err()
case <-time.After(100 * time.Millisecond):
}
}
stop()
err = <-done
waited = true
if err != nil {
return err
}
fmt.Printf("worker_drained=true running=%d\n", w.Stats().Running)
return nil
}