feat: add bounded polling and evidence-based workflow recovery examples

sdk/go/examples/internal/flowdemo/runtime.go

@@ -0,0 +1,119 @@
+// Package flowdemo 仅为可运行流程示例提供初始化和有界等待，不属于公开SDK或业务恢复策略。
+package flowdemo
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+	"time"
+
+	orbit "git.yuntuo.hk/k2safe/orbit/sdk/go"
+)
+
+func Client() (*orbit.Client, string, string, error) {
+	raw, err := os.ReadFile(os.Getenv("ORBIT_CREDENTIALS_FILE"))
+	if err != nil {
+		return nil, "", "", err
+	}
+	var credentials struct {
+		Token   string `json:"token"`
+		QueueID string `json:"queue_id"`
+	}
+	if json.Unmarshal(raw, &credentials) != nil || credentials.Token == "" || credentials.QueueID == "" {
+		return nil, "", "", errors.New("invalid private credentials file")
+	}
+	client, err := orbit.NewClient(os.Getenv("ORBIT_URL"), orbit.Options{Token: credentials.Token})
+	if err != nil {
+		return nil, "", "", err
+	}
+	operation, err := orbit.NewWorkerMessageID()
+	return client, credentials.QueueID, operation, err
+}
+
+// PublishStart 每次示例运行创建独立身份；不将重新运行命令当作未知响应的原键恢复。
+func PublishStart(ctx context.Context, api *orbit.Client, operation, name string, spec orbit.WorkflowSpecification, input json.RawMessage) (orbit.WorkflowInstance, error) {
+	var empty orbit.WorkflowInstance
+	fmt.Printf("scenario=%s operation=%s\n", name, operation)
+	created, err := api.CreateWorkflowDefinition(ctx, operation, orbit.CreateWorkflowDefinitionRequest{Name: name + "." + operation, Description: "controlled standalone workflow example"})
+	if err != nil {
+		return empty, err
+	}
+	if _, err = api.PublishWorkflowVersion(ctx, created.Definition.ID, operation, orbit.PublishWorkflowVersionRequest{Version: "v1", Specification: spec, Reason: "publish controlled SDK example"}); err != nil {
+		return empty, err
+	}
+	result, err := api.StartWorkflow(ctx, operation, orbit.StartWorkflowRequest{DefinitionID: created.Definition.ID, Version: "v1", BusinessKey: operation, Input: input})
+	if err != nil {
+		return empty, err
+	}
+	fmt.Printf("workflow=%s version=%s\n", result.Instance.ID, result.Instance.Version)
+	return result.Instance, nil
+}
+
+// Runner 持有一个真实Worker及其结束通知，等待时同时检测Worker异常退出。
+type Runner struct {
+	Worker *orbit.Worker
+	stop   context.CancelFunc
+	done   chan struct{}
+	err    error // err 仅在done关闭后读取，关闭通道建立同步关系。
+}
+
+func StartWorker(ctx context.Context, api *orbit.Client, queue string, handlers ...orbit.WorkerHandler) (*Runner, error) {
+	w, err := orbit.NewWorker(api, orbit.WorkerOptions{QueueID: queue, Capacity: 1, ShutdownTimeout: 5 * time.Second, Handlers: handlers})
+	if err != nil {
+		return nil, err
+	}
+	workerCtx, stop := context.WithCancel(ctx)
+	r := &Runner{Worker: w, stop: stop, done: make(chan struct{})}
+	go func() { r.err = w.Run(workerCtx); close(r.done) }()
+	return r, nil
+}
+
+func (r *Runner) Close() error {
+	r.stop()
+	<-r.done
+	return r.err
+}
+
+func (r *Runner) Wait(ctx context.Context, check func() (bool, error)) error {
+	for {
+		ready, err := check()
+		if err != nil || ready {
+			return err
+		}
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		case <-r.done:
+			return fmt.Errorf("example Worker stopped before expected state: %v", r.err)
+		case <-time.After(100 * time.Millisecond):
+		}
+	}
+}
+
+func (r *Runner) Step(ctx context.Context, api *orbit.Client, workflow, key string, predicate func(orbit.WorkflowStepDetail) bool) (orbit.WorkflowStepDetail, error) {
+	var out orbit.WorkflowStepDetail
+	err := r.Wait(ctx, func() (bool, error) {
+		var err error
+		out, err = api.GetWorkflowStep(ctx, workflow, key)
+		return err == nil && predicate(out), err
+	})
+	return out, err
+}
+
+func (r *Runner) Workflow(ctx context.Context, api *orbit.Client, workflow, state string) (orbit.WorkflowInstance, error) {
+	var out orbit.WorkflowInstance
+	err := r.Wait(ctx, func() (bool, error) {
+		var err error
+		out, err = api.GetWorkflow(ctx, workflow)
+		if err != nil || out.State == state {
+			return err == nil, err
+		}
+		if out.State == "NEEDS_REVIEW" || out.State == "FAILED" || out.State == "CANCELLED" || out.State == "SUCCEEDED" {
+			return false, fmt.Errorf("unexpected workflow state %s; wanted %s", out.State, state)
+		}
+		return false, nil
+	})
+	return out, err
+}