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@@ -0,0 +1,137 @@
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+package task
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+
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+import (
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+ "context"
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+
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+ "v2ray.com/core/common/signal"
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+)
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+
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+type Task func() error
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+
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+type executionContext struct {
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+ ctx context.Context
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+ task Task
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+ onSuccess Task
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+ onFailure Task
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+}
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+
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+func (c *executionContext) executeTask() error {
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+ if c.ctx == nil && c.task == nil {
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+ return nil
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+ }
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+
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+ if c.ctx == nil {
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+ return c.task()
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+ }
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+
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+ if c.task == nil {
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+ <-c.ctx.Done()
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+ return c.ctx.Err()
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+ }
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+
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+ return executeParallel(func() error {
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+ <-c.ctx.Done()
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+ return c.ctx.Err()
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+ }, c.task)
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+}
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+
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+func (c *executionContext) run() error {
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+ err := c.executeTask()
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+ if err == nil && c.onSuccess != nil {
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+ return c.onSuccess()
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+ }
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+ if err != nil && c.onFailure != nil {
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+ return c.onFailure()
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+ }
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+ return err
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+}
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+
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+type ExecutionOption func(*executionContext)
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+
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+func WithContext(ctx context.Context) ExecutionOption {
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+ return func(c *executionContext) {
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+ c.ctx = ctx
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+ }
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+}
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+
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+func Parallel(tasks ...Task) ExecutionOption {
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+ return func(c *executionContext) {
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+ c.task = func() error {
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+ return executeParallel(tasks...)
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+ }
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+ }
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+}
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+
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+func Sequential(tasks ...Task) ExecutionOption {
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+ return func(c *executionContext) {
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+ c.task = func() error {
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+ return execute(tasks...)
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+ }
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+ }
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+}
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+
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+func OnSuccess(task Task) ExecutionOption {
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+ return func(c *executionContext) {
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+ c.onSuccess = task
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+ }
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+}
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+
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+func OnFailure(task Task) ExecutionOption {
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+ return func(c *executionContext) {
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+ c.onFailure = task
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+ }
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+}
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+
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+func Single(task Task, opts ExecutionOption) Task {
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+ return Run(append([]ExecutionOption{Sequential(task)}, opts)...)
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+}
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+
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+func Run(opts ...ExecutionOption) Task {
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+ var c executionContext
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+ for _, opt := range opts {
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+ opt(&c)
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+ }
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+ return func() error {
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+ return c.run()
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+ }
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+}
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+
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+// execute runs a list of tasks sequentially, returns the first error encountered or nil if all tasks pass.
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+func execute(tasks ...Task) error {
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+ for _, task := range tasks {
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+ if err := task(); err != nil {
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+ return err
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+ }
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+ }
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+ return nil
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+}
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+
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+// executeParallel executes a list of tasks asynchronously, returns the first error encountered or nil if all tasks pass.
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+func executeParallel(tasks ...Task) error {
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+ n := len(tasks)
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+ s := signal.NewSemaphore(n)
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+ done := make(chan error, 1)
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+
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+ for _, task := range tasks {
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+ <-s.Wait()
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+ go func(f func() error) {
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+ if err := f(); err != nil {
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+ select {
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+ case done <- err:
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+ default:
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+ }
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+ }
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+ s.Signal()
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+ }(task)
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+ }
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+
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+ for i := 0; i < n; i++ {
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+ select {
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+ case err := <-done:
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+ return err
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+ case <-s.Wait():
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+ }
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+ }
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+
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+ return nil
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+}
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