Michael McGuinness
94 lines
2.2 KiB
Go
94 lines
2.2 KiB
Go
package runner
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import (
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"context"
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"fmt"
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"log/slog"
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"queryorchestration/internal/serviceconfig/queue"
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)
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type Server struct {
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cleanup func() error
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cfg ListenerConfig
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}
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func (c *Server) Listen(ctx context.Context) {
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slog.Info("Listening to queue")
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defer func() {
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if err := c.cleanup(); err != nil {
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fmt.Printf("Error during cleanup: %v", err)
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}
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}()
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// TODO need to slow down the polling so we are not spinning the cpu or burning up API calls.
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for {
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select {
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case <-ctx.Done():
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return
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default:
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err := c.pollMessage(ctx)
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if err != nil {
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slog.Error(err.Error())
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}
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}
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}
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}
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// Alternative without go func if no pool is needed.
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// Just for comment for the next function which needs to be made safe.
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//func (c *Server) pollMessage(ctx context.Context) error {
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// cfg := &queue.Config{
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// URL: c.queueURL,
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// Client: c.client,
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// }
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// result, err := queue.Receive(ctx, cfg, []string{"type"})
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// if err != nil {
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// return fmt.Errorf("message fetch fail: %v", err)
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// }
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//
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// for _, message := range result.Messages {
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// if err := c.controller.Process(ctx, &message); err != nil {
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// return fmt.Errorf("message process fail: %v", err)
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// }
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//
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// if err := queue.Delete(ctx, cfg, &message); err != nil {
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// return fmt.Errorf("message delete fail: %v", err)
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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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func (c *Server) pollMessage(ctx context.Context) error {
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result, err := c.cfg.ReceiveFromQueue(ctx, &queue.ReceiveParams{
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QueueURL: c.cfg.GetQueueURL(),
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})
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if err != nil {
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return fmt.Errorf("message fetch fail: %v", err)
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}
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for _, message := range result.Messages {
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// TODO Need to remove this go func() !!
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// Must not have uncontrolled go routine creation. See commented example above if
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// simple case.
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// if process takes too long to complete then we need to use a thread pool.
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go func() {
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err := c.cfg.GetController().Process(ctx, &message)
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if err != nil {
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slog.Error("message process fail", "err", err)
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}
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err = c.cfg.DeleteFromQueue(ctx, &queue.DeleteParams{
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QueueURL: c.cfg.GetQueueURL(),
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ReceiptHandle: message.ReceiptHandle,
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})
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if err != nil {
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slog.Error("message delete fail", "err", err)
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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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