Making Sense Golang Worker Pattern

1. Publish task/job to workers
   As mentioned earlier, Because workers run concurrently and are
   independent of each other, and because goroutines cannot
   directly return values to their caller, channels are used
   as a coordination mechanism for workers to pull jobs and
   publish results safely.

Take a look of this snippet where a caller publishes

jobs to workers.

{

    ...

    numJobs := len(StudentItems)

    jobs := make(chan models.StudentItem, numJobs)



    for i := 0; i < numJobs; i++ {

        jobs <- StudentItems[i]

    }



    close(jobs)

    ...

}



func InsertStudentWorker(ctx context.Context, tx *sql.Tx, data <-chan models.StudentItem, errCh chan<- error) {

    for d := range data {

        err := repository.InsertStudentItemFromWorker(ctx, tx, d)

        ...

    }

}   

Worker accepts a read-only channel argument (data <-chan models.StudentItem).

This means as task is availble on channel, whichever available worker

will recieves it. Recall that workers

are running concurrently, this means we don't care which worker

will pull task from caller.

Finally, we close jobs channel to prevent goroutine leak.

This illustration demonstrates second step.