58 lines
1.2 KiB
Go
58 lines
1.2 KiB
Go
package queue
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import (
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"sync"
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"github.com/go-errors/errors"
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)
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// JobQueue implements a background job processor using a single channel and wait group.
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//
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// The channel is initialised with a maximum number of concurrent workers. Adding a new job
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// consumes a worker from the channel. After finishing a job, the worker is added back to
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// the channel. When all workers are consumed, adding new job will block.
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//
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// Example usage:
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//
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// jq := NewJobQueue(5)
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// err := jq.Put(func() error {
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// return nil
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// })
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// errors.Join(err, jq.Collect())
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type JobQueue struct {
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wg sync.WaitGroup
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errCh chan error
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}
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func NewJobQueue(maxConcurrency uint) *JobQueue {
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q := &JobQueue{
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errCh: make(chan error, maxConcurrency),
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}
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for i := 0; i < cap(q.errCh); i++ {
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q.errCh <- nil
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}
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return q
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}
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// Put runs a job in the background, returning any error from the previous job.
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func (q *JobQueue) Put(job func() error) error {
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err := <-q.errCh
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q.wg.Add(1)
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go func() {
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defer q.wg.Done()
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q.errCh <- job()
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}()
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return err
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}
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// Collect waits for all jobs to finish, returning any errors.
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func (q *JobQueue) Collect() error {
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q.wg.Wait()
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var err []error
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for i := 0; i < cap(q.errCh); i++ {
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err = append(err, <-q.errCh)
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q.errCh <- nil
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}
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return errors.Join(err...)
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}
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