85 lines
1.2 KiB
Go
85 lines
1.2 KiB
Go
package queue
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import "sync"
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type queue struct {
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sync.Mutex
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items map[*Work]struct{}
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itemc chan *Work
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}
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func New() Queue {
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return newQueue()
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}
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func newQueue() *queue {
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return &queue{
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items: make(map[*Work]struct{}),
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itemc: make(chan *Work, 999),
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}
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}
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func (q *queue) Publish(work *Work) error {
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q.Lock()
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q.items[work] = struct{}{}
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q.Unlock()
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q.itemc <- work
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return nil
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}
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func (q *queue) Remove(work *Work) error {
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q.Lock()
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defer q.Unlock()
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_, ok := q.items[work]
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if !ok {
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return ErrNotFound
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}
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var items []*Work
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// loop through and drain all items
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// from the
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drain:
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for {
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select {
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case item := <-q.itemc:
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items = append(items, item)
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default:
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break drain
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}
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}
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// re-add all items to the queue except
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// the item we're trying to remove
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for _, item := range items {
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if item == work {
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delete(q.items, work)
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continue
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}
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q.itemc <- item
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}
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return nil
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}
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func (q *queue) Pull() *Work {
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work := <-q.itemc
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q.Lock()
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delete(q.items, work)
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q.Unlock()
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return work
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}
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func (q *queue) PullClose(cn CloseNotifier) *Work {
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for {
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select {
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case <-cn.CloseNotify():
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return nil
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case work := <-q.itemc:
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q.Lock()
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delete(q.items, work)
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q.Unlock()
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return work
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}
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}
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}
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