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Diffstat (limited to 'modules/queue/unique_queue.go')
| -rw-r--r-- | modules/queue/unique_queue.go | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/modules/queue/unique_queue.go b/modules/queue/unique_queue.go new file mode 100644 index 0000000000..87e0594ecf --- /dev/null +++ b/modules/queue/unique_queue.go @@ -0,0 +1,29 @@ +// Copyright 2020 The Gitea Authors. All rights reserved. +// Use of this source code is governed by a MIT-style +// license that can be found in the LICENSE file. + +package queue + +import ( + "fmt" +) + +// UniqueQueue defines a queue which guarantees only one instance of same +// data is in the queue. Instances with same identity will be +// discarded if there is already one in the line. +// +// This queue is particularly useful for preventing duplicated task +// of same purpose - please note that this does not guarantee that a particular +// task cannot be processed twice or more at the same time. Uniqueness is +// only guaranteed whilst the task is waiting in the queue. +// +// Users of this queue should be careful to push only the identifier of the +// data +type UniqueQueue interface { + Queue + PushFunc(Data, func() error) error + Has(Data) (bool, error) +} + +// ErrAlreadyInQueue is returned when trying to push data to the queue that is already in the queue +var ErrAlreadyInQueue = fmt.Errorf("already in queue") |