Add Unique Queue infrastructure and move TestPullRequests to this (#9856)

* Upgrade levelqueue to version 0.2.0

This adds functionality for Unique Queues

* Add UniqueQueue interface and functions to create them

* Add UniqueQueue implementations

* Move TestPullRequests over to use UniqueQueue

* Reduce code duplication

* Add bytefifos

* Ensure invalid types are logged

* Fix close race in PersistableChannelQueue Shutdown

modules/queue/unique_queue_redis.go

@@ -0,0 +1,124 @@
+// Copyright 2019 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
+
+// RedisUniqueQueueType is the type for redis queue
+const RedisUniqueQueueType Type = "unique-redis"
+
+// RedisUniqueQueue redis queue
+type RedisUniqueQueue struct {
+	*ByteFIFOUniqueQueue
+}
+
+// RedisUniqueQueueConfiguration is the configuration for the redis queue
+type RedisUniqueQueueConfiguration struct {
+	ByteFIFOQueueConfiguration
+	RedisUniqueByteFIFOConfiguration
+}
+
+// NewRedisUniqueQueue creates single redis or cluster redis queue.
+//
+// Please note that this Queue 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.
+func NewRedisUniqueQueue(handle HandlerFunc, cfg, exemplar interface{}) (Queue, error) {
+	configInterface, err := toConfig(RedisUniqueQueueConfiguration{}, cfg)
+	if err != nil {
+		return nil, err
+	}
+	config := configInterface.(RedisUniqueQueueConfiguration)
+
+	byteFIFO, err := NewRedisUniqueByteFIFO(config.RedisUniqueByteFIFOConfiguration)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(byteFIFO.setName) == 0 {
+		byteFIFO.setName = byteFIFO.queueName + "_unique"
+	}
+
+	byteFIFOQueue, err := NewByteFIFOUniqueQueue(RedisUniqueQueueType, byteFIFO, handle, config.ByteFIFOQueueConfiguration, exemplar)
+	if err != nil {
+		return nil, err
+	}
+
+	queue := &RedisUniqueQueue{
+		ByteFIFOUniqueQueue: byteFIFOQueue,
+	}
+
+	queue.qid = GetManager().Add(queue, RedisUniqueQueueType, config, exemplar)
+
+	return queue, nil
+}
+
+var _ (UniqueByteFIFO) = &RedisUniqueByteFIFO{}
+
+// RedisUniqueByteFIFO represents a UniqueByteFIFO formed from a redisClient
+type RedisUniqueByteFIFO struct {
+	RedisByteFIFO
+	setName string
+}
+
+// RedisUniqueByteFIFOConfiguration is the configuration for the RedisUniqueByteFIFO
+type RedisUniqueByteFIFOConfiguration struct {
+	RedisByteFIFOConfiguration
+	SetName string
+}
+
+// NewRedisUniqueByteFIFO creates a UniqueByteFIFO formed from a redisClient
+func NewRedisUniqueByteFIFO(config RedisUniqueByteFIFOConfiguration) (*RedisUniqueByteFIFO, error) {
+	internal, err := NewRedisByteFIFO(config.RedisByteFIFOConfiguration)
+	if err != nil {
+		return nil, err
+	}
+
+	fifo := &RedisUniqueByteFIFO{
+		RedisByteFIFO: *internal,
+		setName:       config.SetName,
+	}
+
+	return fifo, nil
+}
+
+// PushFunc pushes data to the end of the fifo and calls the callback if it is added
+func (fifo *RedisUniqueByteFIFO) PushFunc(data []byte, fn func() error) error {
+	added, err := fifo.client.SAdd(fifo.setName, data).Result()
+	if err != nil {
+		return err
+	}
+	if added == 0 {
+		return ErrAlreadyInQueue
+	}
+	if fn != nil {
+		if err := fn(); err != nil {
+			return err
+		}
+	}
+	return fifo.client.RPush(fifo.queueName, data).Err()
+}
+
+// Pop pops data from the start of the fifo
+func (fifo *RedisUniqueByteFIFO) Pop() ([]byte, error) {
+	data, err := fifo.client.LPop(fifo.queueName).Bytes()
+	if err != nil {
+		return data, err
+	}
+
+	if len(data) == 0 {
+		return data, nil
+	}
+
+	err = fifo.client.SRem(fifo.setName, data).Err()
+	return data, err
+}
+
+// Has returns whether the fifo contains this data
+func (fifo *RedisUniqueByteFIFO) Has(data []byte) (bool, error) {
+	return fifo.client.SIsMember(fifo.setName, data).Result()
+}
+
+func init() {
+	queuesMap[RedisUniqueQueueType] = NewRedisUniqueQueue
+}