Queue: Make WorkerPools and Queues flushable (#10001)

* Make WorkerPools and Queues flushable

Adds Flush methods to Queues and the WorkerPool
Further abstracts the WorkerPool
Adds a final step to Flush the queues in the defer from PrintCurrentTest
Fixes an issue with Settings inheritance in queues

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Change to for loop

* Add IsEmpty and begin just making the queues composed WorkerPools

* subsume workerpool into the queues and create a flushable interface

* Add manager command

* Move flushall to queue.Manager and add to testlogger

* As per @guillep2k

* as per @guillep2k

* Just make queues all implement flushable and clean up the wrapped queue flushes

* cope with no timeout

Co-authored-by: Lauris BH <lauris@nix.lv>

modules/queue/queue_channel.go

@@ -7,8 +7,6 @@ package queue
 import (
 	"context"
 	"fmt"
-	"reflect"
-	"time"
 
 	"code.gitea.io/gitea/modules/log"
 )
@@ -18,25 +16,23 @@ const ChannelQueueType Type = "channel"
 
 // ChannelQueueConfiguration is the configuration for a ChannelQueue
 type ChannelQueueConfiguration struct {
-	QueueLength  int
-	BatchLength  int
-	Workers      int
-	MaxWorkers   int
-	BlockTimeout time.Duration
-	BoostTimeout time.Duration
-	BoostWorkers int
-	Name         string
+	WorkerPoolConfiguration
+	Workers int
+	Name    string
 }
 
-// ChannelQueue implements
+// ChannelQueue implements Queue
+//
+// A channel queue is not persistable and does not shutdown or terminate cleanly
+// It is basically a very thin wrapper around a WorkerPool
 type ChannelQueue struct {
-	pool     *WorkerPool
+	*WorkerPool
 	exemplar interface{}
 	workers  int
 	name     string
 }
 
-// NewChannelQueue create a memory channel queue
+// NewChannelQueue creates a memory channel queue
 func NewChannelQueue(handle HandlerFunc, cfg, exemplar interface{}) (Queue, error) {
 	configInterface, err := toConfig(ChannelQueueConfiguration{}, cfg)
 	if err != nil {
@@ -46,26 +42,13 @@ func NewChannelQueue(handle HandlerFunc, cfg, exemplar interface{}) (Queue, erro
 	if config.BatchLength == 0 {
 		config.BatchLength = 1
 	}
-	dataChan := make(chan Data, config.QueueLength)
-
-	ctx, cancel := context.WithCancel(context.Background())
 	queue := &ChannelQueue{
-		pool: &WorkerPool{
-			baseCtx:            ctx,
-			cancel:             cancel,
-			batchLength:        config.BatchLength,
-			handle:             handle,
-			dataChan:           dataChan,
-			blockTimeout:       config.BlockTimeout,
-			boostTimeout:       config.BoostTimeout,
-			boostWorkers:       config.BoostWorkers,
-			maxNumberOfWorkers: config.MaxWorkers,
-		},
-		exemplar: exemplar,
-		workers:  config.Workers,
-		name:     config.Name,
+		WorkerPool: NewWorkerPool(handle, config.WorkerPoolConfiguration),
+		exemplar:   exemplar,
+		workers:    config.Workers,
+		name:       config.Name,
 	}
-	queue.pool.qid = GetManager().Add(queue, ChannelQueueType, config, exemplar, queue.pool)
+	queue.qid = GetManager().Add(queue, ChannelQueueType, config, exemplar)
 	return queue, nil
 }
 
@@ -77,22 +60,18 @@ func (c *ChannelQueue) Run(atShutdown, atTerminate func(context.Context, func())
 	atTerminate(context.Background(), func() {
 		log.Warn("ChannelQueue: %s is not terminatable!", c.name)
 	})
+	log.Debug("ChannelQueue: %s Starting", c.name)
 	go func() {
-		_ = c.pool.AddWorkers(c.workers, 0)
+		_ = c.AddWorkers(c.workers, 0)
 	}()
 }
 
 // Push will push data into the queue
 func (c *ChannelQueue) Push(data Data) error {
-	if c.exemplar != nil {
-		// Assert data is of same type as r.exemplar
-		t := reflect.TypeOf(data)
-		exemplarType := reflect.TypeOf(c.exemplar)
-		if !t.AssignableTo(exemplarType) || data == nil {
-			return fmt.Errorf("Unable to assign data: %v to same type as exemplar: %v in queue: %s", data, c.exemplar, c.name)
-		}
+	if !assignableTo(data, c.exemplar) {
+		return fmt.Errorf("Unable to assign data: %v to same type as exemplar: %v in queue: %s", data, c.exemplar, c.name)
 	}
-	c.pool.Push(data)
+	c.WorkerPool.Push(data)
 	return nil
 }