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

Author: zeripath

docs/content/doc/advanced/config-cheat-sheet.en-us.md

@@ -252,6 +252,10 @@ relation to port exhaustion.
 - `BATCH_LENGTH`: **20**: Batch data before passing to the handler
 - `CONN_STR`: **addrs=127.0.0.1:6379 db=0**: Connection string for the redis queue type.
 - `QUEUE_NAME`: **_queue**: The suffix for default redis queue name. Individual queues will default to **`name`**`QUEUE_NAME` but can be overriden in the specific `queue.name` section.
+- `SET_NAME`: **_unique**: The suffix that will added to the default redis
+set name for unique queues. Individual queues will default to
+**`name`**`QUEUE_NAME`_`SET_NAME`_ but can be overridden in the specific
+`queue.name` section.
 - `WRAP_IF_NECESSARY`: **true**: Will wrap queues with a timeoutable queue if the selected queue is not ready to be created - (Only relevant for the level queue.)
 - `MAX_ATTEMPTS`: **10**: Maximum number of attempts to create the wrapped queue
 - `TIMEOUT`: **GRACEFUL_HAMMER_TIME + 30s**: Timeout the creation of the wrapped queue if it takes longer than this to create.

go.mod

@@ -4,7 +4,7 @@ go 1.13
 
 require (
 	cloud.google.com/go v0.45.0 // indirect
-	gitea.com/lunny/levelqueue v0.1.0
+	gitea.com/lunny/levelqueue v0.2.0
 	gitea.com/macaron/binding v0.0.0-20190822013154-a5f53841ed2b
 	gitea.com/macaron/cache v0.0.0-20190822004001-a6e7fee4ee76
 	gitea.com/macaron/captcha v0.0.0-20190822015246-daa973478bae

go.sum

@@ -11,6 +11,8 @@ cloud.google.com/go/bigquery v1.0.1/go.mod h1:i/xbL2UlR5RvWAURpBYZTtm/cXjCha9lbf
 cloud.google.com/go/datastore v1.0.0/go.mod h1:LXYbyblFSglQ5pkeyhO+Qmw7ukd3C+pD7TKLgZqpHYE=
 gitea.com/lunny/levelqueue v0.1.0 h1:7wMk0VH6mvKN6vZEZCy9nUDgRmdPLgeNrm1NkW8EHNk=
 gitea.com/lunny/levelqueue v0.1.0/go.mod h1:G7hVb908t0Bl0uk7zGSg14fyzNtxgtD9Shf04wkMK7s=
+gitea.com/lunny/levelqueue v0.2.0 h1:lR/5EAwQtFcn5YvPEkNMw0p9pAy2/O2nSP5ImECLA2E=
+gitea.com/lunny/levelqueue v0.2.0/go.mod h1:G7hVb908t0Bl0uk7zGSg14fyzNtxgtD9Shf04wkMK7s=
 gitea.com/macaron/binding v0.0.0-20190822013154-a5f53841ed2b h1:vXt85uYV17KURaUlhU7v4GbCShkqRZDSfo0TkC0YCjQ=
 gitea.com/macaron/binding v0.0.0-20190822013154-a5f53841ed2b/go.mod h1:Cxadig6POWpPYYSfg23E7jo35Yf0yvsdC1lifoKWmPo=
 gitea.com/macaron/cache v0.0.0-20190822004001-a6e7fee4ee76 h1:mMsMEg90c5KXQgRWsH8D6GHXfZIW1RAe5S9VYIb12lM=

modules/queue/bytefifo.go

@@ -0,0 +1,61 @@
+// 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
+
+// ByteFIFO defines a FIFO that takes a byte array
+type ByteFIFO interface {
+	// Len returns the length of the fifo
+	Len() int64
+	// PushFunc pushes data to the end of the fifo and calls the callback if it is added
+	PushFunc(data []byte, fn func() error) error
+	// Pop pops data from the start of the fifo
+	Pop() ([]byte, error)
+	// Close this fifo
+	Close() error
+}
+
+// UniqueByteFIFO defines a FIFO that Uniques its contents
+type UniqueByteFIFO interface {
+	ByteFIFO
+	// Has returns whether the fifo contains this data
+	Has(data []byte) (bool, error)
+}
+
+var _ (ByteFIFO) = &DummyByteFIFO{}
+
+// DummyByteFIFO represents a dummy fifo
+type DummyByteFIFO struct{}
+
+// PushFunc returns nil
+func (*DummyByteFIFO) PushFunc(data []byte, fn func() error) error {
+	return nil
+}
+
+// Pop returns nil
+func (*DummyByteFIFO) Pop() ([]byte, error) {
+	return []byte{}, nil
+}
+
+// Close returns nil
+func (*DummyByteFIFO) Close() error {
+	return nil
+}
+
+// Len is always 0
+func (*DummyByteFIFO) Len() int64 {
+	return 0
+}
+
+var _ (UniqueByteFIFO) = &DummyUniqueByteFIFO{}
+
+// DummyUniqueByteFIFO represents a dummy unique fifo
+type DummyUniqueByteFIFO struct {
+	DummyByteFIFO
+}
+
+// Has always returns false
+func (*DummyUniqueByteFIFO) Has([]byte) (bool, error) {
+	return false, nil
+}

modules/queue/queue.go

@@ -74,25 +74,35 @@ type DummyQueue struct {
 }
 
 // Run does nothing
-func (b *DummyQueue) Run(_, _ func(context.Context, func())) {}
+func (*DummyQueue) Run(_, _ func(context.Context, func())) {}
 
 // Push fakes a push of data to the queue
-func (b *DummyQueue) Push(Data) error {
+func (*DummyQueue) Push(Data) error {
 	return nil
 }
 
+// PushFunc fakes a push of data to the queue with a function. The function is never run.
+func (*DummyQueue) PushFunc(Data, func() error) error {
+	return nil
+}
+
+// Has always returns false as this queue never does anything
+func (*DummyQueue) Has(Data) (bool, error) {
+	return false, nil
+}
+
 // Flush always returns nil
-func (b *DummyQueue) Flush(time.Duration) error {
+func (*DummyQueue) Flush(time.Duration) error {
 	return nil
 }
 
 // FlushWithContext always returns nil
-func (b *DummyQueue) FlushWithContext(context.Context) error {
+func (*DummyQueue) FlushWithContext(context.Context) error {
 	return nil
 }
 
 // IsEmpty asserts that the queue is empty
-func (b *DummyQueue) IsEmpty() bool {
+func (*DummyQueue) IsEmpty() bool {
 	return true
 }
 

modules/queue/queue_bytefifo.go

@@ -0,0 +1,227 @@
+// 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 (
+	"context"
+	"encoding/json"
+	"fmt"
+	"sync"
+	"time"
+
+	"code.gitea.io/gitea/modules/log"
+)
+
+// ByteFIFOQueueConfiguration is the configuration for a ByteFIFOQueue
+type ByteFIFOQueueConfiguration struct {
+	WorkerPoolConfiguration
+	Workers int
+	Name    string
+}
+
+var _ (Queue) = &ByteFIFOQueue{}
+
+// ByteFIFOQueue is a Queue formed from a ByteFIFO and WorkerPool
+type ByteFIFOQueue struct {
+	*WorkerPool
+	byteFIFO   ByteFIFO
+	typ        Type
+	closed     chan struct{}
+	terminated chan struct{}
+	exemplar   interface{}
+	workers    int
+	name       string
+	lock       sync.Mutex
+}
+
+// NewByteFIFOQueue creates a new ByteFIFOQueue
+func NewByteFIFOQueue(typ Type, byteFIFO ByteFIFO, handle HandlerFunc, cfg, exemplar interface{}) (*ByteFIFOQueue, error) {
+	configInterface, err := toConfig(ByteFIFOQueueConfiguration{}, cfg)
+	if err != nil {
+		return nil, err
+	}
+	config := configInterface.(ByteFIFOQueueConfiguration)
+
+	return &ByteFIFOQueue{
+		WorkerPool: NewWorkerPool(handle, config.WorkerPoolConfiguration),
+		byteFIFO:   byteFIFO,
+		typ:        typ,
+		closed:     make(chan struct{}),
+		terminated: make(chan struct{}),
+		exemplar:   exemplar,
+		workers:    config.Workers,
+		name:       config.Name,
+	}, nil
+}
+
+// Name returns the name of this queue
+func (q *ByteFIFOQueue) Name() string {
+	return q.name
+}
+
+// Push pushes data to the fifo
+func (q *ByteFIFOQueue) Push(data Data) error {
+	return q.PushFunc(data, nil)
+}
+
+// PushFunc pushes data to the fifo
+func (q *ByteFIFOQueue) PushFunc(data Data, fn func() error) error {
+	if !assignableTo(data, q.exemplar) {
+		return fmt.Errorf("Unable to assign data: %v to same type as exemplar: %v in %s", data, q.exemplar, q.name)
+	}
+	bs, err := json.Marshal(data)
+	if err != nil {
+		return err
+	}
+	return q.byteFIFO.PushFunc(bs, fn)
+}
+
+// IsEmpty checks if the queue is empty
+func (q *ByteFIFOQueue) IsEmpty() bool {
+	q.lock.Lock()
+	defer q.lock.Unlock()
+	if !q.WorkerPool.IsEmpty() {
+		return false
+	}
+	return q.byteFIFO.Len() == 0
+}
+
+// Run runs the bytefifo queue
+func (q *ByteFIFOQueue) Run(atShutdown, atTerminate func(context.Context, func())) {
+	atShutdown(context.Background(), q.Shutdown)
+	atTerminate(context.Background(), q.Terminate)
+	log.Debug("%s: %s Starting", q.typ, q.name)
+
+	go func() {
+		_ = q.AddWorkers(q.workers, 0)
+	}()
+
+	go q.readToChan()
+
+	log.Trace("%s: %s Waiting til closed", q.typ, q.name)
+	<-q.closed
+	log.Trace("%s: %s Waiting til done", q.typ, q.name)
+	q.Wait()
+
+	log.Trace("%s: %s Waiting til cleaned", q.typ, q.name)
+	ctx, cancel := context.WithCancel(context.Background())
+	atTerminate(ctx, cancel)
+	q.CleanUp(ctx)
+	cancel()
+}
+
+func (q *ByteFIFOQueue) readToChan() {
+	for {
+		select {
+		case <-q.closed:
+			// tell the pool to shutdown.
+			q.cancel()
+			return
+		default:
+			q.lock.Lock()
+			bs, err := q.byteFIFO.Pop()
+			if err != nil {
+				q.lock.Unlock()
+				log.Error("%s: %s Error on Pop: %v", q.typ, q.name, err)
+				time.Sleep(time.Millisecond * 100)
+				continue
+			}
+
+			if len(bs) == 0 {
+				q.lock.Unlock()
+				time.Sleep(time.Millisecond * 100)
+				continue
+			}
+
+			data, err := unmarshalAs(bs, q.exemplar)
+			if err != nil {
+				log.Error("%s: %s Failed to unmarshal with error: %v", q.typ, q.name, err)
+				q.lock.Unlock()
+				time.Sleep(time.Millisecond * 100)
+				continue
+			}
+
+			log.Trace("%s %s: Task found: %#v", q.typ, q.name, data)
+			q.WorkerPool.Push(data)
+			q.lock.Unlock()
+		}
+	}
+}
+
+// Shutdown processing from this queue
+func (q *ByteFIFOQueue) Shutdown() {
+	log.Trace("%s: %s Shutting down", q.typ, q.name)
+	q.lock.Lock()
+	select {
+	case <-q.closed:
+	default:
+		close(q.closed)
+	}
+	q.lock.Unlock()
+	log.Debug("%s: %s Shutdown", q.typ, q.name)
+}
+
+// Terminate this queue and close the queue
+func (q *ByteFIFOQueue) Terminate() {
+	log.Trace("%s: %s Terminating", q.typ, q.name)
+	q.Shutdown()
+	q.lock.Lock()
+	select {
+	case <-q.terminated:
+		q.lock.Unlock()
+		return
+	default:
+	}
+	close(q.terminated)
+	q.lock.Unlock()
+	if log.IsDebug() {
+		log.Debug("%s: %s Closing with %d tasks left in queue", q.typ, q.name, q.byteFIFO.Len())
+	}
+	if err := q.byteFIFO.Close(); err != nil {
+		log.Error("Error whilst closing internal byte fifo in %s: %s: %v", q.typ, q.name, err)
+	}
+	log.Debug("%s: %s Terminated", q.typ, q.name)
+}
+
+var _ (UniqueQueue) = &ByteFIFOUniqueQueue{}
+
+// ByteFIFOUniqueQueue represents a UniqueQueue formed from a UniqueByteFifo
+type ByteFIFOUniqueQueue struct {
+	ByteFIFOQueue
+}
+
+// NewByteFIFOUniqueQueue creates a new ByteFIFOUniqueQueue
+func NewByteFIFOUniqueQueue(typ Type, byteFIFO UniqueByteFIFO, handle HandlerFunc, cfg, exemplar interface{}) (*ByteFIFOUniqueQueue, error) {
+	configInterface, err := toConfig(ByteFIFOQueueConfiguration{}, cfg)
+	if err != nil {
+		return nil, err
+	}
+	config := configInterface.(ByteFIFOQueueConfiguration)
+
+	return &ByteFIFOUniqueQueue{
+		ByteFIFOQueue: ByteFIFOQueue{
+			WorkerPool: NewWorkerPool(handle, config.WorkerPoolConfiguration),
+			byteFIFO:   byteFIFO,
+			typ:        typ,
+			closed:     make(chan struct{}),
+			terminated: make(chan struct{}),
+			exemplar:   exemplar,
+			workers:    config.Workers,
+			name:       config.Name,
+		},
+	}, nil
+}
+
+// Has checks if the provided data is in the queue
+func (q *ByteFIFOUniqueQueue) Has(data Data) (bool, error) {
+	if !assignableTo(data, q.exemplar) {
+		return false, fmt.Errorf("Unable to assign data: %v to same type as exemplar: %v in %s", data, q.exemplar, q.name)
+	}
+	bs, err := json.Marshal(data)
+	if err != nil {
+		return false, err
+	}
+	return q.byteFIFO.(UniqueByteFIFO).Has(bs)
+}