1 files changed, 281 insertions, 0 deletions
diff --git a/plugins/memory/memoryjobs/consumer.go b/plugins/memory/memoryjobs/consumer.go
new file mode 100644
index 00000000..fbdedefe
--- /dev/null
+++ b/plugins/memory/memoryjobs/consumer.go
@@ -0,0 +1,281 @@
+package memoryjobs
+
+import (
+	"context"
+	"sync/atomic"
+	"time"
+
+	"github.com/spiral/errors"
+	"github.com/spiral/roadrunner/v2/pkg/events"
+	priorityqueue "github.com/spiral/roadrunner/v2/pkg/priority_queue"
+	jobState "github.com/spiral/roadrunner/v2/pkg/state/job"
+	"github.com/spiral/roadrunner/v2/plugins/config"
+	"github.com/spiral/roadrunner/v2/plugins/jobs/job"
+	"github.com/spiral/roadrunner/v2/plugins/jobs/pipeline"
+	"github.com/spiral/roadrunner/v2/plugins/logger"
+	"github.com/spiral/roadrunner/v2/utils"
+)
+
+const (
+	prefetch      string = "prefetch"
+	goroutinesMax uint64 = 1000
+)
+
+type Config struct {
+	Prefetch uint64 `mapstructure:"prefetch"`
+}
+
+type consumer struct {
+	cfg           *Config
+	log           logger.Logger
+	eh            events.Handler
+	pipeline      atomic.Value
+	pq            priorityqueue.Queue
+	localPrefetch chan *Item
+
+	// time.sleep goroutines max number
+	goroutines uint64
+
+	delayed *int64
+	active  *int64
+
+	listeners uint32
+	stopCh    chan struct{}
+}
+
+func NewJobBroker(configKey string, log logger.Logger, cfg config.Configurer, eh events.Handler, pq priorityqueue.Queue) (*consumer, error) {
+	const op = errors.Op("new_ephemeral_pipeline")
+
+	jb := &consumer{
+		log:        log,
+		pq:         pq,
+		eh:         eh,
+		goroutines: 0,
+		active:     utils.Int64(0),
+		delayed:    utils.Int64(0),
+		stopCh:     make(chan struct{}),
+	}
+
+	err := cfg.UnmarshalKey(configKey, &jb.cfg)
+	if err != nil {
+		return nil, errors.E(op, err)
+	}
+
+	if jb.cfg.Prefetch == 0 {
+		jb.cfg.Prefetch = 100_000
+	}
+
+	// initialize a local queue
+	jb.localPrefetch = make(chan *Item, jb.cfg.Prefetch)
+
+	return jb, nil
+}
+
+func FromPipeline(pipeline *pipeline.Pipeline, log logger.Logger, eh events.Handler, pq priorityqueue.Queue) (*consumer, error) {
+	return &consumer{
+		log:           log,
+		pq:            pq,
+		eh:            eh,
+		localPrefetch: make(chan *Item, pipeline.Int(prefetch, 100_000)),
+		goroutines:    0,
+		active:        utils.Int64(0),
+		delayed:       utils.Int64(0),
+		stopCh:        make(chan struct{}),
+	}, nil
+}
+
+func (c *consumer) Push(ctx context.Context, jb *job.Job) error {
+	const op = errors.Op("ephemeral_push")
+
+	// check if the pipeline registered
+	_, ok := c.pipeline.Load().(*pipeline.Pipeline)
+	if !ok {
+		return errors.E(op, errors.Errorf("no such pipeline: %s", jb.Options.Pipeline))
+	}
+
+	err := c.handleItem(ctx, fromJob(jb))
+	if err != nil {
+		return errors.E(op, err)
+	}
+
+	return nil
+}
+
+func (c *consumer) State(_ context.Context) (*jobState.State, error) {
+	pipe := c.pipeline.Load().(*pipeline.Pipeline)
+	return &jobState.State{
+		Pipeline: pipe.Name(),
+		Driver:   pipe.Driver(),
+		Queue:    pipe.Name(),
+		Active:   atomic.LoadInt64(c.active),
+		Delayed:  atomic.LoadInt64(c.delayed),
+		Ready:    ready(atomic.LoadUint32(&c.listeners)),
+	}, nil
+}
+
+func (c *consumer) Register(_ context.Context, pipeline *pipeline.Pipeline) error {
+	c.pipeline.Store(pipeline)
+	return nil
+}
+
+func (c *consumer) Pause(_ context.Context, p string) {
+	start := time.Now()
+	pipe := c.pipeline.Load().(*pipeline.Pipeline)
+	if pipe.Name() != p {
+		c.log.Error("no such pipeline", "requested pause on: ", p)
+	}
+
+	l := atomic.LoadUint32(&c.listeners)
+	// no active listeners
+	if l == 0 {
+		c.log.Warn("no active listeners, nothing to pause")
+		return
+	}
+
+	atomic.AddUint32(&c.listeners, ^uint32(0))
+
+	// stop the consumer
+	c.stopCh <- struct{}{}
+
+	c.eh.Push(events.JobEvent{
+		Event:    events.EventPipePaused,
+		Driver:   pipe.Driver(),
+		Pipeline: pipe.Name(),
+		Start:    start,
+		Elapsed:  time.Since(start),
+	})
+}
+
+func (c *consumer) Resume(_ context.Context, p string) {
+	start := time.Now()
+	pipe := c.pipeline.Load().(*pipeline.Pipeline)
+	if pipe.Name() != p {
+		c.log.Error("no such pipeline", "requested resume on: ", p)
+	}
+
+	l := atomic.LoadUint32(&c.listeners)
+	// listener already active
+	if l == 1 {
+		c.log.Warn("listener already in the active state")
+		return
+	}
+
+	// resume the consumer on the same channel
+	c.consume()
+
+	atomic.StoreUint32(&c.listeners, 1)
+	c.eh.Push(events.JobEvent{
+		Event:    events.EventPipeActive,
+		Pipeline: pipe.Name(),
+		Driver:   pipe.Driver(),
+		Start:    start,
+		Elapsed:  time.Since(start),
+	})
+}
+
+// Run is no-op for the ephemeral
+func (c *consumer) Run(_ context.Context, pipe *pipeline.Pipeline) error {
+	c.eh.Push(events.JobEvent{
+		Event:    events.EventPipeActive,
+		Driver:   pipe.Driver(),
+		Pipeline: pipe.Name(),
+		Start:    time.Now(),
+	})
+	return nil
+}
+
+func (c *consumer) Stop(_ context.Context) error {
+	start := time.Now()
+	pipe := c.pipeline.Load().(*pipeline.Pipeline)
+
+	select {
+	case c.stopCh <- struct{}{}:
+	default:
+		break
+	}
+
+	for i := 0; i < len(c.localPrefetch); i++ {
+		// drain all jobs from the channel
+		<-c.localPrefetch
+	}
+
+	c.localPrefetch = nil
+
+	c.eh.Push(events.JobEvent{
+		Event:    events.EventPipeStopped,
+		Pipeline: pipe.Name(),
+		Driver:   pipe.Driver(),
+		Start:    start,
+		Elapsed:  time.Since(start),
+	})
+
+	return nil
+}
+
+func (c *consumer) handleItem(ctx context.Context, msg *Item) error {
+	const op = errors.Op("ephemeral_handle_request")
+	// handle timeouts
+	// theoretically, some bad user may send millions requests with a delay and produce a billion (for example)
+	// goroutines here. We should limit goroutines here.
+	if msg.Options.Delay > 0 {
+		// if we have 1000 goroutines waiting on the delay - reject 1001
+		if atomic.LoadUint64(&c.goroutines) >= goroutinesMax {
+			return errors.E(op, errors.Str("max concurrency number reached"))
+		}
+
+		go func(jj *Item) {
+			atomic.AddUint64(&c.goroutines, 1)
+			atomic.AddInt64(c.delayed, 1)
+
+			time.Sleep(jj.Options.DelayDuration())
+
+			select {
+			case c.localPrefetch <- jj:
+				atomic.AddUint64(&c.goroutines, ^uint64(0))
+			default:
+				c.log.Warn("can't push job", "error", "local queue closed or full")
+			}
+		}(msg)
+
+		return nil
+	}
+
+	// increase number of the active jobs
+	atomic.AddInt64(c.active, 1)
+
+	// insert to the local, limited pipeline
+	select {
+	case c.localPrefetch <- msg:
+		return nil
+	case <-ctx.Done():
+		return errors.E(op, errors.Errorf("local pipeline is full, consider to increase prefetch number, current limit: %d, context error: %v", c.cfg.Prefetch, ctx.Err()))
+	}
+}
+
+func (c *consumer) consume() {
+	go func() {
+		// redirect
+		for {
+			select {
+			case item, ok := <-c.localPrefetch:
+				if !ok {
+					c.log.Warn("ephemeral local prefetch queue closed")
+					return
+				}
+
+				// set requeue channel
+				item.Options.requeueFn = c.handleItem
+				item.Options.active = c.active
+				item.Options.delayed = c.delayed
+
+				c.pq.Insert(item)
+			case <-c.stopCh:
+				return
+			}
+		}
+	}()
+}
+
+func ready(r uint32) bool {
+	return r > 0
+}