Batcher just the frame

exporter/internal/queue/batcher.go

@@ -0,0 +1,141 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package queue // import "go.opentelemetry.io/collector/exporter/internal/queue"
+
+import (
+	"context"
+	"math"
+	"sync"
+	"time"
+
+	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/exporter/exporterbatcher"
+	"go.opentelemetry.io/collector/exporter/internal"
+)
+
+type batch struct {
+	ctx     context.Context
+	req     internal.Request
+	idxList []uint64
+}
+
+type Batcher struct {
+	batchCfg exporterbatcher.Config
+
+	queue      Queue[internal.Request]
+	maxWorkers int
+
+	exportFunc func(context.Context, internal.Request) error
+
+	readingBatch *batch
+	timer        *time.Timer
+	shutdownCh   chan bool
+
+	stopWG sync.WaitGroup
+}
+
+func NewBatcher(batchCfg exporterbatcher.Config, queue Queue[internal.Request],
+	maxWorkers int, exportFunc func(context.Context, internal.Request) error) *Batcher {
+	return &Batcher{
+		batchCfg:   batchCfg,
+		queue:      queue,
+		maxWorkers: maxWorkers,
+		exportFunc: exportFunc,
+		stopWG:     sync.WaitGroup{},
+		shutdownCh: make(chan bool, 1),
+	}
+}
+
+// If preconditions pass, flush() take an item from the head of batch list and exports it.
+func (qb *Batcher) flush(batchToFlush batch) {
+	err := qb.exportFunc(batchToFlush.ctx, batchToFlush.req)
+	for _, idx := range batchToFlush.idxList {
+		qb.queue.OnProcessingFinished(idx, err)
+	}
+}
+
+// allocateFlusher() starts a goroutine that calls flushIfNecessary(). It blocks until a worker is available.
+func (qb *Batcher) allocateFlusher(batchToFlush batch) {
+	// maxWorker = 0 means we don't limit the number of flushers.
+	if qb.maxWorkers == 0 {
+		qb.stopWG.Add(1)
+		go func() {
+			qb.flush(batchToFlush)
+			qb.stopWG.Done()
+		}()
+		return
+	}
+	panic("not implemented")
+}
+
+// Start ensures that queue and all consumers are started.
+func (qb *Batcher) Start(ctx context.Context, host component.Host) error {
+	if err := qb.queue.Start(ctx, host); err != nil {
+		return err
+	}
+
+	if qb.batchCfg.Enabled {
+		panic("not implemented")
+	}
+
+	// Timer doesn't do anything yet, but adding it so compiler won't complain about qb.timer.C
+	qb.timer = time.NewTimer(math.MaxInt)
+	qb.timer.Stop()
+
+	if qb.maxWorkers != 0 {
+		panic("not implemented")
+	}
+
+	// This goroutine keeps reading until flush is triggered because of request size.
+	qb.stopWG.Add(1)
+	go func() {
+		defer qb.stopWG.Done()
+		for {
+			idx, _, req, ok := qb.queue.Read(context.Background())
+
+			if !ok {
+				qb.shutdownCh <- true
+				if qb.readingBatch != nil {
+					panic("batching is supported yet so reading batch should always be nil")
+				}
+
+				return
+			}
+			if !qb.batchCfg.Enabled {
+				qb.readingBatch = &batch{
+					req:     req,
+					ctx:     context.Background(),
+					idxList: []uint64{idx}}
+				qb.allocateFlusher(*qb.readingBatch)
+				qb.readingBatch = nil
+			} else {
+				panic("not implemented")
+			}
+		}
+	}()
+
+	qb.stopWG.Add(1)
+	go func() {
+		defer qb.stopWG.Done()
+		for {
+			select {
+			case <-qb.shutdownCh:
+				return
+			case <-qb.timer.C:
+				panic("batching is not yet implemented. Having timer here just so compiler won't complain")
+			}
+
+		}
+	}()
+	return nil
+}
+
+// Shutdown ensures that queue and all Batcher are stopped.
+func (qb *Batcher) Shutdown(ctx context.Context) error {
+	if err := qb.queue.Shutdown(ctx); err != nil {
+		return err
+	}
+	qb.stopWG.Wait()
+	return nil
+}

exporter/internal/queue/batcher_test.go

@@ -0,0 +1,58 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package queue
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"go.opentelemetry.io/collector/component/componenttest"
+	"go.opentelemetry.io/collector/exporter/exporterbatcher"
+	"go.opentelemetry.io/collector/exporter/internal"
+)
+
+func testExportFunc(ctx context.Context, req internal.Request) error {
+	return req.Export(ctx)
+}
+
+func TestBatcher_BatchNotEnabled_InfiniteWorkerPool(t *testing.T) {
+	cfg := exporterbatcher.NewDefaultConfig()
+	cfg.Enabled = false
+
+	q := NewBoundedMemoryQueue[internal.Request](
+		MemoryQueueSettings[internal.Request]{
+			Sizer:    &RequestSizer[internal.Request]{},
+			Capacity: 10,
+		})
+
+	maxWorkers := 0
+	ba := NewBatcher(cfg, q, maxWorkers, testExportFunc)
+
+	require.NoError(t, ba.Start(context.Background(), componenttest.NewNopHost()))
+	t.Cleanup(func() {
+		require.NoError(t, ba.Shutdown(context.Background()))
+	})
+
+	sink := newFakeRequestSink()
+
+	require.NoError(t, q.Offer(context.Background(), &fakeRequest{items: 8, sink: sink}))
+	assert.Eventually(t, func() bool {
+		return sink.requestsCount.Load() == 1 && sink.itemsCount.Load() == 8
+	}, 20*time.Millisecond, 10*time.Millisecond)
+
+	require.NoError(t, q.Offer(context.Background(), &fakeRequest{items: 17, sink: sink}))
+	assert.Eventually(t, func() bool {
+		return sink.requestsCount.Load() == 2 && sink.itemsCount.Load() == 25
+	}, 20*time.Millisecond, 10*time.Millisecond)
+
+	require.NoError(t, q.Offer(context.Background(), &fakeRequest{items: 13, sink: sink}))
+
+	assert.Eventually(t, func() bool {
+		return sink.requestsCount.Load() == 3 && sink.itemsCount.Load() == 38
+	}, 20*time.Millisecond, 10*time.Millisecond)
+}

exporter/internal/queue/fake_request.go

@@ -0,0 +1,63 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package queue // import "go.opentelemetry.io/collector/exporter/internal/queue"
+
+import (
+	"context"
+	"errors"
+	"sync/atomic"
+	"time"
+
+	"go.opentelemetry.io/collector/exporter/exporterbatcher"
+	"go.opentelemetry.io/collector/exporter/internal"
+)
+
+type fakeRequestSink struct {
+	requestsCount *atomic.Int64
+	itemsCount    *atomic.Int64
+}
+
+func newFakeRequestSink() *fakeRequestSink {
+	return &fakeRequestSink{
+		requestsCount: new(atomic.Int64),
+		itemsCount:    new(atomic.Int64),
+	}
+}
+
+type fakeRequest struct {
+	items     int
+	exportErr error
+	delay     time.Duration
+	sink      *fakeRequestSink
+}
+
+func (r *fakeRequest) Export(ctx context.Context) error {
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	case <-time.After(r.delay):
+	}
+	if r.exportErr != nil {
+		return r.exportErr
+	}
+	if r.sink != nil {
+		r.sink.requestsCount.Add(1)
+		r.sink.itemsCount.Add(int64(r.items))
+	}
+	return nil
+}
+
+func (r *fakeRequest) ItemsCount() int {
+	return r.items
+}
+
+func (r *fakeRequest) Merge(_ context.Context,
+	_ internal.Request) (internal.Request, error) {
+	return nil, errors.New("not implemented")
+}
+
+func (r *fakeRequest) MergeSplit(_ context.Context, _ exporterbatcher.MaxSizeConfig,
+	_ internal.Request) ([]internal.Request, error) {
+	return nil, errors.New("not implemented")
+}