Adding the serialization features.

Makefile

@@ -141,7 +141,7 @@ lint: alloylint
 # final command runs tests for all other submodules.
 test:
 	$(GO_ENV) go test $(GO_FLAGS) -race $(shell go list ./... | grep -v /integration-tests/)
-	$(GO_ENV) go test $(GO_FLAGS) ./internal/static/integrations/node_exporter ./internal/static/logs ./internal/component/otelcol/processor/tail_sampling ./internal/component/loki/source/file ./internal/component/loki/source/docker
+	$(GO_ENV) go test $(GO_FLAGS) ./internal/static/integrations/node_exporter ./internal/static/logs ./internal/component/otelcol/processor/tail_sampling ./internal/component/loki/source/file ./internal/component/loki/source/docker ./internal/component/prometheus/remote/queue/serialization
 	$(GO_ENV) find . -name go.mod -not -path "./go.mod" -execdir go test -race ./... \;
 
 test-packages:

internal/component/prometheus/remote/queue/filequeue/filequeue.go

@@ -30,7 +30,7 @@ type queue struct {
 	// block until ready for another record.
 	out func(ctx context.Context, dh types.DataHandle)
 	// existingFiles is the list of files found initially.
-	existingsFiles []string
+	existingFiles []string
 }
 
 // NewQueue returns a implementation of FileStorage.
@@ -61,18 +61,18 @@ func NewQueue(directory string, out func(ctx context.Context, dh types.DataHandl
 		currentMaxID = ids[len(ids)-1]
 	}
 	q := &queue{
-		directory:      directory,
-		maxID:          currentMaxID,
-		logger:         logger,
-		out:            out,
-		dataQueue:      actor.NewMailbox[types.Data](),
-		existingsFiles: make([]string, 0),
+		directory:     directory,
+		maxID:         currentMaxID,
+		logger:        logger,
+		out:           out,
+		dataQueue:     actor.NewMailbox[types.Data](),
+		existingFiles: make([]string, 0),
 	}
 
 	// Save the existing files in `q.existingFiles`, which will have their data pushed to `out` when actor starts.
 	for _, id := range ids {
 		name := filepath.Join(directory, fmt.Sprintf("%d.committed", id))
-		q.existingsFiles = append(q.existingsFiles, name)
+		q.existingFiles = append(q.existingFiles, name)
 	}
 	return q, nil
 }
@@ -115,7 +115,7 @@ func get(logger log.Logger, name string) (map[string]string, []byte, error) {
 // DoWork allows most of the queue to be single threaded with work only coming in and going out via mailboxes(channels).
 func (q *queue) DoWork(ctx actor.Context) actor.WorkerStatus {
 	// Queue up our existing items.
-	for _, name := range q.existingsFiles {
+	for _, name := range q.existingFiles {
 		q.out(ctx, types.DataHandle{
 			Name: name,
 			Pop: func() (map[string]string, []byte, error) {
@@ -124,7 +124,7 @@ func (q *queue) DoWork(ctx actor.Context) actor.WorkerStatus {
 		})
 	}
 	// We only want to process existing files once.
-	q.existingsFiles = nil
+	q.existingFiles = nil
 	select {
 	case <-ctx.Done():
 		return actor.WorkerEnd

internal/component/prometheus/remote/queue/serialization/appender.go

@@ -0,0 +1,121 @@
+package serialization
+
+import (
+	"context"
+	"time"
+
+	"github.com/go-kit/log"
+	"github.com/grafana/alloy/internal/component/prometheus/remote/queue/types"
+	"github.com/prometheus/prometheus/model/exemplar"
+	"github.com/prometheus/prometheus/model/histogram"
+	"github.com/prometheus/prometheus/model/labels"
+	"github.com/prometheus/prometheus/model/metadata"
+	"github.com/prometheus/prometheus/storage"
+)
+
+type appender struct {
+	ctx    context.Context
+	ttl    time.Duration
+	s      types.Serializer
+	logger log.Logger
+}
+
+func (a *appender) AppendCTZeroSample(ref storage.SeriesRef, l labels.Labels, t, ct int64) (storage.SeriesRef, error) {
+	// TODO @mattdurham figure out what to do here later. This mirrors what we do elsewhere.
+	return ref, nil
+}
+
+// NewAppender returns an Appender that writes to a given serializer. NOTE the returned Appender writes
+// data immediately, discards data older than `ttl` and does not honor commit or rollback.
+func NewAppender(ctx context.Context, ttl time.Duration, s types.Serializer, logger log.Logger) storage.Appender {
+	app := &appender{
+		ttl:    ttl,
+		s:      s,
+		logger: logger,
+		ctx:    ctx,
+	}
+	return app
+}
+
+// Append metric
+func (a *appender) Append(ref storage.SeriesRef, l labels.Labels, t int64, v float64) (storage.SeriesRef, error) {
+	// Check to see if the TTL has expired for this record.
+	endTime := time.Now().Unix() - int64(a.ttl.Seconds())
+	if t < endTime {
+		return ref, nil
+	}
+	ts := types.GetTimeSeriesFromPool()
+	ts.Labels = l
+	ts.TS = t
+	ts.Value = v
+	ts.Hash = l.Hash()
+	err := a.s.SendSeries(a.ctx, ts)
+	return ref, err
+}
+
+// Commit is a no op since we always write.
+func (a *appender) Commit() (_ error) {
+	return nil
+}
+
+// Rollback is a no op since we write all the data.
+func (a *appender) Rollback() error {
+	return nil
+}
+
+// AppendExemplar appends exemplar to cache. The passed in labels is unused, instead use the labels on the exemplar.
+func (a *appender) AppendExemplar(ref storage.SeriesRef, _ labels.Labels, e exemplar.Exemplar) (_ storage.SeriesRef, _ error) {
+	endTime := time.Now().Unix() - int64(a.ttl.Seconds())
+	if e.HasTs && e.Ts < endTime {
+		return ref, nil
+	}
+	ts := types.GetTimeSeriesFromPool()
+	ts.Hash = e.Labels.Hash()
+	ts.TS = e.Ts
+	ts.Labels = e.Labels
+	ts.Hash = e.Labels.Hash()
+	err := a.s.SendSeries(a.ctx, ts)
+	return ref, err
+}
+
+// AppendHistogram appends histogram
+func (a *appender) AppendHistogram(ref storage.SeriesRef, l labels.Labels, t int64, h *histogram.Histogram, fh *histogram.FloatHistogram) (_ storage.SeriesRef, _ error) {
+	endTime := time.Now().Unix() - int64(a.ttl.Seconds())
+	if t < endTime {
+		return ref, nil
+	}
+	ts := types.GetTimeSeriesFromPool()
+	ts.Labels = l
+	ts.TS = t
+	if h != nil {
+		ts.FromHistogram(t, h)
+	} else {
+		ts.FromFloatHistogram(t, fh)
+	}
+	ts.Hash = l.Hash()
+	err := a.s.SendSeries(a.ctx, ts)
+	return ref, err
+}
+
+// UpdateMetadata updates metadata.
+func (a *appender) UpdateMetadata(ref storage.SeriesRef, l labels.Labels, m metadata.Metadata) (_ storage.SeriesRef, _ error) {
+	ts := types.GetTimeSeriesFromPool()
+	// We are going to handle converting some strings to hopefully not reused label names. TimeSeriesBinary has a lot of work
+	// to ensure its efficient it makes sense to encode metadata into it.
+	combinedLabels := l.Copy()
+	combinedLabels = append(combinedLabels, labels.Label{
+		Name:  "__alloy_metadata_type__",
+		Value: string(m.Type),
+	})
+	combinedLabels = append(combinedLabels, labels.Label{
+		Name:  "__alloy_metadata_help__",
+		Value: m.Help,
+	})
+	combinedLabels = append(combinedLabels, labels.Label{
+		Name:  "__alloy_metadata_unit__",
+		Value: m.Unit,
+	})
+	ts.Labels = combinedLabels
+	err := a.s.SendMetadata(a.ctx, ts)
+	return ref, err
+}

internal/component/prometheus/remote/queue/serialization/appender_test.go

@@ -0,0 +1,55 @@
+package serialization
+
+import (
+	"context"
+	log2 "github.com/go-kit/log"
+	"github.com/grafana/alloy/internal/component/prometheus/remote/queue/types"
+	"github.com/prometheus/prometheus/model/labels"
+	"github.com/stretchr/testify/require"
+	"testing"
+	"time"
+)
+
+func TestAppenderTTL(t *testing.T) {
+	fake := &counterSerializer{}
+	l := log2.NewNopLogger()
+
+	app := NewAppender(context.Background(), 1*time.Minute, fake, l)
+	_, err := app.Append(0, labels.FromStrings("one", "two"), time.Now().Unix(), 0)
+	require.NoError(t, err)
+
+	for i := 0; i < 10; i++ {
+		_, err = app.Append(0, labels.FromStrings("one", "two"), time.Now().Add(-5*time.Minute).Unix(), 0)
+		require.NoError(t, err)
+	}
+	// Only one record should make it through.
+	require.True(t, fake.received == 1)
+}
+
+var _ types.Serializer = (*fakeSerializer)(nil)
+
+type counterSerializer struct {
+	received int
+}
+
+func (f *counterSerializer) Start() {
+
+}
+
+func (f *counterSerializer) Stop() {
+
+}
+
+func (f *counterSerializer) SendSeries(ctx context.Context, data *types.TimeSeriesBinary) error {
+	f.received++
+	return nil
+
+}
+
+func (f *counterSerializer) SendMetadata(ctx context.Context, data *types.TimeSeriesBinary) error {
+	return nil
+}
+
+func (f *counterSerializer) UpdateConfig(ctx context.Context, data types.SerializerConfig) error {
+	return nil
+}