Add Prometheus adapter

prometheus/adapter.go

@@ -0,0 +1,176 @@
+package prometheus
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/fabxc/tsdb"
+	"github.com/fabxc/tsdb/index"
+	"github.com/prometheus/common/model"
+	"github.com/prometheus/prometheus/storage/local"
+	"github.com/prometheus/prometheus/storage/metric"
+	"golang.org/x/net/context"
+)
+
+type DefaultSeriesIterator struct {
+	it tsdb.SeriesIterator
+}
+
+func (it *DefaultSeriesIterator) ValueAtOrBeforeTime(ts model.Time) model.SamplePair {
+	sp, ok := it.it.Seek(ts)
+	if !ok {
+		return model.ZeroSamplePair
+	}
+	return sp
+}
+
+func (it *DefaultSeriesIterator) Metric() metric.Metric {
+	return it.it.Metric()
+}
+
+func (it *DefaultSeriesIterator) RangeValues(interval metric.Interval) []model.SamplePair {
+	var res []model.SamplePair
+	for sp, ok := it.it.Seek(interval.NewestInclusive); ok; sp, ok = it.it.Next() {
+		if sp.Timestamp > interval.OldestInclusive {
+			break
+		}
+		res = append(res, sp)
+	}
+	return res
+}
+
+func (it *DefaultSeriesIterator) Close() {
+}
+
+// DefaultAdapter wraps a Cinamon storage to implement the default
+// storage interface.
+type DefaultAdapter struct {
+	c *Cinamon
+}
+
+func NewDefaultAdapter(c *Cinamon) *DefaultAdapter {
+	return &DefaultAdapter{c: c}
+}
+
+// Drop all time series associated with the given label matchers. Returns
+// the number series that were dropped.
+func (da *DefaultAdapter) DropMetricsForLabelMatchers(context.Context, ...*metric.LabelMatcher) (int, error) {
+	return 0, fmt.Errorf("not implemented")
+}
+
+// Run the various maintenance loops in goroutines. Returns when the
+// storage is ready to use. Keeps everything running in the background
+// until Stop is called.
+func (da *DefaultAdapter) Start() error {
+	return nil
+}
+
+// Stop shuts down the Storage gracefully, flushes all pending
+// operations, stops all maintenance loops,and frees all resources.
+func (da *DefaultAdapter) Stop() error {
+	return da.c.Close()
+}
+
+// WaitForIndexing returns once all samples in the storage are
+// indexed. Indexing is needed for FingerprintsForLabelMatchers and
+// LabelValuesForLabelName and may lag behind.
+func (da *DefaultAdapter) WaitForIndexing() {
+	da.c.indexer.wait()
+}
+
+func (da *DefaultAdapter) Append(s *model.Sample) error {
+	// Ignore the Scrape batching for now.
+	return da.c.memChunks.append(s.Metric, s.Timestamp, s.Value)
+}
+
+func (da *DefaultAdapter) NeedsThrottling() bool {
+	return false
+}
+
+func (da *DefaultAdapter) Querier() (local.Querier, error) {
+	q, err := da.c.Querier()
+	if err != nil {
+		return nil, err
+	}
+	return defaultQuerierAdapter{q: q}, nil
+}
+
+type defaultQuerierAdapter struct {
+	q *Querier
+}
+
+func (da defaultQuerierAdapter) Close() error {
+	return da.q.Close()
+}
+
+// QueryRange returns a list of series iterators for the selected
+// time range and label matchers. The iterators need to be closed
+// after usage.
+func (da defaultQuerierAdapter) QueryRange(ctx context.Context, from, through model.Time, matchers ...*metric.LabelMatcher) ([]local.SeriesIterator, error) {
+	it, err := da.q.Iterator(matchers...)
+	if err != nil {
+		return nil, err
+	}
+	its, err := da.q.Series(it)
+	if err != nil {
+		return nil, err
+	}
+	var defaultIts []local.SeriesIterator
+	for _, it := range its {
+		defaultIts = append(defaultIts, &DefaultSeriesIterator{it: it})
+	}
+	return defaultIts, nil
+}
+
+// QueryInstant returns a list of series iterators for the selected
+// instant and label matchers. The iterators need to be closed after usage.
+func (da defaultQuerierAdapter) QueryInstant(ctx context.Context, ts model.Time, stalenessDelta time.Duration, matchers ...*metric.LabelMatcher) ([]local.SeriesIterator, error) {
+	return da.QueryRange(ctx, ts.Add(-stalenessDelta), ts, matchers...)
+}
+
+// MetricsForLabelMatchers returns the metrics from storage that satisfy
+// the given sets of label matchers. Each set of matchers must contain at
+// least one label matcher that does not match the empty string. Otherwise,
+// an empty list is returned. Within one set of matchers, the intersection
+// of matching series is computed. The final return value will be the union
+// of the per-set results. The times from and through are hints for the
+// storage to optimize the search. The storage MAY exclude metrics that
+// have no samples in the specified interval from the returned map. In
+// doubt, specify model.Earliest for from and model.Latest for through.
+func (da defaultQuerierAdapter) MetricsForLabelMatchers(ctx context.Context, from, through model.Time, matcherSets ...metric.LabelMatchers) ([]metric.Metric, error) {
+	var mits []index.Iterator
+	for _, ms := range matcherSets {
+		it, err := da.q.Iterator(ms...)
+		if err != nil {
+			return nil, err
+		}
+		// tit, err := q.RangeIterator(from, through)
+		// if err != nil {
+		// 	return nil, err
+		// }
+		// mits = append(mits, index.Intersect(it, tit))
+		mits = append(mits, it)
+	}
+
+	return da.q.Metrics(index.Merge(mits...))
+}
+
+// LastSampleForFingerprint returns the last sample that has been
+// ingested for the given sets of label matchers. If this instance of the
+// Storage has never ingested a sample for the provided fingerprint (or
+// the last ingestion is so long ago that the series has been archived),
+// ZeroSample is returned. The label matching behavior is the same as in
+// MetricsForLabelMatchers.
+func (da defaultQuerierAdapter) LastSampleForLabelMatchers(ctx context.Context, cutoff model.Time, matcherSets ...metric.LabelMatchers) (model.Vector, error) {
+	return nil, fmt.Errorf("not implemented")
+}
+
+// Get all of the label values that are associated with a given label name.
+func (da defaultQuerierAdapter) LabelValuesForLabelName(ctx context.Context, ln model.LabelName) (model.LabelValues, error) {
+	res := da.q.iq.Terms(string(ln), nil)
+	resv := model.LabelValues{}
+	for _, lv := range res {
+		resv = append(resv, model.LabelValue(lv))
+	}
+	return resv, nil
+}