Optimize storage.LabelQuerier.LabelValues implementations

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

model/labels/matcher.go

@@ -26,17 +26,20 @@ const (
 	MatchNotEqual
 	MatchRegexp
 	MatchNotRegexp
+	// MatchSet is a special type for internal use, that matches series with a certain label name.
+	MatchSet
 )
 
 var matchTypeToStr = [...]string{
 	MatchEqual:     "=",
 	MatchNotEqual:  "!=",
 	MatchRegexp:    "=~",
 	MatchNotRegexp: "!~",
+	MatchSet:       "[isSet]",
 }
 
 func (m MatchType) String() string {
-	if m < MatchEqual || m > MatchNotRegexp {
+	if m < MatchEqual || m > MatchSet {
 		panic("unknown match type")
 	}
 	return matchTypeToStr[m]
@@ -92,8 +95,11 @@ func (m *Matcher) Matches(s string) bool {
 		return m.re.MatchString(s)
 	case MatchNotRegexp:
 		return !m.re.MatchString(s)
+	case MatchSet:
+		return true
+	default:
+		panic("labels.Matcher.Matches: invalid match type")
 	}
-	panic("labels.Matcher.Matches: invalid match type")
 }
 
 // Inverse returns a matcher that matches the opposite.
@@ -107,8 +113,9 @@ func (m *Matcher) Inverse() (*Matcher, error) {
 		return NewMatcher(MatchNotRegexp, m.Name, m.Value)
 	case MatchNotRegexp:
 		return NewMatcher(MatchRegexp, m.Name, m.Value)
+	default:
+		panic("labels.Matcher.Matches: invalid match type")
 	}
-	panic("labels.Matcher.Matches: invalid match type")
 }
 
 // GetRegexString returns the regex string.

tsdb/block.go

@@ -82,6 +82,12 @@ type IndexReader interface {
 	// avoiding same calculations twice, however this implementation may lead to a worse performance when called once.
 	PostingsForMatchers(concurrent bool, ms ...*labels.Matcher) (index.Postings, error)
 
+	// PostingsWithLabel returns the postings list iterator for the label name.
+	// The Postings here contain the offsets to the series inside the index.
+	// Found IDs are not strictly required to point to a valid Series, e.g.
+	// during background garbage collections.
+	PostingsWithLabel(name string) (index.Postings, error)
+
 	// SortedPostings returns a postings list that is reordered to be sorted
 	// by the label set of the underlying series.
 	SortedPostings(index.Postings) index.Postings
@@ -501,6 +507,10 @@ func (r blockIndexReader) LabelValues(name string, matchers ...*labels.Matcher)
 	return labelValuesWithMatchers(r.ir, name, matchers...)
 }
 
+func (r blockIndexReader) PostingsWithLabel(name string) (index.Postings, error) {
+	return r.ir.PostingsWithLabel(name)
+}
+
 func (r blockIndexReader) LabelNames(matchers ...*labels.Matcher) ([]string, error) {
 	if len(matchers) == 0 {
 		return r.b.LabelNames()

tsdb/head_read.go

@@ -124,6 +124,10 @@ func (h *headIndexReader) PostingsForMatchers(concurrent bool, ms ...*labels.Mat
 	return h.head.pfmc.PostingsForMatchers(h, concurrent, ms...)
 }
 
+func (h *headIndexReader) PostingsWithLabel(name string) (index.Postings, error) {
+	return h.head.postings.GetWithLabel(name), nil
+}
+
 func (h *headIndexReader) SortedPostings(p index.Postings) index.Postings {
 	series := make([]*memSeries, 0, 128)
 

tsdb/index/index.go

@@ -1484,31 +1484,35 @@ func (r *Reader) SortedLabelValues(name string, matchers ...*labels.Matcher) ([]
 // LabelValues returns value tuples that exist for the given label name.
 // It is not safe to use the return value beyond the lifetime of the byte slice
 // passed into the Reader.
-// TODO(replay): Support filtering by matchers
 func (r *Reader) LabelValues(name string, matchers ...*labels.Matcher) ([]string, error) {
-	if len(matchers) > 0 {
-		return nil, errors.Errorf("matchers parameter is not implemented: %+v", matchers)
-	}
-
 	if r.version == FormatV1 {
 		e, ok := r.postingsV1[name]
 		if !ok {
 			return nil, nil
 		}
 		values := make([]string, 0, len(e))
 		for k := range e {
-			values = append(values, k)
+			isMatch := true
+			for _, m := range matchers {
+				if m.Name == name && !m.Matches(k) {
+					isMatch = false
+					break
+				}
+			}
+
+			if isMatch {
+				values = append(values, k)
+			}
 		}
 		return values, nil
 
 	}
-	e, ok := r.postings[name]
-	if !ok {
-		return nil, nil
-	}
+
+	e := r.postings[name]
 	if len(e) == 0 {
 		return nil, nil
 	}
+
 	values := make([]string, 0, len(e)*symbolFactor)
 
 	d := encoding.NewDecbufAt(r.b, int(r.toc.PostingsTable), nil)
@@ -1528,7 +1532,19 @@ func (r *Reader) LabelValues(name string, matchers ...*labels.Matcher) ([]string
 			d.Skip(skip)
 		}
 		s := yoloString(d.UvarintBytes()) // Label value.
-		values = append(values, s)
+
+		isMatch := true
+		// Try to exclude via matchers for the label name
+		for _, m := range matchers {
+			if m.Name == name && !m.Matches(s) {
+				isMatch = false
+				break
+			}
+		}
+
+		if isMatch {
+			values = append(values, s)
+		}
 		if s == lastVal {
 			break
 		}
@@ -1647,8 +1663,8 @@ func (r *Reader) Postings(name string, values ...string) (Postings, error) {
 		return Merge(res...), nil
 	}
 
-	e, ok := r.postings[name]
-	if !ok {
+	e := r.postings[name]
+	if len(e) == 0 {
 		return EmptyPostings(), nil
 	}
 
@@ -1725,6 +1741,71 @@ func (r *Reader) Postings(name string, values ...string) (Postings, error) {
 	return Merge(res...), nil
 }
 
+func (r *Reader) PostingsWithLabel(name string) (Postings, error) {
+	if r.version == FormatV1 {
+		e := r.postingsV1[name]
+		if len(e) == 0 {
+			return EmptyPostings(), nil
+		}
+
+		var res []Postings
+		for _, off := range e {
+			// Read from the postings table.
+			d := encoding.NewDecbufAt(r.b, int(off), castagnoliTable)
+			_, p, err := r.dec.Postings(d.Get())
+			if err != nil {
+				return nil, errors.Wrap(err, "decode postings")
+			}
+			res = append(res, p)
+		}
+		return Merge(res...), nil
+	}
+
+	e := r.postings[name]
+	if len(e) == 0 {
+		return EmptyPostings(), nil
+	}
+
+	d := encoding.NewDecbufAt(r.b, int(r.toc.PostingsTable), nil)
+	// Skip to start
+	d.Skip(e[0].off)
+	lastVal := e[len(e)-1].value
+
+	skip := 0
+	var res []Postings
+	for d.Err() == nil {
+		if skip == 0 {
+			// These are always the same number of bytes,
+			// and it's faster to skip than to parse.
+			skip = d.Len()
+			d.Uvarint()      // Keycount.
+			d.UvarintBytes() // Label name.
+			skip -= d.Len()
+		} else {
+			d.Skip(skip)
+		}
+		v := yoloString(d.UvarintBytes()) // Label value.
+
+		postingsOff := d.Uvarint64()
+		// Read from the postings table
+		d2 := encoding.NewDecbufAt(r.b, int(postingsOff), castagnoliTable)
+		_, p, err := r.dec.Postings(d2.Get())
+		if err != nil {
+			return nil, errors.Wrap(err, "decode postings")
+		}
+		res = append(res, p)
+
+		if v == lastVal {
+			break
+		}
+	}
+	if d.Err() != nil {
+		return nil, errors.Wrap(d.Err(), "get postings offset entry")
+	}
+
+	return Merge(res...), nil
+}
+
 // SortedPostings returns the given postings list reordered so that the backing series
 // are sorted.
 func (r *Reader) SortedPostings(p Postings) Postings {

tsdb/index/postings.go

@@ -135,13 +135,24 @@ func (p *MemPostings) LabelNames() []string {
 }
 
 // LabelValues returns label values for the given name.
-func (p *MemPostings) LabelValues(name string) []string {
+func (p *MemPostings) LabelValues(name string, matchers ...*labels.Matcher) []string {
 	p.mtx.RLock()
 	defer p.mtx.RUnlock()
 
 	values := make([]string, 0, len(p.m[name]))
 	for v := range p.m[name] {
-		values = append(values, v)
+		isMatch := true
+		// Try to exclude this value through corresponding matchers
+		for _, m := range matchers {
+			if m.Name == name && !m.Matches(v) {
+				isMatch = false
+				break
+			}
+		}
+
+		if isMatch {
+			values = append(values, v)
+		}
 	}
 	return values
 }
@@ -216,6 +227,18 @@ func (p *MemPostings) Get(name, value string) Postings {
 	return newListPostings(lp...)
 }
 
+// GetWithLabel returns a postings list for the given label name.
+func (p *MemPostings) GetWithLabel(name string) Postings {
+	p.mtx.RLock()
+	var ps []Postings
+	for _, srs := range p.m[name] {
+		ps = append(ps, newListPostings(srs...))
+	}
+	p.mtx.RUnlock()
+
+	return Merge(ps...)
+}
+
 // All returns a postings list over all documents ever added.
 func (p *MemPostings) All() Postings {
 	return p.Get(AllPostingsKey())

tsdb/ooo_head_read.go

@@ -212,6 +212,10 @@ func (oh *OOOHeadIndexReader) Postings(name string, values ...string) (index.Pos
 	}
 }
 
+func (oh *OOOHeadIndexReader) PostingsWithLabel(name string) (index.Postings, error) {
+	return oh.head.postings.GetWithLabel(name), nil
+}
+
 type OOOHeadChunkReader struct {
 	head       *Head
 	mint, maxt int64
@@ -410,6 +414,10 @@ func (ir *OOOCompactionHeadIndexReader) Postings(name string, values ...string)
 	return index.NewListPostings(ir.ch.postings), nil
 }
 
+func (ir *OOOCompactionHeadIndexReader) PostingsWithLabel(name string) (index.Postings, error) {
+	return nil, errors.New("not implemented")
+}
+
 func (ir *OOOCompactionHeadIndexReader) SortedPostings(p index.Postings) index.Postings {
 	// This will already be sorted from the Postings() call above.
 	return p

tsdb/postings_for_matchers_cache.go

@@ -25,6 +25,12 @@ type IndexPostingsReader interface {
 	// Found IDs are not strictly required to point to a valid Series, e.g.
 	// during background garbage collections. Input values must be sorted.
 	Postings(name string, values ...string) (index.Postings, error)
+
+	// PostingsWithLabel returns the postings list iterator for the label name.
+	// The Postings here contain the offsets to the series inside the index.
+	// Found IDs are not strictly required to point to a valid Series, e.g.
+	// during background garbage collections.
+	PostingsWithLabel(name string) (index.Postings, error)
 }
 
 // NewPostingsForMatchersCache creates a new PostingsForMatchersCache.

tsdb/postings_for_matchers_cache_test.go

@@ -269,6 +269,10 @@ func (idx indexForPostingsMock) Postings(string, ...string) (index.Postings, err
 	panic("implement me")
 }
 
+func (idx indexForPostingsMock) PostingsWithLabel(string) (index.Postings, error) {
+	panic("implement me")
+}
+
 // timeNowMock offers a mockable time.Now() implementation
 // empty value is ready to be used, and it should not be copied (use a reference)
 type timeNowMock struct {