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storage/metric: remove package

pull/2643/head
Fabian Reinartz 8 years ago
parent
commit
d17b5be48a
  1. 201
      storage/metric/matcher.go
  2. 73
      storage/metric/matcher_test.go
  3. 63
      storage/metric/metric.go
  4. 70
      storage/metric/metric_test.go
  5. 22
      storage/metric/sample.go

201
storage/metric/matcher.go

@ -1,201 +0,0 @@
// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package metric
import (
"fmt"
"regexp"
"strings"
"github.com/prometheus/common/model"
)
// MatchType is an enum for label matching types.
type MatchType int
// Possible MatchTypes.
const (
Equal MatchType = iota
NotEqual
RegexMatch
RegexNoMatch
)
func (m MatchType) String() string {
typeToStr := map[MatchType]string{
Equal: "=",
NotEqual: "!=",
RegexMatch: "=~",
RegexNoMatch: "!~",
}
if str, ok := typeToStr[m]; ok {
return str
}
panic("unknown match type")
}
// LabelMatchers is a slice of LabelMatcher objects. By implementing the
// sort.Interface, it is sortable by cardinality score, i.e. after sorting, the
// LabelMatcher that is expected to yield the fewest matches is first in the
// slice, and LabelMatchers that match the empty string are last.
type LabelMatchers []*LabelMatcher
func (lms LabelMatchers) Len() int { return len(lms) }
func (lms LabelMatchers) Swap(i, j int) { lms[i], lms[j] = lms[j], lms[i] }
func (lms LabelMatchers) Less(i, j int) bool { return lms[i].score < lms[j].score }
// LabelMatcher models the matching of a label. Create with NewLabelMatcher.
type LabelMatcher struct {
Type MatchType
Name model.LabelName
Value model.LabelValue
re *regexp.Regexp
score float64 // Cardinality score, between 0 and 1, 0 is lowest cardinality.
}
// NewLabelMatcher returns a LabelMatcher object ready to use.
func NewLabelMatcher(matchType MatchType, name model.LabelName, value model.LabelValue) (*LabelMatcher, error) {
m := &LabelMatcher{
Type: matchType,
Name: name,
Value: value,
}
if matchType == RegexMatch || matchType == RegexNoMatch {
re, err := regexp.Compile("^(?:" + string(value) + ")$")
if err != nil {
return nil, err
}
m.re = re
}
m.calculateScore()
return m, nil
}
// calculateScore is a helper method only called in the constructor. It
// calculates the cardinality score upfront, so that sorting by it is faster and
// doesn't change internal state of the matcher.
//
// The score is based on a pretty bad but still quite helpful heuristics for
// now. Note that this is an interim solution until the work in progress to
// properly intersect matchers is complete. We intend to not invest any further
// effort into tweaking the score calculation, as this could easily devolve into
// a rabbit hole.
//
// The heuristics works along the following lines:
//
// - A matcher that is known to match nothing would have a score of 0. (This
// case doesn't happen in the scope of this method.)
//
// - A matcher that matches the empty string has a score of 1.
//
// - Equal matchers have a score <= 0.5. The order in score for other matchers
// are RegexMatch, RegexNoMatch, NotEqual.
//
// - There are a number of score adjustments for known "magic" parts, like
// instance labels, metric names containing a colon (which are probably
// recording rules) and such.
//
// - On top, there is a tiny adjustment for the length of the matcher, following
// the blunt expectation that a long label name and/or value is more specific
// and will therefore have a lower cardinality.
//
// To reiterate on the above: PLEASE RESIST THE TEMPTATION TO TWEAK THIS
// METHOD. IT IS "MAGIC" ENOUGH ALREADY AND WILL GO AWAY WITH THE UPCOMING MORE
// POWERFUL INDEXING.
func (m *LabelMatcher) calculateScore() {
if m.Match("") {
m.score = 1
return
}
// lengthCorrection is between 0 (for length 0) and 0.1 (for length +Inf).
lengthCorrection := 0.1 * (1 - 1/float64(len(m.Name)+len(m.Value)+1))
switch m.Type {
case Equal:
m.score = 0.3 - lengthCorrection
case RegexMatch:
m.score = 0.6 - lengthCorrection
case RegexNoMatch:
m.score = 0.8 + lengthCorrection
case NotEqual:
m.score = 0.9 + lengthCorrection
}
if m.Type != Equal {
// Don't bother anymore in this case.
return
}
switch m.Name {
case model.InstanceLabel:
// Matches only metrics from a single instance, which clearly
// limits the damage.
m.score -= 0.2
case model.JobLabel:
// The usual case is a relatively low number of jobs with many
// metrics each.
m.score += 0.1
case model.BucketLabel, model.QuantileLabel:
// Magic labels for buckets and quantiles will match copiously.
m.score += 0.2
case model.MetricNameLabel:
if strings.Contains(string(m.Value), ":") {
// Probably a recording rule with limited cardinality.
m.score -= 0.1
return
}
if m.Value == "up" || m.Value == "scrape_duration_seconds" {
// Synthetic metrics which are contained in every scrape
// exactly once. There might be less frequent metric
// names, but the worst case is limited here, so give it
// a bump.
m.score -= 0.05
return
}
}
}
// MatchesEmptyString returns true if the LabelMatcher matches the empty string.
func (m *LabelMatcher) MatchesEmptyString() bool {
return m.score >= 1
}
func (m *LabelMatcher) String() string {
return fmt.Sprintf("%s%s%q", m.Name, m.Type, m.Value)
}
// Match returns true if the label matcher matches the supplied label value.
func (m *LabelMatcher) Match(v model.LabelValue) bool {
switch m.Type {
case Equal:
return m.Value == v
case NotEqual:
return m.Value != v
case RegexMatch:
return m.re.MatchString(string(v))
case RegexNoMatch:
return !m.re.MatchString(string(v))
default:
panic("invalid match type")
}
}
// Filter takes a list of label values and returns all label values which match
// the label matcher.
func (m *LabelMatcher) Filter(in model.LabelValues) model.LabelValues {
out := model.LabelValues{}
for _, v := range in {
if m.Match(v) {
out = append(out, v)
}
}
return out
}

73
storage/metric/matcher_test.go

@ -1,73 +0,0 @@
// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package metric
import (
"math/rand"
"reflect"
"sort"
"testing"
"github.com/prometheus/common/model"
)
func TestAnchoredMatcher(t *testing.T) {
m, err := NewLabelMatcher(RegexMatch, "", "foo|bar|baz")
if err != nil {
t.Fatal(err)
}
if !m.Match("foo") {
t.Errorf("Expected match for %q but got none", "foo")
}
if m.Match("fooo") {
t.Errorf("Unexpected match for %q", "fooo")
}
}
func TestLabelMatchersSort(t *testing.T) {
// Line up Matchers in expected order:
want := LabelMatchers{
mustNewLabelMatcher(Equal, model.InstanceLabel, "not empty"),
mustNewLabelMatcher(Equal, model.MetricNameLabel, "a:recording:rule"),
mustNewLabelMatcher(Equal, model.MetricNameLabel, "up"),
mustNewLabelMatcher(Equal, "nothing_special but much longer", "not empty"),
mustNewLabelMatcher(Equal, "nothing_special", "not empty but longer"),
mustNewLabelMatcher(Equal, "nothing_special", "not empty"),
mustNewLabelMatcher(Equal, model.JobLabel, "not empty"),
mustNewLabelMatcher(Equal, model.BucketLabel, "not empty"),
mustNewLabelMatcher(RegexMatch, "irrelevant", "does not match empty string and is longer"),
mustNewLabelMatcher(RegexMatch, "irrelevant", "does not match empty string"),
mustNewLabelMatcher(RegexNoMatch, "irrelevant", "(matches empty string)?"),
mustNewLabelMatcher(RegexNoMatch, "irrelevant", "(matches empty string with a longer expression)?"),
mustNewLabelMatcher(NotEqual, "irrelevant", ""),
mustNewLabelMatcher(Equal, "irrelevant", ""),
}
got := make(LabelMatchers, len(want))
for i, j := range rand.Perm(len(want)) {
got[i] = want[j]
}
sort.Sort(got)
if !reflect.DeepEqual(want, got) {
t.Errorf("unexpected sorting of matchers, got %v, want %v", got, want)
}
}
func mustNewLabelMatcher(mt MatchType, name model.LabelName, val model.LabelValue) *LabelMatcher {
m, err := NewLabelMatcher(mt, name, val)
if err != nil {
panic(err)
}
return m
}

63
storage/metric/metric.go

@ -1,63 +0,0 @@
// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package metric
import "github.com/prometheus/common/model"
// Metric wraps a model.Metric and copies it upon modification if Copied is false.
type Metric struct {
Copied bool
Metric model.Metric
}
// Set sets a label name in the wrapped Metric to a given value and copies the
// Metric initially, if it is not already a copy.
func (m *Metric) Set(ln model.LabelName, lv model.LabelValue) {
m.Copy()
m.Metric[ln] = lv
}
// Del deletes a given label name from the wrapped Metric and copies the
// Metric initially, if it is not already a copy.
func (m *Metric) Del(ln model.LabelName) {
m.Copy()
delete(m.Metric, ln)
}
// Get the value for the given label name. An empty value is returned
// if the label does not exist in the metric.
func (m *Metric) Get(ln model.LabelName) model.LabelValue {
return m.Metric[ln]
}
// Gets behaves as Get but the returned boolean is false iff the label
// does not exist.
func (m *Metric) Gets(ln model.LabelName) (model.LabelValue, bool) {
lv, ok := m.Metric[ln]
return lv, ok
}
// Copy the underlying Metric if it is not already a copy.
func (m *Metric) Copy() *Metric {
if !m.Copied {
m.Metric = m.Metric.Clone()
m.Copied = true
}
return m
}
// String implements fmt.Stringer.
func (m Metric) String() string {
return m.Metric.String()
}

70
storage/metric/metric_test.go

@ -1,70 +0,0 @@
// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package metric
import (
"testing"
"github.com/prometheus/common/model"
)
func TestMetric(t *testing.T) {
testMetric := model.Metric{
"to_delete": "test1",
"to_change": "test2",
}
scenarios := []struct {
fn func(*Metric)
out model.Metric
}{
{
fn: func(cm *Metric) {
cm.Del("to_delete")
},
out: model.Metric{
"to_change": "test2",
},
},
{
fn: func(cm *Metric) {
cm.Set("to_change", "changed")
},
out: model.Metric{
"to_delete": "test1",
"to_change": "changed",
},
},
}
for i, s := range scenarios {
orig := testMetric.Clone()
cm := &Metric{
Metric: orig,
Copied: false,
}
s.fn(cm)
// Test that the original metric was not modified.
if !orig.Equal(testMetric) {
t.Fatalf("%d. original metric changed; expected %v, got %v", i, testMetric, orig)
}
// Test that the new metric has the right changes.
if !cm.Metric.Equal(s.out) {
t.Fatalf("%d. copied metric doesn't contain expected changes; expected %v, got %v", i, s.out, cm.Metric)
}
}
}

22
storage/metric/sample.go

@ -1,22 +0,0 @@
// Copyright 2013 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package metric
import "github.com/prometheus/common/model"
// Interval describes the inclusive interval between two Timestamps.
type Interval struct {
OldestInclusive model.Time
NewestInclusive model.Time
}
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