prometheus/scrape/helpers_test.go
Ganesh Vernekar 04ad56d9b8
Append sparse histograms into the Head block (#9013)
* Append sparse histograms into the Head block

Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>

* Add AtHistogram() to Iterator interface. Make HistoChunk conform to Chunk interface.

Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
2021-06-29 20:08:46 +05:30

131 lines
3.6 KiB
Go

// 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 scrape
import (
"context"
"math/rand"
"github.com/prometheus/prometheus/pkg/exemplar"
"github.com/prometheus/prometheus/pkg/histogram"
"github.com/prometheus/prometheus/pkg/labels"
"github.com/prometheus/prometheus/storage"
)
type nopAppendable struct{}
func (a nopAppendable) Appender(_ context.Context) storage.Appender {
return nopAppender{}
}
type nopAppender struct{}
func (a nopAppender) Append(uint64, labels.Labels, int64, float64) (uint64, error) { return 0, nil }
func (a nopAppender) AppendExemplar(uint64, labels.Labels, exemplar.Exemplar) (uint64, error) {
return 0, nil
}
func (a nopAppender) AppendHistogram(uint64, labels.Labels, int64, histogram.SparseHistogram) (uint64, error) {
return 0, nil
}
func (a nopAppender) Commit() error { return nil }
func (a nopAppender) Rollback() error { return nil }
type sample struct {
metric labels.Labels
t int64
v float64
}
type hist struct {
h histogram.SparseHistogram
t int64
}
// collectResultAppender records all samples that were added through the appender.
// It can be used as its zero value or be backed by another appender it writes samples through.
type collectResultAppender struct {
next storage.Appender
result []sample
pendingResult []sample
rolledbackResult []sample
pendingExemplars []exemplar.Exemplar
resultExemplars []exemplar.Exemplar
resultHistograms []hist
pendingHistograms []hist
rolledbackHistograms []hist
}
func (a *collectResultAppender) Append(ref uint64, lset labels.Labels, t int64, v float64) (uint64, error) {
a.pendingResult = append(a.pendingResult, sample{
metric: lset,
t: t,
v: v,
})
if ref == 0 {
ref = rand.Uint64()
}
if a.next == nil {
return ref, nil
}
ref, err := a.next.Append(ref, lset, t, v)
if err != nil {
return 0, err
}
return ref, err
}
func (a *collectResultAppender) AppendExemplar(ref uint64, l labels.Labels, e exemplar.Exemplar) (uint64, error) {
a.pendingExemplars = append(a.pendingExemplars, e)
if a.next == nil {
return 0, nil
}
return a.next.AppendExemplar(ref, l, e)
}
func (a *collectResultAppender) AppendHistogram(ref uint64, l labels.Labels, t int64, sh histogram.SparseHistogram) (uint64, error) {
a.pendingHistograms = append(a.pendingHistograms, hist{h: sh, t: t})
if a.next == nil {
return 0, nil
}
return a.next.AppendHistogram(ref, l, t, sh)
}
func (a *collectResultAppender) Commit() error {
a.result = append(a.result, a.pendingResult...)
a.resultExemplars = append(a.resultExemplars, a.pendingExemplars...)
a.resultHistograms = append(a.resultHistograms, a.pendingHistograms...)
a.pendingResult = nil
a.pendingExemplars = nil
a.pendingHistograms = nil
if a.next == nil {
return nil
}
return a.next.Commit()
}
func (a *collectResultAppender) Rollback() error {
a.rolledbackResult = a.pendingResult
a.rolledbackHistograms = a.pendingHistograms
a.pendingResult = nil
a.pendingHistograms = nil
if a.next == nil {
return nil
}
return a.next.Rollback()
}