prometheus/tsdb/tsdbutil/chunks.go
Matthias Loibl 7e7efaba32
storage: Split chunks if more than 120 samples (#8582)
* storage: Split chunks if more than 120 samples

Signed-off-by: Matthias Loibl <mail@matthiasloibl.com>

* storage: Don't set maxt which is overwritten right away

Signed-off-by: Matthias Loibl <mail@matthiasloibl.com>

* storage: Improve comments on merge_test

Signed-off-by: Matthias Loibl <mail@matthiasloibl.com>

* storage: Improve comments and move code closer to usage

Signed-off-by: Matthias Loibl <mail@matthiasloibl.com>

* tsdb/tsdbutil: Add comment for GenerateSamples

Signed-off-by: Matthias Loibl <mail@matthiasloibl.com>
2021-05-18 18:37:16 +02:00

80 lines
2 KiB
Go

// Copyright 2018 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 tsdbutil
import (
"github.com/prometheus/prometheus/tsdb/chunkenc"
"github.com/prometheus/prometheus/tsdb/chunks"
)
type Samples interface {
Get(i int) Sample
Len() int
}
type Sample interface {
T() int64
V() float64
}
type SampleSlice []Sample
func (s SampleSlice) Get(i int) Sample { return s[i] }
func (s SampleSlice) Len() int { return len(s) }
func ChunkFromSamples(s []Sample) chunks.Meta {
return ChunkFromSamplesGeneric(SampleSlice(s))
}
func ChunkFromSamplesGeneric(s Samples) chunks.Meta {
mint, maxt := int64(0), int64(0)
if s.Len() > 0 {
mint, maxt = s.Get(0).T(), s.Get(s.Len()-1).T()
}
c := chunkenc.NewXORChunk()
ca, _ := c.Appender()
for i := 0; i < s.Len(); i++ {
ca.Append(s.Get(i).T(), s.Get(i).V())
}
return chunks.Meta{
MinTime: mint,
MaxTime: maxt,
Chunk: c,
}
}
// PopulatedChunk creates a chunk populated with samples every second starting at minTime
func PopulatedChunk(numSamples int, minTime int64) chunks.Meta {
samples := make([]Sample, numSamples)
for i := 0; i < numSamples; i++ {
samples[i] = sample{minTime + int64(i*1000), 1.0}
}
return ChunkFromSamples(samples)
}
// GenerateSamples starting at start and counting up numSamples.
func GenerateSamples(start int, numSamples int) []Sample {
samples := make([]Sample, 0, numSamples)
for i := start; i < start+numSamples; i++ {
samples = append(samples, sample{
t: int64(i),
v: float64(i),
})
}
return samples
}