prometheus/tsdb/chunkenc/histo_test.go
Dieter Plaetinck 4d27816ea5
Sparsehistogram: improve dod encoding, testing, encode chunk metadata (#9015)
* factor out different varbit schemes and include Beorn's "optimum" for buckets

Signed-off-by: Dieter Plaetinck <dieter@grafana.com>

* use more compact dod encoding scheme for SHS chunk columns

Signed-off-by: Dieter Plaetinck <dieter@grafana.com>

* remove FB VB and xor dod encoding because we won't use it

Signed-off-by: Dieter Plaetinck <dieter@grafana.com>

* HistoChunk metadata encoding

Signed-off-by: Dieter Plaetinck <dieter@grafana.com>

* add SparseHistogram.Copy()

Signed-off-by: Dieter Plaetinck <dieter@grafana.com>

* histogram test: test appending a few histograms

Signed-off-by: Dieter Plaetinck <dieter@grafana.com>

* add license headers

Signed-off-by: Dieter Plaetinck <dieter@grafana.com>
2021-06-30 16:15:43 +05:30

133 lines
3.1 KiB
Go

// Copyright 2021 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 chunkenc
import (
"testing"
"github.com/prometheus/prometheus/pkg/histogram"
"github.com/stretchr/testify/require"
)
func TestHistoChunkSameBuckets(t *testing.T) {
c := NewHistoChunk()
type res struct {
t int64
h histogram.SparseHistogram
}
// create fresh appender and add the first histogram
app, err := c.Appender()
require.NoError(t, err)
require.Equal(t, c.NumSamples(), 0)
ts := int64(1234567890)
h := histogram.SparseHistogram{
Count: 5,
ZeroCount: 2,
Sum: 18.4,
//ZeroThreshold: 1, TODO
Schema: 1,
PositiveSpans: []histogram.Span{
{Offset: 0, Length: 2},
{Offset: 1, Length: 2},
},
PositiveBuckets: []int64{1, 1, -1, 0}, // counts: 1, 2, 1, 1 (total 5)
NegativeSpans: nil,
NegativeBuckets: []int64{},
}
app.AppendHistogram(ts, h)
require.Equal(t, c.NumSamples(), 1)
exp := []res{
{t: ts, h: h},
}
// add an updated histogram
ts += 16
h.Count += 9
h.ZeroCount++
h.Sum = 24.4
h.PositiveBuckets = []int64{5, -2, 1, -2} // counts: 5, 3, 4, 2 (total 14)
app.AppendHistogram(ts, h)
exp = append(exp, res{t: ts, h: h})
require.Equal(t, c.NumSamples(), 2)
// add update with new appender
app, err = c.Appender()
require.NoError(t, err)
require.Equal(t, c.NumSamples(), 2)
ts += 14
h.Count += 13
h.ZeroCount += 2
h.Sum = 24.4
h.PositiveBuckets = []int64{6, 1, -3, 6} // counts: 6, 7, 4, 10 (total 27)
app.AppendHistogram(ts, h)
exp = append(exp, res{t: ts, h: h})
require.Equal(t, c.NumSamples(), 3)
// 1. Expand iterator in simple case.
it1 := c.iterator(nil)
require.NoError(t, it1.Err())
var res1 []res
for it1.Next() {
ts, h := it1.AtHistogram()
res1 = append(res1, res{t: ts, h: h.Copy()})
}
require.NoError(t, it1.Err())
require.Equal(t, exp, res1)
// 2. Expand second iterator while reusing first one.
//it2 := c.Iterator(it1)
//var res2 []pair
//for it2.Next() {
// ts, v := it2.At()
// res2 = append(res2, pair{t: ts, v: v})
// }
// require.NoError(t, it2.Err())
// require.Equal(t, exp, res2)
// 3. Test iterator Seek.
// mid := len(exp) / 2
// it3 := c.Iterator(nil)
// var res3 []pair
// require.Equal(t, true, it3.Seek(exp[mid].t))
// Below ones should not matter.
// require.Equal(t, true, it3.Seek(exp[mid].t))
// require.Equal(t, true, it3.Seek(exp[mid].t))
// ts, v = it3.At()
// res3 = append(res3, pair{t: ts, v: v})
// for it3.Next() {
// ts, v := it3.At()
// res3 = append(res3, pair{t: ts, v: v})
// }
// require.NoError(t, it3.Err())
// require.Equal(t, exp[mid:], res3)
// require.Equal(t, false, it3.Seek(exp[len(exp)-1].t+1))
}