mirror of https://github.com/prometheus/prometheus
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
371 lines
8.7 KiB
371 lines
8.7 KiB
// 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. |
|
|
|
// The code in this file was largely written by Damian Gryski as part of |
|
// https://github.com/dgryski/go-tsz and published under the license below. |
|
// It was modified to accommodate reading from byte slices without modifying |
|
// the underlying bytes, which would panic when reading from mmap'd |
|
// read-only byte slices. |
|
package chunkenc |
|
|
|
import ( |
|
"math" |
|
"testing" |
|
|
|
"github.com/stretchr/testify/require" |
|
|
|
"github.com/prometheus/prometheus/model/histogram" |
|
) |
|
|
|
// Example of a span layout and resulting bucket indices (_idx_ is used in this |
|
// histogram, others are shown just for context): |
|
// |
|
// spans : [offset: 0, length: 2] [offset 1, length 1] |
|
// bucket idx : _0_ _1_ 2 [3] 4 ... |
|
|
|
func TestBucketIterator(t *testing.T) { |
|
type test struct { |
|
spans []histogram.Span |
|
idxs []int |
|
} |
|
tests := []test{ |
|
{ |
|
spans: []histogram.Span{ |
|
{ |
|
Offset: 0, |
|
Length: 1, |
|
}, |
|
}, |
|
idxs: []int{0}, |
|
}, |
|
{ |
|
spans: []histogram.Span{ |
|
{ |
|
Offset: 0, |
|
Length: 2, |
|
}, |
|
{ |
|
Offset: 1, |
|
Length: 1, |
|
}, |
|
}, |
|
idxs: []int{0, 1, 3}, |
|
}, |
|
{ |
|
spans: []histogram.Span{ |
|
{ |
|
Offset: 100, |
|
Length: 4, |
|
}, |
|
{ |
|
Offset: 8, |
|
Length: 7, |
|
}, |
|
{ |
|
Offset: 0, |
|
Length: 1, |
|
}, |
|
}, |
|
idxs: []int{100, 101, 102, 103, 112, 113, 114, 115, 116, 117, 118, 119}, |
|
}, |
|
// The below 2 sets ore the ones described in compareSpans's comments. |
|
{ |
|
spans: []histogram.Span{ |
|
{Offset: 0, Length: 2}, |
|
{Offset: 2, Length: 1}, |
|
{Offset: 3, Length: 2}, |
|
{Offset: 3, Length: 1}, |
|
{Offset: 1, Length: 1}, |
|
}, |
|
idxs: []int{0, 1, 4, 8, 9, 13, 15}, |
|
}, |
|
{ |
|
spans: []histogram.Span{ |
|
{Offset: 0, Length: 3}, |
|
{Offset: 1, Length: 1}, |
|
{Offset: 1, Length: 4}, |
|
{Offset: 3, Length: 3}, |
|
}, |
|
idxs: []int{0, 1, 2, 4, 6, 7, 8, 9, 13, 14, 15}, |
|
}, |
|
} |
|
for _, test := range tests { |
|
b := newBucketIterator(test.spans) |
|
var got []int |
|
v, ok := b.Next() |
|
for ok { |
|
got = append(got, v) |
|
v, ok = b.Next() |
|
} |
|
require.Equal(t, test.idxs, got) |
|
} |
|
} |
|
|
|
func TestInterjection(t *testing.T) { |
|
scenarios := []struct { |
|
description string |
|
spansA, spansB []histogram.Span |
|
valid bool |
|
interjections []Interjection |
|
bucketsIn, bucketsOut []int64 |
|
}{ |
|
{ |
|
description: "single prepend at the beginning", |
|
spansA: []histogram.Span{ |
|
{Offset: -10, Length: 3}, |
|
}, |
|
spansB: []histogram.Span{ |
|
{Offset: -11, Length: 4}, |
|
}, |
|
valid: true, |
|
interjections: []Interjection{ |
|
{ |
|
pos: 0, |
|
num: 1, |
|
}, |
|
}, |
|
bucketsIn: []int64{6, -3, 0}, |
|
bucketsOut: []int64{0, 6, -3, 0}, |
|
}, |
|
{ |
|
description: "single append at the end", |
|
spansA: []histogram.Span{ |
|
{Offset: -10, Length: 3}, |
|
}, |
|
spansB: []histogram.Span{ |
|
{Offset: -10, Length: 4}, |
|
}, |
|
valid: true, |
|
interjections: []Interjection{ |
|
{ |
|
pos: 3, |
|
num: 1, |
|
}, |
|
}, |
|
bucketsIn: []int64{6, -3, 0}, |
|
bucketsOut: []int64{6, -3, 0, -3}, |
|
}, |
|
{ |
|
description: "double prepend at the beginning", |
|
spansA: []histogram.Span{ |
|
{Offset: -10, Length: 3}, |
|
}, |
|
spansB: []histogram.Span{ |
|
{Offset: -12, Length: 5}, |
|
}, |
|
valid: true, |
|
interjections: []Interjection{ |
|
{ |
|
pos: 0, |
|
num: 2, |
|
}, |
|
}, |
|
bucketsIn: []int64{6, -3, 0}, |
|
bucketsOut: []int64{0, 0, 6, -3, 0}, |
|
}, |
|
{ |
|
description: "double append at the end", |
|
spansA: []histogram.Span{ |
|
{Offset: -10, Length: 3}, |
|
}, |
|
spansB: []histogram.Span{ |
|
{Offset: -10, Length: 5}, |
|
}, |
|
valid: true, |
|
interjections: []Interjection{ |
|
{ |
|
pos: 3, |
|
num: 2, |
|
}, |
|
}, |
|
bucketsIn: []int64{6, -3, 0}, |
|
bucketsOut: []int64{6, -3, 0, -3, 0}, |
|
}, |
|
{ |
|
description: "double prepond at the beginning and double append at the end", |
|
spansA: []histogram.Span{ |
|
{Offset: -10, Length: 3}, |
|
}, |
|
spansB: []histogram.Span{ |
|
{Offset: -12, Length: 7}, |
|
}, |
|
valid: true, |
|
interjections: []Interjection{ |
|
{ |
|
pos: 0, |
|
num: 2, |
|
}, |
|
{ |
|
pos: 3, |
|
num: 2, |
|
}, |
|
}, |
|
bucketsIn: []int64{6, -3, 0}, |
|
bucketsOut: []int64{0, 0, 6, -3, 0, -3, 0}, |
|
}, |
|
{ |
|
description: "single removal of bucket at the start", |
|
spansA: []histogram.Span{ |
|
{Offset: -10, Length: 4}, |
|
}, |
|
spansB: []histogram.Span{ |
|
{Offset: -9, Length: 3}, |
|
}, |
|
valid: false, |
|
}, |
|
{ |
|
description: "single removal of bucket in the middle", |
|
spansA: []histogram.Span{ |
|
{Offset: -10, Length: 4}, |
|
}, |
|
spansB: []histogram.Span{ |
|
{Offset: -10, Length: 2}, |
|
{Offset: 1, Length: 1}, |
|
}, |
|
valid: false, |
|
}, |
|
{ |
|
description: "single removal of bucket at the end", |
|
spansA: []histogram.Span{ |
|
{Offset: -10, Length: 4}, |
|
}, |
|
spansB: []histogram.Span{ |
|
{Offset: -10, Length: 3}, |
|
}, |
|
valid: false, |
|
}, |
|
{ |
|
description: "as described in doc comment", |
|
spansA: []histogram.Span{ |
|
{Offset: 0, Length: 2}, |
|
{Offset: 2, Length: 1}, |
|
{Offset: 3, Length: 2}, |
|
{Offset: 3, Length: 1}, |
|
{Offset: 1, Length: 1}, |
|
}, |
|
spansB: []histogram.Span{ |
|
{Offset: 0, Length: 3}, |
|
{Offset: 1, Length: 1}, |
|
{Offset: 1, Length: 4}, |
|
{Offset: 3, Length: 3}, |
|
}, |
|
valid: true, |
|
interjections: []Interjection{ |
|
{ |
|
pos: 2, |
|
num: 1, |
|
}, |
|
{ |
|
pos: 3, |
|
num: 2, |
|
}, |
|
{ |
|
pos: 6, |
|
num: 1, |
|
}, |
|
}, |
|
bucketsIn: []int64{6, -3, 0, -1, 2, 1, -4}, |
|
bucketsOut: []int64{6, -3, -3, 3, -3, 0, 2, 2, 1, -5, 1}, |
|
}, |
|
} |
|
|
|
for _, s := range scenarios { |
|
t.Run(s.description, func(t *testing.T) { |
|
interjections, valid := compareSpans(s.spansA, s.spansB) |
|
if !s.valid { |
|
require.False(t, valid, "compareScan unexpectedly returned true") |
|
return |
|
} |
|
require.True(t, valid, "compareScan unexpectedly returned false") |
|
require.Equal(t, s.interjections, interjections) |
|
|
|
gotBuckets := make([]int64, len(s.bucketsOut)) |
|
interject(s.bucketsIn, gotBuckets, interjections) |
|
require.Equal(t, s.bucketsOut, gotBuckets) |
|
}) |
|
} |
|
} |
|
|
|
func TestWriteReadHistogramChunkLayout(t *testing.T) { |
|
layouts := []struct { |
|
schema int32 |
|
zeroThreshold float64 |
|
positiveSpans, negativeSpans []histogram.Span |
|
}{ |
|
{ |
|
schema: 3, |
|
zeroThreshold: 0, |
|
positiveSpans: []histogram.Span{{Offset: -4, Length: 3}, {Offset: 2, Length: 42}}, |
|
negativeSpans: nil, |
|
}, |
|
{ |
|
schema: -2, |
|
zeroThreshold: 2.938735877055719e-39, // Default value in client_golang. |
|
positiveSpans: nil, |
|
negativeSpans: []histogram.Span{{Offset: 2, Length: 5}, {Offset: 1, Length: 34}}, |
|
}, |
|
{ |
|
schema: 6, |
|
zeroThreshold: 1024, // The largest power of two we can encode in one byte. |
|
positiveSpans: nil, |
|
negativeSpans: nil, |
|
}, |
|
{ |
|
schema: 6, |
|
zeroThreshold: 1025, |
|
positiveSpans: []histogram.Span{{Offset: 2, Length: 5}, {Offset: 1, Length: 34}, {Offset: 0, Length: 0}}, // Weird span. |
|
negativeSpans: []histogram.Span{{Offset: -345, Length: 4545}, {Offset: 53645665, Length: 345}, {Offset: 945995, Length: 85848}}, |
|
}, |
|
{ |
|
schema: 6, |
|
zeroThreshold: 2048, |
|
positiveSpans: nil, |
|
negativeSpans: nil, |
|
}, |
|
{ |
|
schema: 0, |
|
zeroThreshold: math.Ldexp(0.5, -242), // The smallest power of two we can encode in one byte. |
|
positiveSpans: []histogram.Span{{Offset: -4, Length: 3}}, |
|
negativeSpans: []histogram.Span{{Offset: 2, Length: 5}, {Offset: 1, Length: 34}}, |
|
}, |
|
{ |
|
schema: 0, |
|
zeroThreshold: math.Ldexp(0.5, -243), |
|
positiveSpans: []histogram.Span{{Offset: -4, Length: 3}}, |
|
negativeSpans: []histogram.Span{{Offset: 2, Length: 5}, {Offset: 1, Length: 34}}, |
|
}, |
|
{ |
|
schema: 4, |
|
zeroThreshold: 42, // Not a power of two. |
|
positiveSpans: nil, |
|
negativeSpans: nil, |
|
}, |
|
} |
|
|
|
bs := bstream{} |
|
|
|
for _, l := range layouts { |
|
writeHistogramChunkLayout(&bs, l.schema, l.zeroThreshold, l.positiveSpans, l.negativeSpans) |
|
} |
|
|
|
bsr := newBReader(bs.bytes()) |
|
|
|
for _, want := range layouts { |
|
gotSchema, gotZeroThreshold, gotPositiveSpans, gotNegativeSpans, err := readHistogramChunkLayout(&bsr) |
|
require.NoError(t, err) |
|
require.Equal(t, want.schema, gotSchema) |
|
require.Equal(t, want.zeroThreshold, gotZeroThreshold) |
|
require.Equal(t, want.positiveSpans, gotPositiveSpans) |
|
require.Equal(t, want.negativeSpans, gotNegativeSpans) |
|
} |
|
}
|
|
|