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prometheus/tsdb/ooo_head_test.go

94 lines
3.8 KiB

// Copyright 2022 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 tsdb
import (
"testing"
"github.com/stretchr/testify/require"
)
const testMaxSize int = 32
// Formulas chosen to make testing easy:
func valEven(pos int) int { return pos*2 + 2 } // s[0]=2, s[1]=4, s[2]=6, ..., s[31]=64 - Predictable pre-existing values
func valOdd(pos int) int { return pos*2 + 1 } // s[0]=1, s[1]=3, s[2]=5, ..., s[31]=63 - New values will interject at chosen position because they sort before the pre-existing vals.
func samplify(v int) sample { return sample{int64(v), float64(v), nil, nil} }
func makeEvenSampleSlice(n int) []sample {
s := make([]sample, n)
for i := 0; i < n; i++ {
s[i] = samplify(valEven(i))
}
return s
}
// TestOOOInsert tests the following cases:
// - Number of pre-existing samples anywhere from 0 to testMaxSize-1.
// - Insert new sample before first pre-existing samples, after the last, and anywhere in between.
// - With a chunk initial capacity of testMaxSize/8 and testMaxSize, which lets us test non-full and full chunks, and chunks that need to expand themselves.
// Note: In all samples used, t always equals v in numeric value. when we talk about 'value' we just refer to a value that will be used for both sample.t and sample.v.
func TestOOOInsert(t *testing.T) {
for numPreExisting := 0; numPreExisting <= testMaxSize; numPreExisting++ {
// For example, if we have numPreExisting 2, then:
// chunk.samples indexes filled 0 1
// chunk.samples with these values 2 4 // valEven
// we want to test inserting at index 0 1 2 // insertPos=0..numPreExisting
// we can do this by using values 1, 3 5 // valOdd(insertPos)
for insertPos := 0; insertPos <= numPreExisting; insertPos++ {
chunk := NewOOOChunk()
chunk.samples = makeEvenSampleSlice(numPreExisting)
newSample := samplify(valOdd(insertPos))
chunk.Insert(newSample.t, newSample.v)
var expSamples []sample
// Our expected new samples slice, will be first the original samples.
for i := 0; i < insertPos; i++ {
expSamples = append(expSamples, samplify(valEven(i)))
}
// Then the new sample.
expSamples = append(expSamples, newSample)
// Followed by any original samples that were pushed back by the new one.
for i := insertPos; i < numPreExisting; i++ {
expSamples = append(expSamples, samplify(valEven(i)))
}
require.Equal(t, expSamples, chunk.samples, "numPreExisting %d, insertPos %d", numPreExisting, insertPos)
}
}
}
// TestOOOInsertDuplicate tests the correct behavior when inserting a sample that is a duplicate of any
// pre-existing samples, with between 1 and testMaxSize pre-existing samples and
// with a chunk initial capacity of testMaxSize/8 and testMaxSize, which lets us test non-full and full chunks, and chunks that need to expand themselves.
func TestOOOInsertDuplicate(t *testing.T) {
for num := 1; num <= testMaxSize; num++ {
for dupPos := 0; dupPos < num; dupPos++ {
chunk := NewOOOChunk()
chunk.samples = makeEvenSampleSlice(num)
dupSample := chunk.samples[dupPos]
dupSample.v = 0.123
ok := chunk.Insert(dupSample.t, dupSample.v)
expSamples := makeEvenSampleSlice(num) // We expect no change.
require.False(t, ok)
require.Equal(t, expSamples, chunk.samples, "num %d, dupPos %d", num, dupPos)
}
}
}