mirror of
https://github.com/prometheus/prometheus.git
synced 2024-12-24 21:24:05 -08:00
2fa647f50b
* Test for a previous implematation of Intersect
Before we were moving the postings list everytime we create a new
chained `intersectPostings`. That was causing some postings to be
skipped. This test fails on the older version.
Signed-off-by: Goutham Veeramachaneni <cs14btech11014@iith.ac.in>
* Advance on Seek only when valid.
Issue:
Before in mergedPostings and others we advance everytime we `Seek`,
which causes issues with `Intersect`.
Take the case, where we have a mergedPostings = m merging, a: {10, 20, 30} and
b: {15, 25, 35}. Everytime we `Seek`, we do a.Seek and b.Seek.
Now if we Intersect m with {21, 22, 23, 30}, we would do Seek({21,22,23}) which
would advance a and b beyond 30.
Fix:
Now we advance only when the seeking value is greater than the current
value, as the definition specifies.
Also, posting 0 will not be a valid posting and will be used to signal
finished or un-initialized PostingsList.
Signed-off-by: Goutham Veeramachaneni <cs14btech11014@iith.ac.in>
* Add test for Merge+Intersect edgecase.
Signed-off-by: Goutham Veeramachaneni <cs14btech11014@iith.ac.in>
* Add comments to trivial tests.
Signed-off-by: Goutham Veeramachaneni <cs14btech11014@iith.ac.in>
364 lines
7.3 KiB
Go
364 lines
7.3 KiB
Go
// Copyright 2017 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 (
|
|
"encoding/binary"
|
|
"math/rand"
|
|
"testing"
|
|
|
|
"github.com/stretchr/testify/require"
|
|
)
|
|
|
|
type mockPostings struct {
|
|
next func() bool
|
|
seek func(uint32) bool
|
|
value func() uint32
|
|
err func() error
|
|
}
|
|
|
|
func (m *mockPostings) Next() bool { return m.next() }
|
|
func (m *mockPostings) Seek(v uint32) bool { return m.seek(v) }
|
|
func (m *mockPostings) Value() uint32 { return m.value() }
|
|
func (m *mockPostings) Err() error { return m.err() }
|
|
|
|
func expandPostings(p Postings) (res []uint32, err error) {
|
|
for p.Next() {
|
|
res = append(res, p.At())
|
|
}
|
|
return res, p.Err()
|
|
}
|
|
|
|
func TestIntersect(t *testing.T) {
|
|
var cases = []struct {
|
|
a, b []uint32
|
|
res []uint32
|
|
}{
|
|
{
|
|
a: []uint32{1, 2, 3, 4, 5},
|
|
b: []uint32{6, 7, 8, 9, 10},
|
|
res: nil,
|
|
},
|
|
{
|
|
a: []uint32{1, 2, 3, 4, 5},
|
|
b: []uint32{4, 5, 6, 7, 8},
|
|
res: []uint32{4, 5},
|
|
},
|
|
{
|
|
a: []uint32{1, 2, 3, 4, 9, 10},
|
|
b: []uint32{1, 4, 5, 6, 7, 8, 10, 11},
|
|
res: []uint32{1, 4, 10},
|
|
}, {
|
|
a: []uint32{1},
|
|
b: []uint32{0, 1},
|
|
res: []uint32{1},
|
|
},
|
|
}
|
|
|
|
for _, c := range cases {
|
|
a := newListPostings(c.a)
|
|
b := newListPostings(c.b)
|
|
|
|
res, err := expandPostings(Intersect(a, b))
|
|
require.NoError(t, err)
|
|
require.Equal(t, c.res, res)
|
|
}
|
|
}
|
|
|
|
func TestMultiIntersect(t *testing.T) {
|
|
var cases = []struct {
|
|
p [][]uint32
|
|
res []uint32
|
|
}{
|
|
{
|
|
p: [][]uint32{
|
|
{1, 2, 3, 4, 5, 6, 1000, 1001},
|
|
{2, 4, 5, 6, 7, 8, 999, 1001},
|
|
{1, 2, 5, 6, 7, 8, 1001, 1200},
|
|
},
|
|
res: []uint32{2, 5, 6, 1001},
|
|
},
|
|
// One of the reproduceable cases for:
|
|
// https://github.com/prometheus/prometheus/issues/2616
|
|
// The initialisation of intersectPostings was moving the iterator forward
|
|
// prematurely making us miss some postings.
|
|
{
|
|
p: [][]uint32{
|
|
{1, 2},
|
|
{1, 2},
|
|
{1, 2},
|
|
{2},
|
|
},
|
|
res: []uint32{2},
|
|
},
|
|
}
|
|
|
|
for _, c := range cases {
|
|
ps := make([]Postings, 0, len(c.p))
|
|
for _, postings := range c.p {
|
|
ps = append(ps, newListPostings(postings))
|
|
}
|
|
|
|
res, err := expandPostings(Intersect(ps...))
|
|
|
|
require.NoError(t, err)
|
|
require.Equal(t, c.res, res)
|
|
}
|
|
}
|
|
|
|
func BenchmarkIntersect(t *testing.B) {
|
|
var a, b, c, d []uint32
|
|
|
|
for i := 0; i < 10000000; i += 2 {
|
|
a = append(a, uint32(i))
|
|
}
|
|
for i := 5000000; i < 5000100; i += 4 {
|
|
b = append(b, uint32(i))
|
|
}
|
|
for i := 5090000; i < 5090600; i += 4 {
|
|
b = append(b, uint32(i))
|
|
}
|
|
for i := 4990000; i < 5100000; i++ {
|
|
c = append(c, uint32(i))
|
|
}
|
|
for i := 4000000; i < 6000000; i++ {
|
|
d = append(d, uint32(i))
|
|
}
|
|
|
|
i1 := newListPostings(a)
|
|
i2 := newListPostings(b)
|
|
i3 := newListPostings(c)
|
|
i4 := newListPostings(d)
|
|
|
|
t.ResetTimer()
|
|
|
|
for i := 0; i < t.N; i++ {
|
|
if _, err := expandPostings(Intersect(i1, i2, i3, i4)); err != nil {
|
|
t.Fatal(err)
|
|
}
|
|
}
|
|
}
|
|
|
|
func TestMultiMerge(t *testing.T) {
|
|
var cases = []struct {
|
|
a, b, c []uint32
|
|
res []uint32
|
|
}{
|
|
{
|
|
a: []uint32{1, 2, 3, 4, 5, 6, 1000, 1001},
|
|
b: []uint32{2, 4, 5, 6, 7, 8, 999, 1001},
|
|
c: []uint32{1, 2, 5, 6, 7, 8, 1001, 1200},
|
|
res: []uint32{1, 2, 3, 4, 5, 6, 7, 8, 999, 1000, 1001, 1200},
|
|
},
|
|
}
|
|
|
|
for _, c := range cases {
|
|
i1 := newListPostings(c.a)
|
|
i2 := newListPostings(c.b)
|
|
i3 := newListPostings(c.c)
|
|
|
|
res, err := expandPostings(Merge(i1, i2, i3))
|
|
require.NoError(t, err)
|
|
require.Equal(t, c.res, res)
|
|
}
|
|
}
|
|
|
|
func TestMergedPostings(t *testing.T) {
|
|
var cases = []struct {
|
|
a, b []uint32
|
|
res []uint32
|
|
}{
|
|
{
|
|
a: []uint32{1, 2, 3, 4, 5},
|
|
b: []uint32{6, 7, 8, 9, 10},
|
|
res: []uint32{1, 2, 3, 4, 5, 6, 7, 8, 9, 10},
|
|
},
|
|
{
|
|
a: []uint32{1, 2, 3, 4, 5},
|
|
b: []uint32{4, 5, 6, 7, 8},
|
|
res: []uint32{1, 2, 3, 4, 5, 6, 7, 8},
|
|
},
|
|
{
|
|
a: []uint32{1, 2, 3, 4, 9, 10},
|
|
b: []uint32{1, 4, 5, 6, 7, 8, 10, 11},
|
|
res: []uint32{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11},
|
|
},
|
|
}
|
|
|
|
for _, c := range cases {
|
|
a := newListPostings(c.a)
|
|
b := newListPostings(c.b)
|
|
|
|
res, err := expandPostings(newMergedPostings(a, b))
|
|
require.NoError(t, err)
|
|
require.Equal(t, c.res, res)
|
|
}
|
|
|
|
}
|
|
|
|
func TestMergedPostingsSeek(t *testing.T) {
|
|
var cases = []struct {
|
|
a, b []uint32
|
|
|
|
seek uint32
|
|
success bool
|
|
res []uint32
|
|
}{
|
|
{
|
|
a: []uint32{2, 3, 4, 5},
|
|
b: []uint32{6, 7, 8, 9, 10},
|
|
|
|
seek: 1,
|
|
success: true,
|
|
res: []uint32{2, 3, 4, 5, 6, 7, 8, 9, 10},
|
|
},
|
|
{
|
|
a: []uint32{1, 2, 3, 4, 5},
|
|
b: []uint32{6, 7, 8, 9, 10},
|
|
|
|
seek: 2,
|
|
success: true,
|
|
res: []uint32{2, 3, 4, 5, 6, 7, 8, 9, 10},
|
|
},
|
|
{
|
|
a: []uint32{1, 2, 3, 4, 5},
|
|
b: []uint32{4, 5, 6, 7, 8},
|
|
|
|
seek: 9,
|
|
success: false,
|
|
res: nil,
|
|
},
|
|
{
|
|
a: []uint32{1, 2, 3, 4, 9, 10},
|
|
b: []uint32{1, 4, 5, 6, 7, 8, 10, 11},
|
|
|
|
seek: 10,
|
|
success: true,
|
|
res: []uint32{10, 11},
|
|
},
|
|
}
|
|
|
|
for _, c := range cases {
|
|
a := newListPostings(c.a)
|
|
b := newListPostings(c.b)
|
|
|
|
p := newMergedPostings(a, b)
|
|
|
|
require.Equal(t, c.success, p.Seek(c.seek))
|
|
|
|
// After Seek(), At() should be called.
|
|
if c.success {
|
|
start := p.At()
|
|
lst, err := expandPostings(p)
|
|
require.NoError(t, err)
|
|
|
|
lst = append([]uint32{start}, lst...)
|
|
require.Equal(t, c.res, lst)
|
|
}
|
|
}
|
|
|
|
return
|
|
}
|
|
|
|
func TestBigEndian(t *testing.T) {
|
|
num := 1000
|
|
// mock a list as postings
|
|
ls := make([]uint32, num)
|
|
ls[0] = 2
|
|
for i := 1; i < num; i++ {
|
|
ls[i] = ls[i-1] + uint32(rand.Int31n(25)) + 2
|
|
}
|
|
|
|
beLst := make([]byte, num*4)
|
|
for i := 0; i < num; i++ {
|
|
b := beLst[i*4 : i*4+4]
|
|
binary.BigEndian.PutUint32(b, ls[i])
|
|
}
|
|
|
|
t.Run("Iteration", func(t *testing.T) {
|
|
bep := newBigEndianPostings(beLst)
|
|
for i := 0; i < num; i++ {
|
|
require.True(t, bep.Next())
|
|
require.Equal(t, ls[i], bep.At())
|
|
}
|
|
|
|
require.False(t, bep.Next())
|
|
require.Nil(t, bep.Err())
|
|
})
|
|
|
|
t.Run("Seek", func(t *testing.T) {
|
|
table := []struct {
|
|
seek uint32
|
|
val uint32
|
|
found bool
|
|
}{
|
|
{
|
|
ls[0] - 1, ls[0], true,
|
|
},
|
|
{
|
|
ls[4], ls[4], true,
|
|
},
|
|
{
|
|
ls[500] - 1, ls[500], true,
|
|
},
|
|
{
|
|
ls[600] + 1, ls[601], true,
|
|
},
|
|
{
|
|
ls[600] + 1, ls[601], true,
|
|
},
|
|
{
|
|
ls[600] + 1, ls[601], true,
|
|
},
|
|
{
|
|
ls[0], ls[601], true,
|
|
},
|
|
{
|
|
ls[600], ls[601], true,
|
|
},
|
|
{
|
|
ls[999], ls[999], true,
|
|
},
|
|
{
|
|
ls[999] + 10, ls[999], false,
|
|
},
|
|
}
|
|
|
|
bep := newBigEndianPostings(beLst)
|
|
|
|
for _, v := range table {
|
|
require.Equal(t, v.found, bep.Seek(v.seek))
|
|
require.Equal(t, v.val, bep.At())
|
|
require.Nil(t, bep.Err())
|
|
}
|
|
})
|
|
}
|
|
|
|
func TestIntersectWithMerge(t *testing.T) {
|
|
// One of the reproduceable cases for:
|
|
// https://github.com/prometheus/prometheus/issues/2616
|
|
a := newListPostings([]uint32{21, 22, 23, 24, 25, 30})
|
|
|
|
b := newMergedPostings(
|
|
newListPostings([]uint32{10, 20, 30}),
|
|
newListPostings([]uint32{15, 26, 30}),
|
|
)
|
|
|
|
p := Intersect(a, b)
|
|
res, err := expandPostings(p)
|
|
|
|
require.NoError(t, err)
|
|
require.Equal(t, []uint32{30}, res)
|
|
}
|