prometheus/tsdb/index/postings_test.go
Marco Pracucci 229575de0c
Upgrade upstream Prometheus
Signed-off-by: Marco Pracucci <marco@pracucci.com>
2021-11-03 10:25:35 +01:00

1000 lines
21 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 index
import (
"encoding/binary"
"fmt"
"math/rand"
"sort"
"testing"
"github.com/stretchr/testify/require"
"github.com/prometheus/prometheus/pkg/labels"
)
func TestMemPostings_addFor(t *testing.T) {
p := NewMemPostings()
p.m[allPostingsKey.Name] = map[string][]uint64{}
p.m[allPostingsKey.Name][allPostingsKey.Value] = []uint64{1, 2, 3, 4, 6, 7, 8}
p.addFor(5, allPostingsKey)
require.Equal(t, []uint64{1, 2, 3, 4, 5, 6, 7, 8}, p.m[allPostingsKey.Name][allPostingsKey.Value])
}
func TestMemPostings_ensureOrder(t *testing.T) {
p := NewUnorderedMemPostings()
p.m["a"] = map[string][]uint64{}
for i := 0; i < 100; i++ {
l := make([]uint64, 100)
for j := range l {
l[j] = rand.Uint64()
}
v := fmt.Sprintf("%d", i)
p.m["a"][v] = l
}
p.EnsureOrder()
for _, e := range p.m {
for _, l := range e {
ok := sort.SliceIsSorted(l, func(i, j int) bool {
return l[i] < l[j]
})
if !ok {
t.Fatalf("postings list %v is not sorted", l)
}
}
}
}
func TestIntersect(t *testing.T) {
a := newListPostings(1, 2, 3)
b := newListPostings(2, 3, 4)
cases := []struct {
in []Postings
res Postings
}{
{
in: []Postings{},
res: EmptyPostings(),
},
{
in: []Postings{a, b, EmptyPostings()},
res: EmptyPostings(),
},
{
in: []Postings{b, a, EmptyPostings()},
res: EmptyPostings(),
},
{
in: []Postings{EmptyPostings(), b, a},
res: EmptyPostings(),
},
{
in: []Postings{EmptyPostings(), a, b},
res: EmptyPostings(),
},
{
in: []Postings{a, EmptyPostings(), b},
res: EmptyPostings(),
},
{
in: []Postings{b, EmptyPostings(), a},
res: EmptyPostings(),
},
{
in: []Postings{b, EmptyPostings(), a, a, b, a, a, a},
res: EmptyPostings(),
},
{
in: []Postings{
newListPostings(1, 2, 3, 4, 5),
newListPostings(6, 7, 8, 9, 10),
},
res: newListPostings(),
},
{
in: []Postings{
newListPostings(1, 2, 3, 4, 5),
newListPostings(4, 5, 6, 7, 8),
},
res: newListPostings(4, 5),
},
{
in: []Postings{
newListPostings(1, 2, 3, 4, 9, 10),
newListPostings(1, 4, 5, 6, 7, 8, 10, 11),
},
res: newListPostings(1, 4, 10),
},
{
in: []Postings{
newListPostings(1),
newListPostings(0, 1),
},
res: newListPostings(1),
},
{
in: []Postings{
newListPostings(1),
},
res: newListPostings(1),
},
{
in: []Postings{
newListPostings(1),
newListPostings(),
},
res: newListPostings(),
},
{
in: []Postings{
newListPostings(),
newListPostings(),
},
res: newListPostings(),
},
}
for _, c := range cases {
t.Run("", func(t *testing.T) {
if c.res == nil {
t.Fatal("intersect result expectancy cannot be nil")
}
expected, err := ExpandPostings(c.res)
require.NoError(t, err)
i := Intersect(c.in...)
if c.res == EmptyPostings() {
require.Equal(t, EmptyPostings(), i)
return
}
if i == EmptyPostings() {
t.Fatal("intersect unexpected result: EmptyPostings sentinel")
}
res, err := ExpandPostings(i)
require.NoError(t, err)
require.Equal(t, expected, res)
})
}
}
func TestMultiIntersect(t *testing.T) {
cases := []struct {
p [][]uint64
res []uint64
}{
{
p: [][]uint64{
{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: []uint64{2, 5, 6, 1001},
},
// One of the reproducible 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: [][]uint64{
{1, 2},
{1, 2},
{1, 2},
{2},
},
res: []uint64{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) {
t.Run("LongPostings1", func(bench *testing.B) {
var a, b, c, d []uint64
for i := 0; i < 10000000; i += 2 {
a = append(a, uint64(i))
}
for i := 5000000; i < 5000100; i += 4 {
b = append(b, uint64(i))
}
for i := 5090000; i < 5090600; i += 4 {
b = append(b, uint64(i))
}
for i := 4990000; i < 5100000; i++ {
c = append(c, uint64(i))
}
for i := 4000000; i < 6000000; i++ {
d = append(d, uint64(i))
}
i1 := newListPostings(a...)
i2 := newListPostings(b...)
i3 := newListPostings(c...)
i4 := newListPostings(d...)
bench.ResetTimer()
bench.ReportAllocs()
for i := 0; i < bench.N; i++ {
if _, err := ExpandPostings(Intersect(i1, i2, i3, i4)); err != nil {
bench.Fatal(err)
}
}
})
t.Run("LongPostings2", func(bench *testing.B) {
var a, b, c, d []uint64
for i := 0; i < 12500000; i++ {
a = append(a, uint64(i))
}
for i := 7500000; i < 12500000; i++ {
b = append(b, uint64(i))
}
for i := 9000000; i < 20000000; i++ {
c = append(c, uint64(i))
}
for i := 10000000; i < 12000000; i++ {
d = append(d, uint64(i))
}
i1 := newListPostings(a...)
i2 := newListPostings(b...)
i3 := newListPostings(c...)
i4 := newListPostings(d...)
bench.ResetTimer()
bench.ReportAllocs()
for i := 0; i < bench.N; i++ {
if _, err := ExpandPostings(Intersect(i1, i2, i3, i4)); err != nil {
bench.Fatal(err)
}
}
})
// Many matchers(k >> n).
t.Run("ManyPostings", func(bench *testing.B) {
var its []Postings
// 100000 matchers(k=100000).
for i := 0; i < 100000; i++ {
var temp []uint64
for j := 1; j < 100; j++ {
temp = append(temp, uint64(j))
}
its = append(its, newListPostings(temp...))
}
bench.ResetTimer()
bench.ReportAllocs()
for i := 0; i < bench.N; i++ {
if _, err := ExpandPostings(Intersect(its...)); err != nil {
bench.Fatal(err)
}
}
})
}
func TestMultiMerge(t *testing.T) {
i1 := newListPostings(1, 2, 3, 4, 5, 6, 1000, 1001)
i2 := newListPostings(2, 4, 5, 6, 7, 8, 999, 1001)
i3 := newListPostings(1, 2, 5, 6, 7, 8, 1001, 1200)
res, err := ExpandPostings(Merge(i1, i2, i3))
require.NoError(t, err)
require.Equal(t, []uint64{1, 2, 3, 4, 5, 6, 7, 8, 999, 1000, 1001, 1200}, res)
}
func TestMergedPostings(t *testing.T) {
cases := []struct {
in []Postings
res Postings
}{
{
in: []Postings{},
res: EmptyPostings(),
},
{
in: []Postings{
newListPostings(),
newListPostings(),
},
res: EmptyPostings(),
},
{
in: []Postings{
newListPostings(),
},
res: newListPostings(),
},
{
in: []Postings{
EmptyPostings(),
EmptyPostings(),
EmptyPostings(),
EmptyPostings(),
},
res: EmptyPostings(),
},
{
in: []Postings{
newListPostings(1, 2, 3, 4, 5),
newListPostings(6, 7, 8, 9, 10),
},
res: newListPostings(1, 2, 3, 4, 5, 6, 7, 8, 9, 10),
},
{
in: []Postings{
newListPostings(1, 2, 3, 4, 5),
newListPostings(4, 5, 6, 7, 8),
},
res: newListPostings(1, 2, 3, 4, 5, 6, 7, 8),
},
{
in: []Postings{
newListPostings(1, 2, 3, 4, 9, 10),
newListPostings(1, 4, 5, 6, 7, 8, 10, 11),
},
res: newListPostings(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11),
},
{
in: []Postings{
newListPostings(1, 2, 3, 4, 9, 10),
EmptyPostings(),
newListPostings(1, 4, 5, 6, 7, 8, 10, 11),
},
res: newListPostings(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11),
},
{
in: []Postings{
newListPostings(1, 2),
newListPostings(),
},
res: newListPostings(1, 2),
},
{
in: []Postings{
newListPostings(1, 2),
EmptyPostings(),
},
res: newListPostings(1, 2),
},
}
for _, c := range cases {
t.Run("", func(t *testing.T) {
if c.res == nil {
t.Fatal("merge result expectancy cannot be nil")
}
expected, err := ExpandPostings(c.res)
require.NoError(t, err)
m := Merge(c.in...)
if c.res == EmptyPostings() {
require.Equal(t, EmptyPostings(), m)
return
}
if m == EmptyPostings() {
t.Fatal("merge unexpected result: EmptyPostings sentinel")
}
res, err := ExpandPostings(m)
require.NoError(t, err)
require.Equal(t, expected, res)
})
}
}
func TestMergedPostingsSeek(t *testing.T) {
cases := []struct {
a, b []uint64
seek uint64
success bool
res []uint64
}{
{
a: []uint64{2, 3, 4, 5},
b: []uint64{6, 7, 8, 9, 10},
seek: 1,
success: true,
res: []uint64{2, 3, 4, 5, 6, 7, 8, 9, 10},
},
{
a: []uint64{1, 2, 3, 4, 5},
b: []uint64{6, 7, 8, 9, 10},
seek: 2,
success: true,
res: []uint64{2, 3, 4, 5, 6, 7, 8, 9, 10},
},
{
a: []uint64{1, 2, 3, 4, 5},
b: []uint64{4, 5, 6, 7, 8},
seek: 9,
success: false,
res: nil,
},
{
a: []uint64{1, 2, 3, 4, 9, 10},
b: []uint64{1, 4, 5, 6, 7, 8, 10, 11},
seek: 10,
success: true,
res: []uint64{10, 11},
},
}
for _, c := range cases {
a := newListPostings(c.a...)
b := newListPostings(c.b...)
p := Merge(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([]uint64{start}, lst...)
require.Equal(t, c.res, lst)
}
}
}
func TestRemovedPostings(t *testing.T) {
cases := []struct {
a, b []uint64
res []uint64
}{
{
a: nil,
b: nil,
res: []uint64(nil),
},
{
a: []uint64{1, 2, 3, 4},
b: nil,
res: []uint64{1, 2, 3, 4},
},
{
a: nil,
b: []uint64{1, 2, 3, 4},
res: []uint64(nil),
},
{
a: []uint64{1, 2, 3, 4, 5},
b: []uint64{6, 7, 8, 9, 10},
res: []uint64{1, 2, 3, 4, 5},
},
{
a: []uint64{1, 2, 3, 4, 5},
b: []uint64{4, 5, 6, 7, 8},
res: []uint64{1, 2, 3},
},
{
a: []uint64{1, 2, 3, 4, 9, 10},
b: []uint64{1, 4, 5, 6, 7, 8, 10, 11},
res: []uint64{2, 3, 9},
},
{
a: []uint64{1, 2, 3, 4, 9, 10},
b: []uint64{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11},
res: []uint64(nil),
},
}
for _, c := range cases {
a := newListPostings(c.a...)
b := newListPostings(c.b...)
res, err := ExpandPostings(newRemovedPostings(a, b))
require.NoError(t, err)
require.Equal(t, c.res, res)
}
}
func TestRemovedNextStackoverflow(t *testing.T) {
var full []uint64
var remove []uint64
var i uint64
for i = 0; i < 1e7; i++ {
full = append(full, i)
remove = append(remove, i)
}
flp := newListPostings(full...)
rlp := newListPostings(remove...)
rp := newRemovedPostings(flp, rlp)
gotElem := false
for rp.Next() {
gotElem = true
}
require.NoError(t, rp.Err())
require.False(t, gotElem)
}
func TestRemovedPostingsSeek(t *testing.T) {
cases := []struct {
a, b []uint64
seek uint64
success bool
res []uint64
}{
{
a: []uint64{2, 3, 4, 5},
b: []uint64{6, 7, 8, 9, 10},
seek: 1,
success: true,
res: []uint64{2, 3, 4, 5},
},
{
a: []uint64{1, 2, 3, 4, 5},
b: []uint64{6, 7, 8, 9, 10},
seek: 2,
success: true,
res: []uint64{2, 3, 4, 5},
},
{
a: []uint64{1, 2, 3, 4, 5},
b: []uint64{4, 5, 6, 7, 8},
seek: 9,
success: false,
res: nil,
},
{
a: []uint64{1, 2, 3, 4, 9, 10},
b: []uint64{1, 4, 5, 6, 7, 8, 10, 11},
seek: 10,
success: false,
res: nil,
},
{
a: []uint64{1, 2, 3, 4, 9, 10},
b: []uint64{1, 4, 5, 6, 7, 8, 11},
seek: 4,
success: true,
res: []uint64{9, 10},
},
{
a: []uint64{1, 2, 3, 4, 9, 10},
b: []uint64{1, 4, 5, 6, 7, 8, 11},
seek: 5,
success: true,
res: []uint64{9, 10},
},
{
a: []uint64{1, 2, 3, 4, 9, 10},
b: []uint64{1, 4, 5, 6, 7, 8, 11},
seek: 10,
success: true,
res: []uint64{10},
},
}
for _, c := range cases {
a := newListPostings(c.a...)
b := newListPostings(c.b...)
p := newRemovedPostings(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([]uint64{start}, lst...)
require.Equal(t, c.res, lst)
}
}
}
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, uint64(ls[i]), bep.At())
}
require.False(t, bep.Next())
require.NoError(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(uint64(v.seek)))
require.Equal(t, uint64(v.val), bep.At())
require.NoError(t, bep.Err())
}
})
}
func TestIntersectWithMerge(t *testing.T) {
// One of the reproducible cases for:
// https://github.com/prometheus/prometheus/issues/2616
a := newListPostings(21, 22, 23, 24, 25, 30)
b := Merge(
newListPostings(10, 20, 30),
newListPostings(15, 26, 30),
)
p := Intersect(a, b)
res, err := ExpandPostings(p)
require.NoError(t, err)
require.Equal(t, []uint64{30}, res)
}
func TestWithoutPostings(t *testing.T) {
cases := []struct {
base Postings
drop Postings
res Postings
}{
{
base: EmptyPostings(),
drop: EmptyPostings(),
res: EmptyPostings(),
},
{
base: EmptyPostings(),
drop: newListPostings(1, 2),
res: EmptyPostings(),
},
{
base: newListPostings(1, 2),
drop: EmptyPostings(),
res: newListPostings(1, 2),
},
{
base: newListPostings(),
drop: newListPostings(),
res: newListPostings(),
},
{
base: newListPostings(1, 2, 3),
drop: newListPostings(),
res: newListPostings(1, 2, 3),
},
{
base: newListPostings(1, 2, 3),
drop: newListPostings(4, 5, 6),
res: newListPostings(1, 2, 3),
},
{
base: newListPostings(1, 2, 3),
drop: newListPostings(3, 4, 5),
res: newListPostings(1, 2),
},
}
for _, c := range cases {
t.Run("", func(t *testing.T) {
if c.res == nil {
t.Fatal("without result expectancy cannot be nil")
}
expected, err := ExpandPostings(c.res)
require.NoError(t, err)
w := Without(c.base, c.drop)
if c.res == EmptyPostings() {
require.Equal(t, EmptyPostings(), w)
return
}
if w == EmptyPostings() {
t.Fatal("without unexpected result: EmptyPostings sentinel")
}
res, err := ExpandPostings(w)
require.NoError(t, err)
require.Equal(t, expected, res)
})
}
}
func BenchmarkPostings_Stats(b *testing.B) {
p := NewMemPostings()
var seriesID uint64
createPostingsLabelValues := func(name, valuePrefix string, count int) {
for n := 1; n < count; n++ {
value := fmt.Sprintf("%s-%d", valuePrefix, n)
p.Add(seriesID, labels.FromStrings(name, value))
seriesID++
}
}
createPostingsLabelValues("__name__", "metrics_name_can_be_very_big_and_bad", 1e3)
for i := 0; i < 20; i++ {
createPostingsLabelValues(fmt.Sprintf("host-%d", i), "metrics_name_can_be_very_big_and_bad", 1e3)
createPostingsLabelValues(fmt.Sprintf("instance-%d", i), "10.0.IP.", 1e3)
createPostingsLabelValues(fmt.Sprintf("job-%d", i), "Small_Job_name", 1e3)
createPostingsLabelValues(fmt.Sprintf("err-%d", i), "avg_namespace-", 1e3)
createPostingsLabelValues(fmt.Sprintf("team-%d", i), "team-", 1e3)
createPostingsLabelValues(fmt.Sprintf("container_name-%d", i), "pod-", 1e3)
createPostingsLabelValues(fmt.Sprintf("cluster-%d", i), "newcluster-", 1e3)
createPostingsLabelValues(fmt.Sprintf("uid-%d", i), "123412312312312311-", 1e3)
createPostingsLabelValues(fmt.Sprintf("area-%d", i), "new_area_of_work-", 1e3)
createPostingsLabelValues(fmt.Sprintf("request_id-%d", i), "owner_name_work-", 1e3)
}
b.ResetTimer()
for n := 0; n < b.N; n++ {
p.Stats("__name__")
}
}
func TestMemPostings_Delete(t *testing.T) {
p := NewMemPostings()
p.Add(1, labels.FromStrings("lbl1", "a"))
p.Add(2, labels.FromStrings("lbl1", "b"))
p.Add(3, labels.FromStrings("lbl2", "a"))
before := p.Get(allPostingsKey.Name, allPostingsKey.Value)
p.Delete(map[uint64]struct{}{
2: {},
})
after := p.Get(allPostingsKey.Name, allPostingsKey.Value)
// Make sure postings gotten before the delete have the old data when
// iterated over.
expanded, err := ExpandPostings(before)
require.NoError(t, err)
require.Equal(t, []uint64{1, 2, 3}, expanded)
// Make sure postings gotten after the delete have the new data when
// iterated over.
expanded, err = ExpandPostings(after)
require.NoError(t, err)
require.Equal(t, []uint64{1, 3}, expanded)
deleted := p.Get("lbl1", "b")
expanded, err = ExpandPostings(deleted)
require.NoError(t, err)
require.Equal(t, 0, len(expanded), "expected empty postings, got %v", expanded)
}
func TestPostingsCloner(t *testing.T) {
for _, tc := range []struct {
name string
check func(testing.TB, *PostingsCloner)
}{
{
name: "seek beyond highest value of postings, then other clone seeks higher",
check: func(t testing.TB, pc *PostingsCloner) {
p1 := pc.Clone()
require.False(t, p1.Seek(9))
require.Equal(t, uint64(0), p1.At())
p2 := pc.Clone()
require.False(t, p2.Seek(10))
require.Equal(t, uint64(0), p2.At())
},
},
{
name: "seek beyond highest value of postings, then other clone seeks lower",
check: func(t testing.TB, pc *PostingsCloner) {
p1 := pc.Clone()
require.False(t, p1.Seek(9))
require.Equal(t, uint64(0), p1.At())
p2 := pc.Clone()
require.True(t, p2.Seek(2))
require.Equal(t, uint64(2), p2.At())
},
},
{
name: "seek to posting with value 3 or higher",
check: func(t testing.TB, pc *PostingsCloner) {
p := pc.Clone()
require.True(t, p.Seek(3))
require.Equal(t, uint64(4), p.At())
require.True(t, p.Seek(4))
require.Equal(t, uint64(4), p.At())
},
},
{
name: "seek alternatively on different postings",
check: func(t testing.TB, pc *PostingsCloner) {
p1 := pc.Clone()
require.True(t, p1.Seek(1))
require.Equal(t, uint64(1), p1.At())
p2 := pc.Clone()
require.True(t, p2.Seek(2))
require.Equal(t, uint64(2), p2.At())
p3 := pc.Clone()
require.True(t, p3.Seek(4))
require.Equal(t, uint64(4), p3.At())
p4 := pc.Clone()
require.True(t, p4.Seek(5))
require.Equal(t, uint64(8), p4.At())
require.True(t, p1.Seek(3))
require.Equal(t, uint64(4), p1.At())
require.True(t, p1.Seek(4))
require.Equal(t, uint64(4), p1.At())
},
},
{
name: "iterate through the postings",
check: func(t testing.TB, pc *PostingsCloner) {
p1 := pc.Clone()
p2 := pc.Clone()
// both one step
require.True(t, p1.Next())
require.Equal(t, uint64(1), p1.At())
require.True(t, p2.Next())
require.Equal(t, uint64(1), p2.At())
require.True(t, p1.Next())
require.Equal(t, uint64(2), p1.At())
require.True(t, p1.Next())
require.Equal(t, uint64(4), p1.At())
require.True(t, p1.Next())
require.Equal(t, uint64(8), p1.At())
require.False(t, p1.Next())
require.True(t, p2.Next())
require.Equal(t, uint64(2), p2.At())
require.True(t, p2.Next())
require.Equal(t, uint64(4), p2.At())
},
},
{
name: "at before call of next shouldn't panic",
check: func(t testing.TB, pc *PostingsCloner) {
p := pc.Clone()
require.Equal(t, uint64(0), p.At())
},
},
{
name: "ensure a failed seek doesn't allow more next calls",
check: func(t testing.TB, pc *PostingsCloner) {
p := pc.Clone()
require.False(t, p.Seek(9))
require.Equal(t, uint64(0), p.At())
require.False(t, p.Next())
require.Equal(t, uint64(0), p.At())
},
},
} {
t.Run(tc.name, func(t *testing.T) {
pc := NewPostingsCloner(newListPostings(1, 2, 4, 8))
tc.check(t, pc)
})
}
t.Run("cloning an err postings", func(t *testing.T) {
expectedErr := fmt.Errorf("foobar")
pc := NewPostingsCloner(ErrPostings(expectedErr))
p := pc.Clone()
require.False(t, p.Next())
require.Equal(t, expectedErr, p.Err())
})
}