ceremonyclient/pebble/internal/cache/robin_hood_test.go
Cassandra Heart 2e2a1e4789
v1.2.0 (#31)
2024-01-03 01:31:42 -06:00

242 lines
5.0 KiB
Go

// Copyright 2020 The LevelDB-Go and Pebble Authors. All rights reserved. Use
// of this source code is governed by a BSD-style license that can be found in
// the LICENSE file.
package cache
import (
"fmt"
"io"
"runtime"
"testing"
"time"
"github.com/cockroachdb/pebble/internal/base"
"golang.org/x/exp/rand"
)
func TestRobinHoodMap(t *testing.T) {
rng := rand.New(rand.NewSource(uint64(time.Now().UnixNano())))
rhMap := newRobinHoodMap(0)
defer rhMap.free()
goMap := make(map[key]*entry)
randomKey := func() key {
n := rng.Intn(len(goMap))
for k := range goMap {
if n == 0 {
return k
}
n--
}
return key{}
}
ops := 10000 + rng.Intn(10000)
for i := 0; i < ops; i++ {
var which float64
if len(goMap) > 0 {
which = rng.Float64()
}
switch {
case which < 0.4:
// 40% insert.
var k key
k.id = rng.Uint64()
k.fileNum = base.FileNum(rng.Uint64()).DiskFileNum()
k.offset = rng.Uint64()
e := &entry{}
goMap[k] = e
rhMap.Put(k, e)
if len(goMap) != rhMap.Count() {
t.Fatalf("map sizes differ: %d != %d", len(goMap), rhMap.Count())
}
case which < 0.1:
// 10% overwrite.
k := randomKey()
e := &entry{}
goMap[k] = e
rhMap.Put(k, e)
if len(goMap) != rhMap.Count() {
t.Fatalf("map sizes differ: %d != %d", len(goMap), rhMap.Count())
}
case which < 0.75:
// 25% delete.
k := randomKey()
delete(goMap, k)
rhMap.Delete(k)
if len(goMap) != rhMap.Count() {
t.Fatalf("map sizes differ: %d != %d", len(goMap), rhMap.Count())
}
default:
// 25% lookup.
k := randomKey()
v := goMap[k]
u := rhMap.Get(k)
if v != u {
t.Fatalf("%s: expected %p, but found %p", k, v, u)
}
}
}
t.Logf("map size: %d", len(goMap))
}
const benchSize = 1 << 20
func BenchmarkGoMapInsert(b *testing.B) {
rng := rand.New(rand.NewSource(uint64(time.Now().UnixNano())))
keys := make([]key, benchSize)
for i := range keys {
keys[i].fileNum = base.FileNum(rng.Uint64n(1 << 20)).DiskFileNum()
keys[i].offset = uint64(rng.Intn(1 << 20))
}
b.ResetTimer()
var m map[key]*entry
for i, j := 0, 0; i < b.N; i, j = i+1, j+1 {
if m == nil || j == len(keys) {
b.StopTimer()
m = make(map[key]*entry, len(keys))
j = 0
b.StartTimer()
}
m[keys[j]] = nil
}
}
func BenchmarkRobinHoodInsert(b *testing.B) {
rng := rand.New(rand.NewSource(uint64(time.Now().UnixNano())))
keys := make([]key, benchSize)
for i := range keys {
keys[i].fileNum = base.FileNum(rng.Uint64n(1 << 20)).DiskFileNum()
keys[i].offset = uint64(rng.Intn(1 << 20))
}
e := &entry{}
b.ResetTimer()
var m *robinHoodMap
for i, j := 0, 0; i < b.N; i, j = i+1, j+1 {
if m == nil || j == len(keys) {
b.StopTimer()
m = newRobinHoodMap(len(keys))
j = 0
b.StartTimer()
}
m.Put(keys[j], e)
}
runtime.KeepAlive(e)
}
func BenchmarkGoMapLookupHit(b *testing.B) {
rng := rand.New(rand.NewSource(uint64(time.Now().UnixNano())))
keys := make([]key, benchSize)
m := make(map[key]*entry, len(keys))
e := &entry{}
for i := range keys {
keys[i].fileNum = base.FileNum(rng.Uint64n(1 << 20)).DiskFileNum()
keys[i].offset = uint64(rng.Intn(1 << 20))
m[keys[i]] = e
}
b.ResetTimer()
var p *entry
for i, j := 0, 0; i < b.N; i, j = i+1, j+1 {
if j == len(keys) {
j = 0
}
p = m[keys[j]]
}
if testing.Verbose() {
fmt.Fprintln(io.Discard, p)
}
}
func BenchmarkRobinHoodLookupHit(b *testing.B) {
rng := rand.New(rand.NewSource(uint64(time.Now().UnixNano())))
keys := make([]key, benchSize)
m := newRobinHoodMap(len(keys))
e := &entry{}
for i := range keys {
keys[i].fileNum = base.FileNum(rng.Uint64n(1 << 20)).DiskFileNum()
keys[i].offset = uint64(rng.Intn(1 << 20))
m.Put(keys[i], e)
}
b.ResetTimer()
var p *entry
for i, j := 0, 0; i < b.N; i, j = i+1, j+1 {
if j == len(keys) {
j = 0
}
p = m.Get(keys[j])
}
if testing.Verbose() {
fmt.Fprintln(io.Discard, p)
}
runtime.KeepAlive(e)
}
func BenchmarkGoMapLookupMiss(b *testing.B) {
rng := rand.New(rand.NewSource(uint64(time.Now().UnixNano())))
keys := make([]key, benchSize)
m := make(map[key]*entry, len(keys))
e := &entry{}
for i := range keys {
keys[i].id = 1
keys[i].fileNum = base.FileNum(rng.Uint64n(1 << 20)).DiskFileNum()
keys[i].offset = uint64(rng.Intn(1 << 20))
m[keys[i]] = e
keys[i].id = 2
}
b.ResetTimer()
var p *entry
for i, j := 0, 0; i < b.N; i, j = i+1, j+1 {
if j == len(keys) {
j = 0
}
p = m[keys[j]]
}
if testing.Verbose() {
fmt.Fprintln(io.Discard, p)
}
}
func BenchmarkRobinHoodLookupMiss(b *testing.B) {
rng := rand.New(rand.NewSource(uint64(time.Now().UnixNano())))
keys := make([]key, benchSize)
m := newRobinHoodMap(len(keys))
e := &entry{}
for i := range keys {
keys[i].id = 1
keys[i].fileNum = base.FileNum(rng.Uint64n(1 << 20)).DiskFileNum()
keys[i].offset = uint64(rng.Intn(1 << 20))
m.Put(keys[i], e)
keys[i].id = 2
}
b.ResetTimer()
var p *entry
for i, j := 0, 0; i < b.N; i, j = i+1, j+1 {
if j == len(keys) {
j = 0
}
p = m.Get(keys[j])
}
if testing.Verbose() {
fmt.Fprintln(io.Discard, p)
}
runtime.KeepAlive(e)
}