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tailscale/net/art/table_test.go

551 lines
15 KiB
Go

net/art: implement the Table type, a multi-level art route table. Updates #7781 │ sec/op │ TableInsertion/ipv4/10 1.562µ ± 2% TableInsertion/ipv4/100 2.398µ ± 5% TableInsertion/ipv4/1000 2.097µ ± 3% TableInsertion/ipv4/10000 2.756µ ± 4% TableInsertion/ipv4/100000 2.473µ ± 13% TableInsertion/ipv6/10 7.649µ ± 2% TableInsertion/ipv6/100 12.09µ ± 3% TableInsertion/ipv6/1000 14.84µ ± 5% TableInsertion/ipv6/10000 14.72µ ± 8% TableInsertion/ipv6/100000 13.23µ ± 41% TableDelete/ipv4/10 378.4n ± 5% TableDelete/ipv4/100 366.9n ± 3% TableDelete/ipv4/1000 418.6n ± 3% TableDelete/ipv4/10000 609.2n ± 11% TableDelete/ipv4/100000 679.2n ± 28% TableDelete/ipv6/10 504.2n ± 4% TableDelete/ipv6/100 959.5n ± 12% TableDelete/ipv6/1000 1.436µ ± 6% TableDelete/ipv6/10000 1.772µ ± 15% TableDelete/ipv6/100000 1.172µ ± 113% TableGet/ipv4/10 32.14n ± 11% TableGet/ipv4/100 38.58n ± 2% TableGet/ipv4/1000 45.03n ± 2% TableGet/ipv4/10000 52.90n ± 7% TableGet/ipv4/100000 135.2n ± 11% TableGet/ipv6/10 41.55n ± 1% TableGet/ipv6/100 44.78n ± 2% TableGet/ipv6/1000 49.03n ± 2% TableGet/ipv6/10000 65.38n ± 5% TableGet/ipv6/100000 525.0n ± 39% │ avg-B/op │ TableInsertion/ipv4/10 25.18Ki ± 0% TableInsertion/ipv4/100 17.63Ki ± 0% TableInsertion/ipv4/1000 14.14Ki ± 0% TableInsertion/ipv4/10000 12.92Ki ± 0% TableInsertion/ipv4/100000 11.13Ki ± 0% TableInsertion/ipv6/10 76.87Ki ± 0% TableInsertion/ipv6/100 98.33Ki ± 0% TableInsertion/ipv6/1000 91.44Ki ± 0% TableInsertion/ipv6/10000 90.39Ki ± 0% TableInsertion/ipv6/100000 87.19Ki ± 0% TableDelete/ipv4/10 3.230 ± 0% TableDelete/ipv4/100 4.020 ± 0% TableDelete/ipv4/1000 3.990 ± 0% TableDelete/ipv4/10000 4.000 ± 0% TableDelete/ipv4/100000 4.000 ± 0% TableDelete/ipv6/10 16.00 ± 0% TableDelete/ipv6/100 16.00 ± 0% TableDelete/ipv6/1000 16.00 ± 0% TableDelete/ipv6/10000 16.00 ± 0% TableDelete/ipv6/100000 16.00 ± 0% │ avg-allocs/op │ TableInsertion/ipv4/10 2.900 ± 0% TableInsertion/ipv4/100 2.330 ± 0% TableInsertion/ipv4/1000 2.070 ± 0% TableInsertion/ipv4/10000 1.980 ± 0% TableInsertion/ipv4/100000 1.840 ± 0% TableInsertion/ipv6/10 6.800 ± 0% TableInsertion/ipv6/100 8.420 ± 0% TableInsertion/ipv6/1000 7.900 ± 0% TableInsertion/ipv6/10000 7.820 ± 0% TableInsertion/ipv6/100000 7.580 ± 0% TableDelete/ipv4/10 1.000 ± 0% TableDelete/ipv4/100 1.000 ± 0% TableDelete/ipv4/1000 1.000 ± 0% TableDelete/ipv4/10000 1.000 ± 0% TableDelete/ipv4/100000 1.000 ± 0% TableDelete/ipv6/10 1.000 ± 0% TableDelete/ipv6/100 1.000 ± 0% TableDelete/ipv6/1000 1.000 ± 0% TableDelete/ipv6/10000 1.000 ± 0% TableDelete/ipv6/100000 1.000 ± 0% │ routes/s │ TableInsertion/ipv4/10 640.3k ± 2% TableInsertion/ipv4/100 417.1k ± 5% TableInsertion/ipv4/1000 477.0k ± 3% TableInsertion/ipv4/10000 362.8k ± 5% TableInsertion/ipv4/100000 404.5k ± 15% TableInsertion/ipv6/10 130.7k ± 1% TableInsertion/ipv6/100 82.69k ± 3% TableInsertion/ipv6/1000 67.37k ± 5% TableInsertion/ipv6/10000 67.93k ± 9% TableInsertion/ipv6/100000 75.63k ± 29% TableDelete/ipv4/10 2.642M ± 6% TableDelete/ipv4/100 2.726M ± 3% TableDelete/ipv4/1000 2.389M ± 3% TableDelete/ipv4/10000 1.641M ± 12% TableDelete/ipv4/100000 1.472M ± 27% TableDelete/ipv6/10 1.984M ± 4% TableDelete/ipv6/100 1.042M ± 11% TableDelete/ipv6/1000 696.5k ± 6% TableDelete/ipv6/10000 564.4k ± 13% TableDelete/ipv6/100000 853.6k ± 53% │ addrs/s │ TableGet/ipv4/10 31.11M ± 10% TableGet/ipv4/100 25.92M ± 2% TableGet/ipv4/1000 22.21M ± 2% TableGet/ipv4/10000 18.91M ± 8% TableGet/ipv4/100000 7.397M ± 12% TableGet/ipv6/10 24.07M ± 1% TableGet/ipv6/100 22.33M ± 2% TableGet/ipv6/1000 20.40M ± 2% TableGet/ipv6/10000 15.30M ± 5% TableGet/ipv6/100000 1.905M ± 28% │ B/op │ TableGet/ipv4/10 4.000 ± 0% TableGet/ipv4/100 4.000 ± 0% TableGet/ipv4/1000 4.000 ± 0% TableGet/ipv4/10000 4.000 ± 0% TableGet/ipv4/100000 4.000 ± 0% TableGet/ipv6/10 16.00 ± 0% TableGet/ipv6/100 16.00 ± 0% TableGet/ipv6/1000 16.00 ± 0% TableGet/ipv6/10000 16.00 ± 0% TableGet/ipv6/100000 16.00 ± 0% │ allocs/op │ TableGet/ipv4/10 1.000 ± 0% TableGet/ipv4/100 1.000 ± 0% TableGet/ipv4/1000 1.000 ± 0% TableGet/ipv4/10000 1.000 ± 0% TableGet/ipv4/100000 1.000 ± 0% TableGet/ipv6/10 1.000 ± 0% TableGet/ipv6/100 1.000 ± 0% TableGet/ipv6/1000 1.000 ± 0% TableGet/ipv6/10000 1.000 ± 0% TableGet/ipv6/100000 1.000 ± 0% Signed-off-by: David Anderson <danderson@tailscale.com>
2 years ago
// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
package art
import (
crand "crypto/rand"
"fmt"
"math/rand"
"net/netip"
"runtime"
"strconv"
"testing"
"time"
"tailscale.com/types/ptr"
)
func TestInsert(t *testing.T) {
t.Parallel()
pfxs := randomPrefixes(10_000)
slow := slowPrefixTable[int]{pfxs}
fast := Table[int]{}
for _, pfx := range pfxs {
fast.Insert(pfx.pfx, pfx.val)
}
t.Logf(fast.debugSummary())
seenVals4 := map[*int]bool{}
seenVals6 := map[*int]bool{}
for i := 0; i < 10_000; i++ {
a := randomAddr()
slowVal := slow.get(a)
fastVal := fast.Get(a)
if a.Is6() {
seenVals6[fastVal] = true
} else {
seenVals4[fastVal] = true
}
if slowVal != fastVal {
t.Errorf("get(%q) = %p, want %p", a, fastVal, slowVal)
}
}
// Empirically, 10k probes into 5k v4 prefixes and 5k v6 prefixes results in
// ~1k distinct values for v4 and ~300 for v6. distinct routes. This sanity
// check that we didn't just return a single route for everything should be
// very generous indeed.
if cnt := len(seenVals4); cnt < 10 {
t.Fatalf("saw %d distinct v4 route results, statistically expected ~1000", cnt)
}
if cnt := len(seenVals6); cnt < 10 {
t.Fatalf("saw %d distinct v6 route results, statistically expected ~300", cnt)
}
}
func TestInsertShuffled(t *testing.T) {
t.Parallel()
pfxs := randomPrefixes(10_000)
rt := Table[int]{}
for _, pfx := range pfxs {
rt.Insert(pfx.pfx, pfx.val)
}
for i := 0; i < 10; i++ {
pfxs2 := append([]slowPrefixEntry[int](nil), pfxs...)
rand.Shuffle(len(pfxs2), func(i, j int) { pfxs2[i], pfxs2[j] = pfxs2[j], pfxs2[i] })
rt2 := Table[int]{}
for _, pfx := range pfxs2 {
rt2.Insert(pfx.pfx, pfx.val)
}
// Diffing a deep tree of tables gives cmp.Diff a nervous breakdown, so
// test for equivalence statistically with random probes instead.
for i := 0; i < 10_000; i++ {
a := randomAddr()
val1 := rt.Get(a)
val2 := rt2.Get(a)
if (val1 == nil && val2 != nil) || (val1 != nil && val2 == nil) || (*val1 != *val2) {
t.Errorf("get(%q) = %s, want %s", a, printIntPtr(val2), printIntPtr(val1))
}
}
}
}
func TestDelete(t *testing.T) {
t.Parallel()
const (
numPrefixes = 10_000 // total prefixes to insert (test deletes 50% of them)
numPerFamily = numPrefixes / 2
deleteCut = numPerFamily / 2
numProbes = 10_000 // random addr lookups to do
)
// We have to do this little dance instead of just using allPrefixes,
// because we want pfxs and toDelete to be non-overlapping sets.
all4, all6 := randomPrefixes4(numPerFamily), randomPrefixes6(numPerFamily)
pfxs := append([]slowPrefixEntry[int](nil), all4[:deleteCut]...)
pfxs = append(pfxs, all6[:deleteCut]...)
toDelete := append([]slowPrefixEntry[int](nil), all4[deleteCut:]...)
toDelete = append(toDelete, all6[deleteCut:]...)
slow := slowPrefixTable[int]{pfxs}
fast := Table[int]{}
for _, pfx := range pfxs {
fast.Insert(pfx.pfx, pfx.val)
}
for _, pfx := range toDelete {
fast.Insert(pfx.pfx, pfx.val)
}
for _, pfx := range toDelete {
fast.Delete(pfx.pfx)
}
seenVals4 := map[*int]bool{}
seenVals6 := map[*int]bool{}
for i := 0; i < numProbes; i++ {
a := randomAddr()
slowVal := slow.get(a)
fastVal := fast.Get(a)
if a.Is6() {
seenVals6[fastVal] = true
} else {
seenVals4[fastVal] = true
}
if slowVal != fastVal {
t.Fatalf("get(%q) = %p, want %p", a, fastVal, slowVal)
}
}
// Empirically, 10k probes into 5k v4 prefixes and 5k v6 prefixes results in
// ~1k distinct values for v4 and ~300 for v6. distinct routes. This sanity
// check that we didn't just return a single route for everything should be
// very generous indeed.
if cnt := len(seenVals4); cnt < 10 {
t.Fatalf("saw %d distinct v4 route results, statistically expected ~1000", cnt)
}
if cnt := len(seenVals6); cnt < 10 {
t.Fatalf("saw %d distinct v6 route results, statistically expected ~300", cnt)
}
}
func TestDeleteShuffled(t *testing.T) {
t.Parallel()
const (
numPrefixes = 10_000 // prefixes to insert (test deletes 50% of them)
numPerFamily = numPrefixes / 2
deleteCut = numPerFamily / 2
numProbes = 10_000 // random addr lookups to do
)
// We have to do this little dance instead of just using allPrefixes,
// because we want pfxs and toDelete to be non-overlapping sets.
all4, all6 := randomPrefixes4(numPerFamily), randomPrefixes6(numPerFamily)
pfxs := append([]slowPrefixEntry[int](nil), all4[:deleteCut]...)
pfxs = append(pfxs, all6[:deleteCut]...)
toDelete := append([]slowPrefixEntry[int](nil), all4[deleteCut:]...)
toDelete = append(toDelete, all6[deleteCut:]...)
rt := Table[int]{}
for _, pfx := range pfxs {
rt.Insert(pfx.pfx, pfx.val)
}
for _, pfx := range toDelete {
rt.Insert(pfx.pfx, pfx.val)
}
for _, pfx := range toDelete {
rt.Delete(pfx.pfx)
}
for i := 0; i < 10; i++ {
pfxs2 := append([]slowPrefixEntry[int](nil), pfxs...)
toDelete2 := append([]slowPrefixEntry[int](nil), toDelete...)
rand.Shuffle(len(toDelete2), func(i, j int) { toDelete2[i], toDelete2[j] = toDelete2[j], toDelete2[i] })
rt2 := Table[int]{}
for _, pfx := range pfxs2 {
rt2.Insert(pfx.pfx, pfx.val)
}
for _, pfx := range toDelete2 {
rt2.Insert(pfx.pfx, pfx.val)
}
for _, pfx := range toDelete2 {
rt2.Delete(pfx.pfx)
}
// Diffing a deep tree of tables gives cmp.Diff a nervous breakdown, so
// test for equivalence statistically with random probes instead.
for i := 0; i < numProbes; i++ {
a := randomAddr()
val1 := rt.Get(a)
val2 := rt2.Get(a)
if val1 == nil && val2 == nil {
continue
}
if (val1 == nil && val2 != nil) || (val1 != nil && val2 == nil) || (*val1 != *val2) {
t.Errorf("get(%q) = %s, want %s", a, printIntPtr(val2), printIntPtr(val1))
}
}
}
}
// 100k routes for IPv6, at the current size of strideTable and strideEntry, is
// in the ballpark of 4GiB if you assume worst-case prefix distribution. Future
// optimizations will knock down the memory consumption by over an order of
// magnitude, so for now just skip the 100k benchmarks to stay well away of
// OOMs.
//
// TODO(go/bug/7781): reenable larger table tests once memory utilization is
// optimized.
var benchRouteCount = []int{10, 100, 1000, 10_000} //, 100_000}
net/art: implement the Table type, a multi-level art route table. Updates #7781 │ sec/op │ TableInsertion/ipv4/10 1.562µ ± 2% TableInsertion/ipv4/100 2.398µ ± 5% TableInsertion/ipv4/1000 2.097µ ± 3% TableInsertion/ipv4/10000 2.756µ ± 4% TableInsertion/ipv4/100000 2.473µ ± 13% TableInsertion/ipv6/10 7.649µ ± 2% TableInsertion/ipv6/100 12.09µ ± 3% TableInsertion/ipv6/1000 14.84µ ± 5% TableInsertion/ipv6/10000 14.72µ ± 8% TableInsertion/ipv6/100000 13.23µ ± 41% TableDelete/ipv4/10 378.4n ± 5% TableDelete/ipv4/100 366.9n ± 3% TableDelete/ipv4/1000 418.6n ± 3% TableDelete/ipv4/10000 609.2n ± 11% TableDelete/ipv4/100000 679.2n ± 28% TableDelete/ipv6/10 504.2n ± 4% TableDelete/ipv6/100 959.5n ± 12% TableDelete/ipv6/1000 1.436µ ± 6% TableDelete/ipv6/10000 1.772µ ± 15% TableDelete/ipv6/100000 1.172µ ± 113% TableGet/ipv4/10 32.14n ± 11% TableGet/ipv4/100 38.58n ± 2% TableGet/ipv4/1000 45.03n ± 2% TableGet/ipv4/10000 52.90n ± 7% TableGet/ipv4/100000 135.2n ± 11% TableGet/ipv6/10 41.55n ± 1% TableGet/ipv6/100 44.78n ± 2% TableGet/ipv6/1000 49.03n ± 2% TableGet/ipv6/10000 65.38n ± 5% TableGet/ipv6/100000 525.0n ± 39% │ avg-B/op │ TableInsertion/ipv4/10 25.18Ki ± 0% TableInsertion/ipv4/100 17.63Ki ± 0% TableInsertion/ipv4/1000 14.14Ki ± 0% TableInsertion/ipv4/10000 12.92Ki ± 0% TableInsertion/ipv4/100000 11.13Ki ± 0% TableInsertion/ipv6/10 76.87Ki ± 0% TableInsertion/ipv6/100 98.33Ki ± 0% TableInsertion/ipv6/1000 91.44Ki ± 0% TableInsertion/ipv6/10000 90.39Ki ± 0% TableInsertion/ipv6/100000 87.19Ki ± 0% TableDelete/ipv4/10 3.230 ± 0% TableDelete/ipv4/100 4.020 ± 0% TableDelete/ipv4/1000 3.990 ± 0% TableDelete/ipv4/10000 4.000 ± 0% TableDelete/ipv4/100000 4.000 ± 0% TableDelete/ipv6/10 16.00 ± 0% TableDelete/ipv6/100 16.00 ± 0% TableDelete/ipv6/1000 16.00 ± 0% TableDelete/ipv6/10000 16.00 ± 0% TableDelete/ipv6/100000 16.00 ± 0% │ avg-allocs/op │ TableInsertion/ipv4/10 2.900 ± 0% TableInsertion/ipv4/100 2.330 ± 0% TableInsertion/ipv4/1000 2.070 ± 0% TableInsertion/ipv4/10000 1.980 ± 0% TableInsertion/ipv4/100000 1.840 ± 0% TableInsertion/ipv6/10 6.800 ± 0% TableInsertion/ipv6/100 8.420 ± 0% TableInsertion/ipv6/1000 7.900 ± 0% TableInsertion/ipv6/10000 7.820 ± 0% TableInsertion/ipv6/100000 7.580 ± 0% TableDelete/ipv4/10 1.000 ± 0% TableDelete/ipv4/100 1.000 ± 0% TableDelete/ipv4/1000 1.000 ± 0% TableDelete/ipv4/10000 1.000 ± 0% TableDelete/ipv4/100000 1.000 ± 0% TableDelete/ipv6/10 1.000 ± 0% TableDelete/ipv6/100 1.000 ± 0% TableDelete/ipv6/1000 1.000 ± 0% TableDelete/ipv6/10000 1.000 ± 0% TableDelete/ipv6/100000 1.000 ± 0% │ routes/s │ TableInsertion/ipv4/10 640.3k ± 2% TableInsertion/ipv4/100 417.1k ± 5% TableInsertion/ipv4/1000 477.0k ± 3% TableInsertion/ipv4/10000 362.8k ± 5% TableInsertion/ipv4/100000 404.5k ± 15% TableInsertion/ipv6/10 130.7k ± 1% TableInsertion/ipv6/100 82.69k ± 3% TableInsertion/ipv6/1000 67.37k ± 5% TableInsertion/ipv6/10000 67.93k ± 9% TableInsertion/ipv6/100000 75.63k ± 29% TableDelete/ipv4/10 2.642M ± 6% TableDelete/ipv4/100 2.726M ± 3% TableDelete/ipv4/1000 2.389M ± 3% TableDelete/ipv4/10000 1.641M ± 12% TableDelete/ipv4/100000 1.472M ± 27% TableDelete/ipv6/10 1.984M ± 4% TableDelete/ipv6/100 1.042M ± 11% TableDelete/ipv6/1000 696.5k ± 6% TableDelete/ipv6/10000 564.4k ± 13% TableDelete/ipv6/100000 853.6k ± 53% │ addrs/s │ TableGet/ipv4/10 31.11M ± 10% TableGet/ipv4/100 25.92M ± 2% TableGet/ipv4/1000 22.21M ± 2% TableGet/ipv4/10000 18.91M ± 8% TableGet/ipv4/100000 7.397M ± 12% TableGet/ipv6/10 24.07M ± 1% TableGet/ipv6/100 22.33M ± 2% TableGet/ipv6/1000 20.40M ± 2% TableGet/ipv6/10000 15.30M ± 5% TableGet/ipv6/100000 1.905M ± 28% │ B/op │ TableGet/ipv4/10 4.000 ± 0% TableGet/ipv4/100 4.000 ± 0% TableGet/ipv4/1000 4.000 ± 0% TableGet/ipv4/10000 4.000 ± 0% TableGet/ipv4/100000 4.000 ± 0% TableGet/ipv6/10 16.00 ± 0% TableGet/ipv6/100 16.00 ± 0% TableGet/ipv6/1000 16.00 ± 0% TableGet/ipv6/10000 16.00 ± 0% TableGet/ipv6/100000 16.00 ± 0% │ allocs/op │ TableGet/ipv4/10 1.000 ± 0% TableGet/ipv4/100 1.000 ± 0% TableGet/ipv4/1000 1.000 ± 0% TableGet/ipv4/10000 1.000 ± 0% TableGet/ipv4/100000 1.000 ± 0% TableGet/ipv6/10 1.000 ± 0% TableGet/ipv6/100 1.000 ± 0% TableGet/ipv6/1000 1.000 ± 0% TableGet/ipv6/10000 1.000 ± 0% TableGet/ipv6/100000 1.000 ± 0% Signed-off-by: David Anderson <danderson@tailscale.com>
2 years ago
// forFamilyAndCount runs the benchmark fn with different sets of
// routes.
//
// fn is called once for each combination of {addr_family, num_routes},
// where addr_family is ipv4 or ipv6, num_routes is the values in
// benchRouteCount.
func forFamilyAndCount(b *testing.B, fn func(b *testing.B, routes []slowPrefixEntry[int])) {
for _, fam := range []string{"ipv4", "ipv6"} {
rng := randomPrefixes4
if fam == "ipv6" {
rng = randomPrefixes6
}
b.Run(fam, func(b *testing.B) {
for _, nroutes := range benchRouteCount {
routes := rng(nroutes)
b.Run(fmt.Sprint(nroutes), func(b *testing.B) {
fn(b, routes)
})
}
})
}
}
func BenchmarkTableInsertion(b *testing.B) {
forFamilyAndCount(b, func(b *testing.B, routes []slowPrefixEntry[int]) {
b.StopTimer()
b.ResetTimer()
var startMem, endMem runtime.MemStats
runtime.ReadMemStats(&startMem)
b.StartTimer()
for i := 0; i < b.N; i++ {
var rt Table[int]
for _, route := range routes {
rt.Insert(route.pfx, route.val)
}
}
b.StopTimer()
runtime.ReadMemStats(&endMem)
inserts := float64(b.N) * float64(len(routes))
allocs := float64(endMem.Mallocs - startMem.Mallocs)
bytes := float64(endMem.TotalAlloc - startMem.TotalAlloc)
elapsed := float64(b.Elapsed().Nanoseconds())
elapsedSec := b.Elapsed().Seconds()
b.ReportMetric(elapsed/inserts, "ns/op")
b.ReportMetric(inserts/elapsedSec, "routes/s")
b.ReportMetric(roundFloat64(allocs/inserts), "avg-allocs/op")
b.ReportMetric(roundFloat64(bytes/inserts), "avg-B/op")
})
}
func BenchmarkTableDelete(b *testing.B) {
forFamilyAndCount(b, func(b *testing.B, routes []slowPrefixEntry[int]) {
// Collect memstats for one round of insertions, so we can remove it
// from the total at the end and get only the deletion alloc count.
insertAllocs, insertBytes := getMemCost(func() {
var rt Table[int]
for _, route := range routes {
rt.Insert(route.pfx, route.val)
}
})
insertAllocs *= float64(b.N)
insertBytes *= float64(b.N)
var t runningTimer
allocs, bytes := getMemCost(func() {
for i := 0; i < b.N; i++ {
var rt Table[int]
for _, route := range routes {
rt.Insert(route.pfx, route.val)
}
t.Start()
for _, route := range routes {
rt.Delete(route.pfx)
}
t.Stop()
}
})
inserts := float64(b.N) * float64(len(routes))
allocs -= insertAllocs
bytes -= insertBytes
elapsed := float64(t.Elapsed().Nanoseconds())
elapsedSec := t.Elapsed().Seconds()
b.ReportMetric(elapsed/inserts, "ns/op")
b.ReportMetric(inserts/elapsedSec, "routes/s")
b.ReportMetric(roundFloat64(allocs/inserts), "avg-allocs/op")
b.ReportMetric(roundFloat64(bytes/inserts), "avg-B/op")
})
}
var addrSink netip.Addr
func BenchmarkTableGet(b *testing.B) {
forFamilyAndCount(b, func(b *testing.B, routes []slowPrefixEntry[int]) {
genAddr := randomAddr4
if routes[0].pfx.Addr().Is6() {
genAddr = randomAddr6
}
var rt Table[int]
for _, route := range routes {
rt.Insert(route.pfx, route.val)
}
addrAllocs, addrBytes := getMemCost(func() {
// Have to run genAddr more than once, otherwise the reported
// cost is 16 bytes - presumably due to some amortized costs in
// the memory allocator? Either way, empirically 100 iterations
// reliably reports the correct cost.
for i := 0; i < 100; i++ {
_ = genAddr()
}
})
addrAllocs /= 100
addrBytes /= 100
var t runningTimer
allocs, bytes := getMemCost(func() {
for i := 0; i < b.N; i++ {
addr := genAddr()
t.Start()
writeSink = rt.Get(addr)
t.Stop()
}
})
b.ReportAllocs() // Enables the output, but we report manually below
allocs -= (addrAllocs * float64(b.N))
bytes -= (addrBytes * float64(b.N))
lookups := float64(b.N)
elapsed := float64(t.Elapsed().Nanoseconds())
elapsedSec := float64(t.Elapsed().Seconds())
b.ReportMetric(elapsed/lookups, "ns/op")
b.ReportMetric(lookups/elapsedSec, "addrs/s")
b.ReportMetric(allocs/lookups, "allocs/op")
b.ReportMetric(bytes/lookups, "B/op")
})
}
// getMemCost runs fn 100 times and returns the number of allocations and bytes
// allocated by each call to fn.
//
// Note that if your fn allocates very little memory (less than ~16 bytes), you
// should make fn run its workload ~100 times and divide the results of
// getMemCost yourself. Otherwise, the byte count you get will be rounded up due
// to the memory allocator's bucketing granularity.
func getMemCost(fn func()) (allocs, bytes float64) {
var start, end runtime.MemStats
runtime.ReadMemStats(&start)
fn()
runtime.ReadMemStats(&end)
return float64(end.Mallocs - start.Mallocs), float64(end.TotalAlloc - start.TotalAlloc)
}
// runningTimer is a timer that keeps track of the cumulative time it's spent
// running since creation. A newly created runningTimer is stopped.
//
// This timer exists because some of our benchmarks have to interleave costly
// ancillary logic in each benchmark iteration, rather than being able to
// front-load all the work before a single b.ResetTimer().
//
// As it turns out, b.StartTimer() and b.StopTimer() are expensive function
// calls, because they do costly memory allocation accounting on every call.
// Starting and stopping the benchmark timer in every b.N loop iteration slows
// the benchmarks down by orders of magnitude.
//
// So, rather than rely on testing.B's timing facility, we use this very
// lightweight timer combined with getMemCost to do our own accounting more
// efficiently.
type runningTimer struct {
cumulative time.Duration
start time.Time
}
func (t *runningTimer) Start() {
t.Stop()
t.start = time.Now()
}
func (t *runningTimer) Stop() {
if t.start.IsZero() {
return
}
t.cumulative += time.Since(t.start)
t.start = time.Time{}
}
func (t *runningTimer) Elapsed() time.Duration {
return t.cumulative
}
// slowPrefixTable is a routing table implemented as a set of prefixes that are
// explicitly scanned in full for every route lookup. It is very slow, but also
// reasonably easy to verify by inspection, and so a good correctness reference
// for Table.
type slowPrefixTable[T any] struct {
prefixes []slowPrefixEntry[T]
}
type slowPrefixEntry[T any] struct {
pfx netip.Prefix
val *T
}
func (t *slowPrefixTable[T]) delete(pfx netip.Prefix) {
ret := make([]slowPrefixEntry[T], 0, len(t.prefixes))
for _, ent := range t.prefixes {
if ent.pfx == pfx {
continue
}
ret = append(ret, ent)
}
t.prefixes = ret
}
func (t *slowPrefixTable[T]) insert(pfx netip.Prefix, val *T) {
for _, ent := range t.prefixes {
if ent.pfx == pfx {
ent.val = val
return
}
}
t.prefixes = append(t.prefixes, slowPrefixEntry[T]{pfx, val})
}
func (t *slowPrefixTable[T]) get(addr netip.Addr) *T {
var (
ret *T
bestLen = -1
)
for _, pfx := range t.prefixes {
if pfx.pfx.Contains(addr) && pfx.pfx.Bits() > bestLen {
ret = pfx.val
bestLen = pfx.pfx.Bits()
}
}
return ret
}
// randomPrefixes returns n randomly generated prefixes and associated values,
// distributed equally between IPv4 and IPv6.
func randomPrefixes(n int) []slowPrefixEntry[int] {
pfxs := randomPrefixes4(n / 2)
pfxs = append(pfxs, randomPrefixes6(n-len(pfxs))...)
return pfxs
}
// randomPrefixes4 returns n randomly generated IPv4 prefixes and associated values.
func randomPrefixes4(n int) []slowPrefixEntry[int] {
pfxs := map[netip.Prefix]bool{}
for len(pfxs) < n {
len := rand.Intn(33)
pfx, err := randomAddr4().Prefix(len)
if err != nil {
panic(err)
}
pfxs[pfx] = true
}
ret := make([]slowPrefixEntry[int], 0, len(pfxs))
for pfx := range pfxs {
ret = append(ret, slowPrefixEntry[int]{pfx, ptr.To(rand.Int())})
}
return ret
}
// randomPrefixes6 returns n randomly generated IPv4 prefixes and associated values.
func randomPrefixes6(n int) []slowPrefixEntry[int] {
pfxs := map[netip.Prefix]bool{}
for len(pfxs) < n {
len := rand.Intn(129)
pfx, err := randomAddr6().Prefix(len)
if err != nil {
panic(err)
}
pfxs[pfx] = true
}
ret := make([]slowPrefixEntry[int], 0, len(pfxs))
for pfx := range pfxs {
ret = append(ret, slowPrefixEntry[int]{pfx, ptr.To(rand.Int())})
}
return ret
}
// randomAddr returns a randomly generated IP address.
func randomAddr() netip.Addr {
if rand.Intn(2) == 1 {
return randomAddr6()
} else {
return randomAddr4()
}
}
// randomAddr4 returns a randomly generated IPv4 address.
func randomAddr4() netip.Addr {
var b [4]byte
if _, err := crand.Read(b[:]); err != nil {
panic(err)
}
return netip.AddrFrom4(b)
}
// randomAddr6 returns a randomly generated IPv6 address.
func randomAddr6() netip.Addr {
var b [16]byte
if _, err := crand.Read(b[:]); err != nil {
panic(err)
}
return netip.AddrFrom16(b)
}
// printIntPtr returns *v as a string, or the literal "<nil>" if v is nil.
func printIntPtr(v *int) string {
if v == nil {
return "<nil>"
}
return fmt.Sprint(*v)
}
// roundFloat64 rounds f to 2 decimal places, for display.
//
// It round-trips through a float->string->float conversion, so should not be
// used in a performance critical setting.
func roundFloat64(f float64) float64 {
s := fmt.Sprintf("%.2f", f)
ret, err := strconv.ParseFloat(s, 64)
if err != nil {
panic(err)
}
return ret
}