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// Copyright (c) Tailscale Inc & contributors
// SPDX-License-Identifier: BSD-3-Clause
package pool
import (
"slices"
"testing"
)
func TestPool(t *testing.T) {
p := Pool[int]{}
if got, want := p.Len(), 0; got != want {
t.Errorf("got initial length %v; want %v", got, want)
}
h1 := p.Add(101)
h2 := p.Add(102)
h3 := p.Add(103)
h4 := p.Add(104)
if got, want := p.Len(), 4; got != want {
t.Errorf("got length %v; want %v", got, want)
}
tests := []struct {
h Handle[int]
want int
}{
{h1, 101},
{h2, 102},
{h3, 103},
{h4, 104},
}
for i, test := range tests {
got, ok := p.Peek(test.h)
if !ok {
t.Errorf("test[%d]: did not find item", i)
continue
}
if got != test.want {
t.Errorf("test[%d]: got %v; want %v", i, got, test.want)
}
}
if deleted := p.Delete(h2); !deleted {
t.Errorf("h2 not deleted")
}
if deleted := p.Delete(h2); deleted {
t.Errorf("h2 should not be deleted twice")
}
if got, want := p.Len(), 3; got != want {
t.Errorf("got length %v; want %v", got, want)
}
if _, ok := p.Peek(h2); ok {
t.Errorf("h2 still in pool")
}
// Remove an item by handle
got, ok := p.Take(h4)
if !ok {
t.Errorf("h4 not found")
}
if got != 104 {
t.Errorf("got %v; want 104", got)
}
// Take doesn't work on previously-taken or deleted items.
if _, ok := p.Take(h4); ok {
t.Errorf("h4 should not be taken twice")
}
if _, ok := p.Take(h2); ok {
t.Errorf("h2 should not be taken after delete")
}
// Remove all items and return them
items := p.AppendTakeAll(nil)
want := []int{101, 103}
if !slices.Equal(items, want) {
t.Errorf("got items %v; want %v", items, want)
}
if got := p.Len(); got != 0 {
t.Errorf("got length %v; want 0", got)
}
// Insert and then clear should result in no items.
p.Add(105)
p.Clear()
if got := p.Len(); got != 0 {
t.Errorf("got length %v; want 0", got)
}
}
func TestTakeRandom(t *testing.T) {
p := Pool[int]{}
for i := range 10 {
p.Add(i + 100)
}
seen := make(map[int]bool)
for range 10 {
item, ok := p.TakeRandom()
if !ok {
t.Errorf("unexpected empty pool")
break
}
if seen[item] {
t.Errorf("got duplicate item %v", item)
}
seen[item] = true
}
// Verify that the pool is empty
if _, ok := p.TakeRandom(); ok {
t.Errorf("expected empty pool")
}
for i := range 10 {
want := 100 + i
if !seen[want] {
t.Errorf("item %v not seen", want)
}
}
if t.Failed() {
t.Logf("seen: %+v", seen)
}
}
func BenchmarkPool_AddDelete(b *testing.B) {
b.Run("impl=Pool", func(b *testing.B) {
p := Pool[int]{}
// Warm up/force an initial allocation
h := p.Add(0)
p.Delete(h)
b.ResetTimer()
for i := 0; i < b.N; i++ {
h := p.Add(i)
p.Delete(h)
}
})
b.Run("impl=map", func(b *testing.B) {
p := make(map[int]bool)
// Force initial allocation
p[0] = true
delete(p, 0)
b.ResetTimer()
for i := 0; i < b.N; i++ {
p[i] = true
delete(p, i)
}
})
}
func BenchmarkPool_TakeRandom(b *testing.B) {
b.Run("impl=Pool", func(b *testing.B) {
p := Pool[int]{}
// Insert the number of items we'll be taking, then reset the timer.
for i := 0; i < b.N; i++ {
p.Add(i)
}
b.ResetTimer()
// Now benchmark taking all the items.
for i := 0; i < b.N; i++ {
p.TakeRandom()
}
if p.Len() != 0 {
b.Errorf("pool not empty")
}
})
b.Run("impl=map", func(b *testing.B) {
p := make(map[int]bool)
// Insert the number of items we'll be taking, then reset the timer.
for i := 0; i < b.N; i++ {
p[i] = true
}
b.ResetTimer()
// Now benchmark taking all the items.
for i := 0; i < b.N; i++ {
// Taking a random item is simulated by a single map iteration.
for k := range p {
delete(p, k) // "take" the item by removing it
break
}
}
if len(p) != 0 {
b.Errorf("map not empty")
}
})
}
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