feat: wider fuzz tests, stronger options. #9

Merged
mvhutz merged 5 commits from fix/infinite-put-glitch into main 2026-03-25 01:26:57 +00:00
2 changed files with 36 additions and 6 deletions
Showing only changes of commit d07f76207b - Show all commits

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@@ -1,7 +1,10 @@
package cuckoo_test package cuckoo_test
import ( import (
"fmt"
"maps" "maps"
"math"
"os"
"testing" "testing"
"github.com/stretchr/testify/assert" "github.com/stretchr/testify/assert"
@@ -25,8 +28,10 @@ type fuzzStep struct {
} }
type fuzzScenario struct { type fuzzScenario struct {
seedA, seedB uint32 seedA, seedB uint32
steps []fuzzStep capacity, growthFactor uint8
load float64
steps []fuzzStep
} }
func FuzzInsertLookup(f *testing.F) { func FuzzInsertLookup(f *testing.F) {
@@ -44,10 +49,21 @@ func FuzzInsertLookup(f *testing.F) {
return return
} }
seedA, seedB := scenario.seedA, scenario.seedB
growthFactor := max(1, int(scenario.growthFactor))
capacity := int(scenario.capacity)
minimumLoad := math.Abs(math.Mod(scenario.load, 1.0))
fmt.Fprintf(os.Stderr, "seedA=%d seedB=%d capacity=%d growthFactor=%d minimumLoad=%f\n",
seedA, seedB, capacity, growthFactor, minimumLoad)
actual := cuckoo.NewCustomTable[uint32, uint32]( actual := cuckoo.NewCustomTable[uint32, uint32](
offsetHash(scenario.seedA), offsetHash(seedA),
offsetHash(scenario.seedB), offsetHash(seedB),
func(a, b uint32) bool { return a == b }, func(a, b uint32) bool { return a == b },
cuckoo.Capacity(capacity),
cuckoo.GrowthFactor(growthFactor),
cuckoo.MinimumLoad(minimumLoad),
) )
expected := map[uint32]uint32{} expected := map[uint32]uint32{}

View File

@@ -1,5 +1,7 @@
package cuckoo package cuckoo
import "fmt"
// DefaultCapacity is the initial capacity of a [Table]. It is inspired from // DefaultCapacity is the initial capacity of a [Table]. It is inspired from
// Java's [HashMap] implementation, which also uses 16. // Java's [HashMap] implementation, which also uses 16.
// //
@@ -27,19 +29,31 @@ type settings struct {
type Option func(*settings) type Option func(*settings)
// Capacity modifies the starting capacity of each bucket of the [Table]. The // Capacity modifies the starting capacity of each bucket of the [Table]. The
// value must be greater than 0. // value must be non-negative.
func Capacity(value int) Option { func Capacity(value int) Option {
if value < 0 {
panic(fmt.Sprintf("go-cuckoo: Capacity must be non-negative, got %d", value))
}
return func(s *settings) { s.bucketSize = uint64(value) } return func(s *settings) { s.bucketSize = uint64(value) }
} }
// MinimumLoad modifies the [DefaultMinimumLoad] of the [Table]. The value must // MinimumLoad modifies the [DefaultMinimumLoad] of the [Table]. The value must
// be between 0.00 and 1.00. // be between 0.00 and 1.00.
func MinimumLoad(value float64) Option { func MinimumLoad(value float64) Option {
if value < 0.00 || value > 1.00 {
panic(fmt.Sprintf("go-cuckoo: MinimumLoad must be between 0.00 and 1.00, got %f", value))
}
return func(s *settings) { s.minLoadFactor = value } return func(s *settings) { s.minLoadFactor = value }
} }
// GrowthFactor controls how much the capacity of the [Table] multiplies when // GrowthFactor controls how much the capacity of the [Table] multiplies when
// it must resize. The value must be greater than 1. // it must resize. The value must be greater than 0.
func GrowthFactor(value int) Option { func GrowthFactor(value int) Option {
if value <= 0 {
panic(fmt.Sprintf("go-cuckoo: GrowthFactor must be greater than 0, got %d", value))
}
return func(s *settings) { s.growthFactor = uint64(value) } return func(s *settings) { s.growthFactor = uint64(value) }
} }