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v0.3.0
| Author | SHA1 | Date | |
|---|---|---|---|
| 29ba6bfd4d | |||
| 7cc1657403 | |||
| 42c5b5f8f4 | |||
| 867a1d49df | |||
| 322d71f0be |
@@ -114,6 +114,9 @@ linters:
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# Reports uses of functions with replacement inside the testing package.
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# Reports uses of functions with replacement inside the testing package.
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- usetesting
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- usetesting
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# Reports mixed receiver types in structs/interfaces.
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- recvcheck
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settings:
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settings:
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revive:
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revive:
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rules:
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rules:
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103
bucket.go
103
bucket.go
@@ -1,103 +0,0 @@
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package cuckoo
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type entry[K, V any] struct {
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key K
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value V
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}
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type slot[K, V any] struct {
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entry[K, V]
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occupied bool
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}
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type bucket[K, V any] struct {
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hash Hash[K]
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slots []slot[K, V]
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capacity, size uint64
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compare EqualFunc[K]
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}
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// location determines where in the bucket a certain key would be placed. If the
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// capacity is 0, this will panic.
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func (b bucket[K, V]) location(key K) uint64 {
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return b.hash(key) % b.capacity
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}
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func (b bucket[K, V]) get(key K) (value V, found bool) {
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if b.capacity == 0 {
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return
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}
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slot := b.slots[b.location(key)]
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return slot.value, slot.occupied && b.compare(slot.key, key)
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}
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func (b *bucket[K, V]) drop(key K) (occupied bool) {
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if b.capacity == 0 {
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return
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}
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slot := &b.slots[b.location(key)]
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if slot.occupied && b.compare(slot.key, key) {
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slot.occupied = false
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b.size--
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return true
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}
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return false
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}
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func (b *bucket[K, V]) resize(capacity uint64) {
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b.slots = make([]slot[K, V], capacity)
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b.capacity = capacity
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b.size = 0
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}
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func (b bucket[K, V]) update(key K, value V) (updated bool) {
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if b.capacity == 0 {
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return
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}
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slot := &b.slots[b.location(key)]
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if slot.occupied && b.compare(slot.key, key) {
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slot.value = value
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return true
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}
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return false
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}
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func (b *bucket[K, V]) evict(insertion entry[K, V]) (evicted entry[K, V], eviction bool) {
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if b.capacity == 0 {
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return insertion, true
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}
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slot := &b.slots[b.location(insertion.key)]
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if !slot.occupied {
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slot.entry = insertion
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slot.occupied = true
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b.size++
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return
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}
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if b.compare(slot.key, insertion.key) {
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slot.value = insertion.value
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return
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}
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insertion, slot.entry = slot.entry, insertion
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return insertion, true
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}
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func newBucket[K, V any](capacity uint64, hash Hash[K], compare EqualFunc[K]) bucket[K, V] {
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return bucket[K, V]{
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hash: hash,
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capacity: capacity,
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compare: compare,
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size: 0,
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slots: make([]slot[K, V], capacity),
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}
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}
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@@ -2,7 +2,7 @@ package cuckoo
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// An EqualFunc determines whethers two keys are 'equal'. Keys that are 'equal'
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// An EqualFunc determines whethers two keys are 'equal'. Keys that are 'equal'
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// are teated as the same by the [Table]. A good EqualFunc is pure,
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// are teated as the same by the [Table]. A good EqualFunc is pure,
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// deterministic, and fast. By default, [NewTable] uses [DefaultEqualFunc].
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// deterministic, and fast. By default, [New] uses [DefaultEqualFunc].
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//
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//
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// This function MUST NOT return true if the [Hash] digest of two keys
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// This function MUST NOT return true if the [Hash] digest of two keys
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// are different: the [Table] will not work.
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// are different: the [Table] will not work.
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@@ -28,7 +28,7 @@ func ExampleEqualFunc_badEqualFunc() {
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// Two users with the same ID are equal.
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// Two users with the same ID are equal.
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isEqual := func(a, b User) bool { return a.ID == b.ID }
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isEqual := func(a, b User) bool { return a.ID == b.ID }
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userbase := cuckoo.NewCustomTable[User, bool](makeHash(1), makeHash(2), isEqual)
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userbase := cuckoo.NewCustom[User, bool](makeHash(1), makeHash(2), isEqual)
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(userbase.Put(User{"1", "Robert Doe"}, true))
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(userbase.Put(User{"1", "Robert Doe"}, true))
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@@ -56,7 +56,7 @@ func FuzzInsertLookup(f *testing.F) {
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fmt.Fprintf(os.Stderr, "seedA=%d seedB=%d capacity=%d growthFactor=%d\n",
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fmt.Fprintf(os.Stderr, "seedA=%d seedB=%d capacity=%d growthFactor=%d\n",
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seedA, seedB, capacity, growthFactor)
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seedA, seedB, capacity, growthFactor)
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actual := cuckoo.NewCustomTable[uint32, uint32](
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actual := cuckoo.NewCustom[uint32, uint32](
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offsetHash(seedA),
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offsetHash(seedA),
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offsetHash(seedB),
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offsetHash(seedB),
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func(a, b uint32) bool { return a == b },
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func(a, b uint32) bool { return a == b },
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@@ -73,16 +73,16 @@ func FuzzInsertLookup(f *testing.F) {
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delete(expected, step.key)
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delete(expected, step.key)
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_, err = actual.Get(step.key)
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_, ok := actual.Get(step.key)
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assert.Error(err)
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assert.False(ok)
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} else {
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} else {
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err := actual.Put(step.key, step.value)
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err := actual.Put(step.key, step.value)
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assert.NoError(err)
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assert.NoError(err)
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expected[step.key] = step.value
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expected[step.key] = step.value
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found, err := actual.Get(step.key)
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found, ok := actual.Get(step.key)
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assert.NoError(err)
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assert.True(ok)
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assert.Equal(step.value, found)
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assert.Equal(step.value, found)
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}
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}
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@@ -11,7 +11,7 @@ func TestMaxEvictions(t *testing.T) {
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assert := assert.New(t)
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assert := assert.New(t)
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for i := 16; i < 116; i++ {
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for i := 16; i < 116; i++ {
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table := NewTable[int, bool](Capacity(i / 2))
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table := New[int, bool](Capacity(i / 2))
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expectedEvictions := 3 * math.Floor(math.Log2(float64(i)))
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expectedEvictions := 3 * math.Floor(math.Log2(float64(i)))
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assert.Equal(table.maxEvictions(), int(expectedEvictions))
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assert.Equal(table.maxEvictions(), int(expectedEvictions))
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@@ -20,7 +20,7 @@ func TestMaxEvictions(t *testing.T) {
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func TestLoad(t *testing.T) {
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func TestLoad(t *testing.T) {
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assert := assert.New(t)
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assert := assert.New(t)
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table := NewTable[int, bool](Capacity(8))
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table := New[int, bool](Capacity(8))
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for i := range 16 {
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for i := range 16 {
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err := table.Put(i, true)
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err := table.Put(i, true)
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@@ -14,7 +14,7 @@ import (
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func TestNewTable(t *testing.T) {
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func TestNewTable(t *testing.T) {
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assert := assert.New(t)
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assert := assert.New(t)
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table := cuckoo.NewTable[int, bool]()
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table := cuckoo.New[int, bool]()
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assert.NotNil(table)
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assert.NotNil(table)
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assert.Zero(table.Size())
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assert.Zero(table.Size())
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@@ -23,7 +23,7 @@ func TestNewTable(t *testing.T) {
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func TestAddItem(t *testing.T) {
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func TestAddItem(t *testing.T) {
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assert := assert.New(t)
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assert := assert.New(t)
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key, value := 0, true
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key, value := 0, true
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table := cuckoo.NewTable[int, bool]()
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table := cuckoo.New[int, bool]()
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err := table.Put(key, value)
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err := table.Put(key, value)
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@@ -35,7 +35,7 @@ func TestAddItem(t *testing.T) {
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func TestPutOverwrite(t *testing.T) {
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func TestPutOverwrite(t *testing.T) {
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assert := assert.New(t)
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assert := assert.New(t)
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key, value, newValue := 0, 1, 2
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key, value, newValue := 0, 1, 2
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table := cuckoo.NewTable[int, int]()
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table := cuckoo.New[int, int]()
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(table.Put(key, value))
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(table.Put(key, value))
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err := table.Put(key, newValue)
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err := table.Put(key, newValue)
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@@ -50,7 +50,7 @@ func TestPutOverwrite(t *testing.T) {
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func TestSameHash(t *testing.T) {
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func TestSameHash(t *testing.T) {
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assert := assert.New(t)
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assert := assert.New(t)
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hash := func(int) uint64 { return 0 }
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hash := func(int) uint64 { return 0 }
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table := cuckoo.NewCustomTable[int, bool](hash, hash, cuckoo.DefaultEqualFunc[int])
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table := cuckoo.NewCustom[int, bool](hash, hash, cuckoo.DefaultEqualFunc[int])
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errA := table.Put(0, true)
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errA := table.Put(0, true)
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errB := table.Put(1, true)
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errB := table.Put(1, true)
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@@ -63,14 +63,14 @@ func TestSameHash(t *testing.T) {
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func TestStartingCapacity(t *testing.T) {
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func TestStartingCapacity(t *testing.T) {
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assert := assert.New(t)
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assert := assert.New(t)
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table := cuckoo.NewTable[int, bool](cuckoo.Capacity(64))
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table := cuckoo.New[int, bool](cuckoo.Capacity(64))
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|
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assert.Equal(uint64(128), table.TotalCapacity())
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assert.Equal(uint64(128), table.TotalCapacity())
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}
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}
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func TestResizeCapacity(t *testing.T) {
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func TestResizeCapacity(t *testing.T) {
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assert := assert.New(t)
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assert := assert.New(t)
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table := cuckoo.NewTable[int, bool](
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table := cuckoo.New[int, bool](
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cuckoo.Capacity(8),
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cuckoo.Capacity(8),
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cuckoo.GrowthFactor(2),
|
cuckoo.GrowthFactor(2),
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)
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)
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@@ -85,7 +85,7 @@ func TestResizeCapacity(t *testing.T) {
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func TestPutMany(t *testing.T) {
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func TestPutMany(t *testing.T) {
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assert := assert.New(t)
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assert := assert.New(t)
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expected, actual := map[int]bool{}, cuckoo.NewTable[int, bool]()
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expected, actual := map[int]bool{}, cuckoo.New[int, bool]()
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|
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for i := range 1_000 {
|
for i := range 1_000 {
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expected[i] = true
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expected[i] = true
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@@ -100,7 +100,7 @@ func TestPutMany(t *testing.T) {
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|
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func TestGetMany(t *testing.T) {
|
func TestGetMany(t *testing.T) {
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assert := assert.New(t)
|
assert := assert.New(t)
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table := cuckoo.NewTable[int, bool]()
|
table := cuckoo.New[int, bool]()
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|
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for i := range 1_000 {
|
for i := range 1_000 {
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err := table.Put(i, true)
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err := table.Put(i, true)
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@@ -108,12 +108,12 @@ func TestGetMany(t *testing.T) {
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}
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}
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|
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for i := range 2_000 {
|
for i := range 2_000 {
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value, err := table.Get(i)
|
value, ok := table.Get(i)
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if i < 1_000 {
|
if i < 1_000 {
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assert.NoError(err)
|
assert.True(ok)
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assert.Equal(value, true)
|
assert.Equal(value, true)
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} else {
|
} else {
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assert.Error(err)
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assert.False(ok)
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}
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}
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}
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}
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}
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}
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@@ -121,7 +121,7 @@ func TestGetMany(t *testing.T) {
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func TestDropExistingItem(t *testing.T) {
|
func TestDropExistingItem(t *testing.T) {
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assert := assert.New(t)
|
assert := assert.New(t)
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key, value := 0, true
|
key, value := 0, true
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table := cuckoo.NewTable[int, bool]()
|
table := cuckoo.New[int, bool]()
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(table.Put(key, value))
|
(table.Put(key, value))
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|
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err := table.Drop(key)
|
err := table.Drop(key)
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@@ -134,7 +134,7 @@ func TestDropExistingItem(t *testing.T) {
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func TestDropNoItem(t *testing.T) {
|
func TestDropNoItem(t *testing.T) {
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assert := assert.New(t)
|
assert := assert.New(t)
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key := 0
|
key := 0
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table := cuckoo.NewTable[int, bool]()
|
table := cuckoo.New[int, bool]()
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|
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err := table.Drop(key)
|
err := table.Drop(key)
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|
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@@ -146,7 +146,7 @@ func TestDropNoItem(t *testing.T) {
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func TestDropItemCapacity(t *testing.T) {
|
func TestDropItemCapacity(t *testing.T) {
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assert := assert.New(t)
|
assert := assert.New(t)
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key := 0
|
key := 0
|
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table := cuckoo.NewTable[int, bool](
|
table := cuckoo.New[int, bool](
|
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cuckoo.Capacity(64),
|
cuckoo.Capacity(64),
|
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cuckoo.GrowthFactor(2),
|
cuckoo.GrowthFactor(2),
|
||||||
)
|
)
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@@ -164,7 +164,7 @@ func TestDropItemCapacity(t *testing.T) {
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func TestPutNoCapacity(t *testing.T) {
|
func TestPutNoCapacity(t *testing.T) {
|
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assert := assert.New(t)
|
assert := assert.New(t)
|
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key, value := 0, true
|
key, value := 0, true
|
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table := cuckoo.NewTable[int, bool](
|
table := cuckoo.New[int, bool](
|
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cuckoo.Capacity(0),
|
cuckoo.Capacity(0),
|
||||||
)
|
)
|
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|
|
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@@ -177,7 +177,7 @@ func TestPutNoCapacity(t *testing.T) {
|
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|
|
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func TestBadHashCapacity(t *testing.T) {
|
func TestBadHashCapacity(t *testing.T) {
|
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assert := assert.New(t)
|
assert := assert.New(t)
|
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table := cuckoo.NewCustomTable[int, bool](
|
table := cuckoo.NewCustom[int, bool](
|
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func(int) uint64 { return 0 },
|
func(int) uint64 { return 0 },
|
||||||
func(int) uint64 { return 0 },
|
func(int) uint64 { return 0 },
|
||||||
func(a, b int) bool { return a == b },
|
func(a, b int) bool { return a == b },
|
||||||
@@ -197,7 +197,7 @@ func TestBadHashCapacity(t *testing.T) {
|
|||||||
|
|
||||||
func TestDropResizeCapacity(t *testing.T) {
|
func TestDropResizeCapacity(t *testing.T) {
|
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assert := assert.New(t)
|
assert := assert.New(t)
|
||||||
table := cuckoo.NewTable[int, bool](
|
table := cuckoo.New[int, bool](
|
||||||
cuckoo.Capacity(10),
|
cuckoo.Capacity(10),
|
||||||
)
|
)
|
||||||
|
|
||||||
@@ -217,9 +217,7 @@ func TestNewTableBy(t *testing.T) {
|
|||||||
}
|
}
|
||||||
|
|
||||||
assert := assert.New(t)
|
assert := assert.New(t)
|
||||||
table := cuckoo.NewTableBy[User, bool](
|
table := cuckoo.NewBy[User, bool](func(u User) string { return u.id })
|
||||||
func(u User) string { return u.id },
|
|
||||||
)
|
|
||||||
|
|
||||||
err := table.Put(User{nil, "1", "Robert"}, true)
|
err := table.Put(User{nil, "1", "Robert"}, true)
|
||||||
|
|
||||||
|
|||||||
4
doc.go
4
doc.go
@@ -1,8 +1,8 @@
|
|||||||
// Package cuckoo provides a hash table that uses cuckoo hashing to achieve
|
// Package cuckoo provides a hash table that uses cuckoo hashing to achieve
|
||||||
// a worst-case O(1) lookup time.
|
// a worst-case O(1) lookup time.
|
||||||
//
|
//
|
||||||
// While a [NewTable] only supports comparable keys by default, you can create
|
// While a [New] only supports comparable keys by default, you can create
|
||||||
// a table with any key type using [NewCustomTable]. Custom [Hash] functions and
|
// a table with any key type using [NewCustom]. Custom [Hash] functions and
|
||||||
// key comparison are also supported.
|
// key comparison are also supported.
|
||||||
//
|
//
|
||||||
// See more: https://en.wikipedia.org/wiki/Cuckoo_hashing
|
// See more: https://en.wikipedia.org/wiki/Cuckoo_hashing
|
||||||
|
|||||||
@@ -8,25 +8,25 @@ import (
|
|||||||
)
|
)
|
||||||
|
|
||||||
func Example_basic() {
|
func Example_basic() {
|
||||||
table := cuckoo.NewTable[int, string]()
|
table := cuckoo.New[int, string]()
|
||||||
|
|
||||||
if err := table.Put(1, "Hello, World!"); err != nil {
|
if err := table.Put(1, "Hello, World!"); err != nil {
|
||||||
fmt.Println("Put error:", err)
|
fmt.Println("Put error:", err)
|
||||||
}
|
}
|
||||||
|
|
||||||
if item, err := table.Get(1); err != nil {
|
if item, ok := table.Get(1); !ok {
|
||||||
fmt.Println("Error:", err)
|
fmt.Println("Not Found 1!")
|
||||||
} else {
|
} else {
|
||||||
fmt.Println("Found 1:", item)
|
fmt.Println("Found 1:", item)
|
||||||
}
|
}
|
||||||
|
|
||||||
if item, err := table.Get(0); err != nil {
|
if item, ok := table.Get(0); !ok {
|
||||||
fmt.Println("Error:", err)
|
fmt.Println("Not Found 0!")
|
||||||
} else {
|
} else {
|
||||||
fmt.Println("Found 0:", item)
|
fmt.Println("Found 0:", item)
|
||||||
}
|
}
|
||||||
|
|
||||||
// Output:
|
// Output:
|
||||||
// Found 1: Hello, World!
|
// Found 1: Hello, World!
|
||||||
// Error: key '0' not found
|
// Not Found 0!
|
||||||
}
|
}
|
||||||
|
|||||||
@@ -9,7 +9,7 @@ import "fmt"
|
|||||||
const DefaultCapacity uint64 = 16
|
const DefaultCapacity uint64 = 16
|
||||||
|
|
||||||
// DefaultGrowthFactor is the standard resize multiplier for a [Table]. Most
|
// DefaultGrowthFactor is the standard resize multiplier for a [Table]. Most
|
||||||
// hash table implementations use 2.
|
// implementations use 2.
|
||||||
const DefaultGrowthFactor uint64 = 2
|
const DefaultGrowthFactor uint64 = 2
|
||||||
|
|
||||||
// defaultMinimumLoad is the default lowest acceptable occupancy of a [Table].
|
// defaultMinimumLoad is the default lowest acceptable occupancy of a [Table].
|
||||||
@@ -26,10 +26,10 @@ type settings struct {
|
|||||||
}
|
}
|
||||||
|
|
||||||
// An Option modifies the settings of a [Table]. It is used in its constructors
|
// An Option modifies the settings of a [Table]. It is used in its constructors
|
||||||
// like [NewTable], for example.
|
// like [New], for example.
|
||||||
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 subtable of the [Table]. The
|
||||||
// value must be non-negative.
|
// value must be non-negative.
|
||||||
func Capacity(value int) Option {
|
func Capacity(value int) Option {
|
||||||
if value < 0 {
|
if value < 0 {
|
||||||
|
|||||||
103
subtable.go
Normal file
103
subtable.go
Normal file
@@ -0,0 +1,103 @@
|
|||||||
|
package cuckoo
|
||||||
|
|
||||||
|
type entry[K, V any] struct {
|
||||||
|
key K
|
||||||
|
value V
|
||||||
|
}
|
||||||
|
|
||||||
|
type slot[K, V any] struct {
|
||||||
|
entry[K, V]
|
||||||
|
occupied bool
|
||||||
|
}
|
||||||
|
|
||||||
|
type subtable[K, V any] struct {
|
||||||
|
hash Hash[K]
|
||||||
|
slots []slot[K, V]
|
||||||
|
capacity, size uint64
|
||||||
|
compare EqualFunc[K]
|
||||||
|
}
|
||||||
|
|
||||||
|
// location determines where in the subtable a certain key would be placed. If
|
||||||
|
// the capacity is 0, this will panic.
|
||||||
|
func (t *subtable[K, V]) location(key K) uint64 {
|
||||||
|
return t.hash(key) % t.capacity
|
||||||
|
}
|
||||||
|
|
||||||
|
func (t *subtable[K, V]) get(key K) (value V, found bool) {
|
||||||
|
if t.capacity == 0 {
|
||||||
|
return
|
||||||
|
}
|
||||||
|
|
||||||
|
slot := t.slots[t.location(key)]
|
||||||
|
return slot.value, slot.occupied && t.compare(slot.key, key)
|
||||||
|
}
|
||||||
|
|
||||||
|
func (t *subtable[K, V]) drop(key K) (occupied bool) {
|
||||||
|
if t.capacity == 0 {
|
||||||
|
return
|
||||||
|
}
|
||||||
|
|
||||||
|
slot := &t.slots[t.location(key)]
|
||||||
|
|
||||||
|
if slot.occupied && t.compare(slot.key, key) {
|
||||||
|
slot.occupied = false
|
||||||
|
t.size--
|
||||||
|
return true
|
||||||
|
}
|
||||||
|
|
||||||
|
return false
|
||||||
|
}
|
||||||
|
|
||||||
|
func (t *subtable[K, V]) resize(capacity uint64) {
|
||||||
|
t.slots = make([]slot[K, V], capacity)
|
||||||
|
t.capacity = capacity
|
||||||
|
t.size = 0
|
||||||
|
}
|
||||||
|
|
||||||
|
func (t *subtable[K, V]) update(key K, value V) (updated bool) {
|
||||||
|
if t.capacity == 0 {
|
||||||
|
return
|
||||||
|
}
|
||||||
|
|
||||||
|
slot := &t.slots[t.location(key)]
|
||||||
|
|
||||||
|
if slot.occupied && t.compare(slot.key, key) {
|
||||||
|
slot.value = value
|
||||||
|
return true
|
||||||
|
}
|
||||||
|
|
||||||
|
return false
|
||||||
|
}
|
||||||
|
|
||||||
|
func (t *subtable[K, V]) evict(insertion entry[K, V]) (evicted entry[K, V], eviction bool) {
|
||||||
|
if t.capacity == 0 {
|
||||||
|
return insertion, true
|
||||||
|
}
|
||||||
|
|
||||||
|
slot := &t.slots[t.location(insertion.key)]
|
||||||
|
|
||||||
|
if !slot.occupied {
|
||||||
|
slot.entry = insertion
|
||||||
|
slot.occupied = true
|
||||||
|
t.size++
|
||||||
|
return
|
||||||
|
}
|
||||||
|
|
||||||
|
if t.compare(slot.key, insertion.key) {
|
||||||
|
slot.value = insertion.value
|
||||||
|
return
|
||||||
|
}
|
||||||
|
|
||||||
|
insertion, slot.entry = slot.entry, insertion
|
||||||
|
return insertion, true
|
||||||
|
}
|
||||||
|
|
||||||
|
func newSubtable[K, V any](capacity uint64, hash Hash[K], compare EqualFunc[K]) subtable[K, V] {
|
||||||
|
return subtable[K, V]{
|
||||||
|
hash: hash,
|
||||||
|
capacity: capacity,
|
||||||
|
compare: compare,
|
||||||
|
size: 0,
|
||||||
|
slots: make([]slot[K, V], capacity),
|
||||||
|
}
|
||||||
|
}
|
||||||
122
table.go
122
table.go
@@ -1,41 +1,50 @@
|
|||||||
package cuckoo
|
package cuckoo
|
||||||
|
|
||||||
import (
|
import (
|
||||||
|
"errors"
|
||||||
"fmt"
|
"fmt"
|
||||||
"iter"
|
"iter"
|
||||||
"math/bits"
|
"math/bits"
|
||||||
"strings"
|
"strings"
|
||||||
)
|
)
|
||||||
|
|
||||||
// A Table is hash table that uses cuckoo hashing to resolve collision. Create
|
// ErrBadHash occurs when the hashes given to a [Table] cause too many key
|
||||||
// one with [NewTable]. Or if you want more granularity, use [NewTableBy] or
|
// collisions. Try rebuilding the table using:
|
||||||
// [NewCustomTable].
|
//
|
||||||
|
// 1. Different hash seeds. Equal seeds produce equal hash functions, which
|
||||||
|
// always cycle.
|
||||||
|
// 2. A different [Hash] algorithm.
|
||||||
|
var ErrBadHash = errors.New("bad hash")
|
||||||
|
|
||||||
|
// A Table which uses cuckoo hashing to resolve collision. Create
|
||||||
|
// one with [New]. Or if you want more granularity, use [NewBy] or
|
||||||
|
// [NewCustom].
|
||||||
type Table[K, V any] struct {
|
type Table[K, V any] struct {
|
||||||
bucketA, bucketB bucket[K, V]
|
tableA, tableB subtable[K, V]
|
||||||
growthFactor uint64
|
growthFactor uint64
|
||||||
minLoadFactor float64
|
minLoadFactor float64
|
||||||
}
|
}
|
||||||
|
|
||||||
// TotalCapacity returns the number of slots allocated for the [Table]. To get the
|
// TotalCapacity returns the number of slots allocated for the [Table]. To get the
|
||||||
// number of slots filled, look at [Table.Size].
|
// number of slots filled, look at [Table.Size].
|
||||||
func (t Table[K, V]) TotalCapacity() uint64 {
|
func (t *Table[K, V]) TotalCapacity() uint64 {
|
||||||
return t.bucketA.capacity + t.bucketB.capacity
|
return t.tableA.capacity + t.tableB.capacity
|
||||||
}
|
}
|
||||||
|
|
||||||
// Size returns how many slots are filled in the [Table].
|
// Size returns how many slots are filled in the [Table].
|
||||||
func (t Table[K, V]) Size() int {
|
func (t *Table[K, V]) Size() int {
|
||||||
return int(t.bucketA.size + t.bucketB.size)
|
return int(t.tableA.size + t.tableB.size)
|
||||||
}
|
}
|
||||||
|
|
||||||
func log2(n uint64) (m int) {
|
func log2(n uint64) (m int) {
|
||||||
return max(0, bits.Len64(n)-1)
|
return max(0, bits.Len64(n)-1)
|
||||||
}
|
}
|
||||||
|
|
||||||
func (t Table[K, V]) maxEvictions() int {
|
func (t *Table[K, V]) maxEvictions() int {
|
||||||
return 3 * log2(t.TotalCapacity())
|
return 3 * log2(t.TotalCapacity())
|
||||||
}
|
}
|
||||||
|
|
||||||
func (t Table[K, V]) load() float64 {
|
func (t *Table[K, V]) load() float64 {
|
||||||
// When there are no slots in the table, we still treat the load as 100%.
|
// When there are no slots in the table, we still treat the load as 100%.
|
||||||
// Every slot in the table is full.
|
// Every slot in the table is full.
|
||||||
if t.TotalCapacity() == 0 {
|
if t.TotalCapacity() == 0 {
|
||||||
@@ -45,7 +54,7 @@ func (t Table[K, V]) load() float64 {
|
|||||||
return float64(t.Size()) / float64(t.TotalCapacity())
|
return float64(t.Size()) / float64(t.TotalCapacity())
|
||||||
}
|
}
|
||||||
|
|
||||||
// resize clears all buckets, changes the sizes of them to a specific capacity,
|
// resize clears all tables, changes the sizes of them to a specific capacity,
|
||||||
// and fills them back up again. It is a helper function for [Table.grow] and
|
// and fills them back up again. It is a helper function for [Table.grow] and
|
||||||
// [Table.shrink]; use them instead.
|
// [Table.shrink]; use them instead.
|
||||||
func (t *Table[K, V]) resize(capacity uint64) error {
|
func (t *Table[K, V]) resize(capacity uint64) error {
|
||||||
@@ -54,8 +63,8 @@ func (t *Table[K, V]) resize(capacity uint64) error {
|
|||||||
entries = append(entries, entry[K, V]{k, v})
|
entries = append(entries, entry[K, V]{k, v})
|
||||||
}
|
}
|
||||||
|
|
||||||
t.bucketA.resize(capacity)
|
t.tableA.resize(capacity)
|
||||||
t.bucketB.resize(capacity)
|
t.tableB.resize(capacity)
|
||||||
|
|
||||||
for _, entry := range entries {
|
for _, entry := range entries {
|
||||||
if err := t.Put(entry.key, entry.value); err != nil {
|
if err := t.Put(entry.key, entry.value); err != nil {
|
||||||
@@ -66,7 +75,7 @@ func (t *Table[K, V]) resize(capacity uint64) error {
|
|||||||
return nil
|
return nil
|
||||||
}
|
}
|
||||||
|
|
||||||
// grow increases the table's capacity by the [Table.growthFactor]. If the
|
// grow increases the table's capacity by the growth factor. If the
|
||||||
// capacity is 0, it increases it to 1.
|
// capacity is 0, it increases it to 1.
|
||||||
func (t *Table[K, V]) grow() error {
|
func (t *Table[K, V]) grow() error {
|
||||||
var newCapacity uint64
|
var newCapacity uint64
|
||||||
@@ -74,61 +83,68 @@ func (t *Table[K, V]) grow() error {
|
|||||||
if t.TotalCapacity() == 0 {
|
if t.TotalCapacity() == 0 {
|
||||||
newCapacity = 1
|
newCapacity = 1
|
||||||
} else {
|
} else {
|
||||||
newCapacity = t.bucketA.capacity * t.growthFactor
|
newCapacity = t.tableA.capacity * t.growthFactor
|
||||||
}
|
}
|
||||||
|
|
||||||
return t.resize(newCapacity)
|
return t.resize(newCapacity)
|
||||||
}
|
}
|
||||||
|
|
||||||
// shrink reduces the table's capacity by the [Table.growthFactor]. It may
|
// shrink reduces the table's capacity by the growth factor. It may
|
||||||
// reduce it down to 0.
|
// reduce it down to 0.
|
||||||
func (t *Table[K, V]) shrink() error {
|
func (t *Table[K, V]) shrink() error {
|
||||||
return t.resize(t.bucketA.capacity / t.growthFactor)
|
return t.resize(t.tableA.capacity / t.growthFactor)
|
||||||
}
|
}
|
||||||
|
|
||||||
// Get fetches the value for a key in the [Table]. Returns an error if no value
|
// Get fetches the value for a key in the [Table]. Matches the comma-ok pattern
|
||||||
// is found.
|
// of a builtin map; see [Table.Find] for plain indexing.
|
||||||
func (t Table[K, V]) Get(key K) (value V, err error) {
|
func (t *Table[K, V]) Get(key K) (value V, ok bool) {
|
||||||
if item, ok := t.bucketA.get(key); ok {
|
if item, ok := t.tableA.get(key); ok {
|
||||||
return item, nil
|
return item, true
|
||||||
}
|
}
|
||||||
|
|
||||||
if item, ok := t.bucketB.get(key); ok {
|
if item, ok := t.tableB.get(key); ok {
|
||||||
return item, nil
|
return item, true
|
||||||
}
|
}
|
||||||
|
|
||||||
return value, fmt.Errorf("key '%v' not found", key)
|
return
|
||||||
|
}
|
||||||
|
|
||||||
|
// Find fetches the value of a key. Matches direct indexing of a builtin map;
|
||||||
|
// see [Table.Get] for a comma-ok pattern.
|
||||||
|
func (t *Table[K, V]) Find(key K) (value V) {
|
||||||
|
value, _ = t.Get(key)
|
||||||
|
return
|
||||||
}
|
}
|
||||||
|
|
||||||
// Has returns true if a key has a value in the table.
|
// Has returns true if a key has a value in the table.
|
||||||
func (t Table[K, V]) Has(key K) (exists bool) {
|
func (t *Table[K, V]) Has(key K) (exists bool) {
|
||||||
_, err := t.Get(key)
|
_, exists = t.Get(key)
|
||||||
return err == nil
|
return
|
||||||
}
|
}
|
||||||
|
|
||||||
// Put sets the value for a key. Returns error if its value cannot be set.
|
// Put sets the value for a key. Returns error if its value cannot be set.
|
||||||
func (t *Table[K, V]) Put(key K, value V) (err error) {
|
func (t *Table[K, V]) Put(key K, value V) (err error) {
|
||||||
if t.bucketA.update(key, value) {
|
if t.tableA.update(key, value) {
|
||||||
return nil
|
return nil
|
||||||
}
|
}
|
||||||
|
|
||||||
if t.bucketB.update(key, value) {
|
if t.tableB.update(key, value) {
|
||||||
return nil
|
return nil
|
||||||
}
|
}
|
||||||
|
|
||||||
entry, eviction := entry[K, V]{key, value}, false
|
entry, eviction := entry[K, V]{key, value}, false
|
||||||
for range t.maxEvictions() {
|
for range t.maxEvictions() {
|
||||||
if entry, eviction = t.bucketA.evict(entry); !eviction {
|
if entry, eviction = t.tableA.evict(entry); !eviction {
|
||||||
return nil
|
return nil
|
||||||
}
|
}
|
||||||
|
|
||||||
if entry, eviction = t.bucketB.evict(entry); !eviction {
|
if entry, eviction = t.tableB.evict(entry); !eviction {
|
||||||
return nil
|
return nil
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
if t.load() < t.minLoadFactor {
|
if t.load() < t.minLoadFactor {
|
||||||
return fmt.Errorf("bad hash: resize on load %d/%d = %f", t.Size(), t.TotalCapacity(), t.load())
|
return fmt.Errorf("hash functions produced a cycle at load %d/%d: %w", t.Size(), t.TotalCapacity(), ErrBadHash)
|
||||||
}
|
}
|
||||||
|
|
||||||
if err := t.grow(); err != nil {
|
if err := t.grow(); err != nil {
|
||||||
@@ -141,8 +157,8 @@ func (t *Table[K, V]) Put(key K, value V) (err error) {
|
|||||||
// Drop removes a value for a key in the table. Returns an error if its value
|
// Drop removes a value for a key in the table. Returns an error if its value
|
||||||
// cannot be removed.
|
// cannot be removed.
|
||||||
func (t *Table[K, V]) Drop(key K) (err error) {
|
func (t *Table[K, V]) Drop(key K) (err error) {
|
||||||
t.bucketA.drop(key)
|
t.tableA.drop(key)
|
||||||
t.bucketB.drop(key)
|
t.tableB.drop(key)
|
||||||
|
|
||||||
if t.load() < t.minLoadFactor {
|
if t.load() < t.minLoadFactor {
|
||||||
return t.shrink()
|
return t.shrink()
|
||||||
@@ -152,9 +168,9 @@ func (t *Table[K, V]) Drop(key K) (err error) {
|
|||||||
}
|
}
|
||||||
|
|
||||||
// Entries returns an unordered sequence of all key-value pairs in the table.
|
// Entries returns an unordered sequence of all key-value pairs in the table.
|
||||||
func (t Table[K, V]) Entries() iter.Seq2[K, V] {
|
func (t *Table[K, V]) Entries() iter.Seq2[K, V] {
|
||||||
return func(yield func(K, V) bool) {
|
return func(yield func(K, V) bool) {
|
||||||
for _, slot := range t.bucketA.slots {
|
for _, slot := range t.tableA.slots {
|
||||||
if slot.occupied {
|
if slot.occupied {
|
||||||
if !yield(slot.key, slot.value) {
|
if !yield(slot.key, slot.value) {
|
||||||
return
|
return
|
||||||
@@ -162,7 +178,7 @@ func (t Table[K, V]) Entries() iter.Seq2[K, V] {
|
|||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
for _, slot := range t.bucketB.slots {
|
for _, slot := range t.tableB.slots {
|
||||||
if slot.occupied {
|
if slot.occupied {
|
||||||
if !yield(slot.key, slot.value) {
|
if !yield(slot.key, slot.value) {
|
||||||
return
|
return
|
||||||
@@ -173,8 +189,8 @@ func (t Table[K, V]) Entries() iter.Seq2[K, V] {
|
|||||||
}
|
}
|
||||||
|
|
||||||
// String returns the entries of the table as a string in the format:
|
// String returns the entries of the table as a string in the format:
|
||||||
// "table[k1:v1 h2:v2 ...]".
|
// "table[k1:v1 k2:v2 ...]".
|
||||||
func (t Table[K, V]) String() string {
|
func (t *Table[K, V]) String() string {
|
||||||
var sb strings.Builder
|
var sb strings.Builder
|
||||||
sb.WriteString("table[")
|
sb.WriteString("table[")
|
||||||
|
|
||||||
@@ -192,9 +208,9 @@ func (t Table[K, V]) String() string {
|
|||||||
return sb.String()
|
return sb.String()
|
||||||
}
|
}
|
||||||
|
|
||||||
// NewCustomTable creates a [Table] with custom [Hash] and [EqualFunc]
|
// NewCustom creates a [Table] with custom [Hash] and [EqualFunc]
|
||||||
// functions, along with any [Option] the user provides.
|
// functions, along with any [Option] the user provides.
|
||||||
func NewCustomTable[K, V any](hashA, hashB Hash[K], compare EqualFunc[K], options ...Option) *Table[K, V] {
|
func NewCustom[K, V any](hashA, hashB Hash[K], compare EqualFunc[K], options ...Option) *Table[K, V] {
|
||||||
settings := &settings{
|
settings := &settings{
|
||||||
growthFactor: DefaultGrowthFactor,
|
growthFactor: DefaultGrowthFactor,
|
||||||
bucketSize: DefaultCapacity,
|
bucketSize: DefaultCapacity,
|
||||||
@@ -208,8 +224,8 @@ func NewCustomTable[K, V any](hashA, hashB Hash[K], compare EqualFunc[K], option
|
|||||||
return &Table[K, V]{
|
return &Table[K, V]{
|
||||||
growthFactor: settings.growthFactor,
|
growthFactor: settings.growthFactor,
|
||||||
minLoadFactor: settings.minLoadFactor,
|
minLoadFactor: settings.minLoadFactor,
|
||||||
bucketA: newBucket[K, V](settings.bucketSize, hashA, compare),
|
tableA: newSubtable[K, V](settings.bucketSize, hashA, compare),
|
||||||
bucketB: newBucket[K, V](settings.bucketSize, hashB, compare),
|
tableB: newSubtable[K, V](settings.bucketSize, hashB, compare),
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
@@ -217,10 +233,10 @@ func pipe[X, Y, Z any](a func(X) Y, b func(Y) Z) func(X) Z {
|
|||||||
return func(x X) Z { return b(a(x)) }
|
return func(x X) Z { return b(a(x)) }
|
||||||
}
|
}
|
||||||
|
|
||||||
// NewTableBy creates a [Table] for any key type by using keyFunc to derive a
|
// NewBy creates a [Table] for any key type by using keyFunc to derive a
|
||||||
// comparable key. Two keys with the same derived key are treated as equal.
|
// comparable key. Two keys with the same derived key are treated as equal.
|
||||||
func NewTableBy[K, V any, C comparable](keyFunc func(K) C, options ...Option) *Table[K, V] {
|
func NewBy[K, V any, C comparable](keyFunc func(K) C, options ...Option) *Table[K, V] {
|
||||||
return NewCustomTable[K, V](
|
return NewCustom[K, V](
|
||||||
pipe(keyFunc, NewDefaultHash[C]()),
|
pipe(keyFunc, NewDefaultHash[C]()),
|
||||||
pipe(keyFunc, NewDefaultHash[C]()),
|
pipe(keyFunc, NewDefaultHash[C]()),
|
||||||
func(a, b K) bool { return keyFunc(a) == keyFunc(b) },
|
func(a, b K) bool { return keyFunc(a) == keyFunc(b) },
|
||||||
@@ -228,10 +244,10 @@ func NewTableBy[K, V any, C comparable](keyFunc func(K) C, options ...Option) *T
|
|||||||
)
|
)
|
||||||
}
|
}
|
||||||
|
|
||||||
// NewTable creates a [Table] using the default [Hash] and [EqualFunc]. Use
|
// New creates a [Table] using the default [Hash] and [EqualFunc]. Use
|
||||||
// the [Option] functions to configure its behavior. Note that this constructor
|
// the [Option] functions to configure its behavior. Note that this constructor
|
||||||
// is only provided for comparable keys. For arbitrary keys, consider
|
// is only provided for comparable keys. For arbitrary keys, consider
|
||||||
// [NewTableBy] or [NewCustomTable].
|
// [NewBy] or [NewCustom].
|
||||||
func NewTable[K comparable, V any](options ...Option) *Table[K, V] {
|
func New[K comparable, V any](options ...Option) *Table[K, V] {
|
||||||
return NewCustomTable[K, V](NewDefaultHash[K](), NewDefaultHash[K](), DefaultEqualFunc[K], options...)
|
return NewCustom[K, V](NewDefaultHash[K](), NewDefaultHash[K](), DefaultEqualFunc[K], options...)
|
||||||
}
|
}
|
||||||
|
|||||||
Reference in New Issue
Block a user