chore: move from tools/dsa (#1)

Moved the implementation of this hash table from `tools/dsa` #1.

Reviewed-on: #1
Co-authored-by: M.V. Hutz <git@maximhutz.me>
Co-committed-by: M.V. Hutz <git@maximhutz.me>

cuckoo_test.go

@@ -0,0 +1,130 @@
+package cuckoo_test
+
+import (
+	"maps"
+	"math/rand/v2"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"git.maximhutz.com/tools/go-cuckoo"
+)
+
+func TestNewTable(t *testing.T) {
+	assert := assert.New(t)
+
+	table := cuckoo.NewTable[int, bool]()
+
+	assert.NotNil(table)
+	assert.Zero(table.Size())
+}
+
+func TestAddItem(t *testing.T) {
+	assert := assert.New(t)
+	key, value := 0, true
+	table := cuckoo.NewTable[int, bool]()
+
+	err := table.Put(key, value)
+
+	assert.NoError(err)
+	assert.Equal(1, table.Size())
+	assert.True(table.Has(key))
+}
+
+func TestPutOverwrite(t *testing.T) {
+	assert := assert.New(t)
+	key, value, newValue := 0, 1, 2
+	table := cuckoo.NewTable[int, int]()
+	(table.Put(key, value))
+
+	err := table.Put(key, newValue)
+
+	assert.NoError(err)
+	assert.Equal(1, table.Size())
+	assert.True(table.Has(key))
+	found, _ := table.Get(key)
+	assert.Equal(newValue, found)
+}
+
+func TestSameHash(t *testing.T) {
+	assert := assert.New(t)
+	hash := func(int) uint64 { return 0 }
+	table := cuckoo.NewCustomTable[int, bool](hash, hash, cuckoo.DefaultEqualFunc[int])
+
+	errA := table.Put(0, true)
+	errB := table.Put(1, true)
+	errC := table.Put(2, true)
+
+	assert.NoError(errA)
+	assert.NoError(errB)
+	assert.ErrorContains(errC, "bad hash")
+}
+
+func TestStartingCapacity(t *testing.T) {
+	assert := assert.New(t)
+	table := cuckoo.NewTable[int, bool](cuckoo.Capacity(64))
+
+	assert.Equal(uint64(128), table.Capacity())
+}
+
+func TestResizeCapacity(t *testing.T) {
+	assert := assert.New(t)
+	table := cuckoo.NewTable[int, bool](
+		cuckoo.Capacity(8),
+		cuckoo.GrowthFactor(2),
+	)
+
+	for table.Capacity() == 16 {
+		err := table.Put(rand.Int(), true)
+		assert.NoError(err)
+	}
+
+	assert.Equal(uint64(32), table.Capacity())
+}
+
+func TestPutMany(t *testing.T) {
+	assert := assert.New(t)
+	expected, actual := map[int]bool{}, cuckoo.NewTable[int, bool]()
+
+	for i := range 1_000 {
+		expected[i] = true
+		err := actual.Put(i, true)
+
+		assert.NoError(err)
+	}
+
+	assert.Equal(maps.Collect(actual.Entries()), expected)
+	assert.Equal(len(expected), actual.Size())
+}
+
+func TestGetMany(t *testing.T) {
+	assert := assert.New(t)
+	table := cuckoo.NewTable[int, bool]()
+
+	for i := range 1_000 {
+		err := table.Put(i, true)
+		assert.NoError(err)
+	}
+
+	for i := range 2_000 {
+		value, err := table.Get(i)
+		if i < 1_000 {
+			assert.NoError(err)
+			assert.Equal(value, true)
+		} else {
+			assert.Error(err)
+		}
+	}
+}
+
+func TestRemove(t *testing.T) {
+	assert := assert.New(t)
+	table := cuckoo.NewTable[int, bool]()
+
+	assert.False(table.Has(0))
+
+	err := table.Put(0, true)
+	assert.NoError(err)
+
+	assert.True(table.Has(0))
+}