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_fuzz_test.go

@@ -0,0 +1,49 @@
+package cuckoo_test
+
+import (
+	"bytes"
+	"encoding/binary"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"git.maximhutz.com/tools/go-cuckoo"
+)
+
+func offsetHash(seed uint32) cuckoo.Hash[uint32] {
+	return func(x uint32) uint64 {
+		v := uint64(x) ^ uint64(seed)
+		v = (v ^ (v >> 30)) * 0xbf58476d1ce4e5b9
+		v = (v ^ (v >> 27)) * 0x94d049bb133111eb
+		return v ^ (v >> 31)
+	}
+}
+
+func FuzzInsertLookup(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte, seedA, seedB uint32) {
+		assert := assert.New(t)
+
+		table := cuckoo.NewCustomTable[uint32, uint32](
+			offsetHash(seedA),
+			offsetHash(seedB),
+			func(a, b uint32) bool { return a == b },
+		)
+
+		if seedA == seedB {
+			return
+		}
+
+		r := bytes.NewReader(data)
+		var key, value uint32
+		for binary.Read(r, binary.LittleEndian, &key) == nil &&
+			binary.Read(r, binary.LittleEndian, &value) == nil {
+
+			err := table.Put(key, value)
+			assert.NoError(err)
+
+			found, err := table.Get(key)
+			assert.NoError(err)
+			assert.Equal(value, found)
+		}
+	})
+}