Use *byte instead of unsafe.Pointer for C bridge methods

internal/native/cgo_read.go

@@ -15,13 +15,12 @@ import "C"
 import (
 	"io"
 	"log"
-	"unsafe"
 )
 
 //export cgo_read_buffer
 func cgo_read_buffer(
 	bufferIndex C.int,
-	bufPtr unsafe.Pointer,
+	bufPtr *byte,
 	length C.int,
 ) C.int {
 	goLength := int(length)

internal/native/cgo_write.go

@@ -11,12 +11,11 @@ package native
 #include "bsdiff.h"
 */
 import "C"
-import "unsafe"
 
 //export cgo_write_buffer
 func cgo_write_buffer(
 	bufferIndex C.int,
-	dataPtr unsafe.Pointer,
+	dataPtr *byte,
 	size C.int,
 ) C.int {
 	buffer := writers.Get(int(bufferIndex))

internal/native/native.go

@@ -28,12 +28,12 @@ func bytesToUint8PtrAndSize(bytes []byte) (ptr *C.uint8_t, size C.int64_t) {
 	return
 }
 
-func cPtrToSlice(ptr unsafe.Pointer, size int) []byte {
+func cPtrToSlice(ptr *byte, size int) []byte {
 	var slice []byte
 	sliceHeader := (*reflect.SliceHeader)(unsafe.Pointer(&slice))
 	sliceHeader.Cap = size
 	sliceHeader.Len = size
-	sliceHeader.Data = uintptr(ptr)
+	sliceHeader.Data = uintptr(unsafe.Pointer(ptr))
 
 	return slice
 }

internal/native/native_internal_test.go

@@ -0,0 +1,38 @@
+// Copyright (c) 2017-2025 Carl Kittelberger.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE.txt file.
+
+//go:build cgo && go1.20
+// +build cgo,go1.20
+
+package native
+
+import (
+	"crypto/rand"
+	"testing"
+	"unsafe"
+
+	"github.com/stretchr/testify/assert"
+)
+
+const testBytesLen = 512 * 1024
+
+func makeTestBytes() []byte {
+	b := make([]byte, testBytesLen)
+	_, _ = rand.Read(b)
+	return b
+}
+
+func Test_bytesToUint8PtrAndSize(t *testing.T) {
+	b := makeTestBytes()
+	ptr, size := bytesToUint8PtrAndSize(b)
+	assert.EqualValues(t, &b[0], ptr)
+	assert.EqualValues(t, testBytesLen, size)
+}
+
+func Test_cPtrToSlice(t *testing.T) {
+	b := makeTestBytes()
+	bytePtr := unsafe.SliceData(b)
+	b2 := cPtrToSlice(bytePtr, testBytesLen)
+	assert.Equal(t, b, b2)
+}